tag:theconversation.com,2011:/ca/topics/cape-town-drought-40300/articlesCape Town drought – The Conversation2022-05-04T14:31:37Ztag:theconversation.com,2011:article/1818112022-05-04T14:31:37Z2022-05-04T14:31:37ZRemoving alien plants can save water: we measured how much<figure><img src="https://images.theconversation.com/files/459804/original/file-20220426-24-y59x8s.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Alien trees threaten biodiversity, increase the risk of wildfires and also guzzle water.</span> <span class="attribution"><span class="source">Photo courtesy Cape Winelands Biosphere Reserve</span></span></figcaption></figure><p>Humans’ relationship with nature <a href="https://livingplanet.panda.org/en-us/">is broken</a>. We’re <a href="https://ipbes.net/global-assessment">transforming the Earth so dramatically</a> that almost one million plant and animals species face extinction. Losing species unravels the tapestry of nature, changing how ecosystems function and, ultimately, damaging society too.</p>
<p>Nature brings huge benefits to people. Some are tangible. In South Africa alone, the value of these benefits to people is estimated at <a href="https://linkinghub.elsevier.com/retrieve/pii/S2212041617304771">R275 billion annually</a> (about 7% of the country’s gross domestic product). That value includes providing the country with crops, wood, water and fuel. There are other, less immediately tangible benefits, too: air purification, water regulation, water purification, recreation, tourism, and cultural and heritage value.</p>
<p>One of the things that contributes to ecosystem degradation in South Africa is invasion by alien plants. This is estimated to <a href="https://www.sanews.gov.za/south-africa/sa-sees-increase-alien-species">cost the nation R6.5 billion annually</a> in damages and the <a href="https://www.greeneconomycoalition.org/news-and-resources/working-for-water-in-south-africa#:%7E:text=Working%20for%20Water%20currently%20runs,works%20programme%20in%20the%20country">government spends over R400 million annually</a> clearing alien trees. Despite this investment, <a href="https://www.sanews.gov.za/south-africa/sa-sees-increase-alien-species">alien tree invasions continue to increase across the country</a>.</p>
<p>Alien trees <a href="https://theconversation.com/invasive-alien-plants-in-south-africa-pose-huge-risks-but-they-can-be-stopped-94186">threaten biodiversity</a>, increase the risk of more intense and frequent wildfires and also guzzle water. This is an important factor in water scarce regions, like South Africa, that experience droughts.</p>
<p>Alien trees are invading mountainous areas across South Africa. These are important water generating regions and the trees threaten water supplies in several cities, among them Cape Town and Gqeberha. Both have experienced <a href="https://www.dailymaverick.co.za/article/2022-01-19-parts-of-eastern-cape-emerge-from-drought-but-gqeberha-dam-levels-are-still-below-19/">water shortages</a> in recent years.</p>
<p>To find out just how much alien trees threaten water supply, we conducted a <a href="https://www.sciencedirect.com/science/article/abs/pii/S0022169422003468">hydrological study</a>. The research set up the most fine-scale, detailed models possible to try and estimate how alien trees affect streamflow in four small mountains catchments above some of Cape Town’s major dams. This study also used satellite imagery to input accurate information on the types of alien trees and where they are.</p>
<h2>Key findings</h2>
<p>The models predicted that clearing catchment areas fully infested with mature invasive alien trees can increase streamflow by between 15.1% and 29.5%. Although the catchments modelled are currently not fully invaded, this presents a strong argument for preventing full invasion. </p>
<p>The study also found that streamflow gains from clearing alien trees from rivers were almost twice as high as clearing the alien trees from the surrounding land. That’s because alien trees in rivers have access to an almost endless water supply and so use more.</p>
<p>Another interesting finding was that clearing alien trees seemed to have a greater impact on the mid to low flows – in other words during the dry season when the river flow is low, rather than the high flows – during rainfall events in the wet season when the rivers are full. </p>
<p>This makes sense: during rainfall events there is so much water that the negative effects of alien vegetation become less evident. But it is important because it implies that clearing alien trees makes more water available in between rain events, and especially in the dry season. This is useful to improve water security during droughts.</p>
<p>The positive effect of clearing alien trees was also predicted to be higher in dry years compared to wet years. This suggests that clearing alien trees is a viable measure to ensure there will be more water when it is most needed.</p>
<p>It is useful to explain what the savings predicted by our models mean to Cape Town’s overall water supply – and to consumers. For instance, we found that clearing the current levels of invasion in the catchments above the Berg River Dam (currently 9% invaded) could increase streamflow by over 1%. This doesn’t sound like a lot, but it could mean an increase in mean annual volume of as much as 1.5 million m³, or 4.1 million litres per day. </p>
<p>According to the 1:50 year yield model for the Berg River Dam, this equates to a 0.2% increase in yield. Putting this into perspective with a quick first order calculation, from the City of Cape Town’s Water Strategy, we have a value of R9 per kilolitre for the operating costs of desalination. If we multiply this by the 0.2% increase in yield each year from clearing alien trees above the Berg River Dam, we get to an estimated annual equivalent value of that water of around R2 million. </p>
<p>However should the Berg River Dam catchment become fully invaded with alien trees, this would reduce the 1:50 year yield by 4.3%, costing us about R38 million each year if we had to source this water elsewhere.</p>
<h2>Reversing the damage</h2>
<p>Our findings are important for several reasons. First, they can be used to encourage society to redouble its work clearing alien vegetation. Second, they confirm that improved water security is possible for South African cities during their dry seasons or droughts.</p>
<p>It is critical that more work be done to halt and reverse the degradation of ecosystems. This is especially urgent in what the United Nations has dubbed the <a href="https://www.decadeonrestoration.org/">Decade on Ecosystem Restoration</a>. We all have a chance to undo some of the damage we have wrought – and, as our research shows, clearing alien trees must be part of these efforts. </p>
<p><em>Jason Hallowes contributed to this article. We thank Dr James Cullis for help with the yield calculations and cost estimations.</em></p><img src="https://counter.theconversation.com/content/181811/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alanna Rebelo receives funding from the South African Water Research Commission. This work was funded by the Danish Ministry of Foreign Affairs (DANIDA) as part of the SEBEI (Socio-Economic Benefits of Investing in Ecological Infrastructure) Project, grant no: 17-M07-KU. She serves on the boards of the Friends of Tokai Park, South African Wetland Society, South African Hydrological Society, and the International Society of Wetland Scientists: Africa Region. </span></em></p><p class="fine-print"><em><span>Karen Joan Esler receives funding from Water Research Commission. She is affiliated with the International Society for Ecological Restoration. </span></em></p><p class="fine-print"><em><span>Mark New receives funding from a number of national and international research funders, including the South African National Research Foundation, the International Development Research Centre, UK Research and Innovation, the AXA Research Fund and the BNP-Paribas Foundation.</span></em></p><p class="fine-print"><em><span>Petra Brigitte Holden receives funding from the AXA Research Fund, through the AXA Research Chair in African Climate Risk and the International Development Research Centre.</span></em></p>Clearing alien trees from mountain catchments is a more cost-effective approach to providing water than building and maintaining desalination plants.Alanna Rebelo, Senior Researcher, Agricultural Research CouncilKaren Joan Esler, Distinguished Professor of Conservation Ecology, Stellenbosch UniversityMark New, Director, African Climate and Development Initiative, University of Cape TownPetra Brigitte Holden, Researcher, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1768972022-02-14T14:53:13Z2022-02-14T14:53:13ZCities must listen to people to find solutions for climate impacts: stories from Cape Town<figure><img src="https://images.theconversation.com/files/445624/original/file-20220210-26283-uckjqw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> </figcaption></figure><p>A few years ago the South African city of Cape Town was close to reaching “day zero” – the day the taps would run dry as a result of a serious drought. Households had to restrict their water usage, water tariffs increased, and businesses had to rethink how they used water. But the situation affected people unequally. Households experienced it in different ways. The poor and vulnerable suffered the most.</p>
<p>With the changing climate, problems like these aren’t going anywhere. Water scarcity, higher temperatures and changing rainfall patterns will become more common, so finding ways to adapt is important. And in a city where inequality and financial pressures are deep and complex, adaptive change will take time.</p>
<p>It also takes information. For city planners and decision makers, data is essential – but not just quantitative data. They need to engage with people to understand how they experience issues like water scarcity.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RR5kRrGhB0I?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Making sense of a water crisis.</span></figcaption>
</figure>
<p>In today’s episode of Pasha, two researchers discuss <a href="https://www.tandfonline.com/doi/full/10.1080/07900627.2020.1841605">their work</a> on inequality in water and describe a <a href="https://doi.org/10.1080/14693062.2020.1863180">project</a> that brought city authorities and community members together. Gina Ziervogel is in the Department of Environmental and Geographical Science and Johan Enqvist is with the African Climate and Development Initiative, both at the University of Cape Town. </p>
<hr>
<p><strong>Photo:</strong>
“Lines of people waiting to collect natural spring water for drinking in Newlands in the drought in Cape Town South Africa.” Photo by Mark Fisher <a href="https://www.shutterstock.com/image-photo/cape-town-south-africa-january-25-1010387179">Shutterstock</a>.</p>
<p><strong>Music:</strong>
“Happy African Village” by John Bartmann, found on <a href="http://freemusicarchive.org/music/John_Bartmann/Public_Domain_Soundtrack_Music_Album_One/happy-african-village">FreeMusicArchive.org</a> licensed under <a href="https://creativecommons.org/publicdomain/zero/1.0/">CC0 1</a>.</p>
<p>“Ambient guitar X1 - Loop mode” by frankum, found on <a href="https://freesound.org/people/frankum/sounds/393520/">Freesound</a> licensed under <a href="http://creativecommons.org/licenses/by/3.0/">Attribution License.</a></p>
<p><strong>Video:</strong>
“Making sense of a water crisis” filmed by <a href="https://www.odendaalesterhuyse.com/uct">Odendaal Esterhuyse</a></p><img src="https://counter.theconversation.com/content/176897/count.gif" alt="The Conversation" width="1" height="1" />
Academic research can have a direct impact on people's lives. It's crucial to come together to deal with problems like climate change. If we don't, the poor and vulnerable will suffer the most.Ozayr Patel, Digital EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1492872020-11-10T14:41:49Z2020-11-10T14:41:49ZCape Town’s climate strategy isn’t perfect, but every African city should have one<figure><img src="https://images.theconversation.com/files/368538/original/file-20201110-13-ody7ao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fynbos, the biodiverse shrubland in Cape Town, is thought to have the third highest carbon stored per square metre for any biome in South Africa. It must be protected.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>It may take an extreme heatwave, a mega wildfire or a severe coastal storm to begin to appreciate the dangers of climate change. </p>
<p>Africa is likely to be the continent <a href="https://www.un.org/africarenewal/magazine/december-2018-march-2019/global-warming-severe-consequences-africa">hit hardest by climate change</a>. The region is vulnerable to <a href="https://theconversation.com/global-warming-has-already-raised-the-risk-of-more-severe-droughts-in-cape-town-107625">droughts</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/32777515/">heat</a> and <a href="https://journals.sagepub.com/doi/abs/10.1177/0956247808089156">floods</a> and many countries have a low capacity for adaptation because of poor governance and <a href="https://www.bbc.com/news/world-africa-50726701">poverty, limiting individual choices</a>. </p>
<p>Despite this threat, <a href="https://www.c40.org/cities">only 13 cities in Africa are C40 cities</a> – cities committed to taking measurable climate action. Only five in South Africa have climate change strategies. The aim of a climate change strategy is to outline actions to mitigate and adapt to climate change. </p>
<p><a href="https://climate.nasa.gov/solutions/adaptation-mitigation/">Mitigation</a> includes reducing emissions and enhancing the sinks of greenhouse gases. Some examples include shifts to renewable energy and ecosystem restoration. <a href="https://www.epa.gov/arc-x/strategies-climate-change-adaptation">Adaptation</a> is the adjustment of natural or human systems to moderate harm from the impacts of climate change. This could be in the form of storing rainwater, diversifying crops to improve drought resilience, and retreating from coastal risk areas or river flood zones.</p>
<h2>Cape Town</h2>
<p>Cape Town is the latest African city to redraft its climate change strategy. According to a risk and vulnerability <a href="https://oneworldgroup.co.za/oneworld-projects/climate-change-assessment-capetown/">assessment,</a> Cape Town faces many challenges. These include a significant increase in temperatures, long-term decrease in rainfall, changes in rainfall seasonality, more extreme heat days and heat waves, and coastal erosion. Global warming has already <a href="https://theconversation.com/global-warming-has-already-raised-the-risk-of-more-severe-droughts-in-cape-town-107625">raised the risk</a> of more severe droughts in Cape Town threefold.</p>
<p>This <a href="https://drive.google.com/file/d/1sKKefq3UIcFSpIAFSw8_EtCVbGmlvGQ5/view?usp=sharing">new draft strategy</a> contains 35 goals. For adaptation, the goals focus on rising temperatures, water scarcity, water excess, sea level rise and fire risk. For mitigation they focus on clean energy, zero emissions, sustainable transport, inclusivity and the circular waste economy. The strategy also looks at cross-cutting issues, like funding mechanisms and communication strategies. </p>
<p>The city does well to acknowledge that bold action needs to be taken now to prevent the worst climate change impacts. It is appropriate that the strategy aims for carbon neutrality by 2050 and addresses sustainability issues, such as <a href="http://www.capetown.gov.za/City-Connect/Have-your-say/Issues-open-for-public-comment/draft-climate-change-strategy">spatial transformation through dense and transit-oriented growth and development</a> to support an efficient transport system. </p>
<p>But there are some gaps in the strategy. As researchers active in conservation and ecological restoration, we have studied the draft from an ecological perspective. Our <a href="https://drive.google.com/file/d/1pxEWtDKSxZnn7foAw9AqtNEqOSrl4GdU/view?usp=sharing">main concerns</a> are that the role of nature in the proposed climate action is missing, and the strategy as it stands is self-defeating. Natural processes are misunderstood and incorrectly represented, especially as relating to biodiversity conservation and wildfire risk management. We have some suggestions that other cities could consider when drawing up similar strategies. </p>
<h2>A startling omission</h2>
<p>The city of Cape Town encompasses nearly 2,500km² of land which includes natural ecosystems. Some of the <a href="https://www.sciencedirect.com/science/article/pii/S0254629910001390">most important biodiversity</a> in South Africa and globally is located within its bounds. South Africa recognises the value of this biodiversity and is a <a href="https://www.cbd.int/rio/">signatory</a> to <a href="http://www.statssa.gov.za/?p=12813&gclid=Cj0KCQiAhZT9BRDmARIsAN2E-J1rHQrQFnaCELOn7zfCdWY9Hjb79khj0frSc4-NtjkedZlO0UJWljAaAtyEEALw_wcB">several international agreements</a> that commit to conservation, halting species extinctions and sustainable development.</p>
<p>The draft strategy fails to sufficiently highlight the role of biodiversity and natural ecosystems in climate action. The city acknowledges the importance of nature and that it needs to be retained, restored, expanded and optimised. But none of the 35 goals make the link between ecosystems and climate change. Another South African municipality, eThekwini, encompassing the city of Durban, <a href="http://www.durban.gov.za/City_Services/energyoffice/Documents/DCCS%20Biodiversity%20Theme%20Report.pdf">achieves this</a> in a climate change strategy that specifically includes biodiversity.</p>
<p>Natural ecosystems help to <a href="https://ec.europa.eu/environment/nature/info/pubs/docs/climate_change/en.pdf">stabilise climate</a> and restoring them <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0104">mitigates climate change</a>. They deliver services such as clean water and <a href="https://www.cbd.int/doc/publications/cbd-ts-86-en.pdf">carbon sequestration</a>. The United Nations recognises the role of biodiversity in stabilising climate and has declared that the next decade will be the <a href="https://www.decadeonrestoration.org/">Decade on Ecosystem Restoration 2021-2030</a>.</p>
<p>Nature conservation and restoration are inexpensive tools for climate action according to both the <a href="https://ec.europa.eu/environment/nature/info/pubs/docs/climate_change/en.pdf">European Commission</a> and the <a href="https://www.iucn.org/news/climate-change/201812/protecting-climate-protecting-nature">UN</a>. Many nations have pursued conservation and climate action policies <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0121">separately</a>. The result is a failure both to halt biodiversity loss and mitigate climate change. Research shows that climate change mitigation and nature conservation <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0121">require much higher targets</a> for environmental protection. One solution is to streamline these policies. </p>
<p>Cape Town is a case in point. In their proposed climate strategy, none of the goals explicitly deal with biodiversity, conservation or ecosystem restoration. Some of the proposed goals even undermine them. </p>
<h2>Business unusual</h2>
<p>Cape Town has the second highest number of plant extinctions <a href="https://www.nature.com/articles/d41586-019-01810-6">worldwide</a>. It is crucial that the city prevents further extinction by acquiring and restoring reserves for indigenous species. </p>
<p>To include nature in climate action, goals must make provision for ecosystem restoration, such as <a href="http://www.acdi.uct.ac.za/socio-economic-benefits-ecological-infrastructure-sebei">clearing invasive alien trees to improve water security</a>. <a href="http://pza.sanbi.org/vegetation/fynbos-biome">Fynbos</a>, the biodiverse shrubland unique to the area, is thought to have the third highest carbon stored per square metre for any biome in South Africa. It must be protected and restored.</p>
<p>One issue of grave concern is the city’s approach to wildfire risk management in this strategy. There is a stated commitment to suppress fires in natural ecosystems, despite acknowledging that fires are a natural part of fynbos ecosystems. Instead of suppression, which increases risk of mega wildfires, the approach should be to perform ecological burns in natural areas and remove invasive alien trees. <a href="https://www.researchgate.net/publication/257198227_Mega-fires_tipping_points_and_ecosystem_services_Managing_forests_and_woodlands_in_an_uncertain_future">Fire suppression approaches</a> have proven disastrous in <a href="https://www.iol.co.za/capetimes/news/knysna-fires-fuelled-by-invasive-pines-says-study-16929195">Knysna</a>, Australia and California. </p>
<h2>A flawed strategy?</h2>
<p>In the strategy, the City of Cape Town outlines a vision of becoming a climate resilient city that is resource efficient and carbon neutral. It also says that this vision is unrealistic, and that falling short of targets is likely. </p>
<p>Any strategy that has a self defeating vision is not one that should be supported. It would be more productive to adopt a clear vision that can be realised, taking advantage of affordable climate actions such as conservation and ecosystem restoration. </p>
<p>South Africa is known globally for its <a href="http://www.water-alternatives.org/index.php/allabs/211-a6-2-8/file">progressive legislation</a> in acknowledging nature in water resource management. This is an impressive legacy, one that should be followed.</p>
<p>To protect the most vulnerable, African cities must work hard at reducing emissions and improving resilience. They must do this through conserving remaining natural ecosystems and <a href="https://theconversation.com/four-reasons-why-restoring-nature-is-the-most-important-endeavour-of-our-time-147365">restoring</a> degraded ones, <em>as well as</em> exploring renewable energy and technological advancements. This will enable people in cities to enjoy dual benefits: improved resilience to climate change, as well as better air quality, recreational opportunities, health and well-being.</p><img src="https://counter.theconversation.com/content/149287/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alanna Rebelo has received funding from the Danish International Development Agency for research into the benefits of investing in ecological infrastructure. She is affiliated with Friends of Tokai Park. </span></em></p><p class="fine-print"><em><span>Karen Joan Esler receives funding from the Danish National Development Agency and the Water JPI (local funder: Water Research Commission), focusing on the benefits of investing in ecological infrastructure and nature-based solutions for water management respectively.</span></em></p><p class="fine-print"><em><span>Tony Rebelo is affiliated with Friends of Tokai Park, adviser to the Forestry Research Commission, Western Leopard Toad Management Committtee. . </span></em></p><p class="fine-print"><em><span>Michael Samways and Patricia Holmes do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Cape Town’s new climate strategy is a good start. But it falls short when it comes to nature.Alanna Rebelo, Postdoctoral researcher, Stellenbosch UniversityKaren Joan Esler, Distinguished Professor of Conservation Ecology, Stellenbosch UniversityMichael Samways, Professor, Conservation Ecology & Entomology, Stellenbosch UniversityPatricia Holmes, plant ecologist, Stellenbosch UniversityTony Rebelo, Scientist, South African National Biodiversity InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1263612019-11-06T13:22:35Z2019-11-06T13:22:35ZSouth Africa’s real water crisis: not understanding what’s needed<figure><img src="https://images.theconversation.com/files/300270/original/file-20191105-88428-1mq2s90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A serious multi-year drought in parts of South Africa’s <a href="https://www.aljazeera.com/news/2019/10/south-africas-worst-drought-years-affects-farmers-191029043210778.html">Northern</a> and <a href="https://www.heraldlive.co.za/news/2019-10-30-eastern-cape-declares-drought-disaster/">Eastern Cape</a> provinces has seen a number of small towns threatened by total water supply failures and livestock farmers facing financial ruin. </p>
<p>In other parts of the country, heatwave conditions and the late onset of rains have caused local supply failures. Although the dams that supply most of the main urban areas are still at reasonable levels, there are growing fears that the country may be witnessing the start of a major drought. </p>
<p>Cape Town’s experience of extreme <a href="https://theconversation.com/day-zero-is-meant-to-cut-cape-towns-water-use-what-is-it-and-is-it-working-92055">“Day Zero”</a> supply restrictions only adds to these fears. Weather forecasters seem unable to make reliable predictions more than a few weeks in advance. And there are nagging concerns about the government’s ability to identify and address emerging problems. </p>
<p>Unhelpfully, there’s no single water problem and the issues confronted vary widely from place to place. </p>
<p>In Cape Town, water managers thought they could avoid building new infrastructure to supply a growing population by encouraging everyone to use less water. A major <a href="https://theconversation.com/global-warming-has-already-raised-the-risk-of-more-severe-droughts-in-cape-town-107625">drought</a> proved them wrong.</p>
<p>During October’s heatwaves in Gauteng province, water ran dry as local reservoirs were emptied by residents who felt the need to use extra water for their gardens – and municipalities failed to enforce restrictions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/panic-over-water-in-south-africas-economic-hub-is-misplaced-125742">Panic over water in South Africa's economic hub is misplaced</a>
</strong>
</em>
</p>
<hr>
<p>In Adelaide, Eastern Cape, where there has been a critical supply failure, one local councillor was <a href="https://www.farmersweekly.co.za/opinion/blog/letter-from-the-editor/poor-governance-worsens-drought/">reported</a> to have commented that “the Adelaide Dam was at 1% before local authorities woke up”. Even then, there was little they could do because funding wsn’t available. </p>
<p>The problems in Adelaide are repeated daily in towns and villages across the country as municipalities seek to expand the distribution of water without first ensuring that there’s enough supply or putting in place measures to control excessive use. Too often, poor planning and management is revealed when drought strikes, as is currently happening. </p>
<h2>Weather predictions</h2>
<p>If there was more certainty about future weather, there might be less concern. But this is not the case. At the end of September, South African Weather Service <a href="http://www.weathersa.co.za/images/data/longrange/gfcsa/scw.pdf">forecasters</a> said while summer rains would be late and October very dry, November would almost definitely see good rains. </p>
<p>And so far, so good, the rains in Gauteng started on schedule on November 1. </p>
<p>But South Africans shouldn’t expect that forecasting success to continue. It’s unusual for a seasonal forecast to be so confident. </p>
<p>For each three month period, the agency produces two rainfall maps. The first shows the “raw” predictions from the computer models and therefore aren’t statistically significant.</p>
<p>The second map is important because it shows only the areas where forecasters are reasonably confident that the predictions are significant or, in their terminology, sufficiently “skilful”. As a result, the second map is often almost completely blank. </p>
<p>As the first set of maps below shows, the predictions for the three months starting in November were very confident compared with the second set of maps which offered virtually no “skilful guidance” for the three months starting in September. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=270&fit=crop&dpr=1 600w, https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=270&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=270&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=339&fit=crop&dpr=1 754w, https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=339&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/300052/original/file-20191104-88419-18s4fqy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=339&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">South African Weather Service. Date issued: 30 September 2019</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=236&fit=crop&dpr=1 600w, https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=236&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=236&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=297&fit=crop&dpr=1 754w, https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=297&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/300055/original/file-20191104-88368-1ktbur6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=297&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Seasonal climate watch for July to September 2019. Date issued: 28 June 2019.</span>
<span class="attribution"><span class="source">South African Weather Service</span></span>
</figcaption>
</figure>
<p>Moving into 2020, predictions are becoming more uncertain again. Indeed, at the end of September, the South African Weather Service warned that some international forecast models suggest that South Africa may be moving into a (dry) El Niño rainfall phase: </p>
<blockquote>
<p>Opposite forecasts for most of the summer period… increases the uncertainty for the coming summer season.</p>
</blockquote>
<p>The combination of forecast uncertainties and problems on the ground offers politicians an easy opportunity to blame climate change and uncertainty to explain failures in their areas of responsibility. </p>
<p>Explaining Cape Town’s Day Zero debacle, then Western Cape premier Helen Zille was accused of blaming the country’s weather service, <a href="https://www.timeslive.co.za/politics/2018-01-26-zille-tries-to-blame-it-on-the-weatherman">suggesting</a> that the province: </p>
<blockquote>
<p>Finds itself facing a crisis because SA Weather Services got their predictions all wrong…</p>
</blockquote>
<p>Zille would just have been echoing the excuses of Democratic Alliance colleague Patricia de Lille and Nomvula Mokonyane, their African National Congress counterpart, who had happily associated themselves with the notion that Cape Town’s crisis was due to drought becoming <a href="https://mg.co.za/article/2017-11-03-00-cape-town-races-to-beat-day-zero">“the new normal”</a>. </p>
<h2>Unpredictable rainfall</h2>
<p>South Africa’s rainfall has always been variable and unpredictable. This remains one of the larger risks to rain-fed agriculture, as Karoo farmers (Northern Cape) are currently experiencing. Reliable supplies can be provided to urban and industrial water users – and irrigation farmers – if storage infrastructure is built with enough capacity to cope with regular dry periods. But that infrastructure has to be managed with a watchful eye on the ever-changing climate. </p>
<p>If the infrastructure needed is not developed when needed, problems will arise. And if water is drawn without restraint during a dry period, shortages will be the likely outcome.</p>
<h2>Is climate change the problem?</h2>
<p>As Zille, de Lille and Mokonyane have demonstrated, it is easy to blame climate change for water problems. Yet it is by no means certain that climate change will dramatically reduce water supplies. Rising temperatures is one trend that forecasters confidently and correctly predict. But it’s not certain what that temperature increase will do to water availability. </p>
<p>Recent <a href="https://www.nature.com/articles/s41586-019-1441-7">research</a> has shown that African groundwater supplies are not (yet) being negatively affected. Hotter temperatures will see more evaporation from the land surface, but it’s also expected that storms will become more intense. More rain will fall in a shorter time and this produces more recharge than slow, gentle rain.</p>
<p>The same effect could see river flows increase. At the moment, South Africa uses only around <a href="http://www.dwa.gov.za/Documents/Policies/NWRS/Sep2004/pdf/Chapter2.pdf">30%</a> of the water in its rivers and underground. Using more would rapidly become more expensive. But climate change may help. At present, only <a href="http://www.wrc.org.za/wp-content/uploads/mdocs/TT%20518-12.pdf">8%</a> of rainfall actually runs into the rivers and is then available to be used or stored in dams. If rainfall becomes more intense, that proportion will be greater. </p>
<p>Environmentalists <a href="http://arr.ga.gov.au/__data/assets/pdf_file/0011/40412/Draft_ARR_interim_guidance_Format.pdf">warn</a> that intense rainfall will cause floods; they want to slow down and spread out the water, although that will help it to evaporate. On the other hand, many hydrologists and water managers will quietly welcome the extra water that will flow into their systems and would like to help it to get there.</p>
<p>The different challenges faced in different places may look like a single crisis. But the fact is that the underlying problems are often not the same. There’s no single prescription and each locality must understand and address its own particular circumstances. </p>
<p>What is clear is that South Africa’s not yet confronting an absolute water shortage. But the extent of public panic suggests a disturbing level of ignorance about how water is made available and what needs to be done to ensure adequate and reliable supplies. The key to this water security is for government and citizens to understand and manage what the country has. </p>
<p><em>This article is the second in a series looking at South Africa’s water challenges</em></p><img src="https://counter.theconversation.com/content/126361/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Muller has received funding from the Water Research Commission and the African Development Bank for research and advisory work related to the subject matter of this article. He also advises a variety of organisations on water related matters including national, provincial and local government, and business organisations including BUSA, AgriSA and SAICA.
</span></em></p>The real crisis with water supply is that South Africa doesn’t know what it doesn’t know.Mike Muller, Visiting Adjunct Professor, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1257422019-10-27T07:57:48Z2019-10-27T07:57:48ZPanic over water in South Africa’s economic hub is misplaced<figure><img src="https://images.theconversation.com/files/298509/original/file-20191024-170458-obx399.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>It has been a hot, dry October in much of the interior of South Africa. And the rains have started later than usual. So it was not surprising that alarm bells went off when it was announced that the <a href="https://www.water-technology.net/projects/lesotho-highlands/">Lesotho Highlands Water Project</a> tunnel system, which supplies water to some of South Africa’s biggest cities, would be closed for maintenance for two months. </p>
<p>These fears were inflamed by appeals by local authorities in Gauteng province, the country’s economic hub, to use water sparingly. Residents had already seen the recent example of <a href="https://www.theguardian.com/world/2018/may/04/back-from-the-brink-how-cape-town-cracked-its-water-crisis">Cape Town’s water crisis</a>.</p>
<p>Gauteng and the surrounding region gets its water from the 14 interconnected dams of the <a href="http://www6.dwa.gov.za/Vaal/">Integrated Vaal River System</a>. Some of these are in Lesotho, South Africa’s mountainous neighbour. </p>
<p>The Lesotho dams provide over 25% of the water supplied by the Integrated Vaal River System. So a permanent loss of supply from Lesotho would indeed cause shortages for millions of South Africans. But this <a href="https://www.sanews.gov.za/south-africa/lesotho-highlands-water-project-tunnel-shutdown-maintenance">long-planned maintenance</a> merely stores the water in Lesotho’s dams for a few months, to be released later. There are far greater risks emerging in the Integrated Vaal River System that need to be addressed. </p>
<p>Despite the current heat wave, there is in fact no danger of an immediate water shortage in the Gauteng cities of Johannesburg and Pretoria. Specialists concluded very recently that no water use restrictions would be required in the Vaal River System this summer. This followed a detailed review of the state of the dams in the system mapped against possible future rainfall patterns and current consumption levels.</p>
<p>But there are issues that residents of Gauteng and surrounding areas should be concerned about. Specifically, are the authorities responsible for managing water supplies keeping their eye on the ball? And are they ensuring that plans to protect the province from shortages over the next six years will be implemented on time?</p>
<h2>What lies ahead</h2>
<p>Concerns have been fuelled by many well-founded <a href="http://pmg-assets.s3-website-eu-west-1.amazonaws.com/180327AGSA-Challenges_Water_Sanitation.pdf">reports</a> of mismanagement at the Department of Water and Sanitation, which has oversight responsibility for water security. And the experience of a <a href="https://www.fin24.com/Budget/how-medupi-and-kusile-are-sinking-south-africa-20191009">faltering electricity supply</a> has shown that weak management of critical services like water and electricity can easily trigger supply crises. </p>
<p>So where should concerned water users be looking for problems to emerge?</p>
<p>Falling dam levels are not a problem. Dams are built to store water in wet periods to draw on when it’s needed; they rise in the rainy season and fall when it’s dry. If that didn’t happen, they would not be necessary. What people should be checking is whether the authorities are monitoring the situation. </p>
<p>In the case of the Vaal River System, it’s reassuring that the Department of Water and Sanitation technicians did hold their annual operating review to decide whether restrictions were needed. This procedure is what kept the region water secure during the 2015/2016 <a href="http://www.randwater.co.za/SalesAndCustomerServices/Forums%20Presentations/Water%20Services%20Forum%20Presentations/2016/May%202016/Raw%20Water%20Availability%20in%20IVRS%20-%20presented%20to%20WSF%2024%20May%202016.pptx">drought</a>. </p>
<p>The more important question is whether the Integrated Vaal River System supply infrastructure is adequate. </p>
<p>The Department of Water and Sanitation has <a href="http://www6.dwa.gov.za/Vaal/documents/LargeBulkWater/09_Vaal%20Recon%20Executive%20Summary_Final.pdf">plans</a> for interventions to ensure adequate supplies for all major systems, including the Vaal River System, until 2040 and beyond. But plans on paper need to be translated into infrastructure and into changed behaviour among water users. In this area, there is good reason for concern. </p>
<p>The plans anticipate that the Vaal River System has to be expanded. It has long been recognised that the most economical source for new water supplies is an additional dam in Lesotho. </p>
<p>Action is now urgent. By 2012, the decision to build the <a href="http://www.engineeringnews.co.za/article/phase-ii-update-polihali-dam-construction-expected-in-2019-2016-07-29/rep_id:4136">Polihali Dam</a> had been taken by the Lesotho and South African governments. But progress has been repeatedly delayed. One delay was <a href="https://www.dailymaverick.co.za/article/2016-08-05-amabhungane-nomvula-mokonyanes-alleged-interference-in-lesotho-water-project-cited-as-causing-delays/">reportedly</a> caused by the South African minister attempting to redesign the procurement process.</p>
<p>So, by 2017, when the Lesotho Highlands Development Authority got the go-ahead to start design work, the project was already five years late. </p>
<p>Recent <a href="https://mg.co.za/article/2018-04-20-00-challenge-damns-lesotho-water-project">reports</a> from Lesotho suggest that there have been efforts to bypass procurement procedures, despite warnings from the authority that formal tendering processes have to be followed. And, even though preparatory infrastructure construction has already started, South African authorities have not delegated decision-making processes and are taking months to respond on practical project management issues. There are also fears that past mismanagement at the Department of Water and Sanitation may make it harder to raise the loans to fund the main <a href="http://m.engineeringnews.co.za/article/municipal-debt-threatening-water-security-dg-warns-2019-10-22-1">construction work</a>. </p>
<p>Delays at this stage pose a real challenge. If a contractor has to stop work while waiting for a decision on a design change, delay penalties can cost South African water users millions of rands a day. Worse still, any delay extends the period during which the region will be at risk of shortages if there is a drought. </p>
<h2>Demand</h2>
<p>Rand Water, which supplies most of the municipalities in the region, has a licence to take 1,600 million cubic metres of water a year from the Vaal River System. The balance of the system’s supply goes to Eskom, the power utility as well as industry, mining and agriculture. </p>
<p>The population of Gauteng is growing by 3% annually, as people flock in to look for work. The fastest-growing water use sector is domestic supply by municipalities. </p>
<p>But water availability from the Vaal River System will remain the same until the Polihali dam is completed. This means that, to avoid a water crisis in the event of a drought between now and 2026, water use per person in the region is going to have to <a href="https://www.gcro.ac.za/news-events/news/detail/gcro-develops-gauteng-water-security-plan/">reduce</a> by 3% every year. </p>
<p>Over the next six years, all municipalities will have to keep their consumption static, no matter how fast their populations grow. Rand Water has initiated a special “Project 1600” to enforce these <a href="http://www.randwater.co.za/SalesAndCustomerServices/Forums%20Presentations/Mining%20and%20Industry%20Forum%20Presentations/2019/May%202019/Mining%20and%20industrial%20forum%20-23%20%20May%202019.pdf">limits</a>. </p>
<p>Of course, the feared drought disaster might never happen. If good rains fall every year between now and 2026, citizens might be able to squeeze through without tightening their belts. But nature can hit hard and in unexpected ways. Good water management is all about disaster risk reduction, not disaster management. </p>
<p>There are plans to provide enough water to meet the needs of all of South Africa’s major cities until at least 2030. As in the Vaal River System region, what matters is acting on those plans in good time. </p>
<p>Water security requires changing people’s behaviour, building new infrastructure and operating it properly. And this will only be achieved if political heads take the lead and avoid further delays. </p>
<p><em>This article is the first in a series looking at South Africa’s water challenges</em></p><img src="https://counter.theconversation.com/content/125742/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Muller has received funding from the Water Research Commission and the African Development Bank for research and advisory work related to the subject matter of this article. He also advises a variety of organisations on water related matters including national, provincial and local government, AgriSA and business organisations including BUSA and SAICA.</span></em></p>South Africa’s Department of Water and Sanitation has plans in place to ensure adequate water supply until 2040 and beyond.Mike Muller, Visiting Adjunct Professor, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1143792019-04-03T12:47:54Z2019-04-03T12:47:54ZWhat Cape Town’s drought can teach other cities about climate adaptation<figure><img src="https://images.theconversation.com/files/266773/original/file-20190401-177175-1m17hjo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lessons learned from the threat of Cape Town's "Day Zero."</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Extreme weather events, such as <a href="https://www.bbc.com/news/science-environment-47638588">Cyclone Idai</a> that has recently devastated Beira, Mozambique, and <a href="https://www.worldweatherattribution.org/hurricane-harvey-august-2017/">Hurricane Harvey</a> that hit Houston, USA, in 2017,
are the types of <a href="https://tandfonline.com/doi/full/10.1080/07900627.2017.1335186">climate extremes</a> that cities increasingly have to prepare for. </p>
<p>Cities, particularly those with <a href="https://unhabitat.org/un-habitat-thematic-guide-addressing-the-most-vulnerable-first-pro-poor-climate-action-in-informal-settlements/">extensive informal settlements</a> in the developing world, are being hit hard by these new climatic realities. Although rapid onset disasters often have devastating effects, slow onset climate events, such as drought, can also be detrimental. </p>
<p>Cities need to build their capacity to adapt to this range of impacts. One of the best ways to do this is to learn from other cities’ experiences. Drawing lessons from other places that have gone through climate crises is a good way to guard against future shocks and stresses.</p>
<p>One very recent case that cities around the world are watching is Cape Town’s severe drought and the threat of <a href="https://theconversation.com/day-zero-is-meant-to-cut-cape-towns-water-use-what-is-it-and-is-it-working-92055">“Day Zero”</a> – when the city’s taps were due to run dry. Although the city came close to having to turn off the taps, they managed to avoid it. After better rains in 2018 and significant reduction in water use across the city, the dams are now reassuringly fuller than they were in 2017 and 2018, although caution is still needed ahead of the winter rains. </p>
<p>A lot has changed and it’s important to reflect on and share. </p>
<p>I conducted <a href="https://www.africancentreforcities.net/wp-content/uploads/2019/02/Ziervogel-2019-Lessons-from-Cape-Town-Drought_A.pdf">research</a> to establish some key lessons to be drawn from the Cape Town drought. I found that local governments must focus on <a href="https://www.africancentreforcities.net/wp-content/uploads/2019/02/CSP_climate_drought-lessons_20190218.pdf">several important areas</a> if they’re to strengthen urban water resilience and adapt better to climate risk. These include improving data collection and communication, engaging with experts and enabling flexible adaptive decision-making. </p>
<p>And, crucially, I found that governance must be strengthened. Although three years of low rainfall led to very low dam levels, there were breakdowns in the interaction between national, provincial and municipal governments that exacerbated the problem. </p>
<h2>The findings</h2>
<p>The research suggests that effective water management requires systems of mutual accountability between spheres of municipal, provincial and national government. </p>
<p>In South Africa, the national <a href="https://www.gov.za/about-sa/water-affairs">Department of Water and Sanitation</a> is responsible for ensuring that sufficient bulk water is available, often in dams, that can be transferred to municipalities. The municipalities are then mandated to provide clean drinking water. This means that intergovernmental coordination across the spheres of government is vital. </p>
<p>As it stands, different spheres’ mandates overlap. This creates confusion and means the buck is often passed: one sphere of government will insist a particular competency isn’t its job, and hand the work on to another sphere. </p>
<p>For this to be resolved there has to be clarity on shared responsibilities and roles, as well as the development of mutual accountability. To achieve this, technical skills, personal and institutional relations need to be strengthened. This requires strong leadership.</p>
<p>Collaboration within municipal departments also needs to improve. The Cape Town drought highlighted the importance of this. Before 2017, there was limited collaboration between city departments on water issues. During the drought, however, collaboration between certain departments increased considerably as the complexity of the crisis became clear.</p>
<p>Not only is collaboration within government important, it needs to extend beyond government. During a crisis, all of society needs to be engaged, including citizens and the business sector. Technical expertise need to be balanced with opportunities for a broader group to share its perspectives and concerns. Partnerships can help gather the range of perspectives and support needed to respond to complex problems.</p>
<p>Municipalities that, during the course of their normal business activities, have developed strong relationships with their stakeholders will be better placed to respond effectively to a crisis. That’s because they will be able to harness stakeholders’ collective knowledge and contributions more easily. </p>
<p>In Nelson Mandela Bay, the <a href="http://www.nmbbusinesschamber.co.za/">Business Chamber</a> has done this by strengthening relations with the municipality to help to facilitate the ease of doing business in the city. They recognise that all businesses require electricity, water, transport and logistics, for example, and so focus on improving these areas. The municipality developed task teams made up of volunteers from their member companies who have skills set in those areas. </p>
<p>Importantly, there is an agreement that the Metro places high-level executives to sit in the task team meetings to ensure plans are put into practice. These types of relationships can be invaluable during a crisis. </p>
<h2>Moving forward</h2>
<p>While my study focused on Cape Town, its findings can be applied to other cities that want to strengthen their ability to adapt to climate change. Yes, cities need to pay more attention to how climate variability impacts on their resources, particularly water. But just as important is strengthening the governance of the water system. A well-adapted city is one that understands who is responsible for what and has strong trust and partnerships between and within government. </p>
<p>In order to build capacity to adapt, new types of skills are needed. Local government needs to pay more attention to how to build partnerships, enable flexibility and support learning. These are the types of skills needed for a well-adapted city, but still often lacking in local governments.</p><img src="https://counter.theconversation.com/content/114379/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gina Ziervogel receives funding from an AXA grant to work on urban governance through her Chair in the African Climate and Development Initiative. The findings in this article are based on work supported by the Cities Support Programme in South African National Treasury. The views presented are the author's own. </span></em></p>Cities need to pay attention to how extreme weather events effect their resources.Gina Ziervogel, Associate Professor, Department of Environmental and Geographical Science and African Climate and Development Initiative Research Chair, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1113782019-03-06T14:40:26Z2019-03-06T14:40:26ZHow droughts will affect South Africa’s broader economy<figure><img src="https://images.theconversation.com/files/261909/original/file-20190304-92277-zisww5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Droughts have become more commonplace in South Africa in recent years. <a href="https://www.news24.com/SouthAfrica/News/how-severe-is-cape-towns-drought-a-detailed-look-at-the-data-20180123">In the past two decades since 1990,</a> 12 of those years were defined as drier years compared to only seven years in the previous 20 years. </p>
<p>The latest period included three consecutive years of drier conditions, between 2014 to 2016. In some regions, such as the Western Cape, the country’s second largest province in terms of economic contribution, the drought continued into 2017.</p>
<p>These droughts are associated with <a href="https://www.climaterealityproject.org/blog/facts-about-climate-change-and-drought">climate change</a> – <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aae9f9/meta">the effect of human behaviour</a> on the planet’s temperature. </p>
<p>Over the past two years the Western Cape was forced to set <a href="https://www.iol.co.za/news/south-africa/western-cape/cape-town-gets-even-tougher-on-water-restrictions-7512713">strict water restrictions</a> – including curbs on irrigation – as dam levels dropped to below 20%. This had a direct effect on agriculture and food production, as well as ripple effects across the country. </p>
<p>In the province more than <a href="https://www.enca.com/south-africa/western-cape-drought-impact-on-agriculture-estimated-at-r5bn">R5 billion</a> was lost to the economy, largely due to the drought. This matters for the country as a whole because the Western Cape contributes <a href="https://agbiz.co.za/news/632/105/Western-Cape-drought-weighs-on-broader-agricultural-economy">22% to national agricultural GDP</a>. And the deciduous fruit and wine industries, and increasingly the citrus industry, are key exports and contribute significantly to South Africa’s <a href="https://www.iol.co.za/business-report/why-western-cape-agriculture-matters-to-sa-economy-10007415">overall agri-economy</a>.</p>
<p>The economic implications of all of these outcomes are dire. From 2015 to 2017 South Africa’s economic grew by a mere 1.1% average per annum, with the <a href="http://www.statssa.gov.za/publications/P0441/P04413rdQuarter2018.pdf">agricultural sector</a> growing at a rate of less than 0.5%. That’s not enough to make a dent on the country’s biggest challenges, which include high rates of inequality, poverty as well as unemployment. </p>
<h2>Western Cape as a case study</h2>
<p><strong>Tourism sector:</strong> The drought negatively affected the province’s tourism sector. Even though the impact hasn’t been quantified, the number of tourists visiting the province <a href="https://www.businessinsider.co.za/the-impact-of-the-cape-town-drought-on-tourism-was-rather-tiny-2018-7">went down during the drought period</a>. This was also reflected in the fact that year-on-year overnight guests in the region grew at a mere 1% from 2016 to 2017, compared with 7% a year earlier. Some hotels had bookings declining by between 10% and 15% in 2018, compared to 2017. </p>
<p>Tourism in Western Cape is estimated to employ about <a href="https://www.countrylife.co.za/news/38380">300 000 people</a>.</p>
<p><strong>Food prices:</strong> the impact of drought on food prices was severe with staple food items such as maize increasing. This affected mostly poor households which spend relatively large portions of their income on food – as much as <a href="http://www.statssa.gov.za/?p=2564">34% of their total income</a>. </p>
<p>Also, lower agricultural production has affected food supplies. This in turn could increase food prices and food insecurity. </p>
<p><strong>Jobs:</strong> The Western Cape has the biggest agricultural workforce in South Africa – nearly a <a href="https://www.iol.co.za/business-report/why-western-cape-agriculture-matters-to-sa-economy-10007415">quarter of the country’s</a> farm workers are employed in the region. And agriculture and agro-processing are responsible for <a href="https://www.iol.co.za/business-report/why-western-cape-agriculture-matters-to-sa-economy-10007415">18% of employment opportunities</a> in the province.</p>
<p>The drought has led to job losses in the province’s agriculture sector. The 2017 <a href="http://www.statssa.gov.za/?p=10658">third quarterly labour force survey</a> showed that approximately 25,000 jobs were lost from the agricultural sector nationally. More <a href="https://agbiz.co.za/news/632/105/Western-Cape-drought-weighs-on-broader-agricultural-economy">than 20 000 of these were</a> lost in the Western Cape province. Many were associated with the drought.</p>
<p>Most farm workers are unlikely to get jobs elsewhere, which means that job losses will worsen poverty. </p>
<h2>Impact on the fiscus</h2>
<p>If the pattern of drought continues, it’s likely to affect the country’s financial standing too. This is for a number of reasons.</p>
<p>Firstly, the National Treasury will have to continue spending money on disaster relief, as opposed to other economic activities. This year, for example, the South African government may need close <a href="https://www.forbesafrica.com/agriculture/2019/01/27/south-africa-farmers-seek-220-million-in-drought-aid/">to R3 billion sought by farmers</a> severely affected by the drought. </p>
<p>Future assistance could be in the form of helping build infrastructure like boreholes and supporting farmers who need to reduce stock. </p>
<p>Secondly, continuing droughts could force up the country’s import bill. Declining agricultural production could lead to shortages of some food items like maize, wheat and some protein sources such as meat and eggs. This could, in turn, force South Africa to import more. </p>
<p>Thirdly, a shortage of local produce could push up prices. This could affect food inflation and push up the consumer price index. Given that the South African Reserve Bank uses interest rates to control <a href="https://www.fin24.com/Economy/sa-reserve-bank-sees-higher-rates-to-curb-inflation-20181030">inflation</a>, this could lead to higher interest rates which will affect the broader economy.</p>
<h2>Climate change a reality</h2>
<p>Climate change poses a threat to everyone. Governments, farmers and society in general need to take proactive steps to deal with the outcomes of changing weather patterns.</p>
<p>Over time, agricultural production will need to adapt to new methods and approaches. These may include the use of drought-resistant seed varieties, modern technologies to adapt and taking up more crop insurance. These approaches are readily available to farmers who have the resources. It’s the developing, smallholder and emerging farmers that remain at risk. </p>
<p>Governments can assist farmers by providing infrastructure support making new laws that support the conservation of resources. And government can provide financial support for the development of new technologies as well as seed varieties that are adaptable and can withstand severe weather patterns. </p>
<p>This requires better planning. In addition, government must work closely with the agricultural sector.</p><img src="https://counter.theconversation.com/content/111378/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mmatlou Kalaba receives funding from National Research Foundation (NRF). He is affiliated with the Bureau for Food and Agricultural Policy (BFAP) and teh Agricultural Economics Association of South Africa (AEASA). </span></em></p>If the pattern of drought continues in South Africa it’s likely to affect the country’s financial standing too.Mmatlou Kalaba, Senior Lecturer in Agricultural Economics, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1124232019-02-27T13:53:42Z2019-02-27T13:53:42ZCape Town has a plan to manage its water. But there are big gaps<figure><img src="https://images.theconversation.com/files/260969/original/file-20190226-150702-1quu32l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What lessons were learnt from Cape Town's "Day Zero"?</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The City of Cape Town – and southwest Africa more generally – experienced its worst drought on record between 2015 and 2018. With fresh rains as well as careful water management, the city has now emerged from this environmental and economic emergency. </p>
<p>The final consequences of the drought might never be known for certain. This is because the effects on groundwater depletion or biodiversity loss may not appear until years after the event. But the economic impact of the drought is more easily identified. Over 30,000 jobs have been lost in the <a href="https://www.fin24.com/Economy/drought-impact-on-w-cape-economy-worse-than-anticipated-minister-20180301">agricultural sector</a> in the Western Cape region, caused by a 20% decrease in agricultural production. </p>
<p>There are other consequences too, such as the impact on the city’s international reputation, as well as residents’ and policymakers’ experiences of water restrictions and the threat of “Day Zero”. </p>
<p>So what are the lessons learnt?</p>
<p>The City of Cape Town has recently released a <a href="https://www.capetown.gov.za/City-Connect/Have-your-say/Issues-open-for-public-comment/draft-cape-town-water-strategy">draft strategy for water supply and management</a> which aims to ensure safe access to water and sanitation for all the city’s residents, efficient water use, diversified water sources and shared costs and benefits by 2040. This strategy has been strongly informed by events of the past three years and is a bold statement of intent. As such, it sets a benchmark for sustainable development in the city and the wider region. The strategy is aimed at increasing usable water availability and managing that water better. But some elements are missing. </p>
<h2>An uncertain future</h2>
<p>Missing parts of the strategy include the uncertainty of future trends in climate, economic activities, population growth, water demand and infrastructure investment needs. Increasing water availability is easy in theory because it is based on balancing supply to need. But this water needs to come from somewhere. </p>
<p>Rainfall is becoming ever more precarious, groundwater <a href="http://niwis.dws.gov.za/niwis2/DroughtStatusManagement/GroundwaterStatusOverview">aquifers are depleted</a>, and river and dam water is already allocated. Desalinisation is an option. But this is expensive and has unknown environmental impacts. </p>
<p>Another option is water redistribution. In the recent drought, water was diverted from the agriculture sector to supply the city. But this had ripple effects on farming communities and economies. This approach is probably no longer sustainable. </p>
<p>There is also the option of reducing water demand. The new draft strategy doesn’t specifically mention managing demand – it makes vague reference to the need to use water wisely. It may be that the memory of water restrictions is too recent to discuss in this document. But water management is not just about supplying water, it’s about changing hearts and minds. These take much longer to change. For some Capetonians, the drought is over and normal business is resumed. For others, the spectre of Day Zero still remains. </p>
<p>And the plan doesn’t indicate that lessons have been learnt. For example, an innovative <a href="http://www.capetown.gov.za/Family%20and%20home/Residential-utility-services/Residential-water-and-sanitation-services/cape-town-water-map">Water Map</a> used by the City of Cape Town was able to “name and shame” excessive water users, but some township users were exempt from restrictions while other wealthy users largely ignored the water restrictions because they could afford to pay the resulting fines. </p>
<p>This kind of behavioural analysis is important when it comes to equitable planning and water management, and provides a rich source of data for drought epidemiology – Cape Town knows more about how its residents use water than most cities.</p>
<h2>Emerging from disaster</h2>
<p>Over the next decades, it’s anticipated that southern Africa will experience both higher average annual temperatures, in particular in summer. It’s also expected to have <a href="http://www.weathersa.co.za/images/SAWS_CC_REFERENCE_ATLAS_PAGES.pdf">more variable</a> and somewhat lower rainfall. Collectively, these climatic changes will result in greater water insecurity, irrespective of any changes in population, water demand or capacity of water infrastructure.</p>
<p>A <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aae9f9">recent study</a> shows that climate change has trebled drought risk in Cape Town. Future-proofing cities such as Cape Town to withstand water insecurity and drought conditions cannot be done without managing water infrastructure better. In South Africa, <a href="http://www.dwa.gov.za/National%20Water%20and%20Sanitation%20Master%20Plan/Documents/NWSMP%20Call%20to%20Action%20v10.1.pdf">56% of waste water treatment plants</a> are not fully operational. This limits its ability to deliver on the future promises outlined in the City of Cape Town strategy document.</p>
<p>Water restrictions in Cape Town have eased over recent months. But persistent drought still exists elsewhere in the region, in small town rural communities where there’s a lack of water infrastructure, lack of access to dam water supplies and depleting aquifers. Addressing the future water problem for Cape Town should not be done at the expense of the wider region, and must be formulated as a national-scale strategy. This should be a government priority.</p><img src="https://counter.theconversation.com/content/112423/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jasper Knight does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Cape Town’s draft strategy on water supply is out for comment, but important elements are missing from it.Jasper Knight, Professor of Physical Geography, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1076252018-12-19T11:38:27Z2018-12-19T11:38:27ZGlobal warming has already raised the risk of more severe droughts in Cape Town<figure><img src="https://images.theconversation.com/files/247485/original/file-20181127-76767-1ua0jb6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cape Town residents queuing for water during the water crisis.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Between 2015 and 2017 South Africa’s South Western Cape region experienced <a href="https://www.groundup.org.za/article/how-severe-drought-detailed-look-data/">three of its lowest rainfall years on record</a>. This led to the progressive depletion of water supply reservoirs and by the summer of 2017/18 there was a real danger that – without drastic reductions in water use – the region, and especially the city of Cape Town, would run out of water.</p>
<p>Droughts close to this magnitude have occurred in the past (for example in the late <a href="http://dx.doi.org/10.4314/wsa.v29i4.5057">1920s, early 1970s</a>, and <a href="https://www.news24.com/SouthAfrica/News/Drought-begins-to-bite-20030717">2003 to 2004</a>) and led to water shortages in Cape Town. But are they getting worse?</p>
<p>The reliable yield of the South Western Cape water system has, until now, been calculated under the assumption of a <a href="http://www.wmo.int/pages/prog/hwrp/chy/chy14/documents/ms/Stationarity_and_Nonstationarity.pdf">stationary climate</a>. This is the idea that past rainfall can be used to estimate present day as well as future rainfall, and then also water system yields. A water resource model is used to estimate the frequency of failure under all the known past rainfall conditions – in the case of this region, the last 80 or so years. The water system is then designed to be fairly reliable. The supply system for Cape Town and surround areas was designed to maintain supply without imposing water restrictions 98% of the time, or – on average – 49 out of every 50 years.</p>
<p>It’s known that the climate is going to change in the future, as a succession of <a href="http://www.ipcc.ch/report/ar5/syr/">international scientific assessments</a> have shown. And many water resource planners are taking climate change into account when upgrading existing or designing new water supply systems.</p>
<p>But has this changing global climate <em>already</em> altered the risk of droughts like the one Cape Town just experienced? </p>
<p>We assessed this in a recently published <a href="http://iopscience.iop.org/article/10.1088/1748-9326/aae9f9/meta">analysis</a>. Using a <a href="https://www.worldweatherattribution.org/the-role-of-climate-change-in-the-2015-2017-drought-in-the-western-cape-of-south-africa/">range of modelling approaches</a>, we first estimated the frequency and intensity of three-year rainfall amounts over the South Western Cape in a world without human-induced warming of the climate.</p>
<p>We then compared this to drought risk in the world we actually live in, where greenhouse gases and other pollutants have warmed the planet by about one degree.</p>
<h2>A threefold increase in drought risk</h2>
<p>The results from tdifferent models vary but they all show that the risk of drought has increased substantially because of global warming. Our best estimate is that the risk of a drought of this size has increased by a factor of just over three (see graph). </p>
<p>This means that the key assumption of a stable climate, which underpins the design of the water supply system, has been undermined by climate change, at least for the South Western Cape region. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=294&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=294&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=294&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=369&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=369&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247222/original/file-20181126-140534-18xzvby.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=369&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The change in risk of a drought like the one just experienced in Cape Town that is attributable to human influence on climate. The Risk Ratio (RR) is the likelihood of this drought today compared to in world without global warming. An RR greater than 1.0 indicates the risk has increased. For each modelling approach, the best estimate for the RR (the black line) and 95% confidence range (coloured bar) are shown. The synthesis provides the best estimate and confidence range across all modelling approaches, indicating a RR of 3.32, or just over a threefold increase in risk.</span>
</figcaption>
</figure>
<p>Our analysis shows that what has been predicted to happen in Southern Africa under changing climate in the future is already happening, with more dry periods today than, say, 20 or 50 years ago. And so, the water resource system is stressed more frequently and more strongly than had been anticipated.</p>
<p>In addition to assessing current risk, our analysis also showed that with a further doubling of global warming over today from 1.0 to 2.0 degrees – <a href="https://www.ipcc.ch/report/ar5/wg1/">likely to happen</a> sometime in the next 50 years – there is a further threefold increase in risk of severe drought. </p>
<p>This means that droughts which the current water resource system is designed to survive will occur much more frequently. Without adaptation in water supply and demand, events like the 2017-2018 water shortage could occur once every 15 years, on average, compared to the expected once every 50 years.</p>
<p>It’s been <a href="https://www.nature.com/articles/d41586-018-05649-1">suggested</a> that the Cape Town water crisis was largely because of an erosion of water management capability in South Africa.</p>
<p>But we show that another culprit is exacerbating the problem – climate change. Organisations such as Department of Water and Sanitation at the national level, and catchment management agencies at local and regional level, who are responsible for working towards a more resilient water resource system for the future need to do better than in the past and include estimates of the evolving drought risk. Otherwise they’ll always be underestimating this risk as climate change progresses into the future.</p>
<p>Climate change projections are often taken into account when designing future water supply systems and other infrastructure. What Cape Town’s drought teaches us is that climate change is not a thing of a distant future: it is happening already and impacts us today. We are running out of time to reduce greenhouse gas emissions, and more importantly, we can no longer postpone taking precautionary and adaptive actions.</p><img src="https://counter.theconversation.com/content/107625/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark New receives funding from the AXA Research Fund, the BNP Paribas Foundation's Climate Initiative, the International Development Research Centre, DANIDA and the National Research Foundation, among others. </span></em></p><p class="fine-print"><em><span>Friederike Otto receives funding from the BNP Paribas Foundation's Climate Initiative, the British Council India, and the Nature Conservancy, among others.</span></em></p><p class="fine-print"><em><span>Piotr Wolski receives funding from AXA Research Fund under UCT/ACDI Chair in African Climate Risk, and from other governmental and non-governmental funding sources supporting climate and water resources research. </span></em></p>Water supply systems weren’t designed to deal with altering weather patterns brought about by climate change. This needs to change.Mark New, Director, African Climate and Development Initiative, University of Cape TownFriederike Otto, Acting Director, Environmental Change Institute, University of OxfordPiotr Wolski, Senior Researcher in Hydro-Climatology, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1003962018-08-01T13:22:17Z2018-08-01T13:22:17ZHow cities can work with nature when droughts take their toll<figure><img src="https://images.theconversation.com/files/230007/original/file-20180731-136667-1efq6fv.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A residential rain garden in Portland’s Tabor to the River project.</span> <span class="attribution"><a class="source" href="https://www.portlandoregon.gov/bes/47591">City of Portland Government</a></span></figcaption></figure><p>Models of the earth’s changing climate suggest that extreme weather events, including <a href="https://theconversation.com/droughts-and-flooding-rains-climate-change-models-predict-increases-in-both-5470">droughts</a>, will become more frequent. As city populations grow, it will be harder for governments to provide enough water for everyone. According to the <a href="http://www.wri.org/blog/2015/08/ranking-world%E2%80%99s-most-water-stressed-countries-2040">World Resources Institute</a>, the northern and southern parts of Africa will experience high to extremely high water stress if business as usual water usage continues until 2040.</p>
<p>Faced with a drought, it’s tempting for city managers to reduce the amount of space that needs water. Parks, public areas and private gardens are usually the first to go. But there are good reasons to keep nature in cities, and there are ways to do it.</p>
<p>Municipalities typically respond to a drought by limiting water use, and then to look at ways to cover spaces with artificial surfaces like paving instead of lawns and plants.</p>
<p>But there are four reasons why that is a bad idea.</p>
<ol>
<li><p>Impervious surfaces seal the soil. Surface water can’t filter down to recharge the groundwater, and normal biological processes in the upper layers of soil are interrupted. Instead, rainwater goes into the storm-water system. </p></li>
<li><p>Covering up nature reduces biodiversity and habitat quality. Urban nature becomes poorer and there’s less of it. </p></li>
<li><p>Concrete, tar and masonry raise the temperature of built-up areas. Green open spaces <a href="https://www.tpl.org/sites/default/files/Benefits%20of%20GI%20for%20heat%20mitigation%20and%20emissions%20reductions%20in%20cities.pdf">mitigate</a> this so-called urban heat island effect. </p></li>
<li><p>Enjoying nature gives people the opportunity to be healthy and well. </p></li>
</ol>
<h2>Beneficial urban nature</h2>
<p>Nature in cities is good for people – and good for nature itself. Cities with continuous corridors and larger natural areas <a href="https://www.ncbi.nlm.nih.gov/pubmed/25865805">in excess of 50 hectares</a> support greater biodiversity. But even community-level “<a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.12179">stepping stones</a>” of green infrastructure amid the urban landscape are better than nothing. “Stepping stones” aid more mobile species, such as birds and insects, to move around the city, reach bigger natural areas and find what they need for survival. </p>
<p>As for people, even small daily doses of nature such as looking out of a window at a natural scene are good for health and <a href="https://www.sciencedirect.com/science/article/pii/S2212041614001648">wellness</a>. Access to nature has been shown to improve cognitive functioning, reduce hypertension and speed up recovery times following illnesses. </p>
<p>Yet it is these smaller, accessible, everyday forms of nature that are the most vulnerable to the conversion to artificial surfaces.</p>
<h2>Low impact cities</h2>
<p>Instead of covering up urban surfaces, there is an engineering solution in the form of <a href="http://www.futurewater.uct.ac.za/FW-wsd">low impact design</a> that could be applied to water sensitive cities. It’s increasingly found in parks and gardens and it conserves water while preventing overloaded stormwater systems and depleted groundwater. </p>
<p>These designs include lowered flower beds and bog gardens, rain-gardens and mulch-pits, infiltration trenches and swales (channels). The positive unintended consequences include providing breeding grounds for amphibians and dragonflies, stopovers for waterfowl and opportunities for recreation and education whilst contributing to lowering the ambient temperature within a city.</p>
<p>Portland’s <a href="https://www.portlandoregon.gov/bes/47591">Tabor to the River project</a>, in Oregon State, US, demonstrated that bio-swales running alongside streets have improved residents’ <a href="https://www.sciencedirect.com/science/article/pii/S0169204614002539">knowledge of stormwater</a> and how the city fits into the broader ecosystem. </p>
<p>A South African example of stormwater management to increase a sense of connection with nature can be found in Cape Town. The <a href="http://www.capetowngreenmap.co.za/blog/edith-stephens-nature-reserve">Edith Stephens Wetland Park Environmental Education Centre</a> has partnered with community members from one of the poorest settlements in the city to improve surface quality water and access to sanitation. The community living on the banks of the Lotus River has limited access to quality municipal water and people use the river for waste disposal and washing. Their health is directly linked to the health of the river and the wetland system, which purifies the water naturally.</p>
<h2>Green spaces</h2>
<p>The <a href="https://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/report_africa_en.pdf">Siemens African Green City Index</a> measured the environmental performance of Africa’s major cities. The index assessed 15 cities across six categories with up to three criteria in each category – one of which was the amount of green space per capita in each city. Of the 15 indexed, the average is 74 m2/person, nearly double the Asian average of 34 m2/person. The cities spanned a range of densities, though, from Luanda’s 0.1 m2/person – well below the World Health Organisation recommended minimum of 9 m2/person – to Johannesburg’s 230.2 m2/person at the other end of the scale.</p>
<p>But lower densities of urban green space can be under-used. That space can become a hotspot for illicit activities. It’s therefore <a href="https://www.sciencedirect.com/science/article/pii/S0169204614002539">recommended</a> that biodiverse cities have optimal traffic and usage to ensure safety. </p>
<p>An additional trend is that the urban poor typically have fewer safe, accessible green spaces. Although South African cities have relatively high ratios of green space, socio-economically poorer areas typically do not have parks and gardens that are suitable for outdoor leisure time. Instead, being on the periphery of the city, they are often side by side with large preserved areas, that experience low usage-levels for most of the year. This gives the urban poor a high ratio of green space but no regular experience of it for leisure activities. </p>
<h2>Why landscaping matters</h2>
<p>Landscaping in ways that respond to climate change has benefits that go beyond coping with droughts, floods and high temperatures. Done sensitively, it contributes to human health and well-being, integrates wildlife habitats and fosters learning opportunities.</p><img src="https://counter.theconversation.com/content/100396/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peta Brom receives funding from South African Systems Analysis Center (SASAC)</span></em></p><p class="fine-print"><em><span>Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Faced with a drought, it’s tempting for cities to reduce the amount of space that needs water. But this is not a good idea.Kevin Winter, Senior Lecturer in Environmental & Geographical Science, University of Cape TownPeta Brom, PhD candidate in Urban Ecology, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/989962018-07-12T20:17:34Z2018-07-12T20:17:34ZWhat can other cities learn about water shortages from ‘Day Zero’?<figure><img src="https://images.theconversation.com/files/227031/original/file-20180710-70060-7n512t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cape Town narrowly avoided "Day Zero," but that doesn't mean the city is resilient to future water shortages.</span> <span class="attribution"><a class="source" href="https://pixabay.com/en/south-africa-cape-town-2267795/">(Pixabay)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Cape Town was set to run dry on <a href="https://www.cnn.com/2018/02/20/africa/cape-town-day-zero-delayed-intl/index.html">April 12, 2018</a>, leaving its 3.7 million residents without tap water. </p>
<p>“Day Zero” was narrowly averted through drastic cuts in municipal water consumption and last-minute <a href="https://www.cnn.com/2018/02/05/africa/cape-town-day-zero-intl/index.html">transfers from the agricultural sector</a>. But the process was <a href="https://theconversation.com/bold-steps-are-needed-toward-a-new-normal-that-allocates-water-fairly-in-south-africa-92191">painful and inequitable</a>, spurring much controversy. </p>
<p>The city managed to stave off “Day Zero,” but does that mean Cape Town’s water system is resilient? </p>
<p>We think not. </p>
<p>This may well foreshadow trouble <a href="https://globalnews.ca/news/4067957/cape-town-not-run-out-of-water-other-cities-might/">beyond Cape Town</a>. Cities across the Northern Hemisphere, including <a href="http://www.cbc.ca/news/technology/here-are-the-places-in-canada-yes-canada-vulnerable-to-drought-1.4570333">in Canada</a>, are well into another summer season that has already brought <a href="http://www.cbc.ca/news/canada/british-columbia/record-setting-heat-scorches-b-c-s-south-coast-1.4662119">record-setting heat</a>, drought and flooding from increased run-off.</p>
<h2>Water crises are not just about scarcity</h2>
<p>Water scarcity crises are <a href="http://hdr.undp.org/sites/default/files/reports/267/hdr06-complete.pdf">most often a result of mismanagement</a> rather than of absolute declines in physical water supplies. </p>
<p>In Cape Town, lower than average rainfall tipped the scales towards a “crisis,” but the situation was worsened by <a href="https://theconversation.com/cape-town-should-serve-as-a-wake-up-call-for-managing-water-in-south-africa-91107">slow and inadequate governance responses</a>. Setting aside debates around whose responsibility it was to act and when, the bigger issue, in our view, was the persistence of outdated ways of thinking about “uncertainty” in the water system.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/as-a-water-crisis-looms-in-cape-town-could-it-happen-in-canada-90582">As a water crisis looms in Cape Town, could it happen in Canada?</a>
</strong>
</em>
</p>
<hr>
<p>As the drought worsened in 2016, the City of Cape Town’s water managers remained <a href="https://mymedia.leeds.ac.uk/Mediasite/Showcase/default/Presentation/e282379b1eda4fd983b4233eca4d448c1d">confident in the system’s ability to withstand the drought</a>. High-level engineers and managers viewed Cape Town’s water system as uniquely positioned to handle severe drought in part because of the vaunted success of their ongoing <a href="https://greencape.co.za/assets/Sector-files/water/Water-conservation-and-demand-management-WCDM/CoCT-Long-term-water-conservation-and-water-demand-management-strategy-2007.pdf">Water Demand Management strategies</a>. </p>
<p>They weren’t entirely mistaken — demand management has cut overall daily consumption by <a href="https://thebulletin.org/what-cape-town-learned-its-drought11698">50 per cent since 2016</a>. So what went wrong?</p>
<h2>Limits to demand management</h2>
<p>First, Cape Town’s approach to water management was <a href="https://www.access.ac.za/access-position-on-the-winter-rainfall-in-the-western-cape/">not well-equipped to deal with growing uncertainty</a> in rainfall patterns — a key challenge facing cities worldwide. <a href="https://mymedia.leeds.ac.uk/Mediasite/Showcase/default/Presentation/e282379b1eda4fd983b4233eca4d448c1d">Researchers at the University of Cape Town</a> argued recently that the conventional models long used to forecast supply and demand underestimated the probability of failure in the water system. </p>
<p>Second, Cape Town’s water system neared disaster in part because demand management seemed to have reached its limits. Starting late last year, the city imposed a limit on water consumption of 87 litres per person per day. That ceiling thereafter shrunk to <a href="http://www.cbc.ca/news/world/cape-town-graphics-water-1.4577289">50 litres per person per day</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/227501/original/file-20180712-27021-1jfivla.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cape Town residents queue to fill containers from a spring water source on Feb. 2, 2018.</span>
<span class="attribution"><span class="source">(AP Photo/Bram Janssen)</span></span>
</figcaption>
</figure>
<p>Despite these efforts, Cape Town consistently failed to cut demand below the 500-million-litre-per-day citywide target needed to ensure that the system would function into the next rainy season.</p>
<p>The mayor accused the city’s residents of wasting water, but her <a href="http://www.capetown.gov.za/Media-and-news/Day%20Zero%20now%20likely%20to%20happen%20%E2%80%93%20new%20emergency%20measures">reprimanding rhetoric</a> should not be seen as a sign that the citizens were non-compliant. The continuously shrinking water targets were an untenable long-term management strategy. </p>
<h2>Buffers are key to water resilience</h2>
<p>In the end, “Day Zero” was avoided primarily by relying on unexpected buffers, including <a href="https://www.thesouthafrican.com/grabouw-dam-cape-town-water/">temporary agricultural transfers</a> and the private installation of <a href="https://www.newsecuritybeat.org/2018/04/avoiding-water-crisis-whats-cape-town-beyond/">small-scale, residential grey-water systems and boreholes</a> in the city’s wealthier neighbourhoods. The former increased water supply and the latter lowered demand from the municipal system. These buffers are unlikely to be available next year, however, as the <a href="https://www.westerncape.gov.za/110green/files/atoms/files/Water%20Outlook%202018%20%28Rev%2024%29%2017%20April%202018_0.pdf">water allocations for the agricultural sector</a> will not be renewed and there is uncertainty in the long-term sustainability of groundwater withdrawals.</p>
<p>For more than a decade, Cape Town has levelled demand, reduced leaks and implemented pressure management and water restrictions. This made Cape Town’s water system <a href="http://edges.sites.olt.ubc.ca/files/2017/06/The-Future-of-Drought-Management-for-Cape-Town-Summary-for-Policy-Makers.pdf">highly efficient and therefore less resilient</a> because there were fewer reserves to draw from in times of unusual scarcity.</p>
<p>The <a href="http://unesdoc.unesco.org/images/0023/002318/231823E.pdf">UN Water 2015 </a> report found that most cities are not very resilient to water risks. As water managers continue to wait for climate change models to become more certain or more specific, they defer action, <a href="https://doi.org/10.1016/j.gloenvcha.2018.02.010">paralyzing decision-makers</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/damage-from-flooding-doesnt-have-to-be-inevitable-95847">Damage from flooding doesn't have to be inevitable</a>
</strong>
</em>
</p>
<hr>
<p>If we really want our cities to be water-resilient, we must collectively change long-held ideas about water supply and demand. This will require technological and institutional innovation, as well as behavioural change, to create new and more flexible buffers — for example, through water recycling, green infrastructure and other novel measures. </p>
<p>Although Cape Town avoided disaster this year, that does not make it water-resilient. Despite the arrival of the rainy season, Cape Town is still <a href="https://www.thesouthafrican.com/day-zero-experts-highly-likely-cape-town-2019/">likely to face Day Zero</a> at some point in the future. </p>
<p>There’s a good chance that the city is not alone.</p><img src="https://counter.theconversation.com/content/98996/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucy Rodina receives funding from the Social Sciences and Humanities Research Council of Canada. </span></em></p><p class="fine-print"><em><span>Kieran M. Findlater receives funding from Genome Canada and the Social Sciences and Humanities Research Council of Canada.</span></em></p>Cape Town faced down “Day Zero” earlier this year, but that doesn’t mean its water system is resilient. Other cities should also take note.Lucy Rodina, PhD Candidate, University of British ColumbiaKieran M. Findlater, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/984942018-06-20T13:53:27Z2018-06-20T13:53:27ZIndia’s colonial legacy almost caused Bangalore to run out of water<figure><img src="https://images.theconversation.com/files/224026/original/file-20180620-137708-1a8yqwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Well, well, well.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bangalore-bengalurus-skyline-dusk-sunset-mahadevpura-1097570915?src=EZdNEN39TvWz8bM1Opahew-1-38">Shutterstock.</a></span></figcaption></figure><p>On hot summer days in Bangalore, India, it is common to see public water taps on roadsides hissing and spurting as water struggles to come out. People crowd around the tap with pots of brightly coloured plastic, burnished brass or steel, waiting for their turn. Many of these people have come from homes without such luxuries as indoor plumbing and will return carrying enough water to last several days. More privileged citizens have water piped to their houses in larger quantities – and more frequently. But even for them, interrupted water supply and rationing have always been a fact of daily life.</p>
<p>Bangalore is perhaps one of India’s most globally visible cities, owing to its reputation as India’s Silicon Valley. Corporate buildings and malls with shimmering glass facades vie for space with residential high rises and villas, bolstering the city’s popular image as a vibrant and booming metropolis with an entrepreneurial young population. But informal settlements and slums coexist alongside this image of prosperity, and residents – poor and affluent alike – face the trials of living in a city starved of water: a legacy of colonial policies that relied on vast technological solutions to solve local problems.</p>
<p>Bangalore is not alone in its water woes – cities across the globe struggle to meet water requirements every day. Although Cape Town’s water crisis <a href="https://www.bloomberg.com/news/articles/2018-06-19/cape-town-scraps-desalination-barge-plan-as-water-crisis-eases">has eased</a>, residents are <a href="http://www.capetown.gov.za/Family%20and%20home/residential-utility-services/residential-water-and-sanitation-services/Residential-water-restrictions-explained">still limited</a> to using 50 litres of water each, per day. Other settlements <a href="https://news.nationalgeographic.com/2018/02/cape-town-running-out-of-water-drought-taps-shutoff-other-cities/">are also affected</a>. In Mexico City, water supply is frequently interrupted while, in Brazil, São Paulo’s main water reserves were below 15% as of 2017. Indonesia’s capital Jakarta, meanwhile, is facing severe groundwater depletion. Droughts are shaped by each city’s development over time – and these recent shortages have shown just how shaky the infrastructure which supplies their water has become. </p>
<h2>A history of water</h2>
<p>Take <a href="https://theconversation.com/when-cities-were-natures-haven-a-tale-from-bangalore-85411">Bangalore</a>, for example – the city tends to be naturally arid, because of its location in the rain shadow of the Western Ghats hill range. Records from the 6th century onwards <a href="https://link.springer.com/article/10.1007/s12685-017-0199-9">show that</a> successive rulers of the city invested in creating an interconnected, community-managed system of tanks and open wells. The shallow aquifers of the wells were recharged by the tanks, across an elevation gradient that harvested rainwater. </p>
<p>Since around 1799, different authorities took control of the tanks – first the colonial state, and later on the independent Indian government. These tanks were the main water supply infrastructure for almost a century, though they faltered during periods of drought and famine. To meet the rising demand, the Municipal and Public Works Departments considered deepening reservoirs or building new ones. By 1885, the city’s water supply was running low, and the colonial government responded by setting up piped infrastructure, bringing water from <a href="http://www.environmentandsociety.org/arcadia/lost-lakes-bangalore">sources 30km away</a> including the Hesarghatta and then the TG Halli reservoirs. But none of these fixes could meet demand for very long. </p>
<p>Meanwhile, given the new dependency on piped water infrastructure, the old tanks and wells <a href="http://www.environmentandsociety.org/arcadia/pulley-pipe-decline-wells-bangalore">became disused</a>, polluted or built over. After India <a href="https://www.bl.uk/reshelp/findhelpregion/asia/india/indianindependence/transfer/index.html">gained independence</a> in 1947, the Bangalore Water Supply and Sewerage Board (BWSSB) was established. In response to the city’s water supply issues, the board floated the idea of pumping in water from the river Cauvery – more than 100km upstream from Bangalore. The project started in 1974 and continues to this day, reaching its fifth stage in 2018. </p>
<p>With the threat that <a href="http://www.sawasjournal.org/download/369/">water would run out</a> still looming large, authorities have since explored other possibilities. In 2016, the state government proposed to divert water from the <a href="https://thewire.in/environment/yettinahole-karnataka-bengaluru-chikkaballapur">Yettinahole river</a>, 300kms from Bangalore. Scientists also explored the feasibility of <a href="http://ojs.udspub.com/index.php/jsupp/article/view/429">constructing a reservoir</a> under the Arabian Sea, to impound that water for supply. The central government of India went a step further and considered <a href="https://timesofindia.indiatimes.com/india/centre-plans-to-transfer-surplus-godavari-water-to-cauvery-nitin-gadkari/articleshow/61770355.cms">transferring surplus water</a> from the north flowing river Godavari into the southern Cauvery. </p>
<p>The estimated costs of these large-scale proposals <a href="https://thewire.in/environment/yettinahole-karnataka-bengaluru-chikkaballapur">were massive</a> –– <a href="https://thediplomat.com/2016/07/the-cost-of-interlinking-indias-rivers/">billions of dollars</a> could be spent without delivering guaranteed water security. Instead, the authorities seek to reallocate limited supplies of water – though even that is done unfairly and unevenly. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/224032/original/file-20180620-137725-1m8v2vj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A tanker delivers water in Bangalore.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bangalore-india-july-15-water-tanker-82300918?src=mo_CUryeWEE4_zTPRvVnWA-1-1">Ajay Bhaskar/Shutterstock.</a></span>
</figcaption>
</figure>
<p>Piped water supply systems cater only to central Bangalore, while the outskirts rely on alternatives including domestic bore wells or private water tankers, tapping into and depleting deep groundwater aquifers. These services are typically used by the urban poor, but operated on a for-profit basis, which means they actually <a href="https://dlc.dlib.indiana.edu/dlc/bitstream/handle/10535/9277/Art7-1-6.pdf?sequence=1">come at higher costs</a> than the heavily subsidised centralised water supply system. </p>
<h2>An alternative approach</h2>
<p>While governments have floundered, Bangalore has seen a resurgence of <a href="https://www.thenatureofcities.com/2012/10/07/a-tale-of-two-lakes-collective-action-in-cities/">citizen-led collectives</a> working to protect and rejuvenate the old tanks and open wells – and open them up to poor and disadvantaged citizens. These collectives have also innovated, exploring how treated sewage can contribute to the supply. In <a href="http://biometrust.blogspot.com/2015/04/jakkur-lake-ecosystem-and-its-challenges.html">Jakkur Lake</a>, for instance, treated sewage is filtered through a human-made wetland and into the lake itself, fostering a healthy ecosystem as well as helping to recharge groundwater. </p>
<p>Initiatives have blossomed online, too: the Facebook page <a href="https://www.facebook.com/groups/654818214611691/">Open wells of India and the world</a> is a place where members can upload photographs of any open wells they encounter, along with their location. By documenting many little known open wells which survive across the city and beyond, it provides a fascinating glimpse into the potential such options hold for harnessing and storing rain water. One particularly poignant image was shared by local man Vishwanath Srikantaiah: a massive open well, recharged by the Jakkur lake. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/224023/original/file-20180620-137720-nlkd4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An open well near Jakkur lake, replenished.</span>
<span class="attribution"><a class="source" href="https://www.facebook.com/zenrainman/media_set?set=a.10152984175097555.1073741873.564692554&amp%3Btype=3">S. Vishwanath/Facebook</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The efforts of <a href="http://www.biome-solutions.com/">Biome</a>, <a href="http://icfn.in/">India Cares Foundation</a> and <a href="http://bengaluru.citizenmatters.in/bangalore-lake-revival-solutions-part-2-21106">Friends of Lakes</a> – combined with the local expertise of traditional well diggers – have restored <a href="https://economictimes.indiatimes.com/news/politics-and-nation/this-summer-rejuvenated-wells-and-ponds-will-keep-cubbon-park-green/articleshow/63167096.cms">seven public wells</a> within the city’s well-known Cubbon Park. Thanks to an approach that combines local knowledge and innovative problem solving, the wells now produce about 65,000 litres of water per day and help to meet the water demands of the park. </p>
<p>Grand technological visions have proved incapable of meeting Bangalore’s needs since colonial times. But local, community-led measures to manage and replenish water have a good chance of creating a <a href="https://www.thenatureofcities.com/2015/07/02/open-wells-and-urban-resilience/">water-secure, resilient city</a>: an object lesson for those planning cities for the future.</p><img src="https://counter.theconversation.com/content/98494/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hita Unnikrishnan receives funding from a Newton International Fellowship granted to her by the British Academy and hosted by the Urban Institute, The University of Sheffield. She is also a visiting faculty at the Azim Premji University, Bengaluru, India. </span></em></p><p class="fine-print"><em><span>Harini Nagendra receives research funding from the Centre for Urban Ecological Sustainability, Azim Premji University.</span></em></p><p class="fine-print"><em><span>Vanesa Castán Broto receives funding from the Economic and Social Research Funding, the British Academy and the Leverhulme Trust. She is a member of the Board of Directors of the Landscape Research Group Ltd.</span></em></p>Bangalore’s forgotten water wells are being revived, to help the city overcome centuries-old supply issues.Hita Unnikrishnan, Newton International Fellow, University of SheffieldHarini Nagendra, Professor of Sustainability, Azim Premji UniversityVanesa Castán Broto, Professorial Fellow, University of SheffieldLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/985352018-06-18T19:59:51Z2018-06-18T19:59:51Z‘Day Zero’: From Cape Town to São Paulo, large cities are facing water shortages<p><strong>Will South Africa’s second largest city dry up on August 19 of this year? By launching an official countdown, Cape Town City Council wished to highlight the impending cuts to domestic water supply for its more than 3.7 million inhabitants.</strong></p>
<p>The BBC then upped the ante, with an online list of 11 cities that may sooner or later suffer the same fate. Since then, a tide of alarmism has swept through the media. It is as if we are suddenly realizing that water doesn’t flow from the tap by magic!</p>
<h2>What is happening in Cape Town?</h2>
<p>Located on the southern tip of Africa, Cape Town has a distinctly Mediterranean climate. This is why grapes grow so well there. But despite being a boon for winegrowers, that climate is characterized by formidable summer droughts. And with winter ending in the northern hemisphere and summer drawing to a close in the southern hemisphere, now is the time of year when the water reservoirs of Cape Town are typically at their lowest.</p>
<p>The city has a total of six reservoir dams to store water from rivers running down from the Cape Fold mountains, east of the city. Their total storage capacity is around 900 million cubic meters (for comparison, the storage capacity of the Grands Lacs de Seine reservoirs, upstream of Paris, is 810 million cubic meters).</p>
<p>But Cape Town’s current problems are far more serious than a simple seasonal slump: a prolonged drought raging since 2015 means that reservoirs have not been able to recover their reserves over the last three winters (2015, 2016 and 2017), leading to a steady decline in water storage rates (see graph below). Only a significantly premature and rainy winter could now prevent a general water shutdown; even then, it is unlikely that water storage rates will rise to secure levels over the course of one season.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changes in water storage levels at Theewaterskloof dam, the largest of the reservoirs supplying Cape Town with water.</span>
<span class="attribution"><a class="source" href="http://niwis.dws.gov.za/niwis2/SurfaceWaterStorage">South African Department of Water and Sanitation</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Climate impact</h2>
<p>This extraordinary crisis is clearly due to climatic causes (an uninterrupted succession of dry years), with aggravating factors, such as high sustained urban population growth (+80% between 1995 and 2018) and water sharing between the city and agricultural land.</p>
<p>As a matter of fact, the water stored in Cape Town’s water supply reservoirs is not only used for drinking water: a third of its volume is used to irrigate the approximately 37,000 acres of vines and orchards that surround the city.</p>
<p>At the turn of the century, the council implemented an active policy for controlling water consumption, stabilizing it at the level reached in 1999, in spite of a significant rise in population (see graph below). The loss rate through leakage in the water distribution network is low (around 15%) and waste water is increasingly being re-used, in particular to water parks and golf courses.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changes to Cape Town’s water consumption over time.</span>
<span class="attribution"><a class="source" href="https://www.greencape.co.za/assets/Water-Sector-Desk-Content/CoCT-WCWDM-presentation-Z-Basholo-Western-Cape-Water-Forum-160204-2016.pdf">Ville du Cap</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The City has already made plans for a general shutdown, which is now a very serious possibility. Water would be distributed from 200 sites, where inhabitants would be able to collect 25 litres per day, under the surveillance of the army and police.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1067&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1067&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1067&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How to live with only 50 litres (13 US gallons) of water a day.</span>
<span class="attribution"><a class="source" href="http://resource.capetown.gov.za/documentcentre/Documents/Graphics%20and%20educational%20material/50%20Litre%20Life%20Poster-colour.pdf">Ville du Cap</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Local or global crisis?</h2>
<p>Looking beyond South Africa’s current troubles, we can wonder whether this crisis is local, or global.</p>
<p>The BBC published a list of eleven cities with recurring water supply problems; other organizations, such as the World Bank and various scientific journals, have published similar lists.</p>
<p>Numerous regions worldwide have experienced water supply crises in recent years. In 2008, Barcelona was forced to ship in water on tankers and, in 2009-10, Melbourne residents lived under the threat of water cuts following an extraordinarily long drought (1998-2010). The same drought also forced Sydney to implement water restrictions, reducing consumption by 20%.</p>
<p>In France, the island of Mayotte nearly had to call in the tankers in 2017, following a very late start to the rainy season.</p>
<p>While Cape Town’s extraordinary drought may well be considered a local phenomenon, UN demographic predictions for large cities provide little cause for optimism: current rates of population growth in Africa, Asia and North and South America are such that it is clear that water supply will be a major challenge for big cities in the 21st century (see graph below).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Projected population growth rates for the world’s large cities (2014-2030).</span>
<span class="attribution"><a class="source" href="https://esa.un.org/unpd/wup/Maps/CityGrowth/2014_2030GrowthRate.pdf">United Nations</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>There are solutions</h2>
<p>Fortunately, there is nowadays a wide variety of long-term solutions to avoid city water supply crises. These range from reducing water consumption to increasing water storage and improving the management of existing resources.</p>
<p><strong>Change consumption habits</strong>: Changing city dwellers’ consumption habits is the surest way of avoiding water crises. But sociologist Rémi Barbier stresses that this is no easy task. Over the last decade, the French biodiversity agency has launched a number of studies opening up options to reduce water use.</p>
<p><strong>Improve water use management in agriculture</strong>: Better irrigation efficiency worldwide is a major step towards water savings. If we reduced the amount of water used for agriculture by just 10%, we could double the drinking water supply. For many years, efforts concentrated on improved irrigation techniques (such as trickle or drip irrigation, which is slowly replacing surface irrigation, where water floods the field). Today, work is being conducted on recycling urban waste water for irrigation.</p>
<p><strong>Improve distribution efficiency</strong>: We can save large volumes by reducing water losses in water transport and distribution networks. In France, an average of 25% of drinking water is lost to leaks in the network (this reaches up to 40% in places). While this figure is very high, it should be considered in the context of the size of distribution networks (nearly 850,000 km). Locating and repairing leaks is therefore a lot trickier than it sounds and we cannot hope to eliminate them all. It is however possible to reduce their impact by reducing network pressure at night, for instance, so as to limit losses from existing leaks.</p>
<p><strong>Improve natural flow predictions</strong>: In order to optimize the use of surface water, better anticipation of water flows is necessary. Forecasts – in the short-term for high water levels and in the medium- to long term (from a few days to a few weeks or months) for average to low flows – would enable us to better plan water releases and save water. Meteorological and hydrological models are the main tools that will help us better predict these phenomena. In France, a research program on predicting low water levels (Premhyce) will soon lead to an operational forecasting system.</p>
<p><strong>Better manage underground water sources</strong>: For large cities that rely on underground water, the main threat to supply is overuse. This is difficult to control, especially because ground water is accessible to a large number of local occupants, who do not always understand the resource they are using. Water management solutions should be adopted collectively: we must control consumption, allocate usage rights and, above all, make sure these rules are upheld by installing meters on wells.</p>
<h2>What about desalination?</h2>
<p>One of the solutions often proffered for water shortages is industrial production of fresh water by desalinating seawater (or brackish underground water).</p>
<p>Desalination is on the rise in various Near- and Middle Eastern countries, and in Maghreb. In Mediterranean Europe, it is being developed in Spain (Barcelona, the Canary Islands), Cyprus, and Malta. In France, it remains very rare, but the islands of Sein and Houat (in Brittany) have small desalination plants, as does Mayotte.</p>
<p>But desalination remains a very costly solution (around €0.50 per cubic meter for very large plants) and consumes a great deal of energy (from 3.5 to 18kWh per cubic meter, depending on the technique used).</p>
<p>Melbourne provides an instructive example: the Victorian State government built a seawater desalination plant to supply the city with drinking water. Construction began in 2009, during a drought, when water levels in the reservoirs had fallen to a historical low, but the plant did not become operational until 2012, when the drought had already broken. It did not receive its first order for water until 2017.</p>
<p>The current crisis in Cape Town reminds us that water does not automatically flow from our taps. This modern privilege is under threat from climate hazards and the remarkable growth of cities worldwide. Cities will have to seek out water further afield, and will no doubt come into competition with traditional users, such as farmers.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the AXA Research Fund has been supporting nearly 600 projects around the world conducted by researchers from 54 countries. To learn more about this author’s research, visit his <a href="https://www.axa-research.org/en/project/vazken-andreassian">dedicated page</a> on the AXA Research Fund website. This article was co-written with Jean Margat, a hydrogeology expert.</em></p>
<p><em>Translated from the French by Alice Heathwood for <a href="http://www.fastforword.fr/en/">Fast for Word</a>.</em></p><img src="https://counter.theconversation.com/content/98535/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vazken Andréassian received funding from the Axa Research Fund. </span></em></p>In South Africa, Cape Town fears “Day Zero”, when the city will have to ration water drastically. The phenomenon threatens other cities as well but solutions exist.Vazken Andréassian, Ingénieur en chef des ponts, eaux & forêts, directeur d'unité de recherche, InraeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/949982018-05-21T15:22:46Z2018-05-21T15:22:46ZSmall, local solutions can crack water crises: a South African case study<figure><img src="https://images.theconversation.com/files/218627/original/file-20180511-135202-z7ui7a.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People in the HaMakuya community go without potable water for months.</span> <span class="attribution"><span class="source">Melissa McHale</span></span></figcaption></figure><p>World attention has recently been <a href="http://time.com/cape-town-south-africa-water-crisis/">focused</a> on the water crisis facing the South African city of Cape Town, a metropolis of four million people. There is obviously deep sympathy with the plight of the residents. But the drama draws attention away from an even more concerning set of issues. The main one is that many people in rural southern Africa live without any potable water at all. And many are at serious risk because of global <a href="https://researchspace.csir.co.za/dspace/bitstream/handle/10204/7382/Archer%20van%20Garderen2_2013.pdf?sequence=3">climate change</a>.</p>
<p>Residents of the wealthy suburbs of Cape Town have been asked to reduce their consumption to less than 50 litres <a href="https://www.cnn.com/2018/02/01/africa/cape-town-water-crisis-intl/index.html">per person per day</a>, one sixth of the daily consumption of the average American. But elsewhere in village after village in sub-Saharan Africa women walk miles to scoop water from polluted ground wells for their average daily ration of less than <a href="https://www.washingtonpost.com/news/energy-environment/wp/2016/06/01/the-crushing-toll-african-women-pay-to-collect-cleaner-water/?noredirect=on&utm_term=.af62de580b5e">20 litres a day</a>.</p>
<p>We have been studying this kind of crisis in South Africa for the last <a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/120157">two decades</a>. Our most recent work examined water quality, reliability and accessibility in rural communities living along the western edge of one of the world’s largest game reserves, South Africa’s Kruger National Park. </p>
<p>Our data, over the last seven years, reveal a very complex and desperate situation. We set out to understand more than basic water quality problems and integrated social and environmental factors into our research. To do this, we used a variety of methods to collect information about people’s experiences in the different locations they collected, stored and used water. </p>
<p>This approach provides a clear picture of the solutions needed to support people’s quality of life. In some instances, where government’s audit on <a href="https://www.green-cape.co.za/assets/Water-Sector-Desk-Content/DWS-2014-Blue-Drop-report-national-overview-part-1-of-2-2016.pdf">water services</a> found successful water service provisioning, our data found the complete opposite. </p>
<h2>A different research approach</h2>
<p>South Africa’s post-apartheid <a href="http://www.dwa.gov.za/Documents/Legislature/nw_act/NWA.pdf">National Water Act</a> is one of the most advanced examples of legislation globally. It asserts that both people and the environment have constitutional rights to water. But achieving this has yet to be realised.</p>
<p>HaMakuya, a group of 21 villages nestled in the north eastern corner of South Africa, face set of common challenges. These communities remain marginalised. Their situation hasn’t improved since the end of apartheid.</p>
<p>National government surveys claim that these areas are fully provided for when it comes to water. This isn’t true. Communities are plagued by drying boreholes, broken and poorly maintained infrastructure, degraded water resources, increasing droughts, urbanisation pressures and nonfunctional local government structures.</p>
<p>After working with the HaMakuya community for 20 years, we have seen clear evidence of a long-term water crisis that’s getting worse over time. People go without a stable and potable water source for months. Sometimes they don’t even have enough water to cook staple foods <a href="https://www.youtube.com/watch?v=6wPoYtf5poA">like maize meal</a>. </p>
<p>It was not surprising, therefore, when community leaders asked us eight years ago to help them understand and resolve their water resource challenges. The request prompted us to try a different approach to studying the water crisis in the region. We started working with local people, including them as <a href="https://doi.org/10.1007/s11625-015-0334-4">active participants</a>. We also trained young people as environmental monitors to collect long-term water quality data.</p>
<p>We found that every village had a different story. For example there were high concentrations of nitrates in water in one community which posed a health hazard. Another had water that was highly saline in taste. Even villages dependent on the same water source sometimes had different challenges: while one had quality water, others suffered from E. Coli contamination.</p>
<p>This complexity poses a problem for implementing large-scale, regional solutions. But it also provides an opportunity to introduce local, positive changes that have an immediate impact. </p>
<p>What makes the need for local-level solutions even more urgent is that present problems have the maximum impact on the most vulnerable populations. For example, when water is available most of the schools in this region have water that is contaminated with E. coli.</p>
<p>But as local solutions are developed, there also need to be ways of providing feedback, and tracking potential unintended consequences. Many technological solutions have failed because specific cultural, social, and environmental factors were overlooked in trying a quick fix. </p>
<h2>A different approach</h2>
<p>Across the world a range of <a href="https://www.sciencedirect.com/science/article/pii/S0043135413008208">studies</a> on water technologies, planning, and resource challenges show that local, place-based solutions must be invested in. Our work in HaMakuya supports this increasingly important call for a different approach to water management. </p>
<p>And solutions don’t have to involve huge money investments. At the right scale, and with careful consideration of the cultural, social, environmental, and technological landscape, they can lead to sustainable and resilient communities – a hopeful future for people who have been consistently under-resourced and ill-treated.</p>
<p>Grand visions of a Utopian state in which each citizen has equal access to environmental resources are all very well, and laudable. But unless there is investment in the more modest, local complexities of maintenance, training, and village distribution, poor people will continue to suffer at the expense of the wealthier and more distant cities. </p>
<p>The Cape Town crisis has all the hallmarks of crises soon to be faced by <a href="https://www.sciencedirect.com/science/article/pii/S0959378014000880">large cities</a> like <a href="http://www.bbc.com/news/world-42982959">Mexico City</a>, <a href="http://www.abc.net.au/news/2017-07-23/melbourne-water-supply-could-be-under-threat-within-a-decade/8735400">Melbourne</a>, <a href="https://www.sentinelcolorado.com/news/ciruli-colorado-facing-growing-water-shortage/">Denver</a>, and <a href="https://news.nationalgeographic.com/2018/02/cape-town-running-out-of-water-drought-taps-shutoff-other-cities/">Jakarta</a>. We believe that the true political and environmental character of the immediate global emergency is better read in the dust, the creak of ancient pistons, and the meagre, saline seepage from failing wells that have come to define daily life in rural South Africa.</p><img src="https://counter.theconversation.com/content/94998/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melissa McHale receives funding from the National Science Foundation. A large team of researchers and community partners associated with the IMAGINE Program (<a href="https://imaginesouthafrica.wordpress.com/">https://imaginesouthafrica.wordpress.com/</a>) contributed to the research discussed in this article. Notably, Terrie Litzenberger, Elizabeth Nichols, and April James developed the water quality methods and Terrie led our students in implementing that effort on the ground in South Africa. Two graduate students, Scott Beck and Shawn Shiflett, have made a substantial contribution to the interdisciplinary water analysis and will be publishing our results. This work could not have been completed without the time and energy of the HaMakuya community and support provided by the Tshulu Trust.</span></em></p><p class="fine-print"><em><span>David Bunn receives funding from South Africa's National Research Foundation. He is a board member of the Tshulu Trust, and of the Nsasani Trust, both in South Africa.</span></em></p><p class="fine-print"><em><span>Eddie Riddell receives funding from the Water Research Commission, WWF Nedbank Green Trust and the NRF.</span></em></p>Small solutions done properly can play a huge role in dealing with water scarcity.Melissa McHale, Associate Professor, Colorado State UniversityDavid Bunn, Senior Research Scientist, Natural Resource Ecology Laboratory, Colorado State UniversityEddie Riddell, Research Associate, University of KwaZulu-NatalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/940452018-04-03T14:58:01Z2018-04-03T14:58:01ZFive key lessons other cities can learn from Cape Town’s water crisis<figure><img src="https://images.theconversation.com/files/212651/original/file-20180329-189824-uwlzk5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Berg River Dam on 7 March 2018 about 48% full. </span> <span class="attribution"><span class="source">Author supplied</span></span></figcaption></figure><p><a href="https://www.dailymaverick.co.za/opinionista/2018-03-28-day-zero-averted-or-only-postponed-water-trading-the-way-to-go/#.WrzPoC5ubIU">Postponing Day Zero</a> in Cape Town for 2018 comes as no surprise. There was no sense to it once the day had been pushed into the winter rainfall period. It also didn’t make sense for the Western Cape and Cape Town governments to continue drafting detailed <a href="https://www.news24.com/SouthAfrica/News/police-reveal-day-zero-safety-plans-20180228">logistical plans</a> for points of water distribution in the event that taps were turned off across the city. </p>
<p>But Cape Town’s water supplies remain at high risk because the long-term predictions for rainfall in the south-western Cape remain uncertain. Dam levels continue to fall while people are struggling to achieve the city’s target of 450 million litres per day. And yields from new water schemes will only be known in the coming months and next year.</p>
<p>The general perception is that the onset of climate change would be slow and measured. This would afford authorities the time to intervene with considered plans. But climate change is a disrupter and takes no prisoners. Over the past three years, Cape Town and the surrounding regions has experienced successive years of well <a href="https://qz.com/1110143/cape-town-drought-and-water-shortage-in-south-africa-is-now-a-disaste/">below average rainfall</a>. The experience is changing the way people think about water and how it is managed. </p>
<p>There are five key lessons that have been learnt so far.</p>
<p><strong>1. Adaptation to climate change</strong></p>
<p>The big lesson is being better prepared to deal with a prolonged drought. Cape Town was, and continues to be, under prepared. <a href="https://www.groundup.org.za/article/photos-cape-towns-water-crisis/">Over 95%</a> of the city’s water comes from surface water dams. After three years of below average rainfall, the lowest on record, the dams are now running on empty. </p>
<p>Sixty years ago the Australian city of Perth was in a similar position with most of its water supply from dams. The <a href="http://www.bbc.com/news/business-17887572">Australian Big Dry</a> drought changed everything. Over 50% of their water supply comes from desalination plants and 40% from groundwater.</p>
<p>A water resilient city should be capable of reducing risk by diversifying water sources to include supplies from groundwater, storm water, reused water, treated effluent and desalination. Resilient, water sensitive cities also integrate the whole urban water cycle into its water resource management system. This means, for example, being smarter about capturing rainfall across the city, in storing storm water underground, and in reusing treated effluent for a variety of purposes not necessarily for drinking purposes. </p>
<p>Cities are the new catchments. There should be no reason to hesitate on implementing these actions. They won’t only climate proof the city, they’ll also make them healthier and more sustainable places to live.</p>
<p><strong>2. Cities lead</strong></p>
<p>National government can’t be expected to lead cities in dealing with water scarcity and drought. This is the experience of many cities dealing with water scarcity. Local governments are in a better position to take decisive action and act at a local scale where they can engage citizens, communities and businesses in averting the water crisis. National governments are slow to intervene, and when they do their actions are often not at the right scale or timely enough. </p>
<p>Cities need more autonomy to act decisively, although proactive, inter-governmental support and cooperation is both helpful and necessary. </p>
<p><strong>3. Measure more, manage better</strong></p>
<p>‘You can’t manage what you don’t measure’ should be the rallying cry for improving the quality of data and analysis needed to support and inform decisions. A city without reliable data will struggle to implement strategic plans and priorities. A good example is Melbourne, one of the first cities in the world to implement digital water metering <a href="https://www.yvw.com.au/help-advice/water-meters/digital-metering-joint-program">throughout the city</a>. </p>
<p>Measuring and monitoring is essential to understand water demand and flows. But not all data are useful and more data adds little value in the absence of robust analytical and reporting systems.</p>
<p><strong>4. Mixed messages</strong></p>
<p>Public responses to communication and messaging put out by local authorities is often unpredictable. And social media is rapid and unrelenting in its criticism of messages. Politicians and officials often don’t correct these perceptions which can result in misinformation being shared. The City of Cape Town’s public awareness website has been recognised worldwide– for example by the <a href="https://www.awwa.org/">American Water Works Association</a> – as one of the best. But hard evidence does little to <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/awwa.1027">change public opinion.</a></p>
<p>What citizens really want to know is what actions are being taken to alleviate the crisis and relieve the risk. In the case of Cape Town the city has been reporting on the state of the water by supplying information on <a href="https://theconversation.com/nudging-the-city-and-residents-of-cape-town-to-save-water-92192">dam levels, water demand, models and water quality</a>. What it hasn’t done well enough is contain the level of misinformation shared in the public domain and media. </p>
<p><strong>5. Public trust</strong></p>
<p>Above all, public trust is key to encouraging water saving and helping to establish confidence in managing the crisis. Trust is strengthened by a combination of factors. These include honest, credible messaging when progress towards averting the crisis is demonstrated and understood, and when ordinary citizens, communities and businesses are engaged in making a meaningful contribution. Trust gains momentum when citizen voices are heard and when politicians and officials respond accordingly. </p>
<p>Large cities that have experienced ongoing water crises, such as Sao Paulo, are often criticised for failing to establish <a href="https://theconversation.com/sao-paulo-water-crisis-shows-the-failure-of-public-private-partnerships-39483">public-private agreements and robust partnerships</a></p>
<h2>Planning for uncertainty</h2>
<p>How cities anticipate and prepare to adapt to drought conditions depends on factors such as their financial, technical and human capital.</p>
<p>But if cities are going to become more resilient and responsive to climate change then a search for new water supplies will be necessary. It is also essential to establish new forms of governance. Innovative approaches need to be explored because we might not yet know what these should look like. The future is uncertain, but there is a lot that can be done right now and we need to learn some hard lessons.</p><img src="https://counter.theconversation.com/content/94045/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The drought in Cape Town has taught the city some valuable lessons.Kevin Winter, Senior Lecturer in Environmental & Geographical Science, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/917092018-03-06T11:40:16Z2018-03-06T11:40:16ZWhile Mexico plays politics with its water, some cities flood and others go dry<figure><img src="https://images.theconversation.com/files/208978/original/file-20180305-146675-ywnca2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Flooding is a common hazard in Nezahualcoyotl, a Mexican city just outside the nation's capital.</span> <span class="attribution"><span class="source">AP Photos/Eduardo Verdugo</span></span></figcaption></figure><p><a href="https://theconversation.com/los-juegos-politicos-con-el-agua-del-que-son-victimas-los-mexicanos-93914"><em>Leer en español</em></a>.</p>
<p>When Cape Town acknowledged in February that it would <a href="https://www.reuters.com/article/us-safrica-drought/drought-hit-cape-town-dreads-day-zero-when-taps-will-run-dry-idUSKCN1G51DL">run out of water within months</a>, South Africa suddenly became the global poster child for bad water management. Newspapers revealed that the <a href="https://www.reuters.com/article/us-saundersonmeyer-drought-commentary/commentary-in-drought-hit-south-africa-the-politics-of-water-idUSKBN1FP226">federal government had been slow</a> to respond to the city’s three-year drought because the mayor belongs to an opposition party. </p>
<p>Cape Town is not alone. While both <a href="https://www.theguardian.com/uk-news/2018/mar/05/britain-braces-for-floods-and-water-shortages-as-temperatures-rise">rich</a> and poor countries are drying out, the <a href="http://www.bbc.com/news/world-42982959">fast-growing cities of the developing world</a> are projected to suffer the <a href="http://www.wri.org/blog/2013/12/world%E2%80%99s-36-most-water-stressed-countries">most acute shortages in coming years</a>. </p>
<p>Scarcity turns water into a powerful political bargaining chip. From <a href="http://foreignpolicy.com/2015/07/17/at-the-mercy-of-the-water-mafia-india-delhi-tanker-gang-scarcity/">Delhi</a> to <a href="https://in.reuters.com/article/women-cities-kenya-water/feature-kenyan-women-pay-the-price-for-slum-water-mafias-idINKCN0JA0P620141126">Nairobi</a>, its oversight is fraught with inequality, corruption and conflict. </p>
<p>Mexico, too, has seen its water fall prey to cronyism in too many cities. I interviewed 180 engineers, politicians, business leaders and residents in eight Mexican cities for <a href="https://www.press.umich.edu/9210462/water_and_politics">my book on politics and water</a>. I was startled to discover that Mexican officials frequently treat water distribution and treatment not as public services but as political favors. </p>
<h2>When thunderstorms are cause for panic</h2>
<p>Nezahualcoyotl is a city in Mexico State near the nation’s sprawling capital. Just after lunch one Friday afternoon in 2008, Pablo, an engineer, was showing me around town when news of an unexpected thunderstorm began lighting up his team’s cell phones and pagers. </p>
<p>The engineers shouted back and forth, looking increasingly frantic. Having just begun my book research, I did not yet understand why an everyday event like a thunderstorm would elicit such panic. </p>
<p>Pablo explained that Nezahualcoyotl’s aged electric grid often failed during big storms and that the city lacked backup generators. If a power outage shut down the local sanitation treatment plant, raw sewage would flood the streets. </p>
<p>These “aguas negras” <a href="https://www3.epa.gov/npdes/pubs/sso_casestudy_control.pdf">carry nasty bacteria, viruses and parasitic organisms</a> and can cause cholera, dysentery, hepatitis and severe gastroenteritis. If raw sewage also contains industrial wastewater – which is common in rapidly industrializing countries like Mexico – it may also <a href="http://www.dailypioneer.com/columnists/oped/heavy-metal-toxicity-and-water-contamination.html">expose residents to chemicals and heavy metals</a> that can lead to everything from lead poisoning to cancer. </p>
<p>Pablo and his colleagues avoided a flood that day. But I later read news articles confirming how <a href="http://archivo.eluniversal.com.mx/ciudad/51610.html">relatively common sewage overflows are there</a>. Nezahualcoyotl residents have been dealing with this multisystem failure for 30 years, complaining of gastrointestinal illness and skin lesions all the while. </p>
<p>So why hasn’t this public health emergency been fixed? The answer is a primer on the <a href="https://scholar.google.com/citations?user=pkWm4ZAAAAAJ&hl=en&oi=sra">tricky politics of urban water delivery in Mexico</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208944/original/file-20180305-146655-qgb11v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In some Mexican cities, heavy rains routinely cause raw sewage carrying a host of dangerous parasites and bacteria to overflow into the streets.</span>
<span class="attribution"><span class="source">AP Photo/Prometeo Lucero</span></span>
</figcaption>
</figure>
<h2>Profit from dysfunction</h2>
<p>Public malfeasance <a href="https://theconversation.com/governors-gone-wild-mexico-faces-a-lost-generation-of-corrupt-leaders-76858">in Mexico is widespread</a>. Nearly 90 percent of citizens see the state and federal government as corrupt, according to the <a href="http://www.beta.inegi.org.mx/proyectos/enchogares/regulares/encig/2015/">Mexican National Institute of Statistics and Geography</a>.</p>
<p>The country’s water situation, too, is pretty dire. The capital, Mexico City, is “parched and sinking,” <a href="https://www.nytimes.com/interactive/2017/02/17/world/americas/mexico-city-sinking.html">according to a powerful 2017 New York Times report</a>, and 81 percent of residents say they <a href="http://foreignpolicy.com/2015/07/31/the-war-for-privatization-mexicos-water/">don’t drink from the tap</a>, either because they lack running water or they don’t trust its quality. </p>
<p>Officially, <a href="http://www.conagua.gob.mx/CONAGUA07/Publicaciones/Publicaciones/EAM2015_ing.pdf">nearly all Mexicans have access to running water</a>. But in practice, many – particularly poorer people – have <a href="https://muse.jhu.edu/article/315976">intermittent service and very low pressure</a>. </p>
<p>Workers in one city asked me to keep their identity anonymous before explaining why the water infrastructure there was so decrepit. It wasn’t a lack of technology, they said. The mayor’s team actually profits from refusing to upgrade the city’s perpetually defunct hardware. That’s because whenever a generator or valve breaks, they send it to their buddies’ refurbishing shops. </p>
<p>Numerous engineers across Mexico similarly expressed frustration that they were sometimes forbidden from making technical fixes to improve local water service because of a mayor’s “political commitments.” </p>
<p>In Nezahualcoyotl, I met a water director who openly boasted of using public water service for his political and personal gain. In the same breath, he told me that he fought to keep water bills low in this mostly poor city because water was a “human right” but also that he had once turned off supplies to an entire neighborhood for weeks because of a feud with another city employee. </p>
<h2>No voter ID, no water</h2>
<p>Public officials also use water to influence politics.</p>
<p>My sources also alleged that the powerful <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.843.5120&rep=rep1&type=pdf">Revolutionary Institutional Party</a>, or PRI – which has long run Mexico State, and thus controlled its water supply – has turned off the water in towns whose mayors belonged to opposition parties. These tactics are not reported in the Mexican press, but according to my research the cuts tend to occur just before municipal elections – a bid to make the PRI’s political competition look bad.</p>
<p>Water corruption isn’t limited to Mexico State, or to the center-right PRI party. </p>
<p>The millions of Mexicans who lack reliable access to piped water are served by <a href="https://www.nytimes.com/interactive/2017/02/17/world/americas/mexico-city-sinking.html">municipal water trucks</a>, called “pipas,” which drive around filling buildings’ cisterns. This system seems prone to political exploitation. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208982/original/file-20180305-146645-el6xi4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mexican households without steady running water have cisterns filled by ‘pipas,’ or municipal water trucks.</span>
<span class="attribution"><span class="source">AP Photo/Dario Lopez-Mills</span></span>
</figcaption>
</figure>
<p>Interviewees told me that city workers sometimes make people show their voter ID cards, demonstrating their affiliation to the governing party, before receiving their water. Across the country, mayoral candidates chase votes by promising to give residents <a href="http://notipascua.com/agua-gratis-sector-arevalo-cedeno-gracias-pablo-alvarado/">free or subsidized water service</a>, rather than to charge based on consumption. </p>
<p>The phenomenon of trading water as a political favor is probably more common in lower income communities, which <a href="http://www.eluniversal.com.mx/nacion/sociedad/acusan-politizacion-de-agua-despues-del-sismo">rely almost exclusively on the pipas</a>.</p>
<h2>Water is a state secret</h2>
<p>In Xalapa, the capital of Veracruz state, I saw how water can hold a different kind of political power. </p>
<p>There, I found, the location of underground pipes and other critical water infrastructure was guarded like a state secret, known by just a handful of public workers. It made them irreplaceable. </p>
<p>So when customers complained that some municipal employees were asking for bribes to provide water, management hesitated to fire them. The workers controlled valuable information about the city’s water system.</p>
<p>Water may be a <a href="http://www.unesco.org/new/en/media-services/single-view/news/the_right_to_water/">human right</a>. But when politicians manipulate it for their personal or political benefit, some cities flood while others go dry.</p><img src="https://counter.theconversation.com/content/91709/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Veronica Herrera does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In many Mexican cities, water is treated as a political bargaining chip – a favor that public officials can trade for votes, bribes or power.Veronica Herrera, Assistant Professor of Political Science, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/921922018-03-04T07:45:32Z2018-03-04T07:45:32ZNudging the city and residents of Cape Town to save water<figure><img src="https://images.theconversation.com/files/208513/original/file-20180301-152575-u13f6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The dangerously low Threewaterskloof dam, a major supplier of water to the city.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Cape Town could become the world’s first major city to run out of water – what’s been termed Day Zero. Sao Paulo <a href="https://www.iol.co.za/business-report/international/these-11-cities-may-run-out-of-water-like-cape-town-13243926">faced similar difficulties in 2015</a> leading to significant <a href="https://www.theguardian.com/cities/2015/feb/25/sao-paulo-brazil-failing-megacity-water-crisis-rationing">social unrest</a>.</p>
<p>On Day Zero – which could be in mid-July if there’s no significant rain – residents of the city will have to travel to one of 200 city-wide collection points to get the allocated 25 litres per person, per day, under the watchful eye of an armed guard.</p>
<p>The city has done a great deal of work to manage water use, even winning multiple <a href="http://www.capetowngreenmap.co.za/blog/cape-towns-water-blue-green-good">awards</a>, although equity concerns have frequently been raised in relation to these efforts. In light of the ongoing drought, the city is now trying to encourage even stricter targets of <a href="http://www.capetowndrought.com/">50 litres of water per person per day</a> – a difficult goal that continues to raise issues of equity and justice. </p>
<p>To its credit, the city has worked with researchers at <a href="http://www.efdinitiative.org/about-efd/people/visser-martine">the University of Cape Town</a> to test strategies to nudge domestic users into reducing their water use. <a href="https://link.springer.com/article/10.1007/s10603-014-9273-1">Nudges</a> are interventions to encourage behaviour change for better outcomes, or in this context, to achieve <a href="http://heinonline.org/HOL/Page?handle=hein.journals/helr38&div=6&g_sent=1&casa_token=TRiYMCg9RUoAAAAA:xV_3n5ws_WdheF1920T51KsLsn2LG95dtulHBzwhgvOt78kDF1aWUty0FRYExrThtHtqSoQ_9A&collection=journals">environmental or conservation goals</a>.</p>
<p>What key insights could help inform the city’s strategies? Research from psychology and behavioural economics could prove useful to refine efforts and help to achieve further water savings. </p>
<h2>The most effective tactics</h2>
<p>Research suggests the following types of nudges could be effective in promoting conservation behaviours.</p>
<p><strong>Social norms:</strong> International <a href="http://journals.sagepub.com/doi/abs/10.1111/j.1467-9280.2007.01917.x">research</a>, as well as <a href="http://www.wrc.org.za/Pages/Drought/4.2/Water%20demand%20management/behavioural%20nudges_2091-1-13.pdf">studies</a> conducted in Cape Town, suggest that effective conservation can be promoted by giving feedback to consumers on how they perform relative to their neighbours. To this end, Cape Town introduced a <a href="https://theconversation.com/cape-towns-map-of-water-usage-has-residents-seeing-red-90188">water map</a> that highlights homes that are compliant with targets.</p>
<p>But concerns have been raised that this could lead to a backlash against homes that aren’t saving water. In light of these criticisms researchers are working with the city to evaluate the effectiveness of the map and how it compares to other strategies. For instance, might it be more meaningful to communicate information to individual households only, or to highlight successful performance at the neighbourhood level?</p>
<p>The city has also been bundling information on usage with easy to <a href="http://www.capetowndrought.com/">implement water saving tips</a>, something that research has shown to be <a href="https://www.sciencedirect.com/science/article/abs/pii/S0047272711000478">particularly effective</a>.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0047272711000478">Research</a> also suggests that combining behavioural interventions with traditional measures – such as tariff increases and restrictions – are often effective to reduce use in the short-term.</p>
<p><strong>Real-time feedback:</strong> Cape Town is presenting the daily water level in major dams on <a href="http://www.capetowndrought.com/">a dashboard</a>. This approach is consistent with research that shows that real-time information can effectively reduce water and <a href="http://www.jstor.org/stable/41969212?seq=1#page_scan_tab_contents">energy consumption</a>.</p>
<p>Such efforts could even be more effective if information is highlighted in relation to the critical level that’s been set for Day Zero, in this case 13.5%. </p>
<p>In the early days of a drought, it is also advisable to make information like this readily accessible through news outlets, social media, or even text messages. The <a href="http://www.eighty20.co.za/">water tracker</a> produced by eighty20, a private Cape Town-based company, provides an example.</p>
<p><strong>Social recognition:</strong> There’s evidence that efforts to celebrate successes or encourage competition can be effective – for instance, recognising neighbourhoods for meeting conservation targets. Prizes needn’t be monetary. Sometimes simple recognition, such as a certificate, can be effective.</p>
<p>Social recognition was found to be the most successful intervention among nine others nudges tested in <a href="https://www.researchgate.net/publication/323255576_Behavioural_Nudges_for_Water_Conservation_Experimental_Evidence_from_Cape_Town?_iepl%5BviewId%5D=ZuUwXo1hLo3v8A3g43h11QNW&amp;_iepl%5Bcontexts%5D%5B0%5D=publicationCreationEOT&amp;_iepl%5BtargetEntityId%255">research</a> conducted in Cape Town in 2016. In this experiment, households who reduced consumption by 10% were recognised on the city’s website.</p>
<p>Another <a href="https://www.researchgate.net/publication/323258372_The_Effectiveness_of_Competition_and_Responsibility_Assignment_in_Saving_Energy_A_Non-Residential_example_of_the_Power_of_the_Nudge">study</a> showed that competition between the various floors of a government building in the Western Cape led to energy savings of up to 14%. </p>
<p><strong>Cooperation:</strong> In the months ahead, the city would also do well to consider the support it might offer to <a href="https://www.sciencedirect.com/science/article/pii/S1364661313001216">encourage cooperation</a>, particularly as the situation becomes more acute and as tensions rise. </p>
<p>Past studies have shown that <a href="http://www.pnas.org/content/108/48/19193.short">social reputation</a> and efforts to promote <a href="https://www.sciencedirect.com/science/article/pii/S1364661313001216">reciprocity</a> can go a long way to encourage cooperation. The point is argued in a recent <a href="https://www.dailymaverick.co.za/article/2018-03-01-op-ed-a-drought-stricken-cape-town-did-come-together-to-save-water/#.WpfSHoKYP6p">article</a> featuring the importance of cooperation among Capetonians across different income groups.</p>
<p>Some residents of Cape Town are already pushing for a cooperative approach such as helping neighbours who might have difficulty travelling to collection points. Support for these efforts should be an important part of policies in the run up to Day Zero. These are often the examples that provide bright spots in challenging times.</p>
<p><a href="http://www.tandfonline.com/doi/abs/10.1080/00909880600769944">Research</a> also suggests that to navigate moments of crisis effectively, clear and trustworthy communication is critical. This also needs to be a priority.</p>
<h2>A positive strategy</h2>
<p>It is clear that the city of Cape Town and its 3.4 million residents are facing difficult circumstances. The considerable efforts that have been made to pursue evidence based approaches are a step in the right direction. Yet continual refinement and improvement is key – with attention to both the research, as well as to the political realities of the city.</p><img src="https://counter.theconversation.com/content/92192/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Leila Harris receives funding from the Social Sciences and Humanities Research Council of Canada and the Peter Wall Institute for Advanced Studies at the University of British Columbia.</span></em></p><p class="fine-print"><em><span>Jiaying Zhao receives funding from NSERC, Mitacs, NSF, Sloan Foundation, and US Forest Service.</span></em></p><p class="fine-print"><em><span>Martine Visser has worked as an independent researcher with the City of Cape Town and the Western Cape Government on how to incorporate behavioural nudges into their interventions. She receives funding from the School of Economics (UCT), African Climate Development Initiative CDI (UCT), Environment for Development Initiative, SANCOOP (RCN&NRF) and the Water Research Comission.</span></em></p>Cape Town is testing new strategies to nudge domestic users into reducing their water use.Leila Harris, Associate Professor, IRES, Institute for Gender, Race, Sexuality and Social Justice, University of British ColumbiaJiaying Zhao, Assistant Professor, University of British ColumbiaMartine Visser, Professor in the School of Economics, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/926122018-03-01T14:09:46Z2018-03-01T14:09:46ZCape Town’s plans for what happens after Day Zero just won’t work. Here’s why<figure><img src="https://images.theconversation.com/files/208454/original/file-20180301-152572-1fg32mc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Capetonians wait to fill up water containers.</span> <span class="attribution"><span class="source">EPA/Nic Bothma</span></span></figcaption></figure><p>The world <a href="http://www.bbc.com/news/business-42626790">is watching Cape Town</a>, counting down to Day Zero. This represents the point at which the municipality will turn off most of the city’s water distribution system. The date is not certain; it has shifted several times, and is currently predicted <a href="http://coct.co/water-dashboard">to arrive on July 9</a>.</p>
<p>There are measures in place to manage Day Zero and beyond. The city has broadcast a <a href="http://www.capetown.gov.za/Family%20and%20home/Residential-utility-services/Residential-water-and-sanitation-services/critical-water-shortages-disaster-plan">disaster management strategy</a>. It will establish 200 water distribution points across the city, at which citizens can collect their 25 litre daily water allocation.</p>
<p>But is this strategy robust or even feasible? </p>
<p>We used system dynamics, a modelling approach, to understand how the water collection plan might work. The idea was to simulate water collection as per the city’s plan over the course of a single day (24 hours).</p>
<p>We made some key assumptions about population size, the number of taps per distribution site and other factors. Taking these into account, the model found that it would require 12.5 hours to provide water to Cape Town’s entire population per day. And the real figure might be even higher if “random shocks” like conflict happen at the water points. </p>
<p>Our findings suggest that the city’s best technical intervention would be to double the number of distribution points to 400. This would save time and ensure that Cape Town’s whole population can be serviced. Another, perhaps more practical approach, would be to keep 200 distribution points but increase the number of taps and the water pressure at each of them.</p>
<p>But even these strategies won’t help if Cape Town doesn’t address the reality of conflict and related delays. These are unpredictable and incalculable. They are also the greatest indication for why Day Zero should be avoided at all costs.</p>
<h2>Assumptions and insights</h2>
<p>These are the assumptions we made in developing the model:</p>
<ul>
<li><p>Cape Town’s population is estimated at <a href="https://www.westerncape.gov.za/assets/departments/treasury/Documents/Socio-economic-profiles/2016/City-of-Cape-Town/city_of_cape_town_2016_socio-economic_profile_sep-lg.pdf">4 million people</a>. Of these, 700 000 live in two areas that won’t have their taps turned off. These include strategic sites, like hospitals, and informal settlements. Another 800 000 people live in close proximity to informal settlements and could potentially source water there. Based on these assumptions we calculated that 2.5 million people will be required to collect water at designated water points.</p></li>
<li><p>The city plans to set up 200 distribution points with an <a href="http://resource.capetown.gov.za/documentcentre/Documents/Procedures,%20guidelines%20and%20regulations/Disaster%20and%20demand%20FAQ.pdf">average of 50 taps</a> per site. Equal distribution of people per water distribution point is assumed. </p></li>
<li><p>Water distributed is <a href="http://www.capetown.gov.za/Family%20and%20home/Residential-utility-services/Residential-water-and-sanitation-services/critical-water-shortages-disaster-plan">25 litres per person</a>. Individuals are able to collect up to 100 litres a day to cover four days of consumption or share with other members of their household. The model assumes that the whole population must receive their allocation. </p></li>
<li><p>Initial water pressure is assumed at a level which allows outflow of 10 litres per minute, which implies it requires 2.5 minutes to fill 25 litres or service one person</p></li>
<li><p>A waiting delay of half a minute (30 seconds) from changing between containers and people is assumed.</p></li>
</ul>
<p>Once the model had been run using the above assumptions, and the result of 12.5 hours was observed, we ran possible scenarios to shorten the time. These are outlined in figure 1 below.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208503/original/file-20180301-152564-22w4sm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 1: Population serviced per distribution point scenarios.</span>
</figcaption>
</figure>
<p>A combined scenario of 75 taps per site and increasing water pressure to 20 litres to 30 litres per minute, while maintaining the 200 sites (as indicated by the green line), shows that the population would be serviced much faster: within six hours. Doubling distribution points would drop the service time to five hours, which suggests that the combined scenario is more practical. </p>
<h2>Social factors</h2>
<p>The insights outlined in figure 1 would function perfectly as technical solutions. But what happens when social and political factors are introduced into the model?</p>
<p>For instance, how can the city ensure that people are taking the allocated amount of water? How would military order, which has <a href="https://www.news24.com/SouthAfrica/News/police-army-will-help-secure-day-zero-water-distribution-points-zille-20180124">been proposed</a> at distribution points, look in practice? What is the extent of conflict arising at the water points due to long queues? How does this compromise the ability to service people at a distribution point? </p>
<p>These dynamics change the aggregate impact from the well-organised technical solutions proposed above. They can be represented as random shocks, referred to here as “<a href="http://www2.bi.no/library/tadc/ELE3744_9780071179898_191-230.pdf">disruption noise</a>”. This could dramatically increase the time needed to service each person, implying that fewer people are serviced per hour. This is illustrated in figure 2. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208504/original/file-20180301-152555-96qm39.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 2: Average population serviced per hour due to disruption noise.</span>
</figcaption>
</figure>
<p>And, if random shocks happen, the time needed to service the population per distribution point will shoot up to 25 hours. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208506/original/file-20180301-152584-1r2iibl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 3: Comparison of Population Serviced per Distribution in Base and Disruption Noise Scenarios.</span>
</figcaption>
</figure>
<h2>Lessons for other cities</h2>
<p>Cape Town has managed the use of water from the demand side, for a long time. But hasn’t made many interventions on the supply side, which partly has led to the crisis. </p>
<p>Other cities need to learn from this. Better planning is needed, through focusing on the root cause of problems and not their symptoms, identifying the most desirable interventions, and understanding its effect.</p><img src="https://counter.theconversation.com/content/92612/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There are measures in place to manage Day Zero and beyond. Models show that these will not work.Josephine Kaviti Musango, Associate Professor, Stellenbosch UniversityPaul Currie, Researcher, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/917002018-02-25T07:32:06Z2018-02-25T07:32:06ZHow Western Cape farmers are being hit by the drought<figure><img src="https://images.theconversation.com/files/207110/original/file-20180220-116330-qbxfsu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lagoons and vineyards from Gydo Pass in the Western Cape. Water is crucial for such commodities.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Much has been written about the ongoing drought and critical water shortages in the <a href="https://www.news24.com/SouthAfrica/News/how-severe-is-cape-towns-drought-a-detailed-look-at-the-data-20180123">city of Cape Town</a>. Residents are bracing themselves for <a href="http://ewn.co.za/2018/02/20/day-zero-pushed-back-to-9-july">Day Zero</a> – the moment at which most of the city’s domestic taps will run dry. </p>
<p>But there’s also a great deal to worry about beyond the city’s limits and deeper into the surrounding farmlands of the Western Cape. Agriculture is an important part of the province’s socioeconomic fabric. The sector <a href="https://www.greencape.co.za/assets/Uploads/GreenCape-Agri-MIR-2017-electronic-FINAL-v1.pdf">contributes 2%</a> to South Africa’s national GDP, <a href="https://www.fin24.com/Economy/drought-set-to-shake-sas-economy-20180209">more than a fifth of which </a> comes from the Western Cape.</p>
<p>The province’s major commodities are horticulture – fruit, wine and vegetables. It also produces livestock, meat and dairy; and field crops like wheat, barley and canola. All need water – and lots of it. The allocation of water for irrigation varies depending on the catchment area in question. For example, a third of the water in the Western Cape Water Supply System – which also serves the city of Cape Town – goes to irrigation. But in an area south east of Cape Town known as the Breede Gouritz <a href="https://www.greencape.co.za/assets/Uploads/GreenCape-Waste-MIR-2017-electronic-FINAL-v2.pdf">catchment area</a> over 75% goes to irrigation.</p>
<p>Agricultural water is allocated to individual farmers annually on the basis of crop type and area planted. It is given for use if and when the farmer chooses, during and after the growing season. </p>
<p>There’s a real risk that the water shortage could see farmers’ yields decimated during this growing season which is from September to March for irrigated crops, and from from May to October for rainfed crops. The long term impact could also be disastrous. Consecutive loss-making years could bankrupt farmers leading to many abandoning agriculture entirely. And as research elsewhere has shown, it could lead to <a href="https://www.ncbi.nlm.nih.gov/pubmed/22250871">suicides</a>.</p>
<p>In periods of water stress, farmers need support, research assistance and empathy from governments and competing water users. Other countries provide examples of how this can be done.</p>
<h2>The Australian case</h2>
<p>Australia’s Millennium drought was categorised by low rainfall conditions in late 1996 and throughout 1997 <a href="http://www.bom.gov.au/climate/updates/articles/a010-southern-rainfall-decline.shtml">in southern Australia</a>. It included some of its largest cities and agricultural regions. The drought worsened through 2001 and 2002, followed by the years 2006 to 2008 which were the driest on record. Conditions remained hot and dry through to early 2010.</p>
<p>The drought had a severe impact on irrigated agriculture. Farmers in the region relied solely on water from dams for agriculture and domestic consumption. </p>
<p>The social impact on rural communities included unemployment and loss of household income, diminished local businesses and services and recreational opportunities as well social consequences. The drought also changed the way Australian agriculture treated its water resources, and those who depended on them.</p>
<p>But there are some important differences between Australia and South Africa. One is that mechanisation levels are high in Australia and there’s very little unskilled labour. In South Africa there’s a very high dependence on unskilled labour.</p>
<p>In 2017 there were 215 000 employees in the agriculture sector in the region, an estimated 75% <a href="https://www.iol.co.za/business-report/why-western-cape-agriculture-matters-to-sa-economy-10007415">were seasonal workers</a>.</p>
<p>Seasonal workers in South Africa usually settle in the production area, often in informal settlements. Their earnings result from work during the harvest period which stretches from between one month to three. In many cases the earning period must sustain them for the rest of the year. Whole families are dependent on this income and any job losses can have a severe <a href="https://www.news24.com/SouthAfrica/News/work-drying-up-in-western-cape-drought-20171025">impact</a> including food insecurity, delinquency, alcohol and drug dependency and crime, as well as lack of self-esteem and domestic violence. </p>
<p>Significant job losses in the agricultural sector could also lead to considerable social unrest, as <a href="http://www.sahistory.org.za/article/western-cape-farm-workers-strike-2012-2013">happened in the past</a>. </p>
<h2>Impact of the drought</h2>
<p>The drought has already begun to affect how farmers use water. Some of the behaviour changes are worrying. For example, farmers have started hoarding water when it’s available. Some aren’t in a position to store enough water and are withdrawing more than normal for this period (but still within their overall allocation) in the expectation that a post-harvest irrigation will not be available. </p>
<p>But there have been some positive developments too. Some farmers with adequate and even spare water in their own dams have volunteered to donate <a href="http://ewn.co.za/2018/02/06/grabouw-elgin-farmers-to-donate-water-to-ct-agriculturalists">this to the city</a>. </p>
<p>But the lack of rain has already led to lower crop production which has meant that fewer workers are needed.</p>
<p>In many areas production volumes of wine and fruit are expected <a href="https://www.iol.co.za/business-report/the-drought-impact-on-fruit-harvests-and-jobs-in-w-cape-10120645">to fall by 10%-30%</a>. During the Millennium drought, Australia’s agricultural production levels fell <a href="https://www.sciencedirect.com/science/article/pii/S0378377414000523">drastically</a>. </p>
<p>But it is worth noting that the industry in Australia made a full recovery during the relatively wet period after the drought.</p>
<p>So far the damage to trees and vines in the Cape has been limited. While the horticulture industry will suffer economic losses, the industry will recover, if not immediately, then over a few seasons if water for irrigation is restored by next September. It is, however, too soon to say what the long term impact will be in terms of soil quality, farmer confidence and water allocations.</p>
<p>Most domestic users are able to curtail their use of water without affecting their livelihood significantly. But the agricultural industry is completely dependent on an equitable share of this resource. </p>
<p>A very fine equilibrium between accountable water allocation and responsible use of the limited resource is needed for the two competing sets of users. This requires empathy, negotiation, compromise and carefully considered trade-offs, all undertaken with Solomonic wisdom.</p><img src="https://counter.theconversation.com/content/91700/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Johnston receives funding from Water Research Commission, Australia Africa Universities Network. </span></em></p>In periods of water stress, farmers need support, research assistance and empathy from governments and competing water users.Peter Johnston, Climate Scientist & Researcher, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/920552018-02-20T10:00:51Z2018-02-20T10:00:51ZDay Zero is meant to cut Cape Town’s water use: what is it, and is it working?<figure><img src="https://images.theconversation.com/files/207069/original/file-20180220-116327-17xa2vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If Cape Town reaches Day Zero, taps will be closed and people will have to go to collection points for 25 litres of water.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The City of Cape Town has introduced the idea of Day Zero to focus everyone’s attention on managing water consumption as tightly as possible by cajoling water consumers into reducing usage. Day Zero is when most of the city’s taps <a href="https://www.iol.co.za/news/south-africa/western-cape/7-things-you-need-to-know-about-dayzero-12801609">will be switched off</a> – literally. </p>
<p>The consequences of reaching this point will be far reaching. For one, it will mean residents will have to stand in line to collect 25 litres of water per person per day. The water will be sourced from the remaining supplies that are left in the dams. </p>
<p>Day Zero isn’t a fixed target. The city moved it out from <a href="http://ewn.co.za/2018/02/20/day-zero-pushed-back-to-9-july">April 12 to July 9</a>. The reason for this is that a number of factors affect the date. These include how much residents are reducing their demand. There are already signs that water users are saving more. The goal is to achieve an average daily demand of less than 450 million litres which equates to about 50 litres per person per day. The city isn’t there yet, but for the first time figures are consistently closer <a href="https://www.news24.com/SouthAfrica/News/cape-town-isues-first-tender-to-produce-extra-500ml-of-water-20170817">to 500 million litre per day</a>.</p>
<p>The City of Cape Town describes Day Zero as the point at which the <a href="http://www.capetown.gov.za/departments/Disaster%20Risk%20Management%20Centre">Disaster Risk Management Centre</a> introduces phase 2 of its plan. Phase 2 will be triggered when the city’s big six dams supplying Cape Town reach a storage level of 13.5%. This leaves just enough water to supply critical services. This will include sufficient water to distribute to collection sites across the city. </p>
<p>Day Zero is being used in a desperate bid to avoid the final crisis stage – Phase 3 – when there is no longer any surface water available to supply the city. At that point, bottled water that’s been collected from groundwater, springs, and from whatever desalination plants can contribute will be distributed. Phase 3 will mark the point of complete failure.</p>
<h2>What happens on Day Zero</h2>
<p>Day Zero will be the start of active water rationing. As far as possible, drinking water will continue to be supplied to some critical areas. These will include strategic commercial areas, high-density areas with significant risk of increased waterborne disease such as informal settlements, and critical services like hospitals.</p>
<p>But water will be cut off to residential taps and large numbers of households and businesses will be unable to access drinking water in their homes and places of work. People will be forced to go to collection sites across the city to fetch water. </p>
<p>Meanwhile, city authorities intend to maintain sewerage systems with minimal flow by injecting water into the pipelines. It also means that a portion of water collected from the distribution points will have to be used, for example, to flush toilets.</p>
<p>In Phase 2 the plan is to roll out distribution points across the city. This will be impractical and hugely challenging at the very least. Site selection is unlikely to be evenly distributed across the city because distribution sites will depend on existing water pipelines.</p>
<h2>Avoiding Day Zero</h2>
<p>Cape Town is using a relatively simple model to manage water in an effort to move circumstances from a critical zone, and potential failure, to a position where the risk of running out of water is greatly reduced. </p>
<p>Each week the city updates its model to show progress <a href="http://resource.capetown.gov.za/documentcentre/Documents/City%20research%20reports%20and%20review/damlevels.pdf">in avoiding Day Zero</a>. </p>
<p>Tough water restrictions, plus punitive tariffs, will drive down water demand, helping to postpone Day Zero – or even leading to it being cancelled. Reduced demand is one way of postponing Day Zero. But there are other factors too.</p>
<p>The agricultural sector is already using 60% less water than what’s usually allocated to it. Some irrigation boards have closed off their water supply and farmers are reducing the amount they draw from the <a href="https://memeburn.com/2018/02/cape-town-dams-agriculture-usage/">Western Cape Water Supply System</a>.</p>
<p>Another factor is rainfall. But that’s unpredictable. In April 2005 a thunderstorm broke the drought and <a href="https://www.news24.com/SouthAfrica/News/analysis-this-water-crisis-wont-be-cape-towns-last-20170218">provided some relief</a>. </p>
<p>A final factor is that new projects will also bring additional water from tapping into the aquifers and from desalination. </p>
<h2>Painful months ahead</h2>
<p>There are some painful months ahead for Capetonians. For now, Day Zero remains a useful tool in the sense that it’s a target to be avoided. </p>
<p>There are encouraging signs suggesting that the city will get through this difficult period. For now, the city’s water risk model is showing how Day Zero is being managed. This is creating greater trust and confidence in the technical capacity of water managers along with the collective public and private efforts to reduce demand and avoid disaster. </p>
<p>Day Zero is not, as some have suggested, a hoax. It is a vital concept that is helping to strengthen the city’s ability in managing the water crisis.</p><img src="https://counter.theconversation.com/content/92055/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Day Zero will be the start of active water rationing when taps will be cut off and people will have to go to collection sites.Kevin Winter, Senior Lecturer in Environmental & Geographical Science, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/905822018-02-15T23:34:36Z2018-02-15T23:34:36ZAs a water crisis looms in Cape Town, could it happen in Canada?<figure><img src="https://images.theconversation.com/files/206426/original/file-20180214-174963-i579uj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Western Canada faced record droughts and forest fires in 2017.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>The city of Cape Town, South Africa is under extreme water rationing and heading towards complete depletion of its municipal water supply. When Day Zero — <a href="https://theconversation.com/cape-towns-water-crisis-driven-by-politics-more-than-drought-88191">the day the tap runs dry</a> — arrives, it will be the first major city in the world to run out of water. </p>
<p>Though drought has ravaged much of the world in recent decades and severe drought continues over large swaths of Africa, to see a large, developed city run out of water raises questions for us all: Could this happen in Canada? If so, how might we prevent it? </p>
<p>We think of ourselves as the water wealthy country, but Canada is not immune to water shortages or disasters. </p>
<p>Last year, we had <a href="https://www.theglobeandmail.com/news/alberta/in-the-face-of-drought-canadian-farmers-adjust-to-a-changingclimate/article36220413/">record drought over the southern Prairies</a>, <a href="http://cfjctoday.com/article/596264/wildfire-2017-look-back-worst-fire-season-bcs-history">unrivalled dry conditions and forest fires</a> in British Columbia and the Rocky Mountains, and <a href="https://www.theglobeandmail.com/news/national/quebec-ontario-floods-water-management-politics/article37511432/">unprecedented flooding in the Great Lakes-St. Lawrence River basin</a> that left <a href="http://www.pbo-dpb.gc.ca/web/default/files/Documents/Reports/2016/DFAA/DFAA_EN.pdf">millions of Canadians reeling</a> from either <a href="https://globalnews.ca/news/3987982/winter-drought-may-spell-disaster-for-saskatchewan-farmers/">insufficient</a> or <a href="https://www.newswire.ca/news-releases/government-of-canada-funds-flood-mitigation-project-in-ontario-672943553.html">excessive</a> water. </p>
<p>Severe water restrictions have already happened in Canada. In the summer of 2015, both Regina and Moose Jaw, Sask., had to ration water supplies due to the inability to treat a <a href="http://www.cbc.ca/news/canada/saskatchewan/oxygen-bubbles-vex-water-treatment-for-regina-and-moose-jaw-1.3101172">massive algae bloom in Buffalo Pound Lake</a>, which supplies drinking water to both cities. There was enough water in the lake to drink, but it was undrinkable. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/206290/original/file-20180213-44663-1oc0oya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An intense 2015 drought reduced water levels across much of Western Canada, including Lake Diefenbaker, Sask., a source for hydropower and irrigation.</span>
<span class="attribution"><span class="source">John Pomeroy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In the summers since 2014, Vancouver and other cities in British Columbia have had to <a href="http://vancouversun.com/news/local-news/changes-coming-to-metro-vancouver-watering-restrictions">ration water use</a>. Poor summer rainfall and spring snow melt have left municipal water reservoirs unfilled. </p>
<p>This is eerily similar to Cape Town’s situation. </p>
<p>In 2016, a summer drought led to water restrictions in southern Ontario and Nova Scotia. Last summer, water restrictions were imposed on many southern Alberta communities and farms due to low river flows, and a moratorium on new water licenses has been in place on the South Saskatchewan River Basin in Alberta since 2006. Canadian Geographic declared “<a href="https://www.canadiangeographic.ca/article/south-saskatchewan-river-runs-dry">The South Saskatchewan River Runs Dry</a>” in 2010. The river still flows, but at vastly reduced levels from its natural flow in dry years.</p>
<h2>A week without winter</h2>
<p>In Canada, our greatest natural disasters come from <a href="http://dx.doi.org/10.1080/07011784.2015.1131629">floods</a>, <a href="https://link.springer.com/article/10.1007/s10584-015-1375-5">fires</a> and <a href="https://link.springer.com/article/10.1007/s00382-012-1422-0">droughts</a> — and they are getting worse as our climate changes. They are wreaking havoc on the infrastructure of our communities and transportation networks, contributing to impoverishment of disadvantaged Canadians, diminishing our natural resources capital, disturbing our ecosystems and reducing agricultural and energy production. Canada needs to be better prepared. </p>
<p>In 2016, the University of Saskatchewan and three partner universities developed the Global Water Futures (GWF) program to find ways to reduce the impact of these disasters nationally — and globally. </p>
<p>This is now the largest university-led water research program in the world, with more than 220 university professors and more than 450 graduate students and researchers involved in the rapid transformation of our measurement, understanding, management and prediction of water resources. </p>
<p>But <a href="http://www.globalwaterfutures.ca">the GWF findings are distressing</a>: Climate warming from human actions is altering precipitation patterns, reducing snow-packs, accelerating glacier melting, thawing permafrost, degrading water quality, intensifying floods and increasing the risk and extent of droughts. </p>
<p>In short, Canada is “losing its cool.” This matters because our water supplies are dependent upon seasonal or longterm water storage in the form of snow and ice. This makes water from winter snowfalls available in spring and summer when we most acutely need it. </p>
<p>In mid-January this year, daily high temperatures in all the settled parts of Canada, plus much of the Yukon and Mackenzie Valley, were above freezing. It was a week without winter, a <a href="http://www.cbc.ca/news/canada/british-columbia/warm-weather-january-1.4488484">phenomenon that would have been extraordinarily rare</a> in the 20th century.</p>
<h2>Avoiding a Cape Town in Canada</h2>
<p>The impacts of this water insecurity are felt by cities, agricultural communities, Indigenous communities and industries — and are a source of domestic and international tension. </p>
<p>With such unprecedented change, it is clear that historical patterns of water availability, flooding and drought are no longer a reliable guide for the future. </p>
<p>“We’re going to have to understand that bracing for a 100-year storm is maybe going to happen every 10 years now, or every few years,” Prime Minister Justin Trudeau said as he <a href="http://www.cbc.ca/news/politics/trudeau-tour-floods-gatineau-1.4109872">toured the flood zones</a> in Gatineau, Que., in May 2017. </p>
<p>Yet we are the only G7 country without a national flood-forecasting program.</p>
<p>How can Canadians avoid our own Cape Town and advance solutions to our own water security problems? </p>
<p>1) We can start by better integrating and coordinating our water governance, planning and services — by creating a national capability to forecast floods, droughts, water quality and water supply. </p>
<p>2) We can work to reduce flood damages through more active and integrated river basin water management, calculating future flood risk and restricting development in future flood zones. </p>
<p>3) We can reassess our infrastructure, and capability to manage and store water, in expectation of droughts longer and more severe than any experienced. </p>
<p>4) We can manage the cumulative effects of development in our watersheds to reduce the contamination of our lakes and rivers — so that the water we have is safe to drink and sustains our aquatic ecosystems.</p>
<h2>A country of water solutions</h2>
<p>To achieve these water security goals we need more coordinated, inclusive and effective water governance. </p>
<p>Right now, the services the government provides to measure, predict and manage water are fragmented into dozens of federal and provincial ministries. </p>
<p>Indigenous people are left out of water governance and policy decisions, despite their treaty rights and the high exposure of many Indigenous communities to drought, flooding and impaired source water quality. </p>
<p>If we implement coordinated, integrated water management and prediction in a national water security strategy, this will generate a tremendous advantage for Canada. It will also make us a beacon of good governance to the world in the face of increasing climate change threats. </p>
<p>Advances in science, prediction, measurement and policy analysis made by the Global Water Futures program, and others, can contribute to making Canadians safer from water disasters. We can be the water-solutions country that others go to for answers to their water problems. </p>
<p>We need only look to South Africa to see what awaits us if we ignore these threats.</p><img src="https://counter.theconversation.com/content/90582/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Pomeroy is the Canada Research Chair in Water Resources and Climate Change and Director of the Centre for Hydrology at the University of Saskatchewan where he directs the Global Water Futures program. Global Water Futures and his other research projects at the University of Saskatchewan receive research grants from the Government of Canada and several provincial and territorial governments. </span></em></p>We think of Canada as a water-rich country, but we are not immune to water shortages or disasters. With some advance planning, Canada can avoid a water catastrophe.John Pomeroy, Distinguished Professor and Director, Global Water Futures Programme, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/911072018-02-13T17:21:09Z2018-02-13T17:21:09ZCape Town should serve as a wake up call for managing water in South Africa<figure><img src="https://images.theconversation.com/files/206171/original/file-20180213-44636-qun8cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Shutterstock</span> </figcaption></figure><p>There has been fierce finger pointing across various levels of government in Cape Town’s water crisis. There have also been accusations of a <a href="https://theconversation.com/cape-towns-water-crisis-driven-by-politics-more-than-drought-88191">lack of collaboration</a> between the national government, which is run by the African National Congress, and the local and provincial governments that are run by the main opposition party, the Democratic Alliance. </p>
<p>I believe the real problem is the management of South Africa’s water which is affecting the entire country’s water system. The Cape Town situation has laid bare the inadequacies in the country’s water management regimes. In fact, Cape Town’s misfortune could be a wake-up call for the whole country given that there are worrying signs of water crises elsewhere. Recent reports point to water shortages in <a href="https://www.dailymaverick.co.za/article/2018-01-17-eastern-cape-drought-rapidly-overtaking-the-cape-town-crisis/">the Eastern Cape province</a>.</p>
<p>The responsibility for water services is shared across different levels of government in South Africa. The national department of Water Affairs and Sanitation has to provide bulk water infrastructure and supply to municipalities. For their part municipalities are responsible for cleaning and producing the water to potable standards and bringing it to the people. </p>
<p>But the system hasn’t been working very smoothly and urgent action needs to be taken. The country needs all levels of government – national, provincial, local – to prioritise the issue of water management, to revive a tradition of water expertise within its ranks and to reinvest in water related skills. And government must embed a culture of people appreciating how precious water is.</p>
<h2>A potential crisis</h2>
<p>Water specialists have been warning of a possible water crisis <a href="http://www.saice.org.za/downloads/monthly_publications/2011/2011-Civil-Engineering-june.pdf">for some years</a>, particularly the dangers of a failing water management system. This has been driven by the fact that the national department of water and sanitation has steadily lost technical skills. On top of this many engineering positions at national and municipal levels <a href="https://saice.org.za/water-crisis-and-engineering-capacity-a-long-haul-but-we-can-do-it-together/">are vacant</a>. </p>
<p>The shortage of skills is compounded by the fact that the national department is in financial disarray. It received a qualified audit from the auditor general for its 2016/2017 financial year for irregular, <a href="https://pmg.org.za/committee-meeting/24880/">fruitless and wasteful expenditure</a>. There have also been evidence of deteriorating finances that affect projects and contracts management over <a href="https://mg.co.za/article/2017-02-12-nomvula-mokonyanes-water-department-is-bankrupt">the past few months</a>.</p>
<p>Against this backdrop, a recent report by the <a href="https://www.mckinsey.com/%7E/media/mckinsey/dotcom/client_service/sustainability/pdfs/charting%20our%20water%20future/charting_our_water_future_full_report_.ashx">2030 Water Resources Group</a> showed that water demand could potentially outpace supply by 2030. Factors driving this deficit include expanding urban populations and economic growth.</p>
<p>Major water infrastructure projects have been critically delayed, and no alternative solution has been sought to close the water supply-demand gap. For example, the Polihali dam in Lesotho which is meant to supply Gauteng, the economic heartland of the country, will now only be able to provide additional water by 2025 in the best case scenario. </p>
<p>On top of this existing infrastructure has been neglected because of inadequate budgeting and a shortage of skills at both the local and national levels. Infrastructure hasnt’ been maintained or repaired.</p>
<p>At the local level, water conservation and demand management programmes aimed at saving water or using it more efficiently are often absent. Local municipalities can waste <a href="http://www.wrc.org.za/Knowledge%20Hub%20Documents/Research%20Reports/TT%20522-12.pdf">up to 36%</a> of their bulk water through leaking pipes and water theft. They also rely on wastewater treatment plants that are in poor or critical condition. This threatens water quality and poses a pollution risk to water sources.</p>
<h2>Lessons must be learnt</h2>
<p>Cape Town’s misfortune can certainly teach the rest of the country lessons. </p>
<p>Among these is the fact that a problem can escalate quickly if there isn’t adequate planning. </p>
<p>As a semi-arid country and the 30th driest <a href="http://www.dwa.gov.za/drought/">in the world</a>, South Africa is used to operating and managing its sophisticated water supply system under drought conditions. It is supposed to do this by planning for future water needs ahead of time and by swiftly implementing water restrictions to different sectors at the earliest signs of a drought.</p>
<p>But water restrictions are not popular decisions and politicians are often reluctant to impose them.</p>
<p>As for the planning for future water needs, forums exist where different authorities sharing responsibilities for the provision of drinking water can coordinate their actions. One in particular, the steering committee of the Western Cape Water Supply System’s reconciliation strategy, pulls together representatives from the national department of water, the local municipalities, provincial government departments and others.</p>
<p>It has met regularly since 2007, discussing the best way to reconcile water supply and demand requirement. But it failed to anticipate the water shortage or convince anyone that water supply needed to be augmented.</p>
<p>This lack of preparedness raises questions about the adequacy of South Africa’s water planning systems under climate change conditions. And it suggests that the different authorities need to invest in new warning mechanisms and forecasting models, ideally fed with updated hydrological data and realistic water demand projections and ultimately, a new planning and management approach.</p><img src="https://counter.theconversation.com/content/91107/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Magalie Bourblanc does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The poor management of South Africa’s water is affecting the entire country.Magalie Bourblanc, Senior Research fellow, GovInn (Centre for the Study of Governance Innovation), University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/828222018-02-12T02:54:27Z2018-02-12T02:54:27ZFixing cities’ water crises could send our climate targets down the gurgler<figure><img src="https://images.theconversation.com/files/205223/original/file-20180207-74501-hkvy6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Water treatment plants can't afford not to think about electricity too.</span> <span class="attribution"><span class="source">CSIRO/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Two cities on opposing continents, <a href="https://www.cnn.com/2017/02/28/americas/chile-flooding-drinking-water/index.html">Santiago</a>
and <a href="https://www.theguardian.com/cities/2018/feb/03/day-zero-cape-town-turns-off-taps">Cape Town</a>, have been brought to their knees by events at opposing ends of the climate spectrum: flood and drought. </p>
<p>The taps ran dry for Santiago’s 5 million inhabitants in early 2017, due to contamination of supplies by a massive rainfall event. And now Cape Town is heading towards “<a href="http://www.news.com.au/technology/environment/climate-change/cape-town-receives-glimmer-of-hope-as-nervous-countdown-to-day-zero-continues/news-story/1e8db65b14416c7184c7d32e70765579">day zero</a>” on May 11, after which residents will have to collect their drinking water from distribution points. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cape-town-is-almost-out-of-water-could-australian-cities-suffer-the-same-fate-90933">Cape Town is almost out of water. Could Australian cities suffer the same fate?</a>
</strong>
</em>
</p>
<hr>
<p>It’s probably little comfort that Santiago and Cape Town <a href="https://theconversation.com/cape-towns-water-crisis-driven-by-politics-more-than-drought-88191">aren’t alone</a>. Many other cities around the world are <a href="https://www.sbs.com.au/news/from-cape-town-to-melbourne-taps-run-dry-in-crisis-cities">grappling with impending water crises</a>, including in Australia, where <a href="https://www.watercorporation.com.au/water-supply/rainfall-and-dams/streamflow/streamflowhistorical">Perth</a> and <a href="http://www.theage.com.au/victoria/prediction-melbourne-could-begin-to-run-short-of-water-by-2028-20170722-gxgm2q.html">Melbourne</a> both risk running short. </p>
<p>In many of these places governments have tried to hedge their bets by turning to increasingly expensive and energy-ravenous ways to ensure supply, such as <a href="https://www.technologyreview.com/s/534996/megascale-desalination/">desalination plants</a> and bulk water transfers. These two elements have come together in Victoria with the pumping of desalinated water 150km from a treatment plant at Wonthaggi, on the coast, to the Cardinia Reservoir, which is 167m above sea level.</p>
<p>But while providing clean water is a non-negotiable necessity, these strategies also risk delivering a blowout in greenhouse emissions.</p>
<h2>Water pressure</h2>
<p>Climate change puts many new pressures on water quality. Besides the effects of floods and droughts, temperature increases can boost evaporation and promote the growth of toxic algae, while catchments can be <a href="http://www.ecosmagazine.com/?act=view_file&file_id=EC120p8.pdf">contaminated by bushfires</a>.</p>
<p>Canberra experienced a situation similar to Santiago in 2003, when a bushfire burned through 98% of the Cotter catchment, and then heavy rain a few months later washed <a href="http://www.tandfonline.com/doi/abs/10.1080/13241583.2006.11465291">huge amounts of contamination into the Bendora Dam</a>. The ACT government had to commission a A$40 million <a href="https://en.wikipedia.org/wiki/Membrane_bioreactor">membrane bioreactor treatment plant</a> to restore water quality.</p>
<p>At the height of the <a href="https://theconversation.com/au/topics/millennium-drought-22237">Millennium Drought</a>, household water savings and restrictions lowered volumes in sewers (by up to 40% in Brisbane, for example). The resulting increase in salt concentrations put extra pressure on wastewater treatment and reclamation. </p>
<p>The energy needed to pump, treat, distribute and heat water – and then to convey, pump, reclaim or discharge it as effluent, and to move biosolids – is often overlooked. Many blueprints for <a href="https://d231jw5ce53gcq.cloudfront.net/wp-content/uploads/2017/03/Insight-brief_Net-zero-energy8_2.pdf">zero-carbon cities</a> underplay or neglect entirely the carbon footprint of water supply and sewage treatment. </p>
<p><a href="http://www.urbanwateralliance.org.au/publications/UWSRA-tr100.pdf">Some analyses</a> only consider the energy footprint of domestic water heating, rather than the water sector as a whole – which is rather like trying to calculate the carbon footprint of the livestock industry by only looking at cooking.</p>
<p>Yet the growing challenge of delivering a reliable and <a href="http://theconversation.com/the-water-industry-needs-to-join-the-fight-against-superbugs-37233">safe</a> water supply means that energy use is growing. The United States, for example, experienced a 39% increase in electricity usage for drinking water supply and treatment, and a 74% increase for wastewater treatment <a href="http://www.waterrf.org/Pages/Projects.aspx?PID=4454">over the period 1996-2013</a>, in spite of improvements in energy efficiency.</p>
<p>As climate change puts yet more pressure on water infrastructure, responses such as desalination plants and long-distance piping threaten to add even more to this energy burden. The water industry will increasingly be both a contributor to and a casualty of climate change.</p>
<p>How much energy individual utilities are actually using, either in Australia or worldwide, will vary widely according to the source of supply – such as rivers, groundwater or mountain dams – and whether gravity feeds are possible for freshwater and sewage (Melbourne shapes up well here, for example, whereas the Gold Coast doesn’t), as well as factors such as the level of treatment, and whether or not measures such as desalination or bulk transfers are in place.</p>
<p>All of this increases the water sector’s reliance on the electricity sector, which as we know has a <a href="https://theconversation.com/the-electricity-sector-needs-to-cut-carbon-by-45-by-2030-to-keep-australia-on-track-80883">pressing need to reduce its greenhouse emissions</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=243&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=243&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=243&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=305&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=305&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205222/original/file-20180207-28333-18qd6w9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=305&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Desalination plants: great for providing water, not so great for saving electricity.</span>
<span class="attribution"><span class="source">Moondyne/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>One option would be for water facilities to take themselves at least partly “off-grid”, by installing large amounts of solar panels, onsite wind turbines, or Tesla-style batteries (a few plants also harness <a href="https://theconversation.com/biogas-smells-like-a-solution-to-our-energy-and-waste-problems-36136">biogas</a>). Treatment plants are not exactly bereft of flat surfaces – such as roofs, grounds or even ponds – an opportunity <a href="http://www.adelaidenow.com.au/news/south-australia/sa-water-to-put-floating-solar-panels-in-happy-valley-water-treatment-plant-to-bring-down-power-bills/news-story/8585a5f009ad15b381f1bff71457dc1c">seized upon by South Australian Water</a>. </p>
<p>But this is a large undertaking, and the alternative – waiting for the grid itself to become largely based on renewables – will take a long time.</p>
<p>A <a href="https://www.wsaa.asn.au/publication/energy-efficiency-benchmarking-pump-stations-project-fact-sheet">2012 study</a> found large variations in pump efficiency between water facilities in different local authorities across Australia. Clearly there is untapped scope for collaboration and knowledge-sharing in our water sector, as is done in Spain and Germany, where water utilities have integrated with municipal waste services, and in the United States, where the water and power sectors have gone into partnership in many places.</p>
<h2>The developing world</h2>
<p>Climate change and population growth are seriously affecting cities in middle-band and developing countries, and the overall <a href="https://www.technologyreview.com/s/609974/how-nuclear-weapons-research-revealed-new-climate-threats/">outlook is grim</a>. Many places, such as <a href="https://www.nap.edu/read/4937/chapter/6">Mexico City</a>, already have serious water contamination problems. Indeed, in developing nations these problems are worsened by existing water quality issues. Only one-third of wastewater is treated to <a href="https://www3.epa.gov/npdes/pubs/bastre.pdf">secondary standard</a> in Asia, less than half of that in Latin America and the Caribbean, and a minute amount in Africa. </p>
<p>The transfer of know-how to these places is critical to reaching clean energy transitions. Nations making the energy transition – especially China, the world’s largest greenhouse emitter – need to take just as much care to ensure they avoid a carbon blowout as they transition to clean water too.</p>
<p>Just as in the electricity sector, carbon pricing can potentially provide a valuable incentive for utilities to improve their environmental performance. If utilities were monitored on the amount of electricity used per kilolitre of water processed, and then rewarded (or penalised) accordingly, it would encourage the entire sector to up its game, from water supply all the way through to sewage treatment.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-what-australias-growing-cities-need-to-do-to-avoid-running-dry-86301">This is what Australia's growing cities need to do to avoid running dry</a>
</strong>
</em>
</p>
<hr>
<p>Water is a must for city-dwellers – a fact that Cape Town’s officials are now nervously contemplating. It would be helpful for the industry to participate in the strategic planning and land-use debates that affect its energy budgets, and for its emissions (and emissions reductions) to be measured accurately.</p>
<p>In this way the water industry can become an influential participant in decarbonising our cities, rather than just a passive player.</p>
<hr>
<p><em>This article is based on a journal article (in press) co-authored by David Smith, former water quality manager for South East Water, Melbourne.</em></p><img src="https://counter.theconversation.com/content/82822/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Fisher does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Cities all over the world are facing growing challenges to provide clean, reliable water. And many of the fixes, such as desalination plants, have a huge carbon footprint.Peter Fisher, Adjunct Professor, Global, Urban and Social Studies, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/909492018-02-08T14:49:25Z2018-02-08T14:49:25ZDesalination: global examples show how Cape Town could up its game<figure><img src="https://images.theconversation.com/files/205313/original/file-20180207-74512-186pirj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cape Town has started down the road of desalination.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><a href="https://www.timeslive.co.za/news/south-africa/2018-01-30-day-zero-for-cape-town-pushed-back-a-few-days/">Day zero</a> is looming for Cape Town and a dedicated and efficient long-term solution to South Africa’s <a href="https://www.timeslive.co.za/group/Water_CrisiS/">water woes</a> must be found. The weather can’t be controlled and <a href="https://agriorbit.com/facts-western-cape-drought/">drought patterns</a> for the region are set to worsen. It’s time to stop relying solely on rainfall and dam levels for clean water as a critical resource.</p>
<p>South Africa boasts a coastline of over 2500 kilometres so it should be considering the oceans as an abundant water supply. Converting seawater to clean drinking water can be achieved by desalination, a proven technology that’s been used around the world. Desalination involves removing the salinity (dissolved salts and minerals) from water. There are a number of ways of doing this, but the only process that ticks all the boxes in terms of catering for large volumes, environmental impact and cost, is reverse osmosis. </p>
<p>South Africa has around 10 desalination plants dotted along the coast from Lambert’s Bay in the west to <a href="https://zululandobserver.co.za/143100/desalination-plant-officially-launched-richards-bay/">Richards Bay</a> in the east. The output from each is quite small and caters only for households in the immediate vicinity. </p>
<p>Cape Town has started down the road of desalination. A <a href="http://politicsweb.co.za/news-and-analysis/rush-to-get-cape-towns-temporary-desalination-plan">temporary desalination plant</a> is due to start producing 2000 cubic metres of water a day (going up to 7000 in phase 2) starting in March. The city will buy the water at a cost of around R30 per kilolitre. The contract is due to run for 2 years after which the equipment will be removed and the area rehabilitated.</p>
<p>But the city needs to develop far more ambitious plans. With a population of around 4 million people it needs a water output of around 500 000 cubic metres per day to supply each individual with roughly 100 litres. Desalination plants have dramatically increased in number and sophistication around the world due to membrane technology breakthroughs and energy saving equipment. </p>
<p>Three global examples in Saudi Arabia, Spain and Israel show that South Africa could increase water output in a timely and cost effective way.</p>
<h2>State-of-the-art desalination plants</h2>
<p>The <a href="http://www.water-technology.net/projects/ras-al-khair-desalination-plant/">Ras Al Khair</a> (Saudi Arabia) hybrid desalination plant has a drinking water output of 1 036 000 cubic metres per day. It is a hybrid plant because it relies on both multi-stage flash distillation (which is highly electrical and <a href="http://www.desware.net/Energy-Requirements-Desalination-Processes.aspx">energy intensive</a>) and reverse osmosis technology. It was built at a cost of US$7.2 billion between 2011 and 2014.</p>
<p><a href="https://www.theguardian.com/world/2008/apr/06/spain">In response to</a> the worst drought Spain had in years, <a href="http://www.water-technology.net/projects/barcelonadesalinatio/">Barcelona</a> built a seawater desalination plant with drinking water output of 200 000 cubic metres per day. It supplies drinking water to around 1.3 million people in the region. It caters to 20% of the population of Catalonia. Additionally, more than 5200 photovoltaic modules are installed on the roofs of eight buildings of the plant which generate approximately 1 MW of electricity annually. It is the largest reverse osmosis based desalination plant in Europe. Construction started in 2007 and the plant was inaugurated in 2009 at a cost of <a href="http://news.bbc.co.uk/2/hi/europe/8161889.stm">230 million</a> euros.</p>
<p>The plant was built by <a href="http://www.atll.cat/ca/page.asp?id=1">Aguas Ter Llobregat</a>, the public utility responsible for the supply of water to the city which also contributed €28 million to the cost. The public utility’s involvement is remarkable given that it would be comparable to the <a href="http://www.capetown.gov.za/Departments/Water%20and%20Sanitation%20Department">Water and Sanitation</a> Department for the City of Cape Town being in charge of the entire construction of a desalination plant.</p>
<p>The <a href="http://www.water-technology.net/projects/sorek-desalination-plant/">Sorek desalination plant</a> in Israel sets significant new industry benchmarks in desalination technology, capacity and water cost. It provides drinking water output of 624 000 cubic metres per day or 26 000 kilolitres per hour, which is more than all desalination plants in South Africa combined produce daily. It is the largest seawater reverse osmosis desalination plant in the world, built by <a href="http://www.ide-tech.com/">IDE Technologies</a>. It opened in 2013 at a construction cost of around <a href="https://www.technologyreview.com/s/534996/megascale-desalination/">USD$500 million</a>. Sorek will sell water to the Israeli water authority for 2.00 NIS which is around R7 per kilolitre. By comparison, the <a href="http://www.durban.gov.za/Pages/default.aspx">eThekwini municipality</a> that serves the greater Durban area charges customers R16.20 per kl consumption. </p>
<h2>Challenges</h2>
<p><a href="https://pubs.acs.org/doi/pdfplus/10.1021/acs.estlett.7b00167">Challenges</a> remain despite the increase in global investments in reverse osmosis desalination plants. The only proven technology that is economically viable and uses manageable levels of electricity is desalination by <a href="https://www.sciencedirect.com/science/article/pii/S001191640200259X">reverse osmosis</a> (and energy demanding <a href="http://www.brighthubengineering.com/power-plants/29623-how-desalination-by-multi-stage-flash-distillation-works/">multi-stage flash distillation</a>). </p>
<p>The main challenges for reverse osmosis are:</p>
<ul>
<li><p>Most plants in the world are still powered by fossil fuels. This isn’t good for energy sustainability. The use of solar and offshore wind could help. </p></li>
<li><p>Reverse osmosis membrane <a href="https://www.sciencedirect.com/science/article/pii/S0048969717307660">fouling</a>. This means over a period of time, substances deposit on the membrane surfaces and lead to lower performances. Some <a href="http://www.watertreatmentguide.com/membrane_fouling_solutions.htm">solutions</a> to the fouling problem have been suggested. </p></li>
<li><p>The problem of dealing with brine (dissolved salt in water). This means once the water has been removed from the solution, a lot of salt remains that needs to be dealt with efficiently. All desalination systems eventually need to deal with the brine. One route is to return the salt to the sea with ample dilution. This has been done with minimal impact on the <a href="https://carteblanche.dstv.com/desalination/">marine ecosystem</a>. </p></li>
</ul>
<p>We, along with others, are involved in exploring desalination processes to remove salts through emerging technologies such as <a href="http://pubs.rsc.org/en/content/articlelanding/2015/ee/c5ee00519a#!divAbstract">capacitive deionisation</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0001868616302536">redox-active electrodes</a>, and <a href="http://pubs.rsc.org/en/content/articlelanding/2010/jm/b924316j#!divAbstract">absorption</a> studies. The advantages of these processes are that they don’t use much energy and that they’re economically viable. The main disadvantage is that they are best suited for brackish water and can’t yet handle the high salinity levels of seawater. They are also not ready to be scaled up to supply a city’s needs. </p>
<p>In the long term, new and more sustainable methods for water production by desalination and energy recovery must be found. Squeezing fresh water from the ocean might be the only viable way to increase the supply and as the examples show, there is now enough evidence to show that large seawater desalination plants are practical.</p><img src="https://counter.theconversation.com/content/90949/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Werner van Zyl receives funding from the NRF, Eskom (TESP) programme, and the Technology Innovation Agency (TIA). </span></em></p>Global examples show South Africa that desalination could increase water output.Werner van Zyl, Associate Professor of Chemistry, Lecturer in sustainable energy and water systems, University of KwaZulu-NatalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/909332018-02-06T19:14:55Z2018-02-06T19:14:55ZCape Town is almost out of water. Could Australian cities suffer the same fate?<p>The world is watching the unfolding Cape Town water crisis with horror. On “<a href="https://www.theguardian.com/cities/2018/feb/03/day-zero-cape-town-turns-off-taps">Day Zero</a>”, now predicted to be just ten weeks away, engineers will turn off the water supply. The South African city’s four million residents will have to queue at one of 200 water collection points. </p>
<p>Cape Town is the first major city to face such an extreme water crisis. There are so many unanswered questions. How will the sick or elderly people cope? How will people without a car collect their 25-litre daily ration? Pity those collecting water for a big family.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cape-towns-water-crisis-driven-by-politics-more-than-drought-88191">Cape Town's water crisis: driven by politics more than drought</a>
</strong>
</em>
</p>
<hr>
<p>The crisis is caused by a combination of factors. First of all, Cape Town has a very dry climate with annual rainfall of 515mm. Since 2015, it has been in a drought estimated to be a <a href="https://www.groundup.org.za/article/how-severe-drought-detailed-look-data/">one-in-300-year event</a>. </p>
<p>In recent years, the city’s population has grown rapidly – <a href="https://www.groundup.org.za/article/whats-causing-cape-towns-water-crisis/">by 79% since 1995</a>. Many have questioned what Cape Town has done to expand the city’s water supply to cater for the population growth and the lower rainfall. </p>
<h2>Could this happen in Australia?</h2>
<p>Australia’s largest cities have often struggled with drought. Water supplies may decline further due to climate change and uncertain future rainfall. With all capital cities expecting further population growth, this <a href="https://theconversation.com/this-is-what-australias-growing-cities-need-to-do-to-avoid-running-dry-86301">could cause water supply crises</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-what-australias-growing-cities-need-to-do-to-avoid-running-dry-86301">This is what Australia's growing cities need to do to avoid running dry</a>
</strong>
</em>
</p>
<hr>
<p>The situation in Cape Town has strong parallels with Perth in Australia. Perth is half the size of Cape Town, with two million residents, but has endured increasing water stress for nearly 50 years. From 1911 to 1974, the annual inflow to Perth’s water reservoirs <a href="https://www.watercorporation.com.au/water-supply/rainfall-and-dams/streamflow/streamflowhistorical">averaged 338 gigalitres (GL) a year</a>. Inflows have since shrunk by nearly 90% to just 42GL a year from 2010-2016. </p>
<p>To make matters worse, the Perth water storages also had to supply more people. Australia’s fourth-largest city had the fastest capital city population growth, <a href="http://www.abs.gov.au/ausstats/abs@.nsf/mf/3218.0">28.2%</a>, from 2006-2016.</p>
<p>As a result, Perth became Australia’s first capital city unable to supply its residents from storage dams fed by rainfall and river flows. In 2015 the city faced a potentially disastrous situation. River inflows to Perth’s dams dwindled to <a href="https://www.watercorporation.com.au/water-supply/rainfall-and-dams/streamflow/streamflowhistorical">11.4GL for the year</a>. </p>
<p>For its two million people, the inflows equated to only 15.6 litres per person per day! Yet in 2015/6 Perth residents consumed an average of nearly 350 litres each per day. This was the <a href="https://www.watercorporation.com.au/home/faqs/saving-water/how-many-litres-of-water-do-people-in-perth-use-each-year">highest daily water consumption for Australia’s capitals</a>. How was this achieved? </p>
<h2>Tapping into desalination and groundwater</h2>
<p>Perth has progressively sourced more and more of its supply from desalination and from groundwater extraction. This has been expensive and has been the <a href="https://theconversation.com/drought-proofing-perth-the-long-view-of-western-australian-water-36349">topic of much debate</a>. Perth is the only Australian capital to <a href="http://www.bom.gov.au/water/waterinaustralia/files/Water-in-Australia-2014-15.pdf">rely so heavily on desalination and groundwater</a> for its water supply.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/204788/original/file-20180205-19956-1ryj69p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Volumes of water sourced for urban use in Australia’s major cities.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/water/waterinaustralia/files/Water-in-Australia-2014-15.pdf">BOM, Water in Australia, p.52, National Water Account 2015</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Australia’s next most water-stressed capital is Adelaide. That city is supplementing its surface water storages with desalination and groundwater, as well as water “transferred” from the Murray River. </p>
<p>Australia’s other capital cities on the east coast have faced their own water supply crises. Their water storages dwindled to between 20% and 35% capacity in 2007. This triggered multiple actions to prevent a water crisis. Progressively tighter water restrictions were declared.</p>
<p>The major population centres (Brisbane/Gold Coast, Sydney, Melbourne and Adelaide) also built large desalination plants. The community reaction to the desalination plants was mixed. While some welcomed these, others question their <a href="https://theconversation.com/desalination-africa-should-rather-manage-its-water-resources-better-82948">costs and environmental impacts</a>. </p>
<p>The desalination plants were expensive to build, consume vast quantities of electricity and are very expensive to run. They remain costly to maintain, even if they do not supply desalinated water. All residents pay higher water rates as a result of their existence. </p>
<p>Since then, rainfall in southeastern Australia has increased and water storages have refilled. The largest southeastern Australia desalination plants have been placed on “stand-by” mode. They will be switched on if and when the supply level drops. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-role-of-water-in-australias-uncertain-future-45366">The role of water in Australia's uncertain future</a>
</strong>
</em>
</p>
<hr>
<h2>Investing in huge storage capacity</h2>
<p>Many Australian cities also store very large volumes of water in very large water reservoirs. This allows them to continue to supply water through future extended periods of dry weather. </p>
<p>The three largest cities (Sydney, Melbourne and Brisbane) have built very large dams indeed. For example, Brisbane has 2,220,150 ML storage capacity for its 2.2 million residents. That amounts to just over one million litres per resident when storages are full. </p>
<p>In comparison, Cape Town’s four million residents have a full storage capacity of 900,000 ML. That’s 225,000 litres per resident. Cape Town is constructing a number of small desalination plants while anxiously waiting for the onset of the region’s formerly regular winter rains.</p><img src="https://counter.theconversation.com/content/90933/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian A. Wright does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The situation in Perth in particular has some parallels to that of Cape Town, but Australian cities responded to the last big drought by investing in much bigger water supply and storage capacity.Ian A. Wright, Senior Lecturer in Environmental Science, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.