Inquiry slams ‘Swiss cheese effect’ in the Murray-Darling Basin

Irrigators say they like the Windsor Inquiry, but are they looking after their own interests? AAP

The Windsor Inquiry has handed down its report on the Murray-Darling Basin Plan. It recommends a halt to water buybacks, more investment in irrigation efficiency and a new governance model for the Basin.

The Inquiry report has already sparked much debate. Not the flames that greeted the Murray-Darling Basin Authority’s Guide to the proposed Basin Plan, but plenty of heat for a document that is also not the actual Basin Plan.

The Inquiry report tells a very different story about the Murray-Darling Basin to the Guide. The terms of reference have largely determined the tone of each of these reports.

The purpose of the Guide was to explain how limits on the amount of water that can be taken from the Basin were to be set, based on science. The Windsor Inquiry was directed to consider measures to increase irrigation efficiency, in response to rural angst about water buybacks.

The recommendations of the Windsor Inquiry have been welcomed by irrigators, as a focus on infrastructure investment would. They have also disappointed environmentalists who feel that water buybacks should continue, despite their failings.

Ultimately, the Authority has said it will consider the recommendations of the Windsor Inquiry ahead of the release of the Basin Plan. They are not compelled to adopt the Inquiry’s suggestions, but should they?

Reallocation of water through irrigation efficiency

The Government’s $3.1 billion Restoring the Balance program of water buybacks is dismissed as “the Swiss cheese effect” in the Inquiry report. The proposed alternative is to be “more strategic” with water buybacks and to boost irrigation investment.

Needless to say, investment in irrigation infrastructure would also need to be strategic. It would need to avoid the “Vegemite effect” of spreading taxpayer money across irrigation districts.

The poor cost-effectiveness of irrigation efficiency has previously been highlighted by the Victorian Auditor-General and the Productivity Commission.

It is generally understood that strategic investment in irrigation involves:

  1. increasing the efficiency of “backbone” irrigation channels

  2. updating on-farm irrigation equipment to be more efficient

  3. abandoning inefficient parts of the irrigation network.

The first is done by reducing seepage from channels, automating channel control and replacing old water meters. These measures “save” water by reallocating it from other parts of the Basin. This includes seepage to groundwater and outflows to creeks and rivers.

The roll-out of upgrades to the backbone in northern Victoria through the Northern Victoria Irrigation Renewal Project is an example of this type of investment. Unfortunately for some, irrigators that are not connected to the “backbone” of the upgrade face higher costs or are forced to retire from irrigation.

The second element, on-farm efficiency, is a good idea. Many irrigators, particularly in South Australia, have already invested in this where it is cost-effective.

Thirdly, abandoning inefficient irrigation districts goes hand-in-hand with “more strategic” water buybacks. These are the parts of the system that are usually not connected to the backbone. These irrigators may have no choice but to sell their water.

Investment in regional futures involves more than just irrigation efficiency. Technology alone cannot guarantee the resilience of ecosystems and communities in the Basin.

The recommendations to invest in irrigation may be welcomed by irrigators for now, but could create winners and losers in the long-run.

It would be a costly venture if the Murray-Darling Basin Authority were to accommodate these recommendations and would ultimately leave most groups unsatisfied.