Water Resource Management in Southwest Australia: Sharing Climate Change Loss?

On August 29, 2013, the University of Denver Sturm College of Law was honored to welcome Associate Professor Alex Gardner of the University of Western Australia (“UWA”).  Professor Gardner began his legal career as a solicitor in Melbourne, Australia, before receiving his Master of Laws in natural resources law at the University of British Columbia.  Professor Gardner has been on the UWA Faculty of Law since 1988, working with numerous research centers including the UWA Centre for Mining, Energy and Natural Resources Law; the National Center for Groundwater Research and Training; and the Cooperative Research Center for Water Sensitive Cities.  Professor Gardner also holds an Adjunct Professorship at the Australian National University College of Law.

Following a warm welcome, Professor Gardner introduced his presentation, entitled Climate Change and Water Resources Law: A Looming Adaptation Crisis.  He began with a brief overview of the impacts of climate change on southwest Australia, specifically within state of Western Australia, and the correlated decline in precipitation and rise in temperatures.  These impacts will have serious ramifications for management of water resources in the state and adaptation will be necessary in order to secure enough water for both human consumption and environmental preservation.  According to Professor Gardner, an important part of that adaptation for Western Australia will ineludibly require reformation of its water law, especially the right to take and use water.

Professor Gardner then gave a brief overview of the foundations of Australian water law.  Australia is a federation of six states whose constitution is a marriage of English parliamentary democracy and American federal democracy.  The Australian Constitution distributes legislative power and sovereignty over natural resources between the states and the Commonwealth Parliament.  The Commonwealth Parliament, like the United States Congress, has a specified list of legislative powers.  Importantly, those powers do not include the power to legislate with respect to natural resources, while the states retain the residual power to make laws regarding natural resources and water.  The Australian Constitution also gives the states sovereignty over natural resources, granting them the power to regulate water use.

Professor Gardner explained that current Australian water laws are based on a mixture of the English common law riparian tradition and more modern licensing traditions emanating from state statutes.  Under this system, landowners have the right to take and use water for domestic purposes, including livestock watering, while water for commercial purposes requires procurement of a state license.  According to Professor Gardner, the general goal of water management laws in Australia is ecologically sustainable development.  This translates to a heavy emphasis on setting aside sufficient water to maintain the environment before determining the amount available for consumptive use.

Professor Gardner next described the current scientific understanding of climate change impacts on southwest Western Australia.  Specifically, a recent report by the Australian Climate Commission shows that declining rainfall and increasing average temperatures are beginning to have serious negative impacts on agriculture and urban water supplies in southwest Australia.  Even during the recent La Nina event, which saw much of the country inundated with heavy rainfall, the southwest remained dry.  Likewise, recent projections for annual rainfall over the next twenty years almost unanimously predict continued drying in southwestern Australia.  Furthermore, Professor Gardner pointed out that recent studies by the Indian Ocean Climate Initiative all but confirm that rainfall reductions in southwestern Australia are consistent with human-induced climate change.

Professor Gardner then described the water infrastructure and water needs of the southwest.  Southwest Western Australia has a rapidly growing population of roughly two million with an economy historically rooted in agriculture and mining.  Traditionally, the southwest relied on surface water but is now heavily reliant on groundwater in order to compensate for declining precipitation.  Total water consumption in the southwest increased steadily during the last decades of the 20th century.  However, Professor Gardner highlighted the fact that recent data show stabilization of total consumption in the region, population increase notwithstanding.  This trend reflects the growing recognition of water scarcity and the success of reductions in per-capita consumption.  In spite of this, per-capita consumption remains relatively high by both Australian and international standards.  In fact, without further adaptation, growing demand coupled with shrinking supply due to climate change will produce a water shortage of 365 gigaliters by 2060.

Professor Gardner then focused specifically on the effects of climate change on the water supply serving Perth, Western Australia’s largest city.  Traditionally, Perth relied primarily on surface water, especially for its public water supply.  As surface water supplies began to dry up in the late 1970s, Perth began to increase its reliance on groundwater resources, finally resorting to desalination in the early 2000s.  However, according to Professor Gardner, even with increased reliance on desalination, these combined sources are proving insufficient in the face of a rapidly drying climate.  Other sources will be needed in the future to meet the water demands of a rapidly growing population.

Professor Gardner, with input solicited from the audience, then proffered several possible supplementary supplies that Perth can possibly look to in the future.  For example, Professor Gardner suggested wastewater recycling, increased conservation, and inter-basin transfers.  However, due to various obstacles to these supplies, including ecological concerns and political opposition, Professor Gardner identified “managed aquifer recharge” as one of the more promising avenues.

Professor Gardner next discussed each of Perth’s current main water supplies, beginning with the Perth Hills Dams, the major source of surface water for the city.  Distressingly, over the past century, average runoff into these damns has fallen by more than 50% to an all-time low of thirteen gigaliters in 2010, representing a paltry 3% of the historic average.

Groundwater is another major water source for Perth.  Originally seen as a backup to the Perth Hills Dams, the use of the major aquifers underlying Perth, called the Gnangara Groundwater System, has steadily increased over the past decade.  Now the Gnangara supplies roughly 60% of Perth’s water supply.  Increased pumping has led to a steady drop in the level of the aquifer to such a degree that the upper, or superficial, aquifer is now at its lowest level on record.  This drop, in turn, has led to increased drilling into the lower aquifers of the system, the Leederville and Yarragadee aquifers.   Though these lower aquifers contain relatively large amounts of water, increased use of the Leederville and Yarragadee has in fact precipitated the drop in the level of the superficial aquifer due to the hydrologic connection between the superficial and the Leederville and Yarragadee aquifers.

Professor Gardner highlighted Perth’s current groundwater over exploitation with a newspaper article featuring Loch McNess, a lake in Perth’s northern suburbs.  As a boy growing up in Perth, Professor Gardner remembered rowing boats on Loch McNess with his family, an activity that would be impossible now that the lake is essentially dry.  Making the situation worse, Professor Gardner explained how the state water utility has consistently failed to abide by the legal limits on groundwater drawdown already in place.  Unfortunately, it is difficult to tell whether climate change or overuse is the primary factor leading to such low aquifer levels.  Further complicating matters are the large number of other, non-municipal water rights holders, including agricultural and industrial users as well as a significant number of unlicensed users.

In the face of these issues, Perth has increasingly turned to desalination.  Though approximately half of the city’s water now comes from desalination, Professor Gardner predicted that the climate is drying faster than the city can build desalination capabilities, thus requiring increased reliance on other sources such as wastewater recycling.

Professor Gardner then discussed the current state of Western Australia’s water law.  The current licensing scheme in Western Australia includes a landholder eligibility requirement, a fixed term generally ten years in length, and the right to renew the license after the term has expired.  Each license specifies the land upon which the water can be used and the annual maximum water use on that land.  However, the licensed maximum water use is subject to scarcity reductions at the direction of the state water minister.  Though there are limits in place to protect the environment, Professor Gardner explains that limited metering and poor enforcement have severely reduced their efficacy.

Though climate change has hit Western Australia particularly hard, the other states of the Commonwealth have also experienced similar problems.  To deal with these problems, the Commonwealth developed a national water policy.  As Professor Gardner explained, the key principles of the national water policy include transitioning to transferable water rights without landholder requirements, improving metering and reporting, national oversight of states’ water markets, proportional sharing of scarcity, and a comprehensive water planning system.  Western Australia has recently accepted the national water policy, despite initial resistance, and is moving toward implementation of a water property rights regime based on a system of proportional sharing among licensees during water scarcity.

In closing, Professor Gardner compared the changing nature of Australian water law with Colorado water law.  Western Australia is moving towards a property rights regime much like that in Colorado.  However, unlike in Colorado, the new Australian scheme will incorporate a system of central planning that will first provide adequate water for environmental flows.  Another major difference between the Colorado system and the emerging Western Australian system is the formula for sharing scarcity.  Instead of a hierarchy founded on historical priority as used in Colorado, the new system in Western Australia will require proportional sharing of scarcity.


The title picture is a photo of Perth, Western Australia.