Regulating groundwater use efficiency for sustainable development: the experiences of Colorado, the Namoi Catchment, and the Gnangara Mound

Improving water use efficiency (WUE) is becoming increasingly recognised as a remedy to the challenges that groundwater resources face from growing populations and climate uncertainty. While other disciplines have long debated its intricacies, the legal community – particularly in Australia – has only marginally explored the idea of regulating to improve WUE. Yet, legal frameworks can play a fundamental role in improving the efficient use of groundwater, by advancing sustainable development (SD) as the end goal of increased WUE. This further purpose is essential to ensuring that increased efficiency does not leave consumptive use exceeding sustainable levels. The law can also assist in the consistent implementation of WUE measures by providing the regulatory underpinnings for strategic policies. It can promote measures such as trade – which incentivise WUE improvements – while simultaneously guarding against inefficient practices through measures such as monitoring use against licence conditions. Although the significance of markets in advancing WUE remains pertinent, umbrella legal regulation of WUE is required in order to secure sustainable outcomes.
This thesis contends that there is an inextricable connection between WUE and SD where groundwater resources are central to a reliable water future. The best way to regulate is by enacting a ‘toolbox’ of measures that aim to increase WUE and are integrated with measures that can limit consumptive use to sustainable limits. The thesis analyses legal approaches to integrated WUE and SD measures through three case studies: Colorado in the western United States of America; the Namoi Valley in New South Wales, Australia; and the Gnangara Mound in Western Australia.
This thesis seeks to further the legal understanding and application of WUE in three important ways. First, it provides an organised analysis and critique of each jurisdiction’s approach to effectuating WUE through regulatory measures. In so doing, it examines the parallels and distinctions in terms of content and implementation. Second, the thesis considers how principles of SD interact with the object of WUE in each jurisdiction. It notes that, while the water law frameworks analysed are all premised on the principles of both WUE and SD, these principles can nevertheless be isolated from each other in a way that can inhibit a sustainable outcome. Third, the thesis suggests what toolbox measures could be incorporated when regulating for WUE to ensure the SD of groundwater resources. These measures can be applied in other jurisdictions facing similar challenges to their own water futures.