An evidence-based approach for integrating ecological, hydrological and consumptive models to optimize flow management: a proof of concept

Implementing policies to return water to the environment is challenging. We developed an approach to integrate ecological responses with river management models to provide a link between flow and ecology. This paper aims to summarize the findings of a multifaceted project bringing together multiple lines of evidence to achieve a proof-of-concept approach for optimizing water use to support water policy and management decisions. We developed an eco-hydrology model that represents rivers, water storages, operational constraints, flow management, an ecological response and consumptive irrigation demands, which is linked to climate. To demonstrate the proof of concept, we describe a case study where modelling optimization seeks solutions to minimize terrestrial vegetation encroachment (an ecological response) and maximize irrigation net value through flow management. The solutions provide a range of alternative ‘optimal’ management options to consider. Ultimately, hydrological modelling that integrates both consumptive use and ecological response simultaneously is important to enhance stakeholder understanding of the complexities and trade-offs involved in implementing different decisions. Although proof of concept at this stage, the approaches offer potential for integration of river management models and quantitative ecological response models (derived by considering available evidence from many sources) to support water policy and management decisions.