2002 – Water for the Environment? Providing Environmental Flows in the Onkaparinga River

M. Shirley, P. Hill, S. Hannon, B. Abernethy, H. Griffith and S. Gatti

There is an ever increasing focus on the impact of water resource infrastructure, and particularly dams, on downstream hydrology and hence ecology. Over the last few years this focus has led to the rapd development in the philosophy and techniques for estimating the requirements of water dependent ecosystems.

This paper outlines the application of a new framework for estimating environmental water requirements which results in a range of flows, rather than a single recommended flow. Furthermore, a range of strategies for providing this water to the environment will be explored.

The paper uses the current environmental flows study on the Onkaparinga River Catchment for the Onkaparinga Catchment Water Management Board to illustrate the issues and application of the methodology. The natural hydrology of this catchment has been impacted by pumping of water from the River Murray, a major dam (Mt Bold) and the diversion of flow at Clarendon Weir. This substantial multi-disciplinary study over 3 years is estimating environmental water requirements and the strategies for providing this water to the environment.