Environmental Water Reserve
What is the Environmental Water Reserve?
The environment's legally protected share of water in both rivers and groundwater systems (aquifers). The Environmental Water Reserve was declared in October 2005 under the Water (Resource Management) Act 2005.
Why protect the Environmental Water Reserve?
To sustain the long-term health of our rivers and groundwater systems, rivers need water to protect the critical ecosystem processes and precious plants and animals that depend on this water. These include spawning triggers for native fish in spring, watering River Red Gums on river banks, mobilising and scouring sediments from the riverbed and maintaining water in pools for drought intolerant bugs, fish and other fauna such as platypus.
How does the Environmental Water Reserve work?
The ENVIRONMENTAL WATER RESERVE can be held in storage (regulated rivers that have reservoirs), as run-of-river flows (unregulated rivers that don't have reservoirs) or a groundwater level.
- Regulated Environmental Water Reserve in a river is a volumetric entitlement plus a capacity share of a storage reservoir. Water is released to provide the environmental flow components of a river. These flow components commonly include summer low flows (base flows), summer freshes (pulsing flows of short duration), winter low flows, winter freshes, bankfull flows and overbank flows.
- Unregulated Environmental Water Reserve in a river is managed by protecting minimum environmental flow levels from harvesting at storage reservoirs or restricting/banning licensed private diversions when river flows meet environmental flow trigger levels.
- The Environmental Water Reserve for Groundwater is provided by capping the amount of water for extraction at or below a sustainable limit.
How is the Environmental Water Reserve allocated?
Who manages the Environmental Water Reserve and how?
Melbourne Water's Waterways Group work in collaboration with the Department of Sustainability and Environment (DSE) and other water authorities to develop a set of operating rules to manage the Environmental Water Reserve. These documents are commonly referred to as Annual Watering Plans for the environment. The Environmental Water Reserve is then adaptively managed as part of an integrated program of river health and groundwater management, which reflect state and regional environmental priorities and best practice scientific principles.