Reconfiguring the River The 4 th Annual Water Symposium, 20 February 2009, Darling Harbour, Sydney Prof Mike Young, Executive Director Research Chair, Water Economics and Management The Environment Institute The University of Adelaide

Future Proofing the Basin (Feb 2008) Review system size and configuration Finally, at the time of writing this report, the southern River Murray System is virtually out of water. Many wetlands have already been closed, and the level of Lake Alexandrina and Lake Albert is now below sea level. If this coming winter does not deliver well above average rainfall, a review of system size and configuration, and, in particular, a decision as to how best to downsize the entire system should be undertaken. It may not be possible to keep all environmental assets and all irrigation systems going. Parts may have to be abandoned, or accepted as changed forever. If significant amounts of rainfall are not received by the end of August 2008, it would be wise to: Commission a formal review of opportunities to downsize and reconfigure the southern River Murray System.

Volume of Water in the System Indicative template for sharing and allocating water

4 Water needed to ensure conveyance EntitlementsEnvironment Flood water Shared Water Entitlements Volume of water available Environment with a fully-specified share

It’s still dry

Murray Inflows in GL (excluding Snowy & Darling) Inflows are similar to evaporative losses!

Long drys DRY WET Total River Murray System Inflows (including Darling River) 8 yrs 12 yrs 52 yrs

Insufficient planning for less water

With half as much water Users Environment River Flow Environment River Flow Users

Downsize and reconfigure? Users Environment River Flow Environment River Flow Users River Flow Environment Users

Opportunities 1.Downsizing the system 2.Smart environmental asset management 3.Dynamic river height management 4.Dynamic river salinity management

Downsizing opportunities Reduce the system area –Lake Mokoan, Victoria –Barren Box Swamp, Murrumbidgee –Others Reconfigure Lower Lakes? Reconfigure the Choke and associated forests? Menindee Lakes? Other lakes, billabongs, reaches etc? Remove some weirs and locks

Smart Asset management Defining assets classes –Ecological value? –Recreation and other values? Prioritizing within asset classes –Maintain some parts, degree of representation, etc Empower environmental managers to manage –70% of Environmental water entitlements held in regional trusts –100% carry-over of unused water for all with adjustment for evaporative losses

Smart Unregulated flow management? Asset targeting Less water is required to optimise the value of ecological assets if the system form can be manipulated

Source: River Murray Environmental Management Unit, SA

Dynamic River Salinity Management Each Salinity Interception Scheme included in the entitlement and allocation regime –Credits for water released to river –Debits for groundwater pumped away from the river Seasonal variation in river salinity Who is responsible for salinity impacts from wetlands?

Dynamic river height management The biggest dam in the system is on either side of the river –Groundwater Lowering the river means that wetlands can be left dry for varying periods –But recreation opportunities less

A river infrastructure and environmental asset review? Recognising that the system may need to be operated with much less water, review and evaluate options to make more effective use of the river by –Downsizing the demand that the river system places on the available water resource –Prioritizing and optimising environmental water use –Dynamically managing river salinity and height

Contact: Prof Mike Young Water Economics and Management Phone: Mobile: Download our reports and subscribe to Jim McColl and my droplets at