Ecology trial for Canning catchment
Released 14 Mar 2007
The effect of flows in one of WA's iconic river systems is the subject of a trial to be conducted by the Department of Water and the Swan Catchment Council later this month.
Department of Water Director Resource Use, Rob Hammond, said the Environmental Water Requirements Flow trial will allow the Department's scientists to control the release of water and measure what volume and duration of flows are required to meet our environmental objectives for the Canning River.
"This trial is an important project in helping us determine how water flows affect the local ecology and their role in the water cycle," said Mr Hammond.
"Initially, we'll be measuring low flows within the existing river channel and testing the capacity and suitability of the water delivery infrastructure that's in place at present. This involves measuring flows from six existing 'tap' release points that deliver scheme water to the river downstream of Canning Dam during the traditionally hot, dry summer-autumn periods.
"We can then look at the Department's modelling for flow requirements and the best ways to maintain pool depths and other features of the system that affect water quality and the efficient use of water.
"This trial is an important way to test our understanding of the causes and likelihood of algal blooms and anoxia, or loss of oxygen, in the Canning River. We're establishing the most effective ways to protect our water systems and good science is vital to that goal," he said.
"Activities in any catchment area have the potential to impact on water quality. In the Canning catchment, extensive land clearing, development and pressure on the local ecology has resulted in pollutants entering the system from a range of different sources, including industry, agriculture, septic systems, lawn fertilisers and stormwater runoff," he said.
Mr Hammond said the Department of Water is now the lead agency for determining Environmental Water Requirements for rivers and there is a long history of regulating flows in the Canning catchment. The requirements are tailored to each river, taking into consideration the local ecology and the need to maintain the health of the system.
The trial will incorporate a series of investigations, linking data from six monitoring sites along the river with computer modelling of the physical and ecological environment and will examine threshold flow rates for river pools that may prevent anoxia.
The monitoring will focus on the lower reaches from Pioneer Park, Gosnells, up to Soldiers Road, Roleystone. Flows will be reduced for four days, to a level that maintains base flow for licensed water users in the area before being gradually increased over the next three days.
The water release trial is scheduled to begin March 14 on the Canning River between Araluen and Gosnells. The Department of Water is asking all licensed water users and householders in the area who have a land-right to pump water to please reduce or, wherever possible, restrict surface water extraction from the Canning River for the duration of the trial period. This measure will provide the Department's scientists with a more accurate reading of river levels and increase the effectiveness of the trial.
For further information please contact the project coordinator Laurence Radin during business hours on 0401175977.
Contact: Peter Collins
Phone: (08) 6364 6848 / 0434 603 441