13/2/04
The Water Corporation has started work on a $3million project to replace two sets of floodgates on Busselton's Vasse-Wonnerup Estuaries.
Government Enterprises Minister Nick Griffiths said the two estuaries were part of an internationally significant wetland system, the seasonal home to thousands of migratory birds and one of the most important waterbird habitat areas in the South-West.
The Minister said the floodgates played a crucial role in maintaining water levels and water quality in the estuaries. The structures also preserved the surrounding environment for wildlife and protect residential and farming properties from flooding.
The Vasse and Wonnerup estuaries collect water from four local rivers - the Vasse, Sabina and Abba Rivers, which drain into the Vasse Estuary and the Ludlow River which drains into the Wonnerup Estuary.
The two existing wooden floodgate structures have been in place for almost 100 years. They control drainage from the estuaries to the Wonnerup Inlet Channel which discharges to the ocean.
Mr Griffiths said both wooden floodgates would be replaced with concrete, box-culvert structures within about 20 metres of the current locations.
Key components of the floodgate replacement project were:
- construction of coffer dams upstream and downstream of the floodgates;
- construction of temporary bypass pipes;
- removal of existing floodgates;
- construction of new concrete floodgates; and
- site restoration and preservation of materials for a community Interpretive Centre.
Mr Griffiths said the new floodgates would accommodate vehicle access to improve safety when maintenance operations were carried out. They were equipped with a remote fish monitoring device and automatic gate operation.
"Both floodgate will be equipped with a check-board facility to allow fresh water to be retained in the estuaries at the end of winter and hinged floodgates on the downstream side to allow maximum discharge during periods of high rainfall and river flows," the Minister said.
"The project will be conducted according to a comprehensive environmental management plan which addresses issues such as dewatering, the management of excavated acid sulfate soils and heritage issues."
Mr Griffiths said construction work was expected to be completed in May.
Minister's office: 9222 8950
