Tuesday 15 November 2016
It’s a weir that looks nothing like a weir, and it’s proving to be a win win for the Shire’s northern water supply and the Brogo river wildlife.
The project started with Bega Valley Shire Council’s Water Services team working with NSW Fisheries and an environmental consultant to redesign and replace an ineffective shingle weir downstream of the Brogo Dam.
Council’s Manager of Water and Sewerage Services, Jim Collins said the old weir stood in the path of migrating fish species and it required frequent maintenance following heavy downpours.
“When designing the new weir we needed to satisfy operational, environmental and aesthetic criteria,” he said.
“We basically needed the weir to provide a water level high enough for the pumps that service the Bermagui, Quaama and Cobargo areas, while providing a way through for migrating river wildlife, and for it all to blend into an area of significant natural beauty.
“The solution came with a design that looks nothing like a conventional weir, choosing instead a stepped rock ramp arranged in four rows across the main flow path.
“Construction has just finished and we couldn’t be happier with how the new weir looks and works.
“One of the big problems with the old weir was the constant need for repair following significant rainfall. After each heavy storm Council workers were required to wade into the river and reconstruct the weir by hand from salvaged rocks washed away in the storm.
“The new weir uses boulders that weigh at least a tonne, and the new structure blends into the river, allowing grayling, Australian bass and other native fish to easily access the upstream habitat.
“This project has provided a much needed solution that compliments work underway at the other end of the system with construction of a four million litre reservoir to service the Bermagui area,” Mr Collins said.
For more information please contact Bega Valley Shire Council on 6499 2222.
Photograph: The stepped rock weir blending in with the surrounding Brogo environment.