Monitoring at lakes Nowergup and McNess continues

Pierre Horwitz from ECU with Water Minister Dave Kelly with and Wanneroo MLA Sabine Winton and at Lake Joondalup, the biggest of a chain of wetlands known as the ‘linear lakes’ that includes Lake Nowergup.

MONITORING of water quality and fauna at Lake Nowergup and Lake McNess in response to groundwater use and climate change will continue this year.

Pierre Horwitz from Edith Cowan University’s Centre for Ecosystem Management said both Lake Nowergup and Loch McNess (which is in Yanchep National Park, and included as a wetland on the Gnangara mound), are included in the suite of wetlands the university has been monitoring for 22 years.

Wanneroo MLA Sabine Winton said as a long-time advocate for Lake Nowergup she was pleased the McGowan Government was placing an emphasis on continuing the important work of scientific monitoring of the local lake systems, including Lake Nowergup.

Ms Winton said understanding the changing conditions and health of the wetlands in the northern corridor was very important.

“Lake Nowergup to the north of Wanneroo is a perfect example of how important this scientific work has been for our continued understanding of the changing conditions and health of this important wetland,’’ she said.

“Lake Nowergup is the deepest permanent lake in the metropolitan area and has a high diversity of birds with more than 56 species recorded.”

Water Minister Dave Kelly said ECU had been appointed through a competitive process managed by the Department of Water and Environmental Regulation to conduct wetland vegetation and macroinvertebrate and water quality studies on the Gnangara mound in 2018.

He said the Gnangara groundwater system was Perth’s biggest and most reliable fresh water resource and provided almost half of Perth’s water supply.

The system also supports Perth’s natural lakes and wetlands which are some of the most biologically diverse and ecologically important areas on the Swan Coastal Plain.

Surface waters in many of the wetlands supported by the Gnangara groundwater system have declined over the last 30 years, and ongoing assessment helps target management responses.

He said responses to declining water levels so far included reducing the amount of groundwater taken for public water supply, changing abstraction patterns to limit the take from sensitive areas affecting wetlands and locating groundwater replenishment sites.

“Since this assessment work started more than two decades ago, climate change has reduced the average winter rainfall by around 25 per cent of the long-term average over that time,’’ he said.

“For this reason, we have given the greenlight for further groundwater replenishment to support the use of this system for public water supply and we are working with water users to be more water efficient.”

Stretching about 2200sqkm along the coastal plain north of the Swan River to Gingin and east to the Darling Scarp, the Gnangara groundwater system has four main aquifers the Gnangara mound and the Mirrabooka, Leederville and Yarragadee aquifers.