State government invests millions into Thirlmere Lakes research

For years there has been no conclusive evidence explaining why the water in Thirlmere Lakes has fluctuated.

Hopefully that is about to change.

Wollondilly MP Jai Rowell today announced that the state government will invest $1.9 million into a research program at Thirlmere Lakes.

Scientific experts from the University of New South Wales, University of Wollongong and Australian Nuclear Science and Technology Organisation will investigate the sensitivity of the wetland systems to external influences over the next four years.

The study will consider the effects of mining activity and groundwater extraction, and will attempt to understand how water moves at the surface and within the groundwater systems of the area.

“This announcement is for a significant amount of money that will be used to investigate the changing water levels in the lakes,” Mr Rowell said.

“The community has been calling for this study for several years.

“We want to get to the bottom of the cause and the study will include all the relevant people.

“Thirlmere Lakes is close to the hearts of the community [so] I know how important it is to understand the changing water levels.

“Countless people have fond memories of swimming and visiting the lakes and I want future generations to be able to do the same.”

In 2011, the state government appointed a group of four independent scientists and a community representative to evaluate possible causes for the low water levels in the lakes.​ 

The committee and the state’s chief scientist agreed that more research needed to be done to fully understand how the lake system worked before they could properly understand what was affecting water levels.

“The study was inconclusive and we don’t know if they lakes are affected by mining or weather or something else” Mr Rowell said.

“That is why further studies need to be done. It is a massive project that will determine what will happen with the preservation of the lakes into the future.”

This research builds on the $200,000 lake water level monitoring system established in 2014 which has been continuously tracking water levels and provides real-time information on the water levels in each of the five lakes in Thirlmere Lakes National Park.

The data has shown the water levels respond to local rainfall although the exact causes of fluctuating water levels is unknown.​ 

Mr Rowell said he was eager to find out whether the lakes were filling up or being drained.

“No one has been able to conclusively answer that yet and I want to know if the lakes need government intervention or whether they will recharge naturally,” he said.

“I’m not afraid to share all and any findings with the community.”

Mr Rowell said he was pleased the government would work with scientists and environmental groups “to get to the bottom” of the water fluctuation.

He said there had not been a “delay” in the allocation of funding for this project, but rather it had gone through the usual budgetary process and chief scientist’s department.

Researchers will conduct geological mapping and geophysical surveys and environmental isotopes investigations into periodic and recent water losses from Thirlmere Lakes.

The geomorphology, sub-surface characteristics and long-term perspectives on lake-filling and drying will be investigated as well as surface water to groundwater interaction and the development of an integrated water balance budget for Thirlmere Lakes to provide a detailed understanding of hydrological dynamics​.