Thirlmere Lakes

Thirlmere Lakes are at the edge of the Warragamba hydrological catchment, draining via the Little River and Nattai River to Warragamba Dam. Water flows out of the lakes when water levels rise above natural topographical constraints. The lakes have a very small catchment area and are reliant on local rainfall to maintain lake levels.

Thirlmere Lakes are located within a Schedule 2 Special Area and the SCA works closely with the National Parks and Wildlife Service to manage any impacts on water quality or quantity in accordance with the Thirlmere Lakes National Park Plan of Management. This includes surveillance and regular inspections of special areas and enforcing compliance with access conditions and restrictions.

In response to concerns regarding declining water levels in Thirlmere Lakes, in 2010 the NSW Office of Water conducted an assessment of possible causes and potential groundwater connectivity. The report concluded that declining lake levels are likely a result of climatic conditions and that there was no evidence to suggest that mine fracturing or subsidence has affected water levels in any substantial way. The report is available on the Office of Water’s website.

The NSW Government has recently announced an independent inquiry into the reduction in water levels in Thirlmere Lakes and expects to receive a report by the end of June 2012.