This is an article from the Autumn Gecko in 2013

A Council aquatic weed control program funded partly by the Blue Mountains Environment Levy and partly by the Federal Government’s Caring for our Country initiative is dramatically improving the condition of Glenbrook Lagoon by tackling a water-weed infestation that has ‘choked’ the lagoon for many years.
Cabomba is an aquatic Weed of National Significance and an aquarium escapee. If the weed escaped into the Hawkesbury Nepean and World Heritage National Park rivers, it could seriously damage the natural environment, Sydney’s water supply, fisheries, tourism and water-based recreation. So far, Council’s control program has successfully reduced the amount of Cabomba in the lagoon by 95% since December last year, and major risk areas have been cleared of weed including the outlet, boat ramp and open water column.
Local residents have commented that the lagoon looks more ‘alive and inviting’ as the water body opens up. They are also seeing more birdlife.
But even more important changes are happening in the water, at the microscopic level.
Recent tests by Council have found pollution-sensitive water insects that have not been seen in the lagoon for many years, which indicates the natural ecosystem is recovering.
The Glenbrook Lagoon Bushcare group have played a vital role in securing funding for this program and in providing on-ground support. Council would like to give a big thank you to the group and, in particular, to David Porter for his considerable assistance during the project.

Phase 2 of the control program will commence in Spring /Summer 2013, depending on weed re-growth.

This is the first time in Australia that such a large natural body of water has been so successfully treated for the Cabomba weed using this technique – another first for the Blue Mountains! For more information about this project, visit:
http://www.bmcc.nsw.gov.au/sustainableliving/environmentalinformation/glenbrooklagoon