Wetland To Clean Up Catchment

Newcastle Herald

Wednesday September 15, 2004

By DAMON CRONSHAW Lake Macquarie Reporter

WORK has begun to build the biggest artificial wetland in Lake Macquarie.

The wetland will be 5700 square metres in total and 1.5 metres deep at its lowest point.

It will treat stormwater run-off from 185 hectares of the Cockle Creek catchment and is being built in Aruma Place, behind Cardiff industrial estate.

About 16,000 native plants will be planted during the project, including five species of aquatic plants and 14 species of other plants around its edges.

The Office of the Lake Macquarie and Catchment Co-ordinator, which runs a program to clean up the lake, will spend about $235,000 on the wetland.

Office co-ordinator Jeff Jansson said the wetland was being built in "the most developed catchment in Lake Macquarie".

"It will be the most important artificial wetland we've built, as well as the largest," Mr Jansson said.

Cockle Creek catchment was heavily developed with residential areas and light industry and produced high nutrient loads and other contaminants in stormwater run-off, he said.

It took in several waterways and fed into Cockle Creek, which had been identified as one of the major points where sediment and nutrients ran into Lake Macquarie, Mr Jansson said.

Water quality in the northern end of the lake was not as good as the southern end, and the artificial wetland would help improve the situation.

The project is expected to be completed in November.

The entire Cockle Creek catchment spans 10,600 hectares and is estimated to put 23,900 tonnes of sediment, 86.4 tonnes of nitrogen and eight tonnes of phosphorus into the lake each year, he said.

Three further stormwater treatment devices were planned for the catchment in the next 10 months, Mr Jansson said.