Floating Wetlands Pilot Project

Project Owner:

Northern Beaches Council

Curl Curl Lagoon Friends Inc

Project start:

November 2019

Project finish:

June 2021 (Estimated) 




Dept. Industry, Innovation & Science Communities Environment Program


Progress updates for this project are published under News & Events on this website's Home Page. 

What's this project about?

The aim of this project is to prove the concept of introducing a floating, sustainable platform of wetlands plants into Curl Curl Lagoon. If successful, this pilot could lead to the establishment of a permanent floating wetlands in future. 


What benefits would a floating wetland bring?

A permanent floating wetland in Curl Curl Lagoon could provide bird habitat and a safe nesting area as well as filter and clean the currently heavily polluted water.

Working to restore the degraded natural environmental ecosystem will involve members of the local community and instil pride in place. The community will see a future in which restoration is possible and that innovative solutions that include native vegetation can play a part in regeneration.

How is the project funded?

This project has been largely funded by a grant of $20,000 from the federal Department of Industry, Innovation and Science's Communities Environment Program.  Curl Curl Lagoon Friends administers this grant, provides volunteer manpower and co-ordinates community involvement.  Council is leading the project, providing technical design, overseeing construction of facilities, conducting water testing operations and documenting results and conclusions.

Member for Warringah in the Australian Parliament Ms. Zali Steggall OAM, MP (Independent) was instrumental in inviting Curl Curl Lagoon Friends to apply for the CEP grant in the first place. 

What are the details?

This project is a collaboration between Sydney’s Northern Beaches Council and Curl Curl Lagoon Friends Inc.

Ideas for establishing a floating wetland in Curl Curl Lagoon were presented to the Association's 2015 Annual General Meeting by Sydney-based water quality improvement specialists SPEL Environmental.

The first aim is to determine the most suitable aquatic plant species for vegetating a floating reed bed. The second aim will is to measure the water quality improvement gains made by installing a floating reed bed in lagoon water.

This pilot program would trial various saltmarsh band wetland plants to determine those that would survive best as they break down contaminants through biological processes (bioremediation).

Aquaculture tanks using water from Curl Curl Lagoon would be used to test efficacy of water filtration and suitability of plant species. By determining the right plant species that would thrive in the lagoon, monitoring and comparing the water quality of control lagoon water and plant-filtered lagoon water, a larger-scale project located in the lagoon itself could be developed.

Northern Beaches Council manages a parcel of land adjacent to Curl Curl Lagoon and John Fisher Park that is currently used by a community centre, community garden and council native nursery. The site selected for installation of the aquaculture tank and pump is ideal for security, sharing facilities and for access to the lagoon.

Council's Coast and Catchment unit will establish the site, preparing for project works and
installation of equipment. Specialists from within the Coast and Catchment unit will research, source and plant wetland species; monitor water quality and report findings. Council will supply in-kind plants where possible.

Curl Curl Lagoon Friends executive committee volunteers will provide communications strategy
and execution, liaise with community members and organise information sessions for local school students and community members interested in learning more.

Progress will be monitored and recorded by Coast & Catchment. CCLF will verify final completion.

How healthy is Curl Curl Lagoon water?

Water quality baseline - regular measurements of its water quality since 2010 have placed Curl Curl Lagoon within lowest 5% -20% tier of lagoons in NSW. Lagoon Health Report Cards cover the period up until 2015/16. 


Greendale Creek was not included in Council’s most recent (2014/15) Creek Assessment Report that covered 21 creek sites in Warringah LGA. The Creek's water quality is not publicly reported.


Causes of Poor Water Quality – toxins leaching into groundwater coming from under former tip areas on Northern and Southern banks of waterway is main cause of water pollution. A second cause are physical and chemical pollutants washed into waterway from stormwater drains coming from streets in catchment. A third source of pollutants is stormwater entering Greendale Creek from the Brookvale Industrial Area under which a section of the Creek flows. 

What action can be taken to improve water quality?

Biological treatment is possible, however, by harnessing the natural ability of plants and microbes to absorb nutrients (such as phosphorus and nitrogen) and break down contaminants through biological processes known as bioremediation. 


What role can wetlands play?

Wetlands can improve water quality in Intermittently Opening and Closing Lakes and Lagoons (ICOLLs), managing runoff, wastewater and industrial contaminants. 


Wetlands enable natural processes to biologically filter water as it passes through shallow areas of dense aquatic vegetation and permeable bottom soils. By planting wetland plants in a platform that floats on the surface of the water, the roots and microbes take up sediment that then becomes part of the plant material and biomass. 


This process would reduce turbidity and increase the level of oxygen in the Lagoon's water, enabling the ecosystem to support more plant and animal life.