Big Swamp Project

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In 2011 we received a $2 million grant from the Federal Government’s Caring for our country initiative to undertake the Big Swamp/Cattai Wetlands project “A Hidden Gem in our Valley”.  The funding was provided over three years to help achieve the outcomes identified in the 2010 Big Swamp feasibility study(PDF, 8MB) , which was undertaken with affected landowners and the local community.

The project contributes to the improvement of the water quality of the Manning River by restoring a state-recognised acid sulfate soil ‘hot spot’. This involves on-ground works to restore the area’s natural hydrology and reinstate the original coastal wetland community. The feasibility study identified that the only realistic solution was for Council to acquire the affected land. 

The Big Swamp is between Crowdy Bay National Park and Coopernook State Forest. It is north-east of the Cattai Wetlands and east of the Pacific Highway and Moorland Village.  Currently a mix of farmland and remnant coastal wetland, it was once a large wetland that fed into Cattai Creek and supported an extensive array of wildlife, particularly birdlife.

The Big Swamp project area is around 2000 hectares and includes all land below 2 metres sea level. This does not mean whole properties are involved – only the low lying areas. The land is privately owned, involving over 15 landowners.

During the early 1900’s a large portion of the Big Swamp was drained under a public works program to ‘reclaim’ the land for agriculture, but by 1912 the Pipeclay Canal project was declared a failure. An article published in the Sydney Morning Herald reported on its failings and the associated environmental effects, which we now know as acid sulfate soils.

In 1999 the State Government identified twenty-six acid sulfate soil hot spots in NSW, four of which are in the Greater Taree local government area. Leading experts in the field recognise the Cattai Creek-Pipeclay Canal area as one of the worst hot spots in NSW.

The impacts of these soils are often experienced on-site with poor agricultural production (limited crop production, water unsuitable for stock). Downstream water quality is the biggest issue which can result in a reduction in oyster production and fish kills. Acidity in this area has had pH readings as low as 2.4 (in comparison, saltwater has a pH of 8). Given the acid is generated when these soils are exposed to air, re-wetting the soils is often the answer.

The $2 million grant funded component of the project is now complete and has achieved the following results:

  • Preparation of a Hydrological Study to identify, prioritise and guide the remediation of acid sulfate soils within the Big Swamp project area.
  • Purchase and remediation of around 700 hectares of private land affected by acid sulfate soils.
  • Filling of over 14kms of paddock drains, removal of floodgates and levees, and the creation of two new tidal swales.
  • The establishment of a long-term water quality and vegetation monitoring program.
  • Secured around $250,000 in additional funding from the State Government to continue the project.
  • The review of the 2004 Cattai Wetlands Plan of Management in consultation with the community and the revised actions documented in the Cattai Wetlands Future Directions Strategy(PDF, 16MB).
  • Construction of additional visitor facilities at the Cattai Wetlands including an outdoor educational facility.

We will keep on pursuing funding so the project can be continued as around 1200 hectares of land within the Big Swamp project area is still producing acid sulfate runoff into the Manning River. 

We will also continue to monitor a range of environmental indicators on site to determine how successful the project has been and to guide future remediation efforts.

The Big Swamp hydrological study(PDF, 18MB) is a technical document which provides a comprehensive scientific analysis of the on-ground acid sulfate soil remediation activities proposed for the Big Swamp project.  The Executive summary(PDF, 3MB)  provides an overview of the aims and outcomes of the Study including the development of potential restoration strategies, the prioritisation of remediation areas, and the provision of information to show that the on-ground works will not negatively influence local flooding patterns. 

The Water Research Laboratory (WRL) of the University of New South Wales, who undertook the Study, delivered a presentation(PDF, 9MB)  to local residents on the findings of the Hydrological Study. A full copy of the Study can be obtained by contacting Council’s Environmental Services Section.