Floodgate structures are a dominant feature of NSW coastal floodplain landscapes. They exclude tidal flows, primarily preventing brackish or saline water inundation of land, and prevent backflooding that could otherwise occur from rises on the main river system. However the negative impacts of floodgate structures on ecosystems include restriction of fish movement, drying out of wetlands and reduced water quality.
The North Coast Floodgate project was established to address the issues associated with the 1004 floodgate structures in coastal rivers between the Manning River at Taree and the Tweed River on the border with Queensland. It aimed to improve coastal floodplain management practices based on in situ trials of floodgate modifications, removal or changed management.
Initial investment from the NSW Environmental Trust program was $522,000. Other cash and in-kind contributions from Councils, Industry bodies and individual landholders have totalled an additional $1,567,490 – over triple the initial investment value.
This project has resulted in both immediate and longer-term benefits to water quality through the continued flushing of previously stagnating waterways. Fish passage was improved at the same time, with over 606 kilometres restored to a more natural regime.