Big Swamp
Wetlands
Coralville, New South Wales, Australia Creating a new standard for large-scale intertidal restorations. Big Swamp is the local name for a series of drained agricultural floodplains located on the Manning River estuary on the mid-north coast of New South Wales, Australia. Historically a large, brackish backswamp known for its abundant bird populations, the Big Swamp floodplain has undergone major hydrologic changes over the past 120 years due to the construction of drainage networks, canals, levees, and floodgates. Unfortunately, the combination of extensive drainage and sulfidic subsoils has acidified the soil and adjacent waters. Following rainfall events, large plumes of acidic water spread through the lower estuary, lowering the pH and creating anoxic conditions toxic to aquatic life. To overcome these issues, the project team, led by MidCoast Council, undertook a detailed study followed by an extensive earthworks program to remediate the site. They filled in over 13 kilometers of canals in the drainage network, established a new tidal wetland ecosystem, enhanced the natural tidal flushing dynamics, and restored over 820 hectares of low-lying land. This nature-based approach has significantly improved water quality and has received multiple awards, including the prestigious Green Globe Award.
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