Coastal Adaptation Investigation
Assessment of potential coastal adaptation options for two towns...
Coffs Creek, Coffs Harbour, is a popular recreation area for locals and tourists and a highly urbanised waterway. The use of the waterway and the impacts of urbanisation present multiple challenges to the creek’s management, especially regarding public health and safety, ecological impact, and stormwater pollution pressures. Coffs Creek has a history of increased sedimentation, pollutant loads and flooding, resulting in challenging stormwater management and operation considerations.
To improve the health of Coffs Creek and the management of the local stormwater assets, Coffs Harbour City Council engaged Water Technology to develop an Operational Stormwater Management Plan (SMP) for Coffs Creek, Coffs Harbour. This study developed solutions to remedy current waterway issues whilst reducing ongoing maintenance requirements. The SMP was specific to Coffs Creek but presented in a transferable manner to other catchments within the Local Government Area.
Scope:
Stormwater Management Plan
Location:
Coffs Harbour New South Wales
Client:
Coffs Harbour City Council
As part of this project, Water Technology performed an onsite inspection of all stormwater outlets feeding to Coffs Creek, completed a literature review on past studies and a gap analysis on Council’s stormwater data. Following the review stages, Water Technology created a systematic, pragmatic and succinct operational maintenance manual to guide Council on best practices in managing waterway pollution, municipal infrastructure and estuarine health. A variety of potential in-network stormwater quality improvement devices (SQID) were suggested for implementation, with supporting computational analyses to illustrate their net benefits, and sequential procedural protocols were provided to aid in identifying common waterway problems and their remedies.
Water Technology identified that there was a history of insufficient maintenance of the gross pollutants traps (GPTs), pollutant nets, bioretention basins and stormwater pits contributing to Coffs Creek. It was clear that by addressing the gross pollutant build-up, and its sources, that the existing problems of constriction and localised flooding would be partially or fully resolved. Long-term sediment build-up and limited maintenance also contributed to progressive mangrove forest intrusion into Council stormwater assets which subsequently limited maintenance capabilities due to environmental constraints. Water Technology guided Coffs Harbour City Council through the process of obtaining permits and collating the supporting documentation required to operate in these environmentally significant areas.
