The Evans River is located within the Richmond Valley Council (RVC) local government area in the Northern Rivers region of NSW. Relative to the neighbouring Richmond River catchment (6,900 square kilometres), the Evans River has a small catchment (90 square kilometres). However, the floodplains of the Richmond and Evans Rivers are linked, and during floods the Evans River receives floodwater from the Richmond. The Evans River provides a shorter flow path for floodwaters to drain from the Mid-Richmond basin to the Pacific Ocean at Evans Head, hence is a critical part of the Richmond River system. The objectives for this study are to:
- Develop and calibrate a hydraulic model of the Evans River;
- Use the hydraulic model to define existing flood risk for design events ranging from a 20 year average recurrence interval (ARI) event to the probable maximum flood (PMF);
- Identify approximate travel times of the riverine flood along the Evans River;
- Identify any specific access issues to property during flood events;
- Identify any drainage infrastructure which may be undersized and cause flooding issues; and
- Assess the likely implications to flood risk under a future (2100) climate by considering sea level rise.
