The Hastings River is located on the Mid North Coast of New South Wales about 300 kilometres north of Sydney. The river drains a catchment area of 3,700 square kilometres and discharges to the Pacific Ocean at Port Macquarie. Tidal influence extends for about 32 kilometres upstream from the river mouth to Bains Bridge, which crosses the river about 3 kilometres to the west of Wauchope. The general approach and methodology employed to achieve the study objectives involved:

• compilation and review of available information, including previously completed flood studies, streamflow gauge records, rainfall records, topographic mapping of the floodplain, hydrographic surveys of the river channels and details of bridge crossings;
• site inspections to establish catchment roughness, slope, and land-use, and to identify additional survey needs and critical hydraulic controls such as bridges and weirs;
• the collection of historical flood information, including records of peak flood levels for historical floods (such as occurred in 1963, 1968 and 1978);
• the development of a computer based hydrologic model to simulate the transfer of rainfall into runoff and its concentration in streams during the flood;
• the development of a computer based hydraulic model to simulate the movement of floodwaters through the lower reaches of the floodplain, generally downstream of tidal limits of all streams;
• calibration and verification of the models; and,
• the determination of peak water levels and flow velocities at selected locations along the Hastings, Wilson and Maria Rivers for the predicted 200, 100, 50 and 20 year recurrence floods and the probable maximum flood (PMF).