Hawkesbury-Nepean River ADCP Flow Gauging

Client: Sydney Water
Year: 2011-2012
Project Reference: 2011086

As part of a large scale numerical modelling project, WRL was contracted by Sydney Water to undertake flow gauging of two locations in the Hawkesbury-Nepean River estuary. For calibration of the numerical model, flow and water quality measurements were required in multiple locations within the model domain. A total of six locations were co-currently gauged over a complete spring and neap tidal cycle.

An RDI Workhorse Monitor 600 kHz ADCP and a Sontek Riversurveyer M9 were utilised for flow measurement. Transects were repeated across the river over a 14 hour period, for both the spring and neap tide surveys, to capture the full flood and ebb tidal cycle. Previous bathymetric survey data collected by Sydney Water was assessed prior to ensure that locations with symmetric channel geometry were chosen.

As part of the flow gauging, water quality monitoring was also undertaken throughout the profile at hourly intervals.

All data was checked for quality and suppled to Sydney Water following the successful completion of the field program. The data collected by WRL, in conjunction with the 4 other river locations gauged, was used to calibrate to Hawkesbury-Nepean River estuary numerical model.