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Flood study

Hawkesbury-Nepean Valley Regional Flood Study

The Hawkesbury-Nepean Valley Regional Flood Study is a technical document describing the flood behaviour of the main Hawkesbury-Nepean River from Bents Basin near Wallacia downstream to Brooklyn Bridge, and associated backwater flooding, for existing conditions and under projected climate change. It does not include local catchment flooding or local overland flow inundation. The modelling of infrastructure options to mitigate downstream flooding is beyond the scope of this flood study and is addressed separately. This Regional Flood Study describes the flood behaviour dominated by Hawkesbury-Nepean riverine flooding and its backwater effects. Local catchments are modelled to have the same duration rainfall event as that which causes the highest flood levels in the main river. Shorter duration events are likely to result in higher flood levels within tributaries such as South Creek, requiring separate investigations. Local councils should be consulted to ascertain whether information is available to understand the combined flood risk at particular locations in the valley.

Additional Information

Field Value
Title Hawkesbury-Nepean Valley Regional Flood Study
Commission Date February 27, 2017
Publication Date July 26, 2019
Themes Emergency Management
Spatial Extent
Map data © OpenStreetMap contributors
Tiles by MapBox
Author/ Prepared by WMAwater
Publish date August 8, 2019
Update date August 14, 2019
River Basin 212 - Hawkesbury
Place Name Hawkesbury-Nepean Valley from Bents Basin to M1 Bridge near Brooklyn including backwater flooding up South and Eastern Creeks
Approval State Approved
Submitted for approval August 10, 2019
Submitted by Stephen Yeo
Approved August 16, 2019
Approved by ses-sysadmin
Data Comment

The Regional Flood Study calculates flood levels, extents, depths, provisional flood hazard and hydraulic categories for the 1 in 5, 1 in 10, 1 in 20, 1 in 50, 1 in 100, 1 in 200, 1 in 500, 1 in 1000, 1 in 2000, 1 in 5000 AEP events and the probable maximum flood (PMF).

Identifier 6ee14f52-a1ab-4986-865a-14544fcb65a2