Flooding

Flooding is a significant issue that affects existing and future developments in the Parramatta Local Government Area (LGA).

Catchment modelling

Council undertakes catchment modelling to develop an understanding of the flooding and water quality problems that exist in the City. Catchment modelling studies look at flood levels for different storm size scenarios, areas of inundation, problem areas where pipes are under capacity and pollution hot-spots. Plans done to date are:

• Subiaco Creek sub-Catchment Management Plan
• Vineyard Creek sub-Catchment Management Plan
• Duck Creek sub-Catchment Management Plan
• Duck River Flood Study Review
• Claycliff Creek catchment Review
• Drainage Review of localised flooding areas

Drainage Construction and Maintenance

Drainage works and upgrades are undertaken across the city to manage nuisance or local overland flooding. Works include increasing channel, pit and pipe capacities, replacing damaged or end of life drainage assets, scheduled maintenance of known hot spots and reports of system blockages.

Floodplain Risk Management Planning

Floodplain Management Plans are prepared by Council, in accordance with the NSW Government’s Floodplain Development Manual - the management of flood liable land (April 2005), to identify ways to reduce the risk of damage from flooding.

The Manual recommends a staged process involving the following steps:

1. Establish a Floodplain Risk Management Committee
2. Data collection and compilation
3. Undertake Flood Study
4. Preparation of a Floodplain Risk Management Study and Plan
5. Plan Implementation
6. Plan Monitoring and review

These plans include measures such as:

• Flood modification measures (e.g. retarding basins, levees, channel improvements)
• Property modification measures (e.g. rezoning, house raising, voluntary purchase)
• Response modification measures (e.g. education, emergency response and recovery planning, insurance)

Floodplain Risk Management Studies and Plans have been undertaken for:

• North Wentworthville
• Upper Parramatta River
• Brickfield Creek (Supplementary)
• Lower Parramatta River
• Eastwood and Terrys Creek (in preparation)
• Duck River (in preparation)

Actions identified in the Floodplain Risk Management Plan, in particular those identified as ‘flood modification measures’, receive funding through Council’s flood mitigation budget.

Caption: Flood waters engulf Parramatta Ferry Wharf, Charles Street Parramatta (2007)