Floodplain management

Floodplain management

Managing floods in the local area

Floodplain management plans for the City's local area have been developed and adopted by Council. The plans include flood mitigation measures and what can be done to help affected areas.

Under the NSW Government's flood prone land policy the City is required to manage flooding issues and put plans into place to safeguard flood-prone areas.

The local area has been divided into 8 catchments covering 2,666ha. Click an area of the map below to show further information for each catchment.

 

Centennial Park catchment Alexandra Canal catchment Johnstons Creek catchment Blackwattle Bay catchment Darling Harbour catchment Sydney City catchment Woolloomooloo catchment Rushcutters Bay catchment

 

Due to high urbanisation since the 19th century across the local area there are not many natural creeks or open surface water bodies in the catchment areas to accommodate stormwater.

Generally, stormwater from frequent minor storm events is managed by conventional pits and pipe systems. In less frequent, but major rainfall events, stormwater in excess of the conventional systems travels along low gradients of the catchments, ultimately draining into Sydney Harbour and Botany Bay.

The combination of steep and flat terrain, high density residential, commercial and industrial areas has made areas susceptible to flash flooding. Being aware of the potential for flooding and knowing how to respond will make flood events more manageable.

We are progressively introducing the floodplain management plans, in the final stage of the floodplain risk management process, as outlined in the NSW Government's flood prone land policy.

Interim floodplain management policy

Council endorsed its draft interim floodplain management policy in May 2014.

The policy is a responsible and forward-thinking approach to manage flooding issues, which will ensure development in the city is not at undue risk of flood and that proposals do not increase flood risk for existing properties.

Links

NSW Government: Floodplain Development ManualNSW State Emergency Service FloodSafeBureau of Meteorology: NSW weather and warnings summary

Local flooding history

Since 1910, the City of Sydney's local area has experienced 35 floods classified as serious, severe or minor. In 13 cases, high rainfall resulted in localised flooding. During this period 4 floods were classified extreme:

  • November 1984
  • March 1975
  • January 1973
  • August 1971.

Floods can occur at any time and in the future could be bigger than any previously recorded event. 

Past flood events

Date
Average time between floods of this size
January 1938
10–20 years
September 1943
20 years
June 1949
5 years
January 1955
5–10 years
November 1961
10–20 years
August 1971
20–50 years
January 1973
20–50 years
February 1973
10 years
March 1975
Greater than 1 in 100 years
November 1984
Greater than 1 in 200 years
January 1991
5–20 years
April 1998
10 years
February 2001
1 year

High rainfall storm events

Note: Rainfall levels recorded at Centennial Park, Randwick Bowling Club and Randwick Racecourse since 1888, which caused minor flooding throughout the city. 

Date
Rainfall (mm)
January 1933
189
February 1956
192
February 1958
185
February 1959
265
November 1961
270
May 1962
258
March 1975
261
August 1975
221
October 1975
205
March 1978
237
November 1984
240
April 1988
193
February 1992
294


Downloads Document Downloads
Downloads
Interim floodplain management policy PDF 346.0 KB Download

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Last updated: Wednesday, 24 August 2016