Floods in the Nepean District

The Penrith district is located on the western edge of the County of Cumberland, along the eastern bank of the Nepean River, with Emu Plains opposite on the western bank. A large part of Emu Plains extends onto the flood plain but Penrith is located on relatively flood free land. The lower parts of Penrith can be flooded when water from the Nepean River backs up into various small creeks. Settlers were attracted to the Nepean district by good prospects for agriculture. However, periodic floods which built up the fertile soil along the river banks, at times, caused disastrous losses of crops and buildings.

EARLY FLOODS
There were a number of early floods, varying in severity. The first flood on record – apparently a small occurrence – was in 1795. Others followed in 1799, 1806 and 1809. In 1810, after a series of major floods on the Hawkesbury, Governor Macquarie proclaimed the ‘Macquarie Towns’ of Windsor, Richmond, Wilberforce, Castlereagh and Pitt Town in an attempt to ensure that development was restricted to higher ground, free of flooding. The devastation caused by flooding in February, 1817 prompted Governor Macquarie to issue a notice exhorting settlers, in the strongest possible terms, to build their residences above the established flood levels.

The most devastating flood occurred in June 1867, the Nepean River being estimated to have reached a height of about 13.4 metres in the river, and 27.47 metres on land, ie 27.74 metres AHD (Australian Height Datum). This flood carried away the approaches to the recently rebuilt Victoria Bridge. Emu Plains, Castlereagh and the lower parts of Penrith were all under flood, causing immense loss of property. Many houses were carried into the river by landslides. Many residents were forced to take refuge in public buildings such as the Penrith Hospital and the public schools. A major flood such as that of 1867 caused inundation of over 16,000 dwellings and damage costing in the order of $1.4 billion.

The 1867 flood depicted in the Sydney Morning Herald on 24 June 1867

There have been other notable floods since – particularly that of July 1900 and March 1914. Again there was much flooding of streets and loss of houses and property along the river.

FLOOD MANAGEMENT
Warragamba Dam, completed in 1960, has reduced flood levels in the Penrith area. In 1982, a Flood Plain Management Study for the Hawkesbury-Nepean Valley was released. It called for liaison between local councils and relevant state government authorities in order to reduce flood losses, improve the environment of flood plain areas and collect information and promote research in the area of flood mitigation. It listed specific projects which would assist its aims, including stabilization of the Nepean’s western bank over 700 metres upstream from the Victoria Bridge and stream clearing along the Nepean River between Menangle and Wallacia Bridge.

The 1 in 100 year flood level used by Penrith Council is 26.1m AHD (Australian Height Datum) at Victoria Bridge, Nepean River, Penrith.

Flood mitigation is a management issue that arose in the 1950’s when there was a change from a drought-dominated regime to a flood-dominated regime in the Hawkesbury-Nepean Catchment. The increased magnitude and frequency of flooding at that time imposed a demand for some protection of flood plains. (Geomorphology of the Hawkesbury-Nepean River system)

DATES OF MAJOR FLOODS IN THE PENRITH AREA SINCE EUROPEAN SETTLEMENT

March 1799	March, 1806
August 1809	February 1817
August 1857	August 1860
June-July 1864	June 1867 (the biggest)
May 1869	May 1889
July 1900	July 1904
February 1908	1912
March 1914	June 1925
January 1933	1943/44
June 1949	November 1961
March 1978	August 1986
April-May 1988	August 1990

For more information on the history of floods in the Penrith area please visit the Local Studies Room at Penrith Library. Alternatively, have a look at the following websites.

For more information on Floods in the Penrith City area:

• Map of the extent of the 1867 across Penrith – from SES website
• Extent of the 1867 Flood over the Hawkesbury-Nepean Region – from SES website