Lismore Flooding - Introduction

The Northern Rivers district of NSW, Australia is one of the most flood prone areas of the country outside of the tropics. With Lismore at the junction of two major streams - Leycester Creek and Wilsons River - it is often subject to significant flooding.

Topography and the alignment of the Northern NSW coast relative to prevailing weather patterns allows for prolonged orographically enhanced rainfall events from time to time - particularly during late Summer, Autumn and early Winter. During those months large slow-moving (blocking) high pressure systems are often positioned around 40 degrees south and provide a long fetch of moisture-laden southeast to easterly winds onto the North Coast. Flood producing heavy rainfall can occur if the high combines with a trough, low pressure system, tropical cyclone, upper trough / cold pool and even the monsoon trough. It is not essential for a strong 'blocking' high pressure system to help cause a flood, but it is nearly always present for the major events - as it keeps the rain producing systems in the same area longer. Some examples of flood producing weather patterns:

Lismore aerial photo and location map from Google Maps. Click for larger view.

Richmond River Flood Plain and Catchment Maps

The Wilsons River, Leycester Creek and tributaries upstream from Lismore represent only about one-quarter of the Richmond River catchment, however the majority of flooding occurs in this area and through to Coraki. The Nightcap Range to the north of Lismore, and hills extending through Bangalow to near Alstonville often receive much higher rainfall than the rest of the region due to orographic effects and because it is closer to the coast and the source of rain-bearing clouds. The floodplain is also narrower due to hilly terrain. South and west of Lismore the terrain is quite flat and the floodplain very wide in comparison.

Major flooding of the Richmond River upstream from Coraki requires heavy rainfall west of the Nightcap and Border Ranges and into the eastern parts of the Richmond Range. This occurs far less frequently than Lismore flooding, with February 1954 and January 2008 the stand-out events for Casino, Kyogle and Wiangaree.

Heavy rainfall occurring over the generally flat country and eastern parts of the Richmond Range in the southwest of the catchment contributes to flooding at Coraki, Woodburn and downstream. Heavy rainfall on the southern side of the Alstonville Plateau also affects the Lower Richmond River.

Another part of the catchment is the Teven Valley and North Creek northwest and north of Ballina. Flooding can occur in this area during very heavy rainfall although those waters quickly enter the Richmond River.

Richmond River catchment map source

Lismore Flood Heights

The Lismore flood gauge is on the rowing club building in Magellan Street and the figures below are all taken from that point. Australian Height Datum (AHD) was introduced in the late 1990s. AHD flood height measurements are 0.78 metres lower than the old gauge readings that many readers may recall. Flood heights in other parts of Lismore vary depending on a number of factors including the volume and speed of water coming down the Wilsons River and Leycester Creeks, the amount of local flooding due to heavy rain in Lismore, whether the Browns Creek pump is operational and whether levees have or are being overtopped.

The Lismore central business district used to begin flooding when the Wilsons River reached 9.42m AHD. Water would flow into the streets near the old Post Office at the corner of Molesworth and Magellan streets. Major flows into the city would occur by 9.72m AHD with most of the CBD inundated when the river level reached 10.22m AHD.

A concrete wall flood levee was built over a couple of years and finished in March 2005. It protects the CBD from floods up to about 10.65m AHD. Flood waters during major events will still top the levee but will start to enter streets at the Browns Creek spillway on Molesworth Street between Woodlark and Zadoc streets. A long established earthen levee protects South Lismore from all but major floods exceeding 10.95m AHD. North Lismore has no flood protection and is the first area to be cut off.

The highest recorded Lismore flood levels were on 21st February 1954 and 11th March 1974. Signs such as this one are displayed on power poles throughout the city.

Tropical cyclone tracking map links are listed where it is known they directly or indirectly contributed to a flood event. Infrared satellite picture loops are available for all flood events since 1983.

Flood Pictures

11th May 1987

The Mother's Day Flood: Lismore was hit with an unprecedented second major flood event in the space of two months. These flood pictures were taken overlooking the Lismore basin then around the central business district. The flood peak had dropped about 20cm by this time.
[11th May 1987 Pictures]

27th April 1989

Two floods in one month! After the biggest flood since 1974 hit the region on 2nd April 1989, a second flood for the same calendar month occurred. A few photos were taken near the Lismore rowing club and Browns Creek pump.
[27th April 1989 Pictures]

2nd February 2001

Major flooding returns to the Lismore region - it had been 12 years since the last major flood to hit Lismore. This CBD inundation proved to be the final straw to get the Lismore flood levee built. The pictures on the 1st were taken near Eltham, and on the 2nd near Eltham and in the Lismore CBD.
[1st Feb 2001 Pictures] [2nd Feb 2001 Pictures] [Event Report]

10th March 2001

Major flooding along the Clarence River occurred this time with a smaller event in Lismore. The flood photos are taken of the Wilsons River at Eltham and along the Bangalow Road leading into Lismore.
[9th Mar 2001 Pictures] [10th Mar 2001 Pictures]

30th June 2005

Just three months after the Lismore CBD flood levee was finished, it was given its first test. Major flooding peaked at the low end of the major level. It illustrated how well the levee worked in protecting the CBD from 90 per cent of floods that occur in the region. The flood photographs are taken near Eltham and around Lismore.
[30th Jun 2005 Pictures] [1st Jul 2005 Pictures] [Event Report]

20th January 2006

Moderate flooding along the Wilsons River into Lismore with a major flood in the Brunswick Valley. The pictures are taken around Eltham and Lismore.
[19th Jan 2006 Pictures] [20th Jan 2006 Pictures] [21st Jan 2006 Pictures]

6th March 2006

Moderate flooding and wild seas occurred due to an intense low off the coast. The river peak in Lismore was quite slow to arrive with floodwaters persisting from the 4th to the 6th. The pictures are taken near Eltham and the Tweed Coast.
[4th March 2006 Pictures]

5th January 2008

Major flooding occurred along the Richmond River in January 2008 with Kyogle hit hard. Lismore was lucky and only saw moderate flooding. Most low lying areas along the Richmond River were inundated with some record stream rises.

[4th Jan 2008 Flood Pictures][flood gallery] taken from McLeans Ridges, Eltham, Boatharbour and Lismore.
[5th Jan 2008 Flood Pictures][flood gallery] taken at South Lismore, Fairy Hill, Casino, Leycester, Rock Valley, Kyogle and Lismore.
[6th Jan 2008 Flood Pictures][flood gallery] taken McKees Hill to Clovass on the Bruxner Hwy.
[7th Jan 2008 Flood Pictures][flood gallery] taken from a NSW State Emergency Service (SES) helicopter between Lismore and Coraki including stranded cattle rescued along the Wilsons River near Coraki.
[8th Jan 2008 Flood Pictures][flood gallery] taken between Lismore and Coraki from the SES chopper, and at Coraki.
[9th Jan 2008 Flood Pictures][flood gallery] taken around Coraki from the SES helicopter then during two SES flood boat operations.