• Bureau of Meteorology Flood Warning Centre
• NSW Water Real-time data for the Richmond River Basin

Skip to the photographs of flooding in and around the Lismore area.

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 at the western end of Magellan Street (red dot on the Lismore Map) 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 to mark the highest level floodwaters reached.

Daily rainfall data from all Bureau of Meteorology sites in the Northern Rivers have been added for each flood event.

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.