Many large and damaging floods have been recorded in Dunedin since the time of European settlement. Over the years, work has been done on both the Water of Leith and Lindsay Creek in attempts to limit their effect on the city.
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Major flood events
Existing flood protection works
The largest on record was in 1929. Estimated as greater than a one in 200 year event, it caused serious flood damage in the city. The Leith was choked with trees and boulders and floodwaters surged out, causing massive disruption to residents and businesses in the city.
Leith Lindsay - a history of flooding (188 KB)
Considerable damage occurred in the lower reaches of the Leith. About an acre of the Botanic Gardens was swept away.
(Flooded caravan park in 1923 - Photo on the right)
The Water of Leith was in high flood and caused considerable damage to its tree-lined banks. Large portions of the banks were carried away. The stream also destroyed the newly erected bridge by the Water of Leith Hotel, as well as the one at the Dunedin Botanic Gardens.
This appears to have been the largest of the pre-1900 floods. The Botanic Gardens again suffered severe damage, and protective works constructed after previous floods were carried away. A small house near the St David Street bridge was swept away.
Bridges in the Woodhaugh area were severely damaged. The banks of the stream were undermined.
Considerable damage was done by overflows in the lower reaches of the Water of Leith. The impact of the flood is believed to have lowered the bed of the Leith through the town by as much as 0.5m.
A minor flood was recorded, with an overflow at Harbour Terrace, due to some extent to the work then being carried out by the Otago Harbour Board in connection with the new reclamation channel.
An extensive flood caused serious damage, followed by a less severe event a month later.
The highest recorded flood in the Water of Leith. Estimates suggest a peak flow of at least 200 cumecs. Another smaller flood occurred in June 1929 and a third flood came through in December.
Flooding in the vicinity of Rockside Road, 1923
The Leith broke its banks at one place, but no damage resulted.
Serious flooding in Dunedin City.
Low-lying parts of the city were inundated, no serious damage.
Several parts of Dunedin City were flooded and many people were forced to leave their homes.
Serious flooding, North East Valley streets inundated.
Peak flow at St David Street - estimated 114 cumecs (a one in 100 year flood is estimated at 171 cumecs).
Peak flow at St David Street - estimated 97 cumecs, but stopped in the channel.
Peak flow at St David Street - estimated 114 cumecs.
Peak flow at St David Street - estimated 84 cumecs.
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Existing flood protection works
Since 1929 a number of things have been done to lower the risk of floods escaping from the channel of the Leith, but the protection is only against a flood of one in 20 years or less.
Similar levels of protection exist on Lindsay Creek, which also poses a threat to the surrounding areas.
Water of Leith
Before the 1929 flood, concrete and stone walls had already been built to prevent bank erosion and enable better use of adjoining land. The Otago Harbour Board had constructed a concrete channel from Forth Street to the harbour in 1913 -14.
Immediately after the 1929 flood the concrete channel was duplicated from Forth Street to the harbour. Concrete and stone walls along the channel were strengthened and raised. In the early 1950s the Dunedin City Council extended the channel upstream of Forth Street.
In the late 50s the Water of Leith channel from George Street to Great King Street was straightened by building a high velocity concrete channel. Boulder traps were built upstream of George Street and in the late 1960s a larger boulder trap was built upstream of the lower Malvern Street bridge.
Protection works have been built over the years in areas most affected by floods. The most significant works were carried out after the 1929 flood and included realignment, deepening and reinforced walling of the channel from Chambers Street to the Water of Leith.
In 1965 works were completed on the realignment of the concrete channel from Chambers Street to the North Road bridge. Following the March 1968 flood the concrete lined channel was extended immediately upstream of North Road to prevent further erosion of the bridge abutments.
In the 1970s the left bank was walled between Allen Street and Selwyn Street.Back to top of page