Otago Regional Council has just announced that the flood mitigation works along the Water of Leith, between the Union Street Bridge and the Leith Street Footbridge, will start shortly.
Being conducted as part of the Leith Flood Protection Scheme, this project will involve riverbank excavation and associated works.
These works will take place between January and June 2017.
The current scheme is designed to cope with a flow of 171 cumecs (cubic meters per second) measured at the St David St footbridge in most reaches of the Leith.
This flow has an Average Recurrence Interval (ARI) of 100 years.
Extensive hydraulic modelling, using both computer and physical models, was carried out to determine the level of a 100 year ARI design event for different reaches of the Leith.
The hydraulic model’s development and verification was based on observations and data collected during past flooding in the Leith.
The Water of Leith rises in north Dunedin, and flows 14km through the Glenleith, Woodhaugh and North Dunedin suburbs. It is a stream with the potential to inflict serious damage to property on the floodplain.