West London Dyke Reconstruction Project (UTRCA Weekly, February 4, 2022)
The West London Dyke stretches nearly 2.4 kilometres along the North Thames River from Oxford Street to the Forks of the Thames, and then west along the main Thames River to Cavendish Park. The City of London owns the dyke and the Upper Thames River Conservation Authority (UTRCA) undertakes major maintenance as part of its flood control program.
Construction of the original West London Dyke began in the late 1880s. By the early 1900s, the dyke had been reinforced, extended, and raised at least twice. The dyke was overtopped by the April 1937 flood and again, to a lesser extent, in 1947.
The dyke has been the focus of major ongoing rehabilitation efforts, as the City of London and the UTRCA have partnered on a $26 million project to replace the old structure.
Before the current rehabilitation efforts, the dyke protected approximately 1,200 structures and 2,600 people in the Blackfriars, Petersville, and Cavendish floodplain area to just less than the 250-year Regulatory Flood level. Once all the upgrades are completed, the dyke will protect this area to the Regulatory Flood standard, reducing risks from flooding and improving the City’s climate change resiliency.
We asked John Dony, UTRCA Water Control Structures Technologist, for more information about the project.
What is the 250-year flood level and why is the dyke built to that level of protection?
“A 250 year flood is a flood event that has a 1-in-250 chance of happening in any given year, or a 0.4% annual probability. In the Upper Thames River watershed, the 1937 Flood, which was the largest flood event recorded on the Thames, is deemed equivalent to a 250-year storm event. Once the project is completed, the West London Dyke will protect the structures behind it to the 250-year flood level.”
Who are the partners involved in this project?
“We are working closely with the City of London, which owns the dyke. This includes coordinating with their different departments such as Environmental Services, Stormwater and Sewer Engineering, Transportation Planning and Design, Parks Planning and Design, and Financial Services. We have received multi-year federal funding for the current phases of the project under the Disaster Mitigation and Adaptation Fund. Funding for previous phases came from the federal National Disaster Mitigation Program. We have also received provincial funding for many of the phases through the Water Erosion Control Infrastructure program.
As an outcome of our Indigenous outreach, we will be planting more native tree species as part of the West London Dyke project than were there before construction. This will have obvious ecological benefits, while also complementing the natural beauty of the downtown London core.”
When is the full project expected to be completed?
“Construction on the West London Dyke Reconstruction Project began in 2007 and is expected to be completed by 2026/2027.”
https://thamesriver.on.ca/west-london-dyke-reconstruction-project-utrca-weekly-february-4-2022/
