City opens bidding process in long-awaited Springbank Dam decommissioning

The more than decade-long saga surrounding London's inoperative Springbank Dam is one step closer to being over.

On Tuesday, the city issued a request for bids for the dam's decommissioning, a project set to get underway this summer and last roughly seven months.

The project will see everything but the dam's concrete structure removed, said Ashley Rammeloo, the city's director of water, wastewater and stormwater.

"We'll be removing the gates that are currently sitting on the bed of the river, the hydraulics that would move those gates, as well as the electrical room components," she said.

"Included in this work is 175 meters of shoreline remediation. We'll be removing some of this concrete and rubble that's along the shoreline, and replacing it with a much more naturalized slope."

Work to decommission the dam is expected to begin in July at a cost of up to $3 million, Rammeloo said. It will come nearly a century after its construction in 1929 for the benefit of upstream recreation, and to provide a reservoir for drinking water.

The dam's current woes date back to July 2000, when it was damaged by debris during a bout of heavy rainfall that caused severe flooding in the river and in other parts of the city. 

A Canadian Press report at the time stated that so much debris had jammed against the dam that "water flowed around the south side of the structure."

An environmental assessment three years later recommended the dam be fixed, with the addition of new hydraulic gates, according to the city. 

It was during a test of those gates in June 2008 that the dam wound up in its current condition, after anchor bolts attached to the base of one gate broke off. The three other gates were lowered into the river, and have remained that way for nearly 16 years.

The mishap led to a multi-year court battle after the city filed a $5.2 million suit against the firm which designed and supplied the gates, and the engineering consultant involved in the project. The suit was settled in December 2015 for $3.77 million.

In January 2018, city council voted to decommission the dam, and in May 2019 voted to partially remove the structure, a project that will be paid for with the money from the settlement. 

The decision to partially remove the dam came after public feedback, and after environmental studies found it would benefit local fish, turtle and freshwater mussel species.

"It has been a long road to get here. We are glad to see this coming to a conclusion, and getting this set up for the future, and the naturalization, and that free flowing river that we want," Rammeloo said.

More than 30 trees will be removed in the area for a combination of factors, the city says, including, "structural defects, expected construction impacts, and undesirable/invasive species." New trees will be planted as part of the project.

A stretch of the Thames Valley Parkway between Rivers Edge Drive and Springbank Gate will be closed to pedestrians and cyclists for the duration of the work.

Decommissioning the dam comes out of the city's One River Master Plan from 2019. Under the plan, the city is also replacing some 470 metres of erosion control infrastructure along the eastern shore of the river in Harris Park.