A little more than a month after celebrating the completion of the new Lakeside Drive bridge over Blackwater Creek, Lynchburg City Council received an update on the next phase of the project, which includes the draining of College Lake and the removal of the dam that sits under the old bridge.
College Lake dam, classified as “high hazard” by the National Inventory of Dams (NID), has operated recently under a conditional dam safety permit due to safety issues, according to a presentation given by Erin Hawkins, Lynchburg’s water quality manager. According to the NID, a dam receives a high hazard classification where downstream flooding would likely result in loss of human life.
Tim Mitchell, the city’s director of water resources, said it’s been an “intensive effort for the last several years for us,” noting any time there is a flood watch, the department can check on the lake levels and dam with an app on their phones. Additionally, he said the dam undergoes weekly inspections to ensure its integrity.
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The College Lake dam was built in the mid-1930s. Among other safety-related incidents, the aging structure nearly failed during a powerful rainstorm in August 2018, when floodwaters severely damaged it and sent water over the top. The city urged about 150 residents living downstream to evacuate their homes. The dam held up to the storm.
Presently, the lake itself is owned by the university, while the dam is owned by the city of Lynchburg.
This week, Hawkins presented a timeline for the current project to city council, laying out the next steps in the process that will return the water on its natural path of flowing freely into Blackwater Creek.
“We are looking to go to bid in late September or early October, which would put us into an optimal construction window starting in late January or early February,” Hawkins said.
She noted the construction window is important because it gives the city an “optimal weather pattern time period for the dam removal.”
Hawkins also said construction on the project will take up to two years to complete and the dam removal portion of the project is slated for the first quarter of 2023.
After the dam removal, the focus will shift to restoration, making sure there is a “stable ecosystem” upstream from where the dam currently sits, Hawkins said.
The de-watering of the lake will happen through a siphoning process, which will take longer than the traditional “bathtub effect” of draining the lake through a plug in the dam.
“What this siphon system does is allow us to control the rate of water that comes down. Rather than taking less than a day, it will take many, many weeks, and possibly up to a month or two to drown out the lake to acceptable levels for construction,” Hawkins said.
In addition to being able to control the water levels, Hawkins said the siphon process will allow the workers to control the sediment better, because “we don’t want to see that sediment buildup behind the dam move downstream freely” during construction.
In short, siphoning will help keep Blackwater Creek as clean as possible during the construction process.
“[Blackwater Creek] is already impaired, and we don’t want to exacerbate that,” Hawkins said.
However, the process won’t always be pretty, Hawkins said. When it comes time to begin draining the lake, she said the area could be subjected to unpleasant odors, construction noises and an unattractive view, as the lake bed begins to appear.
“As this area becomes dry again, it is going to see a change. We’re going to have a period of time where it’s not going to smell so great. It’s not going to look all that great,” Hawkins explained.
“But we’re going to have all these control measures put in place to help manage the sediment and these will improve throughout the duration of the project.”
As the sediment is gathered from the lake bed, it will be put into sediment stockpiles on site, something that will save the city “multiple millions of dollars” instead of hauling it to an off-site location, Hawkins said.
In the long term, the city hopes to create wetland habitat areas surrounding the creek. Should there be intense rainfall, the water would reengage the floodplains.
Additionally, officials hope to provide educational opportunities for students in the Lynchburg school system as well as departments at the University of Lynchburg.
According to city documents, the project will cost $20 million, including design and construction. However, the city has leveraged multiple grants and low-interest loans, one of which saw $2.5 million forgiven recently, according to Mitchell.
With the project soon to be underway, several councilors expressed excitement about the plan, like Ward IV Councilman Chris Faraldi, who said it “has the chance to be a real gem” in the city.
“Before the dam was built, this once was a stream,” Hawkins said during her presentation.
“Now, we are bringing Blackwater Creek back to life in this area, so to speak.”