After years of operating below full capacity, the Erie Lake dam is set to undergo repairs aimed at stopping seepage discovered in 2022.
The Town Council approved a construction contract on Feb. 24, and work could start next week, according to town spokesperson Gabi Rae.
The path around the lake will be fully closed during construction and is expected to remain closed through summer 2026. The fishing dock on the western side of the lake and the parking lot near U.S. 287 are also closed to the public, Rae said. Additional lake access points and parking areas are planned for installation this summer.
During a regular inspection with state dam engineers in 2022, a seep was discovered in the dam along the lake’s east side, and they ordered the lake level lowered to slow the leakage and determine its cause. Reducing the lake to roughly 10 feet deep stopped the observed seepage, according to the town’s website, which is why Erie Lake has not been completely full for the past several years.
The normal operating depth at the outlet of the dam is 11 to 12 feet, according to Rae, with a maximum of 13 feet. The level restriction set by the state engineer applies near the foot of the dam, Rae added. The lake is about 4 feet deeper in the middle.
“Lowering the water level stopped the visible leak, but not the underlying cause,” the town’s website states.
The town hired HDR Engineering to determine the source of the seepage and do the design work for a solution. The firm concluded the best approach is to install an upstream cutoff wall on the inside face of the dam, which it described as the most effective method for reducing the risk of internal erosion and water loss through the foundation.
Between design engineering contracts and the construction agreement, Erie could spend about $2.4 million to stabilize the Erie Lake dam.
The town’s contract with HDR Engineering was amended three times, increasing from the original $298,956 to $595,362, and Geo-Solutions was selected as the contractor to complete the repairs under an agreement that caps the town’s payment at $1,862,021.
Erie Lake is a drinking water reservoir for the town, and it is managed by the Parks and Open Space Division for the public to access recreational opportunities including fishing, hiking and wildlife viewing. Swimming and boating are prohibited, according to the town’s website.
Including its trails, the Erie Lake Open Space, near the intersection of Arapahoe Road and U.S 287, is around 20 acres, and connects to Schofield Open Space, Strieby Open Space and Arapahoe Ridge Open Space.