Agimak Lake Dam Rehabilitation

Agimak Lake Dam (UTM U15 5473900 N, 596398 E) is located approximately 250 km west of the City of Thunder Bay on the east shore of Agimak Lake, within the Ontario Ministry of Natural Resources and Forestry’s Thunder Bay Ignace District. The Township of Ignace borders Agimak Lake on the east side. Access to dam site is from Lakeshore Drive. Discharge from the Agimak Lake Dam flows into Agimak River, which passes through the centre of the Township. Beyond Ignace, the river continues flowing to the north-east, passing through Sandbar Lake, then moving north through Little Indian Lake, Indian Lake, and finally Barrell Lake, which discharges into the English River.

Agimak Lake Dam was constructed in 1965. The dam is a concrete structure comprised of two (2) 4.27 m wide stoplog-controlled sluiceways. Each sluiceway is designed to contain a maximum of four and a half (4.5) stoplogs. The full stoplog dimensions are 4.623 m x 0.25 m x 0.3m. The half stoplogs are dimension 4.623 m x 0.25 m x 0.15 m. The third stoplog in the north sluiceway has an orifice cut into the bottom half of the stoplog to provide the required downstream flow augmentation for municipal sewage effluent dilution. A square 0.45 m x 0.45 m low-level cast iron sluice gate is situated in the centre pier. The sluice gate is presently inoperable. The concrete deck is 12.2 m long and 3 m wide. The dam is 2.4 m high from sill to top of deck. The abutments are earth-filled with 4.6 m sheet pile wing walls on the upstream face and timber cribbing on the downstream. An overhead gantry winch structure spans across both sluiceways and metal fencing surrounds the perimeter of the dam.

Several deficiencies were identified during a 2018 inspection and repair options were identified to extend the life of the dam.