Little Long Dam Safety Project

Val Rita, Ontario

Kiewit was selected as the general contractor for the Little Long Dam Safety Project, a critical upgrade aimed at improving dam safety and spillway capacity along the Mattagami River in northern Ontario.

With the region’s increasing risk of extreme weather events, the enhancements to the dam and spillway will significantly improve flood management capabilities. Kiewit is increasing the discharge capacity by 2,650 cubic meters per second by constructing two new sluiceway bays on each side of the existing Adam Creek Spillway. The total flow of the dam will reach 8,680 cubic meters per second, which is three times the flow of Niagara Falls.

The spillway upgrade includes the installation of four new sluicegates/spillway gates adjacent to the existing eight-gate spillway along with the refurbishment of 12 total gates. Additionally, Kiewit is replacing the existing hoisting systems on both the Adam Creek Spillway and the Little Long Spillway to enhance operational reliability. To support these improvements, the project also includes the construction of two new bridges, one on each side of the sluiceway.

These upgrades will allow the dam to meet new regulatory requirements established by the Province of Ontario and provide increased protection for four major hydroelectric generating stations. By reinforcing the region’s critical water infrastructure, the Little Long Dam Safety Project will improve public and environmental safety while ensuring long-term resilience against potential large-scale flooding events.

Read more about the Little Long Dam Safety Project on Kiewit Newsroom.