Alternate solution saves time and money

December 22, 2021 | Kieways 2021 Q4

The Little Long Dam Safety project is setting the stage for the next decade of hydro-electric infrastructure development in Canada, and Peter Kiewit Sons ULC is leading the project as both engineer and contractor.

Located approximately 70 kilometers (43 miles) northeast of Kapuskasing, Ontario, Little Long Dam serves as a crucial passageway, managing the flow of water until it reaches the Arctic Ocean. The client, Ontario Power Generation (OPG), undertook the project to meet new regulatory requirements established by the Province of Ontario and to protect its four major hydro-electric generating stations in the event of large-scale flooding in the area.

This part of northeast Ontario experiences massive amounts of water flowing through the Mattagami River in April and July due to freshet (a thaw resulting from melting snow or ice).

Upon completion, the Little Long Main Dam will have the capacity to discharge total flow of 8,680 cubic meters of water per second or three times the amount of
Niagara Falls.

This project will significantly improve safety — public safety, environmental safety and the safety of OPG’s critical hydro-electric assets.

“If the integrity of the dam became compromised, it could pose a risk to the local communities,” said Kiewit Project Manager Simon Gagne.

Engineering solution

To take preventive action, OPG set out to rehab existing infrastructure and increase discharge capacity from Adams Creek to a bypass channel that would protect its four Lower Mattagami River hydro-electric stations — Little Long, Smoky Falls, Harmon and Kipling. To achieve this, the original plan was to expand capacity by constructing a separate new four-gate spillway adjacent to the existing eight-gate spillway, thereby increasing the spill capacity by 50%. However, when Kiewit became involved, they proposed an alternate solution: integrate construction of the four additional gates into the existing spillway structure, which was deemed to be more efficient, and of lower risk than constructing a new stand-alone structure.

“Kiewit’s proposal and engineering efforts optimized the construction arrangement, shortened the project schedule, and minimized the project cost,” said Pranav Jindal, OPG senior manager for northeast major projects.

Building four additional gates in the existing Adam Creek sluiceway structure simplified the work in many ways. With the new concept, Kiewit was able to keep the spillway in full operation during most of the construction, as well as reduce the footprint of construction operations. Using the existing structure also minimized disturbances to the dyke core.

“OPG ultimately decided to go with this approach because it demonstrated the best value,” Jindal said.

The project will sequentially put gates in service from January 2022 to September 2023 and is planned to be completed by September 2023.

Community impact

The Little Long Dam Safety project has provided significant opportunities to local First Nation communities to engage on the project. This included input on environmental related activities, as well as new employment and business contract opportunities.

The estimate of contracts awarded to Indigenous businesses is about $42 million. Additionally, 57 Indigenous community members are employed on the project, making a positive impact on the community.

“Kiewit maintains a solid reputation as being a contractor that partners with and works to train Indigenous employees. We’re very proud of that,” said Gagne.

The COVID-19 pandemic has presented an added challenge on the project, considering that this is a camp job where all workers live in the same space. The project team has been very proactive in implementing safety measures to mitigate any potential spread of COVID-19.

These protocols have ensured that this essential project could continue operations and stay on schedule while working around the natural weather cycle of the region.

Looking ahead

With the increasing amount of aging hydro-infrastructure across North America, projects like Little Long Dam appear to be an indicator of what’s to come in the future. Rehabilitating hydro-structures and upgrading existing capabilities will spur a renewable energy transition.

Kiewit’s work on Little Long Dam illustrates how these complex projects require not only the manpower to construct, but also the brainpower to propose engineering innovations that propel projects forward, ultimately ensuring that they enable efficient energy delivery when it’s needed most.

A key factor that makes these solutions and project execution possible is a collaborative relationship between owner and contractor. “OPG continues to have a very healthy and open relationship with Kiewit throughout this project. We see us as #ONETEAM striving for a common goal,” says Jindal.

And according to Gagne, in the end, “a successful flagship project like Little Long Dam Safety will definitely help demonstrate to the industry what Kiewit is capable of.”


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