The makeover at Bluestone Dam has been a slow process – but the final part of the process is now underway.
Located on the scenic New River in southern West Virginia, the dam is a massive concrete structure built in the 1940s to reduce flooding across the state. It’s enjoyed a long history of success, preventing more than $6 billion in flood damages during its lifetime - but the ability of the dam to withstand a major storm was called into question in the late 1990s.
For 20 years the U.S. Army Corps of Engineers has worked to bring the dam up to modern safety standards as part of its Dam Safety Assurance project.
That has been accomplished through four “Phases” of work, including building a massive concrete thrust block to strengthen the dam, and stabilizing the dam with a unique system of over 500 rock anchors that are directionally drilled deep into the bedrock and help the dam resist the intense forces of extreme storm waters.
Now work has begun on the final “Phase” at Bluestone, which involves redesigning and strengthening the stilling basin. That’s the area just below the dam – it includes stone and large concrete baffles that removes the energy from the water before it continues downstream. Studies have shown that an intense storm might actually wash away the stone in that basin and cause erosion, undermining the dam.
Huntington District Commander Jason Evers said, “To keep that from happening, we’re going to use concrete to ‘armor’ the stilling basin. But the dam has to keep water moving while that’s happening, so we’re putting coffer dams in the middle of the basin – that way we can dewater half of the basin and do the work while the other half continues to keep the river flowing.”
The work was made possible because in 2018, the Congress passed the Bipartisan Budget Act which appropriated $17 Billion to the U.S Army Corps of Engineers for infrastructure projects. That included all the funds required for the Huntington District to complete this phase of work.
The District was challenged to take this unprecedented opportunity to “Move Dirt” and make sure projects like this one was implemented quickly.
Senior project manager Aaron Smith said, “The team at Bluestone Dam took that challenge to heart and advanced the start of the primary spillway work by over four years. In the past year alone, the Corps has awarded five contracts to start this work. We can see significant progress already, as installation is underway of a $22 million temporary coffer dam by Brayman Construction. The goal is to have this coffer dam in place so we’re ready to begin the stilling basin modifications next year.”
The coffer dam will form a concrete dividing wall that will divide the basin – one side will continue normal water flow while the other side is lined with concrete and larger concrete baffles will be constructed. Once one side is finished (including the installation of a permanent dividing wall, allowing easy dewatering of the area for future inspections), the process will be reversed.
When completed, the dam will be able to handle all but the most catastrophic weather event - and will continue doing the job it has done so well for the past 70 years - protecting the residents who live downriver from its towering walls.