High water at Canyon Ferry Reservoir is eroding the shoreline on Cemetery Island and Cave Point, prompting the Bureau of Reclamation to award $729,471 for bank stabilization work.
S&K Environmental of Arlee will probably begin hauling equipment to the sites this fall, but not do the actual stabilization work until the reservoir’s water level is at its lowest point next spring, according to Shawn Bryant, acting facility manager at Canyon Ferry for the Bureau of Reclamation.
“The contract just got awarded about a week and a half ago, so we haven’t had a preconstruction meeting with the contractor yet,” Bryant said. “But we’ll base part of the work on reservoir levels; it has to be low enough to get the toe of that stabilization in at the right elevation, and typically the lowest level is in March or April. But at the Cemetery Island site, they may want to stage the materials there this year.”
Bryant noted that high water in 2009, 2010 and 2011 raised the reservoir levels so much that water was in the flood pool for sustained periods of time. That accelerated the erosion of about 450 feet of shoreline on the east and northeast side of Cemetery Island, which is the closest point to where bodies are interred.
He anticipates the contractor will use barges to bring materials to the island.
“We’re using a bio-engineered approach there,” Bryant said. “There will be some rock riprapped to the shore and some pretty big logs placed in a configuration that helps stabilize it. But it will look fairly natural; we’ll also incorporate vegetation like willows and natural grasses.”
About 600 to 700 feet of shoreline on Cave Point, which is southeast of Kim’s Marina and home to a recently constructed picnic shelter, is being eaten away by waves and high water, he added.
“Because of the prevailing winds across the long stretch of the reservoir, the waves really hammered that point,” Bryant said. “One of the reasons for doing the stabilization is to protect that shelter.”
He said the work at Cave Point will be similar to what’s being done at Cemetery Island, with riprap at the lowest elevation, transitioning into engineered log jams and then vegetation.
“It’s a natural and sustainable approach,” Bryant added.
Reporter Eve Byron: 447-4076 or email@example.com
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