Dam Design and Construction

KRRC reports progress with removing JC Boyle Dam

KRRC reports progress with removing JC Boyle Dam
(photo courtesy KRRC)

Crews have broken through the cofferdam at the JC Boyle Dam site, returning the river to its historic path and restoring fish passage in that reach of the Klamath River.

JC Boyle Dam is one of the four dams, and the only one in Oregon, slated for removal as a part of the Klamath River Dam removal project.

The Lower Klamath Hydropower Project occupies about 400 acres of federal land administered by the U.S. Department of Interior, Bureau of Land Management. The four developments are: J.C. Boyle Dam, a 98 MW project with an earthfill dam built in 1958; Copco No. 1 Dam, a 20 MW project with a concrete dam built in 1918; Copco No. 2 Dam, a 27 MW project with a concrete dam built in 1925; and Iron Gate Dam, an 18 MW project with an earthfill dam built in 1962.

JC Boyle Dam was an earthfill dam with a concrete spillway. The earthen portion of the dam extended over the original path of the river, while the concrete portion was constructed outside the river’s path. The reservoir waters were drained in January. Since that time, construction crews used the cofferdam, a smaller dam built behind the larger dam during its construction in the 1950s, to route the river through the base of the spillway while the earthen portion of the dam was deconstructed. Crews finished removing the earthen portion, allowing them to break the cofferdam, restoring the river in that reach to a free-flowing state that will allow volitional fish passage.

“While there is still work to be done, today is a historic day for this reach of the Klamath River,” noted Mark Bransom, chief executive officer of the Klamath River Renewal Corporation (KRRC). “It was an honor to be able to witness this reach of river coming back to life alongside area Tribes. Each milestone brings the river into a healthier state.”

Crews will continue deconstructing the concrete spillway in the coming weeks, then they will restore the natural slope on the river’s left side and conclude construction activities related to JC Boyle Dam removal.

The removal of Copco No. 1, Iron Gate and JC Boyle dams are expected to be complete sometime this fall, in time for the fall run of chinook salmon. Copco No. 2 Dam was removed this past summer. The restoration of the former reservoir footprints is under way and will continue for several years until vegetation is successfully established and water clarity has returned to baseline conditions.

KRRC is a private, independent nonprofit 501(c)(3) organization formed in 2016 by 23 signatories of the amended Klamath Hydroelectric Settlement Agreement.