Condit Dam on the lower White Salmon River will not reach its centennial.
That's because PacifiCorp, owner of the hydroelectric project, agreed to the terms proposed by federal regulators on June 13 in an order that allows the process for decommissioning the 98-year-old concrete dam to begin.
The Federal Energy Regulatory Commission completed its review of PacifiCorp's required dam removal design and mitigation plans, and approved them on June 8. FERC ordered the dam's removal back in December 2010.
Another key decision for reaching agreement on a settlement for license surrender and dam removal came when the U.S. Corps of Engineers issued PacifiCorp a sediment management permit. That, according to PacifiCorp, was "the final major regulatory step."
Bottom line: The 125-foot-high, 471-foot-long dam, located about 3.3 miles upstream from the mouth of the White Salmon River, is coming out starting this fall, almost 12 years after the signing a 1999 multi-party settlement agreement that called for the impoundment's removal.
"We have notified our contractors to move forward," said PacifiCorp program manager Todd Olson. "The project has been in the planning stages for more than a decade. These recent regulatory approvals enable us to now move forward with the commitment we made to the settlment parties to remove the dam as soon as feasible."
PacifiCorp estimates decommissioning of Condit Dam will cost about $32 million. That sum includes money already spent on planning as well as funds for the restoration work that will follow dam removal.
JR Merit Industrial Contractors, Inc., of Vancouver, is the contractor on the decommissioning project, and Kleinfelder, an international consulting engineering firm with an office in Portland, Ore., is providing engineering and construction support.
Decommissioning plans call for the contractor to breach the dam in October to release Northwestern lake through a manmade 13-foot-long hole near the base of the dam. To get the dam ready for that event, the contractor must excavate a 90-foot-long drain tunnel, dredge the upstream side of the dam at the drain tunnel, shore up the Klickitat County bridge that crosses Northwestern Lake and relocate a City of White Salmon water pipeline that's currently buried under the reservoir.
Following the initial breach and draining of the reservoir, the contractor will demolish the remaining portion of the dam, beginning next spring. That part of the project is expected to be completed by Aug. 31, 2012. Restoration of the drained reservoir and surrounding environs will be finished by the end of 2012.
PacifiCorp project manager Tom Hickey said the corporation plans to implement a public safety plan for the project area. "Safety for everyone involved is a key priority," he noted. "It will be important for people in the area to abide by closure signs and stay out of the project area" during the operation.