Army Corps of Engineers commence work to reduce flood risks in Conconully

Seattle District, USACE
Published Oct. 17, 2022
Photo of a man operating a bulldozer extracting dirt from Salmon Creek, a creek in the town of Conconully, in Okanogan County, in Washington State.

Contractors remove sediment that has inundated Salmon Creek and the town of Conconully, Okanogan County, Washington, during the July 4, 2022, flash flood. Approximately 3,500 cubic yards have been removed and has consequently increased the channel capacity up to six feet in certain reaches of the creek.

A group of people holding buckets and wearing tall rubber boots and other protective gear, wade in the de-watered Salmon Creek, to rescue stranded fish.

Representatives from the town of Conconully, Okanogan County, State of Washington Parks Department, Colville Confederated Tribes, and U.S. Army Corps of Engineers, Seattle District scout Salmon Creek to rescue and relocate stranded fish, after the creek was de-watered ahead of construction work. Over 20 participants from the local community, State, Tribal and Federal agencies rescued more than 100 fish.

U.S. Army Corps of Engineers’ officials are gearing up and mobilizing equipment this week in response to a direct assistance request to mitigate risks to life safety and safeguard public infrastructure in Conconully, Washington.

The area became more vulnerable to flash flooding after the 2021 Muckamuck wildfire burned about 13,750 acres northwest of the town, increasing flood risk due to additional runoff that occurs over post-wildfire burn scars.

On July 4, 2022, a flash flood clogged the north fork of Salmon Creek with ash, sediment and woody debris, forcing flood waters and debris to jump the creek banks into the Town of Conconully, impacting homes and businesses.

Given the increased likelihood of imminent flooding in the Muckamuck watershed, the Governor of Washington requested the Corps provide direct assistance to protect the Town of Conconully and its public infrastructure.

The $639,500 federally funded project increases Salmon Creek channel capacity by reconnecting existing side channels and floodplains.  The project includes removing sediment and debris as well as installing debris catch structures to reduce large debris-flow impacts downstream in town.

Channel capacity through Conconully will be increased by removing previous depositions and debris out from underneath bridges.  In addition to reducing flood risk to the town of Conconully, the project will reestablish lost habitat for native species in the creek.

Construction will take place at five sites, both upstream of and in town, and is expected to be complete by early November.

Throughout the planning process, the Corps directly coordinated with the Town of Conconully, Okanogan County, Washington Emergency Management Division and the Colville Tribe in addition to several other interested agencies and stakeholders to develop a plan to mitigate flood risks to Conconully.

Scott Lawrence

Release no. 22-016