Okanogan County site of ‘notable’ failures

OLYMPIA – Okanogan County has experienced several “notable” dam failures over the years, according to the state Department of Ecology.

-Loup Loup dam, near Malott, failed in April 1938. The 50-foot-high hydraulic fill dam failed when the emergency spillway was undercut during a flood.

The water destroyed 25 homes and left 75 people homeless. A half-mile of state highway also was destroyed.

-Sid White Dam, near Riverside, failed in May 1971. The earthen dam failed because of seepage through animal burrows. The water caused a second dam to fail and dumped debris into Riverside.

-Hawkins Dam, near Twisp, failed in August 2014 because of spillway erosion. The area burned during the Carlton Complex fire, then was hit with heavy rain.

Erosion in the spillway scoured a channel 360 feet long with an estimated volume of 6,600 cubic yards of debris.

Dams on three of the five irrigation impoundment lakes, known as Wenner Lakes, failed, contributing to the torrent of water rushing down Beaver Creek. Part of Highway 153 was washed away; homes and out-buildings in the area were damaged.

Okanogan County has 45 dams. Some fall under the state Department of Ecology’s jurisdiction; others – such as Grand Coulee and Chief Joseph - fall under federal authority.

The state rates dams by hazard class, with 1A being the highest (greater than 300 lives at risk) to 3 (low, with no lives at risk).

Grand Coulee Dam and associated impoundments are listed with Grant County. It has a hazard class of 1A.

As of the state’s latest dam inspections report, in 2016, other local dams include:

Ferry County

Hecla Groundwater Management Impoundment – stream not listed, 2E.

Hecla Day Mine Aspine Tailings – Granite Creek tributary, 2.

Hecla Day Mine Aspen Tailings Saddle – Granite Creek tributary, 2.

Kinross Gold Kettle River Reclamation Pond – North Fork San Poil River, 2.

Kinross Gold Kettle River Tailings – North Fork San Poil River, 1C.

Longeway – San Poil River tributary, 3.

Republic Sewage Lagoon No. 1 – San Poil River, 3.

Republic Sewage Lagoon No. 2 – San Poil River, 3.

Republic Sewage Lagoon No. 3 – San Poil River, 3.

Twin Lakes – Stranger Creek, 3.

Okanogan County

Aspen Lake - Methow River tributary, 3.

Beaver Lake - Beaver Creek, 3

Beth Lake - North Fork Beaver Creek, 2.

Blue Lake – Sinlahekin Creek, 3.

Bonaparte Lake – Bonaparte Creek, 3

Brown Lake – Johnson Creek tributary, 3.

Campbell Lake – Beaver Creek tributary, 3.

Chalfa – Benson Creek tributary, 2 (Wenner Lakes No. 3).

Chewack Canal Diversion – Chewuch River, 3.

Chief Joseph – Columbia River, 1A.

Conconully – Salmon Creek, 1A.

Conconully Sewage Lagoon No. 1 – Salmon Creek, 3.

Conconully Sewage Lagoon No. 2 – Salmon Creek, 3.

Conconully Sewage Lagoon No. 3, Salmon Creek, 3.

Crazy Rapids Reservoir - Okanogan River, 3.

Davis Lake – Bear Creek tributary, 3.

Doran’s – Methow River tributary, 3.

Enloe – Similkameen River, 1C.

Fancher’s – Antoine Creek, 1C.

Fish Lake – Coulee Creek, 3.

Horse Spring Coulee – Horse Spring Coulee, 3.

Indian Dan Canyon – Indian Dan Canyon Creek, 3.

Leader Lake – Tallant Creek tributary, 1B.

Leader Lake Saddle – Tallant Creek tributary, 1C.

Little Green Lake – Salmon Creek tributary, 2.

Milles Lake – Twisp River tributary, 2.

Moccasin Lake – Thompson Creek tributary, 2.

Owhi Lake – Little Nespelem Creek, 3.

Patterson Lake – Rader Creek, 1C.

Pearrygin Lake – Lake Creek, 3.

Rabel – Benson Creek tributary, 2 (Wenner Lakes No. 2).

Salmon Lake – Salmon Creek, 1A.

Sasse Reservoir – Okanogan River tributary, 3.

Schallow Lake – Coulee Creek, 3.

Sinlahekin No. 1 – Sinlahekin Creek, 1C.

Sinlahekin No. 2 – Sinlahekin Creek, 2.

Sinlahekin No. 3 – Sinlahekin Creek, 1C.

Spectacle Lake Dike – Okanogan River, 1B.

Stout Reservoir – Chiliwist Creek tributary, 2.

Sullivan Pond – Chewuch River tributary, 3.

Wenner Lake No. 5 – Benson Creek tributary, 3 (Wenner Lake No. 5).

Whitestone Lake – Okanogan River tributary, 3.

Wolley – Columbia River tributary, 3.

Wright Ponds-West Pond – Pearrygin Creek tributary, 3.

Zosel – Okanogan River, 2.


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