Crews rehab Boundary Dam maintenance gate

May 06, 2011

The 312-ton gate used during maintenance of Boundary Dam's seven sluice gates is getting a little maintenance itself. The Seattle City Light project is costing about $1.2 million.

City Light workers recently started abrasive blasting to remove old paint and gunk that has accumulated on the gate since its last rehab in 1983. Next, workers will refinish the gate and replace its bearings and wheels.

The maintenance gate, which is 72 feet tall and 32 feet wide, is slid in front of a sluice gate to seal it off so that crews can work on the sluice gate.

Knight Construction of Deer Park last fall prepared the maintenance gate to move to the upper de-latch point on the dam face, which required underwater cleaning of a travel slot. Crews from Mill Creek-based McClure & Sons then floated the gate to a nearby recreation area and placed it onto a new concrete pad.

Associated Underwater Services of Spokane was on standby for support and safety during gate retrieval and the towing operation.

Fife-based Centennial Contractors built the pad as a subcontractor to Wm. Winkler Co. of Spokane. Garco Construction of Spokane erected a temporary steel building around the gate so that crews could work out of the weather.

Spokane Rock Products earlier this year won an award from the Inland Northwest Associated General Contractors for supplying concrete for the 320-cubic-yard pad.

The Spokane office of GeoEngineers performed geotechnical, special inspection and testing services on the slab.

Dan Dawson Construction of Ione performed site work and Clean Harbors Environmental Services will be removing hazardous materials.

The temporary building will be taken down this fall and McClure will move the gate back into position on the dam, where City Light crews will reinstall it.

A City Light spokesman said the temporary building will be relocated for reuse as storage for two projects next spring that will overhaul dam equipment.

City Light this week closed the dam's Forebay Recreation Area to camping until early August so it can safely work on the gate.

Boundary Dam, on the Pend Oreille River in northeast Washington, provides about 60 percent of City Light's power. 

Journal Staff of Daily Journal of Commerce

http://www.djc.com/news/co/12029077.html