November rain slowed the reopening of the Patterson Creek Bridge on Duthie Hill Road, the King County Department of Transportation announced Tuesday afternoon that the bridge is open to traffic.
The bridge, which had been closed for replacement since August, but King County pushed back the reopening until Nov. 20.
The King County Road Services Division began construction Aug. 16 to replace the more than 60-year-old Patterson Creek Bridge.
The bridge, located between Sammamish and Fall City, was built in 1951 and its creosote-treated timber supports were decaying. The replacement bridge will increase safety and improve traffic flow for the more than 5,200 vehicles that use the road daily, the county said. The old bridge was 24 feet wide with narrow shoulders, and the new bridge is 38 feet wide with two 11-foot-wide traffic lanes and 8-foot-wide shoulders.
The bridge is over Patterson Creek, which flows through a deep, flat, depositional channel at the project location. The banks of the ditched channel are high, steep, and covered with reed canarygrass, nightshade, and blackberry. The slow, deep, cool waters and abundant cover from undercut banks and overhanging vegetation provide important rearing and refuge habitat for five species of salmonid fishes: coho salmon, Chinook salmon, cutthroat trout, and rainbow/steelhead trout. These fishes also use the mainstem creek as a migration corridor to spawning and rearing habitat in tributaries such as Canyon Creek and Tributary 07.0377, and the Snoqualmie River.