Auburn-Black Diamond Road Emergency Repairs
King County, WA

KPG prepared final plans, specifications, and estimates for a 1,600-ft storm bypass pipe and stabilization of two major slope failures along Big Soos Creek. These projects were undertaken to reduce regional ground movements which required closure of Auburn-Black Diamond Road during the Winter of 1997.

The storm bypass alignment utilized 30-inch to 42-inch buried HDPE pipe with unrestrained sleeves to allow for future ground movements. Lack of vehicle access and permit sensitivities to salmon species in Big Soos Creek required boulders to stabilize the failed slope from further intrusion by Big Soos Creek.