Grand Coulee Riverbank Stabilization – Case History of the Design of Remedial Measures

Planned peaking operations at Grand Coulee Dam will cause river fluctuations of up to 1 feet daily for the authorized plant and up to 38 feet daily for a proposed plant expansion. Treatment of the historically unstable riverbanks was required to offset the destabilizing effect of the peaking operations. Consideration of the geologic history of the bank materials, estimation of future pore pressure conditions, formulation of the stabilization criteria, and the success in reducing pore pressure levels in varved clays in the bank were some of the important aspects of this project