Book Description

The downstream portions of the spillway and regulating outlets and 720 ft of exit channel for Wynoochee Dam were reproduced in a 1:40-scale model to check performance of various elements of the project. Modifications to the left wall of the spillway chute did not provide satisfactory conditions for all discharges when equal quantities of flow passed through each gate. Acceptable flow conditions existed when the spillway design discharge of 52,500 cfs was reduced to 43,500 cfs (9,000 cfs through sluices) and the discharge ratio through the left bay was increased for spillway flows greater than 25,000 cfs. The left bay can be used to pass spillway discharges of 10,000 cfs and lower. Use of the right bay only will cause flow to impinge on the left bank. (Modified author abstract).