Mud Mountain Dam Sedimentation Survey (WA)
A sedimentation survey that began in 1946 established 64 cross-sections, including seven ranges for tributaries that are below the maximum pool elevation of 1215 feet NGVD29. Surveying for approximately 25 of these ranges was conducted on a regular basis until 1986. WEST Consultants, Inc. conducted a ground survey for these 25 ranges, obtaining cross-section data between valley walls to determine sediment aggradation or degradation for each location.

New monuments at the cross-section end points were installed at the edge of the valley wall, replacing the original monuments situated above the maximum pool. WEST then provided a stream profile, obtaining Thalweg elevations at each range and at changes in slope of the stream bottom.