Water Resources Collections and Archives

Ritchie Creek drains 2.6 square miles before joining the Napa River north of Bale, California. A six- foot high dam was built in 1912 on Ritchie Creek to facilitate water development. The dam interfered with steelhead trout migration upstream to potential spawning habitats and was removed in 1993. Ten years after dam removal, we resurveyed four cross sections and compared them with the cross sections taken in the same location in 1993 just prior to dam removal. Our survey documented sediment erosion of 679 cubic yards upstream of the dam site, which is less than the probable yearly sediment yield for the watershed basin. Our survey also showed slight sediment aggradation of 99 cubic yards downstream of the dam site. In addition we surveyed a longitudinal profile of 1,162 feet in length and two additional cross sections at restoration sites.