Plugging Leaks with Concrete and Plastic

摘要

Increasing leakage at Pacific Gas and Electric Company's Strawberry Dam signaled a dilemma with the 1916-vintage structure ― a dilemma that likely faces, or will face, a growing number of dam owners and operators owing to the aging of dams across North America. PG&E's approach provides a textbook solution to such problems, though the utility encountered a good deal more work than it had expected. Leakage through the dam (primarily through the structure's nine expansion joints) is measured at a toe weir. From 1969 through 1986, leakage averaged about 6 cubic feet per second (cfs) with a full reservoir. In 1987, the leakage rate jumped to about 13 cfs and continued to progressively increase to a maximum of about 21 cfs by 1998.