Water Diverted From Lake Tahoe Has Been Within Authorized Levels

Pursuant to a congressional request, GAO reviewed the management of water releases from the Lake Tahoe Dam to determine how release rates are established and to determine if such releases have met or exceeded the established rates during the last 10 years.

Essentially, releases from the Lake Tahoe Dam are regulated by court decree and monitored by a court-appointed water master. According to the water master, releases from Lake Tahoe are made only when flows in the river below the dam are not sufficient to meet the Floriston rates. When releases are made, they are the minimum required to meet these rates. By regulating releases in this manner, the water master ensures that the lake is maintained at its highest level. Records show that, during the past 10 years, releases from the lake have not resulted in improper reductions in its level; only water stored in the reservoir of the lake has been released. Water contained in the lake below its natural rim has not been withdrawn for downstream use since 1934. Although the level of the lake fell below its natural rim during the 1977 drought, no pumping was requested, and the lake has recovered from the effects of the drought. A Federal court recently authorized release of water in excess of the Floriston rates to preclude possible flooding of the shoreline. If the Floriston rates were not exceeded, it was projected that the lake would crest well above the maximum authorized.