USACE CWMS - Tulare Lakebed Watershed

The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin:
- GeoHMS (Geospatial Hydrologic Modeling Extension)
- ResSIM (Reservoir System Simulation)
- RAS (River Analysis System)
- FIA (Flood Impact Analysis)

The natural river and stream channels have been modified
extensively over the years for irrigation, water supply, flood control, recreation, power production, and
other purposes. Four flood control dams have been built on the major rivers leading to Tulare Lake;
Isabella and Pine Flat Dams were built in the early 1950's, Success and Terminus Dams in the early
1960's. Isabella Lake, Pine Flat Lake, Success Lake, and Lake Kaweah (formed by Terminus Dam)
together provide nearly 2 million acre-feet of water storage for the southern San Joaquin Valley. The
remaining rivers, streams, and creeks located in the basin have minor or no storage facilities along their
channel, however there is an extensive irrigation and flood control diversion and canal system throughout
the basin. Pine Flat and Isabella Lake are both reservoirs filled mainly by snowmelt, and Lake Kaweah
and Success Lake both received their runoff mainly from rainfall.
The Tulare Lakebed area has an extensive levee and diversion system designed to manage irrigation
flows and minor flood flows from the four projects and the surrounding uncontrolled drainage area. These
levees are designed to confine floodwaters to the smallest practicable area. However, large amounts of
uncontrolled runoff may cause damage in the Tulare Lakebed area, even when they are less than the
maximum flows the rivers are designed to handle. The magnitude of flows may exceed the diversion
system capacity and damage land protected by the levee system or adjacent areas. Two basins
(Hacienda and South Wilber) at the south end of Tulare Lakebed have been reserved for flood control
storage. The total storage capacity of these two basins is 37,000 acre-feet. Canal flows can either be
pumped into the storage basins or allowed to enter by gravity flow.