The proposed reservoir will provide many benefits to farmers, residents and businesses within the Kaweah/St Johns region. The benefits are detailed here.
In general, the reservoir will store Kaweah River water belonging to or accessible by the owners in accordance with their long-held water rights. The ability of the reservoir to carry out its intended functions described below is in no way dependent on utilization of any others’ water supplies within the Kaweah Basin.
The reservoir is envisioned to utilize both existing and new water control structures that will allow the diversion of up to 500 cubic feet per second from the Kaweah River. The existing McKay Point check structures will regulate flow in the river and new gated structures and spill ways will control the diversions into the reservoir. With 4,000 acre-feet of total capacity, the reservoir could go from empty to full in just 4 days. Most of our peak rain flood events are of relatively short duration, so the new reservoir will provide an immediately available place to capture floodwaters. Diverting the water may help prevent a rain flood event from overwhelming creeks and channels around Visalia. Water would be returned to the Lower Kaweah and the St. Johns rivers when it is safe and beneficial to do so through new gravity water control structures and/or pumping plants.
More efficient capture and distribution of water
The new reservoir will allow for “re-regulation” of water, which means the more effective capture and distribution of water, thereby providing water to farmers when they need it most.
Currently, during times of flood release from Terminus Dam, water that is not needed immediately for irrigation must be diverted to groundwater recharge basins so that it doesn’t flood and damage valuable farmland. Later, when it is needed for irrigation, the water must be recovered from the groundwater via individual growers’ groundwater wells. This process requires significant energy use and generates no income to offset the costs of effective water distribution. There are times, too, when these flood releases exceed recharge capacity, which means a valuable local water supply escapes the Kaweah Basin area and its underlying groundwater aquifers.
The new reservoir will provide a place to temporarily put flood water until it can be delivered to growers, thereby addressing the needs of both farmers and the project owners for surface water and its benefits.
The hydroelectric generators at the Terminus Reservoir outlets at Lake Kaweah will be able to produce more power and more power during times of peak demand once the McKay Point Reservoir is available.
This will help deliver clean energy when it is most needed. The resulting revenue will support the maintenance of the new reservoir and other projects as needed to deliver irrigation water for the region’s agriculture industry.
The new reservoir will allow for water releases to be decreased during off-peak times of the day and increased during on-peak times. The reservoir will balance the total amount of water needed by downstream water users.
More storage yields more water
During wet years, floodwater from the Kaweah River, Dry Creek and Yokohl Creek typically floods farmland and/or is diverted by pumps into the Friant-Kern Canal for disposal in the Kern River (assuming the Kern has available capacity) near Bakersfield. The McKay Point Reservoir will capture some of this floodwater and hold it until it can be safely released back into the Kaweah and St. Johns rivers. It is envisioned that the reservoir could fill and empty multiple times during certain wet years.