Conveyance Canal Improvement Plan
South Sutter Water District has proposed to improve its conveyance canal to improve water use efficiency in the District and to conjunctively manage its water resources for maximum benefit. This process involves three phases, which are discussed below.
Conveyance Canal Improvement Plan
SSWD’s existing main conveyance canal is approximately 21.6 miles in length and is designed to divert +410 cubic feet per second (cfs). The canal delivers water to eight principle lateral channels extending in a westerly direction so as to service nearly all the lands within SSWD by gravity. The size of the main canal is gradually reduced through the system to a capacity of 50 cfs at the terminus near Pleasant Grove Creek.
SSWD’s Conveyance Canal Improvement Plan involves improvements to existing canal structures for the purpose of increasing the system capacity by approximately 23 percent (up to a total peak diversion of 505 cfs). The additional water for conveyance will be obtained from increases in diversion of stored water and water that is spilled from Camp Far West Reservoir.
The plan will involve three phases described below, which build upon the water rights settlement described above. Work on the project will progress down the existing conveyance canal: Phase I starts at the diversion dam and ends at the siphon under High 65 and the railroad, Phase II is the siphon replacement, and Phase III involves improving conveyance in laterals and canals on the downstream side of the siphon. In greater detail:
- Phase I – complete in Spring of 2003, Phase 1 involved the removal and replacement of large-diameter double corrugated metal culvert pipes along the existing Conveyance Canal (including earthwork, concrete inlet and outlet transition structures), stone protection, and surface restoration. Work also included installation of an automatic slide gate check structure, removal of existing pipes, replacement of concrete abutments at various structures, and construction of a reinforced concrete pipe overflow for the existing Van Jop Hydroelectric Plant. The total cost for this phase was approximately $900,000.
- Phase II – An additional siphon pipe will be installed adjacent to the existing siphon at Highway 65, effectively doubling the capacity to move water in the canal under Highway 65 and the railroad. Phase II is estimated to cost $700,000 and construction is expected to begin in 2004.
- Phase III – The lateral canals and ditches, stemming from the main conveyance canal, will be enlarged and enhanced to provide additional flexibility and reliability throughout SSWD. An early cost estimate for Phase III totals $1.5 million.
The estimated total project cost is $3.1 million.
Improving SSWD’s Conveyance Canal would:
- Increase the flexibility, timing, and reliability of surface water supplies for SSWD.
- Replenish groundwater supplies for extraction in drier years.
- Recharge the groundwater basin to reduce the effect of declining groundwater levels.
- Provide the ability to meet additional water needs (including CALFED targeted benefits and other environmental objectives) outside of SSWD.
- Replace older conveyance structures currently in need of repair with advanced canal control technology, which will allow for increased flexibility of SSWD’s system.
- Enhance SSWD’s conjunctive water management activities.
- Reduce the need for cropping changes during drier water years.
- Increased power generation from hydroelectric generation/decreased usage for pumping.
- Increase water use efficiency by installing state-of-the-art water control and measurement structures that improve the accuracy and timing of flows through the system.