WSP12980

• File Number: 8210.140.20.C
• Description: Imperial Irrigation District ‎(IID)‎
• State: CA
• Basin: Colorado Mainstem
• Date: 1/9/1996
• Author: Imperial Irrigation District
• Title: Water Requirements and Availability Sutdy ‎(draft)‎
• Water Supply Pro - Doc Type: Publication

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an accurate conservation potential and cost estimate to additional EHL lining. Thus, for the
purposes of this study, no conservation potential has been assigned to concrete lining the EHL.

The 1984 USBR report concluded that soils along the Central Main and Rositas Supply Canals
had such low seepage rates that further consideration for concrete lining was not warranted.
Similarly, while the 1984 USBR report estimated that lining of the Westside Main Canal (WSM)
could conserve approximately 9,000 acre-feet of water annually, seepage studies conducted
during the IIDIMWD water conservation program indicated savings of only one-third of that
amount. Likewise, seepage tests of the Vail Supply Canal indicated that concrete lining would
not result in any significant water savings.

IV.A.3 Additional Reservoirs
Within the IID, reservoirs are classified according to the function they serve. One function is to
reduce main canal fluctuations by absorbing surplus flows and buffering shortages to keep
downstream water users on order. The second function is to provide additional storage capacity
within the system for future use and to increase operating flexibility.

The focus of this Chapter is to evaluate the conservation potential of additional reservoirs.
Preliminary estimated conservation potentials are presented for the potential addition of two new
reservoirs along the All-American Canal (storage capacities ranging from 3,000 to 8,000 acre-
feet) and the possible addition of reservoirs on-farm and adjacent to or in-line with laterals with
capacities of approximately 10 and 30 acre-feet respectively.

IV.A.3a Existing Regulating Reservoirs
The District currently operates six regulating reservoirs as a part of its ongoing water
conservation program. These reservoirs receive and store surplus water that would have been
lost as operational discharge. Existing reservoir capacities range from 300 to 476 acre-feet. In
total, the District's regulating reservoirs currently have a storage capacity of nearly 2,400 acre-
feet (see Table IV.A.3a-l). Reservoirs contribute to water conservation by allowing for
increased irrigation and operational efficiency. Regulating reservoirs accept and release surplus

Draft: Subject To Revision 12/21/95

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