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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order). The MPI is a full service system that allows for significantly greater user flexibility (full
ending flows) and increased operational manageability of the gravity-flow distribution system."
The MPI concept automates the laterals within each system with drop leaf gates to pass full
ending flows. These remaining sixteen interceptor projects are estimated to conserve 102,595
and 54,050 acre-feet of water annually for MPIs and LFIs, respectively. This value is the
quantity of operational discharge and end flows that would be captured from the laterals within
the interceptor systems. (Additional Lateral InterceDtor Systems: Implementation Priority Stuc!y,
CH2M HILL, 11/93)

It is anticipated that it would take eight years to construct these systems. While these systems
would take existing farmland out of production, they would allow the water users the flexibility
of turning back water orders if their irrigation is completed before their gate is scheduled to be
closed. District operating rules would need to be modified to allow for the water users to turn
back water, and the conditions for this procedure would need to be defined. There is also the
possibility that additional zanjeros would be needed to adjust gates to accept these flows.

IV.A.5 Additional Irrigation Flexibility
Irrigation flexibility allows the water user to order and receive water in varying time increments
(run-times) instead of the traditional 24-hour flows. The nD/MWD conservation program served
as the impetus for the implementation of a 12-hour delivery project for all District customers,
allowing them twice the flexibility of standard deliveries. In 1995, this project was credited with
26,000 acre-feet of water conserved through reductions in deliveries, and represented savings
from a wide variety of irrigation methods including drip, flat, gated pipe and row, and sprinkler
and pump. Additional flexibility in the duration of a delivery conserves water through decreases
in orders, as water users are better able to order quantities of water that more closely match their
demand. This water savings may also been seen through decreases in tail water as excess water
orders are eliminated or reduced.

The 26,000 acre-foot conservation estimate for 12-hour deliveries in 1995 includes a deduction
that was applied due to increased lateral spillage resulting from the starting and stopping of 12-

Draft: Subject To Revision 12/21/95

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