WSP07975

• File Number: 8278.100
• Description: Title I - Yuma Desalting Plant
• Basin: Colorado Mainstem
• Date: 10/1/1987
• Author: USDOI/BOR
• Title: Yuma Desalting Plant Operations Study - Draft Special Report
• Water Supply Pro - Doc Type: Publication

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stream replacement provided that the AAC is upgraded with
concrete lining and that additional water is made available for
use elsewhere in Southern California. The estimated cost of
conserving water is about $123 per acre-feet of water conserved.
The current plan call for the project to be 100 percent funded by
the Metropolitan Water District (MWD). The Federal Government
would purchase reject stream replacement water from MHD at a cost
of about $123 per acre-foot. This is the amount that will be
used in computing reject stream replacement costs when proposed
plans require reject stream replacement.

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Model studies with YDPSHORT.rOR approximate the case described
above with a YDP capacity of 66.7 Mgal/d and reject stream
replacement requirements of 38,400 acre-feet per year. Thus, a
YDP capacity of 66.7 Mgal/d and reject stream requirements of
38,400 acre-feet per year will be used as the base case in
comparing all plans. This base case would meet the salinity
differential requirements of the Minute when the salinity of the
Colorado River at Imperial Darn is 879 mg/L, the objective of the
Colorado River Water Quality Improvement Program (Title I and
Title II).

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Advantages:
.Plan A-I preserves the current Arizona and California
apportionment.
.Is politically acceptable.
.Satisfies the Minute.
"The salinity of the product is easily verifiable, and lower
salinity water delivered to Mexico creates environmental
benefits.
.Plan recovers about 70 percent of Wellton-Mohawk drainage water
at a suitable quality for delivery to Mexico and is acceptable
to local environmental and government interests.
.Operation of the YDP creates local jobs.
.Implementation is certain by early 1990's if continued funding
is adequate.

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Disadvantages:
.Costly to operate.
.Operation and maintenance (O&M) budget required for any future
year is difficult or impossible to predict with accuracy.
"While salinity of the product can be accurately verified and
river salinity can be accurately calculated, the current
salinity verifications are accomplished by sampling once per
day and may not accurately reflect the plant's effect on river
salinity.
.Model studies indicate YDP cannot meet Minute at salinities
approaching 650 mg/L.

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