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5.18 Water Resources

AVEK operates four water treatment plants (WTPs). The Quartz Hill WTP is capable of
producing 90 million gallons per day (mgd) or 270 acre-feet per day (afd) of treated
Aqueduct water. The Eastside WTP is capable of producing 10 mgd (30 afd). The Rosamond
WTP can produce 14 mgd (42 afd), and the Acton WTP can produce 4 mgd (12 afd) of treated
water. AVEK does not provide supplemental treatment for recycled water and does not
distribute recycled water. The bulk of AVEK’s imported water is treated and distributed by
water purveyors to customers throughout the Agency’s service area. AVEK also provides
untreated SWP water to local farmers and ranchers. All of the Project land, and more than
38,000 acres of land owned by TRC, are located within AVEK’s jurisdictional boundaries and
have been subject to AVEK assessments for several decades.

Consistent with California Water Code requirements, the 2015 UWMP provides population
growth, water supply, and water demand projections through 2035 for AVEK. The analysis
anticipates that the Agency’s service area population will be 460,700, an increase of
approximately 101,200 from 2015 (AVEK 2016). The 2015 UWMP estimates that AVEK’s
2035 average year water supplies will be 89,010 afy, including 85,460 afy of SWP deliveries
and 3,550 afy of groundwater produced in accordance with the Judgment and Physical
Solution. AVEK’s 2035 average year demand is estimated to be 86,250 afy, resulting in an
average year surplus supply of approximately 2,760 acre-feet by 2035. The 2015 UWMP
anticipates that AVEK’s SWP deliveries, groundwater, and recovered banked water supplies
will be less than demand during dry and multiple-dry years. The single-dry year shortfall in
2035 is estimated to be 39,500 acre-feet, and the maximum multiple-dry year period
shortfall is estimated to be 29,300 acre-feet (AVEK 2016). Since AVEK provides a
supplemental water supply to retail agencies, the UWMP anticipates that the supply
difference in single-dry and multiple-dry years will be met by increased groundwater
pumping (recovery of banked supplies or return flows), use of recycled water, and/or
reductions in demand by the retail agencies and other Agency customers, such as the Project.
As discussed below, the Project will be served by two water banks and will generate and use
recycled water in a manner that will ensure single-dry and multiple-dry year water supply
reliability in the Project area consistent with the Agency’s UWMP.

2013 Antelope Valley Integrated Regional Water Management Plan

An integrated regional water management planning process has been conducted for several
years in the Antelope Valley, and an integrated plan was first published in 2007 by an
11-member regional water management group. The AVIRWMP was most recently updated
in 2013 and provides an analysis of average year, single-dry year, and multiple-dry year
regional supply and demand conditions through 2035 (RWMG 2013). The AVIRWMP
projections assume that the region’s population will increase by about 157,000 residents
from 2010 to 2035. Table 5.18-1 summarizes the population growth estimates used in the
AVIRWMP projections.

R:\Projects\PAS\CEN\000306\Draft EIR\5.18 Water Resources-051117.docx 5.18-30 Centennial Project
Draft EIR