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WOODARD
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<br /> Table 11: SCWSP Supply Available to the City Under Normal and Dry Year Conditions
<br /> Estimated Supply(AFY
<br /> 2020 2025 2030 2035 2040
<br /> Contracted Phase I Allotment 6,887 6,887 6,887 -- --
<br /> Contracted Phase 11 Allotment -- -- -- 10,671 10,671
<br /> Normal Year
<br /> Projected SCWSP Allocation 98% 99% 100% 100% 100%
<br /> Projected SCWSP Supply 6,760 6,811 6,863 10,671 10,671
<br /> Single-Dry Year
<br /> Projected SCWSP Allocation 74% 74% 75% 75% 75%
<br /> Projected SCWSP Supply 5,070 5,108 5,147 8,037 8,037
<br /> Multiple-Dry Year-First Year
<br /> Projected SCWSP Allocation 85% 86% 86% 87% 87%
<br /> Projected SCWSP Supply 5,858 5,903 5,948 9,287 9,287
<br /> Multiple-Dry Year-Second Year
<br /> Projected SCWSP Allocation 88% 88% 89% 90% 90%
<br /> Projected SCWSP Supply 6,027 6,073 6,119 9,555 9,555
<br /> Multiple-Dry Year-Third Year
<br /> Projected SCWSP Allocation 83% 83% 84% 85% 85%
<br /> Projected SCWSP Supply 5,694 5,737 5,781 9,026 9,026
<br /> Source:City of Lathrop 2019 WSMP,Table 5-7(EKI,2019)
<br /> 2.3.1.1 Potential Future Requirements of the Bay-Delta Plan
<br /> The future reliability of the City's full SCWSP allocation is uncertain due to ongoing planning efforts by the SWRCB.
<br /> On December 12, 2018, the SWRCB adopted revisions to the Water Quality Control Plan for the San Francisco
<br /> Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan). The adopted changes include increasing flows on the
<br /> San Joaquin River and its tributaries, including the Stanislaus River, starting at 40 percent of unimpaired flow from
<br /> February to June, with a range of 30 to 50 percent depending on biological conditions. The SWRCB also approved a
<br /> framework for accepting voluntary agreements to pursue a combination of flow and"non-flow" measures that improve
<br /> conditions for fish and wildlife where allowances for reduced river flows may be developed.
<br /> Historical median February through June flows from 1984 to 2009 in the Stanislaus River were approximately 40
<br /> percent of unimpaired flows,meaning that flows were below the starting goal of 40 percent in half of the years between
<br /> 1984 and 2009. Based on preliminary estimates made by SSJID(2016),the 40 percent unimpaired flows criteria would
<br /> increase the SCWSP supply shortfall in a single-dry year from 25 to 36 percent(11 percent increase), and from 16 to
<br /> 29 percent(13 percent increase)during the third consecutive year of multiple-dry years by 2040(EKI,2019).10 Potential
<br /> supply impacts have significant uncertainty and will be updated in the City of Lathrop 2020 UWMP based on information
<br /> provided by SSJID and others. At this time, it is uncertain how these new flow criteria and potential voluntary
<br /> agreements would directly affect SCWSP supplies and the frequency of shortfalls. Given current uncertainties, these
<br /> 10 Based on information presented by OID and SSJID,combined OID and SSJID formula water available under 40%unimpaired flow criteria
<br /> will be 381,000 AFY during 1976-1977,and 422,000 AFY during 2015-2016.These values were used for the basis of a single-dry year and
<br /> the third consecutive year of multiple-dry years,respectively.The SCWSP projected supplies are calculated as 50%of combined OID and
<br /> SSJID formula water available,similar to what was assumed in SSJID's 2015 UWMP.
<br /> Califia(0011533.00) 27 Woodard&Curran, Inc.
<br /> River Islands Phase 2 Development Water Supply Assessment September 2020
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