water year. This helps alleviate issues associated with how supply capability is presented to fulfill requirements of the UWMP Act versus how supplies might be accounted for to demonstrate consistency with WR P1. Since WR P1 considers Water Use Efficiency (WUE) savings as a source of water supply, water suppliers such as IRWD need to explicitly calculate and report WUE savings separately from service area demands to accurately reflect normal water year demands (as required in the calculation of reduced Delta reliance). To prevent overestimating the effect of WUE savings on regional self-reliance, Guidebook Appendix C methods indicate that WUE savings must then be added back to the normal year demands to represent demands without WUE savings. Table B-1 shows the results of these calculations for IRWD service area demands. Supporting narratives and documentation for the data shown in Table B-1 are provided below.
Table B-1: Calculation of Water Use Efficiency
Service Area WUE Demands (Acre-Feet)
Baseline (2010)
2015
2020
2025
2030
2035
2040
2045
Service Area Water Demands with WUE Accounted For Non-Potable Water Demands 1 Potable Service Area Demands with WUE Accounted For
116,710 101,972 96,445
96,556
86,875
87,471
88,013
88,042
26,203
37,335
25,359
29,478
33,758
33,762
33,812
33,758
90,507
64,637
71,086
67,078
53,116
53,709
54,201
54,284
Total Service Area Population
Baseline (2010)
2015
2020
2025
2030
2035
2040
2045
Service Area Population
336,876 381,463 418,163 450,323 464,444 466,475 468,404 471,202
WUE Since Baseline (Acre-Feet) Per Capita Water Use (GPCD) Change in Per Capita Water Use from Baseline (GPCD) Estimated WUE Since Baseline
Baseline (2010)
2015
2020
2025
2030
2035
2040
2045
240
151
152
133
102
103
103
103
(89)
(88)
(107)
(138)
(137)
(137)
(137)
37,849 72,311 * Non-potable water demands include only recycled water. Additional data for non-potable (raw, untreated) water use projections were unavailable in some previous UWMP tables. To prevent confusion only recycled water values were used. Recycled water is produced to meet 41,260 53,909 71,664 71,617 71,643
Appendix B - 6
IRWD – 2025 Urban Water Management Plan – Reduced Delta Reliance
Powered by FlippingBook