Item 28 - Urban Water Management Plan and Water Shortage Contingency Plan

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Santa Ana 2020 Urban Water Management Plan arcadis.com 7-17 DWR Submittal Table 7-5: Five-Year Drought Risk Assessment Tables to address Water Code Section 10635(b) Surplus/Shortfall w/o WSCP Action 0 Planned WSCP Actions (use reduction and supply augmentation) WSCP - supply augmentation benefit 0 WSCP - use reduction savings benefit 0 Revised Surplus/(shortfall)0 Resulting % Use Reduction from WSCP action 0% Note: Groundwater is sustainably managed through the BPP and robust management measures (Section 6.3.4 and Appendix G), direct and indirect recycled water uses provide additional local supply (Section 6.6), and based on MET’s UWMP, imported water is available to close any potable water supply gap that local sources cannot meet (Section 7.5.1). 7.5.3 Water Source Reliability Locally, approximately 77% (BPP for Water Year 2021-22) of the City’s total water supply can rely on OC Basin groundwater through FY 2024-25. The BPP is projected to increase to 85% starting in FY 2024-25. Based on various storage thresholds and hydrologic conditions, OCWD, who manages the OC Basin, has numerous management measures that can be taken, such as adjusting the BPP or seeking additional supplies to refill the basin, to ensure the reliability of the Basin. For more information on the OC Basin’s management efforts, refer to Section 6.3. Additionally, the City’s use of direct (OCWD GAP) and indirect recycled water (OCWD GWRS) should also be considered. The ability to continue producing water locally greatly improves the City’s water reliability. More detail on these programs is available in Section 6.6 . Furthermore, as discussed in Section 6.2 the City has a 10-year purchase agreement with MET that sets a minimum and maximum volume of water to be purchased from MET annually, and over the 10-year contract term. Currently, the City is not currently purchasing near the maximum levels. As so, the City is contractually able to purchase significantly more MET water should the need arise. Moreover, although they would not normally be considered part of the City’s water portfolio, the emergency interconnections the City has with the surrounding Cities of Costa Mesa, Fountain Valley, Garden Grove, Orange, Tustin, and Southern California Water Company could help mitigate any water supply shortages, though shortages are not expected. Emergency interconnections are described in Section 6.8. The City’s DRA concludes that its water supplies meet total water demand, assuming a five-year consecutive drought from FY 2020-21 through FY 2024-25 (Table 7-5). For simplicity, the table shows supply to balance the modeled demand in the table. However, based on the purchase agreement the City