55B - RESO - CIVIC CENTER WATER SUPPLY

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CITY OF SANTA ANA CIVIC CENTER FACILITIES STRATEGIC PLAN WATER SUPPLY ASSESSMENT This preferred resource mix includes conservation, local resources such as water recycling and groundwater recovery, Colorado River supplies and transfers, SWP supplies and transfers, in- region surface reservoir storage, in- region groundwater storage, out -of- region banking, treatment, conveyance and infrastructure improvements. There are various factors that may impact reliability of supplies such as environmental, legal, imported water quality, groundwater water quality, and climate change. These factors are discussed in Section 3.6 .2 of the City's UWMR The City's UWMP provides a description of water supply reliability and vulnerability to seasonal or climatic shortage. The City's ability to meet supply demands is contingent upon its ability to maintain its water production assets in proper working order. Normal -Year Reliability Comparison The water demand forecasting model, developed for the OC Reliability Study to project the 25 -year demand for Orange County water agencies, also isolated the impacts that weather and future climate can have on water demand through the use of a statistical model. The explanatory variables of population, temperature, precipitation, unemployment rate, drought restrictions, and conservation measures were used to create the statistical model. The impacts of hot/dry weather condition are reflected as a percentage increase in water demands from the average condition. The average (normal) demand is represented by the average water demand of 1990 to 2014 (CDM Smith, Final Technical Memorandum #1 of Orange County Reliability Study, April 2016). The City is 100 percent reliable for normal year demands from 2020 through 2040. The City has entitlements to receive imported water from Metropolitan via the regional distribution system. Although pipeline and connection capacity rights do not guarantee the availability of water, per se, they do guarantee the ability to convey water when n is available to the Metropolitan distribution system. All imported water supplies are assumed available to the City from existing water transmission facilities. The demand and supplies listed below also include local groundwater supplies that are available to the City through OCWD by a pre - determined pumping percentage. Single -Dry Year Reliability Comparison A single -dry year is defined as a single year of no to minimal rainfall within a period that average precipitation is expected to occur. The water demand forecasting model developed for the OC Reliability Study isolated the impacts that weather and future climate can have on water demand through the use of a statistical model. The impacts of hot/dry weather condition are reflected as a percentage increase in water demands from the average condition (1990- 2014). For a single dry year condition (FY2013 -14), the model projects a six percent increase in demand for the OC Basin area where the City's service area is located (CDM Smith, Final Technical Memorandum #1 of Orange County Reliability Study, April 2016). Detailed information of the model can be obtained from the City of Santa Ana, The City has documented that it is 100 percent reliable for single dry year demands from 2020 through 2040 with a demand increase of six percent from normal demand with significant reserves held by Metropolitan, local groundwater supplies, and conservation. 15