SU0015801 - Laserfiche WebLink

Home Browse Search

Water Supply Assessment Griffith Energy Storage Project 2.0 SUPPLY AND DEMAND ANALYSIS The WSA assesses if the demand associated with a project is available. The Project is estimated to require 10,000,000 total gallons of water(30.7 acre-feet)for construction use for a 12-month duration, plus 3 months of Project commissioning. That volume of water is equal to roughly 30 gallons per minute continuously for 12 months of construction use. One existing domestic well is located within the Project site. Per historic boring reports the well is 200 feet deep with the static water level depth at 32 feet. Downhole video surveys and a pumping test will be needed to confirm these values, the condition of the well, and if rehabilitation of the well will be needed prior to use. There is no public water system that provides water to the Project site, but the Project site is adjacent to the City of Tracy which has a public water system. The expectation is that the construction contractor may choose to haul water from the City of Tracy. This analysis includes both groundwater sources as well as public water supply sources from the City of Tracy. 2.1 SAN JOAQUIN RIVER HYDROLOGY REGION (TRACY SUBBASIN) The Project site is located within the Tracy Subbasin (Basin 5-022.15)of the San Joaquin River Hydrologic Region. Per the California Groundwater Update 2020 (Bulletin 118)the San Joaquin River Hydrological Region covers 15,200 square miles in Central California and provides nearly 4 million acre- feet per year of water to the area. The California Department of Water Resources (DWR) has identified the basin as a medium priority basin and therefore requires a Groundwater Sustainability Plan (GSP) pursuant to the Sustainable Groundwater Management Act (SGMA) (DWR 2019). SGMA requires medium-and high-priority basins to develop groundwater sustainability agencies (GSAs), develop GSPs, and manage groundwater for long-term sustainability. The Tracy Subbasin GSP was finalized in 2021 (GEI 2021)and will be updated every 5 years as additional information for the subbasin becomes available.The GSP identifies sustainability indicators for the subbasin,defines significant and undesirable results,minimum thresholds,and measures objectives that will be used to guide and define sustainable conditions and overall groundwater management goals within a 20-year period(GEI 2021). The GSP describes the six agencies throughout the subbasin(GSAs)that are responsible for sustainably managing groundwater in the subbasin,with each GSA having jurisdiction within their respective areas.Key components for defining sustainable conditions include water quality and groundwater level monitoring and monitoring of land subsidence via satellite-based-radar measurements. The GSP also provides technical information used to develop water budgets under historical and current conditions and under future use conditions with climate change consideration.The water budgets were developed using a state- developed model for the entire Central Valley.The water budgets show a surplus for the historic conditions and a deficit for future conditions with climate change.The GSP presents management actions for the subbasin to resolve deficits predicted by the model-based future groundwater budget.The management actions include one project that can resolve the deficit that includes reducing groundwater pumping by 1,000 AFY. There are also two supplemental projects: one project that benefits the Upper aquifer by reducing pumping by up to 3,000 acre-feet per year(AFY)and a second project that can increase recharge to the Lower aquifer by up to 3,000 AFY(GEI 2021). Table 1 provides the projected water budgetforthe Tracy Subbasin.Underfuture usage,with expectations of future developments and population growth and no climate change component through the year 2065, OTETRA TECH 5 February 2023