|
Administrative Draft Environmental Impact Report
<br /> Gill Medical Center Project
<br /> Table 4.12-1 shows the water demand and available water supplies and change in groundwater storage
<br /> over the past 50 years, for different hydrologic water year types (DWR 2021 b). During wet and normal
<br /> years, which have occurred for 24 of the past 50 years, there is a net increase in groundwater in storage in
<br /> the Subbasin, ranging from an average of 20,000 acre-feet per year under normal hydrologic conditions
<br /> to an average of 185,000 acre-feet per year during wet hydrologic conditions. During below normal, dry,
<br /> and critically dry hydrologic conditions, which have occurred for 26 of the past 50 years, there is a net
<br /> decrease in groundwater storage of 113,000 acre-feet per year, 164,000 acre-feet per year, and 223,000
<br /> acre-feet per year, respectively. Over the last 50 years, the amount of groundwater in storage has
<br /> decreased by an average of 34,000 acre-feet per year, or a total of 1,700,000 acre-feet. The largest annual
<br /> change in groundwater storage of 223,000 acre-feet per year shown in Table 4.12-1 represents 0.4
<br /> percent of the total groundwater in storage in the Subbasin. The cumulative reduction of groundwater in
<br /> storage over the last 50 years is 3.2 percent of the total groundwater in storage in the Subbasin.
<br /> Table 4.12-1.Historical Water Demand and Supplies Based on Hydrological Water Year Type
<br /> Water Year Type San Joaquin River Index
<br /> Component Wet Above Below Dry Critical 50-Year
<br /> Normal Normal
<br /> Number of Years' 17 7 4 8 14 50
<br /> Precipitation,AFIYear 1,376,000 987,000 866,000 790,000 652,000 984,000(15.4)
<br /> Precipitation,inches 21.6 15.5 13.6 12.4 10.2
<br /> Water Demand(AF/year)
<br /> Ag Demand 1,088,000 1,107,000 1,108,000 1,112,000 1,117,000 1,104,000
<br /> Urban Demand 230,000 228,000 225,000 225,000 222,000 226,000
<br /> Total Demand2 1,318,000 1,335,000 1,333,000 1,337,000 1,339,000 1,330,000
<br /> Water Supply(AF/year)
<br /> Total Surface Water Supply 565,000 559,000 518,000 507,000 488,000 529,000
<br /> Agricultural 450,000 446,000 416,000 408,000 395,000 426,000
<br /> Urban and Industrial 114,000 113,000 102,000 98,000 93,000 103,000
<br /> Total Groundwater Supply 753,000 776,000 815,000 830,000 851,000 801,000
<br /> Agricultural 639,000 662,000 693,000 705,000 725,000 681,000
<br /> Urban and Industrial 115,000 116,000 124,000 126,000 128,000 121,000
<br /> Total Supply(AF/year)2 1,318,000 1,335,000 1,333,000 1,337,000 1,339,000 1,330,000
<br /> Chane in Groundwater Storage 185,000 20,000 -113,000 -164,000 -223,000 -34,000
<br /> (AF/year)2
<br /> Hydrology and Water Quality 4.12-8 October 2021
<br />
|