ARCHIVED REPORTS_1988_4 - Laserfiche WebLink

Home Browse Search

0 0 J. H. KLEINFELDER & ASSOCIATES File: W-2022-1/11:312 June 19, 1986 Page 4 Ground Water It is our opinion that wells may be developed on the site which would supply ground water of sufficient quantity, the desired production of 3,500 gallons per minute. Deep wells drilled along the northeast border of the site would have the best potential for providing the desired supply. This conclusion is based on data obtained from the Department of Water Resources; Water and Power Resources Service, San Joaquin County; landowners and developers in the site area; and laboratory tests performed on water samples obtained in the area. In order to produce sufficient quantities of water, wells would most likely penetrate the Plio-Pleistocene Corcoron clay layer, which generally separates more saline water above from less saline water below. Well depths on the order of 600 to 900 feet should be anticipated. It is doubtful that a dependable ground -water supply can be obtained from wells drilled in the western hills of the site. These hills are located in the rainshadow of the Coast Ranges and receive approximately 10 inches or less of rain annually. In addition, the rock formations of the eastern Coast Ranges are considered non-waterbearing. Rainwater drains off the hills in the form of surface runoff and small springs, into q the basins and ultimately into the valley auifers. It is probable that small quantities of water are trapped within the Corral Hollow drainage, however, there would not be sufficient quantities or recharge to supply the proposed community for the long term. It appears that the quantity and quality of available ground water on and around the northeast portion of the site varies greatly. The major sources of recharge for the aquifers along the northeast side of the site are from deep ground water inflow from the south and southeast. Minor amounts are contributed from surface runoff of the Coast Ranges. We understand that during well development for Lone Star Industries, Granite Construction and Country Estates Subdivision dry wells were drilled before encountering sufficient quantities. Lone Star Industries and Granite Construction are located approximately 3\4 to one mile north of the site and Country Estates Subdivision is located on the east end of the site. A landowner to the west of the site informed us that he had attempted several 500 to 600 -foot deep wells with no significant ground water encountered. In our opinion, the relatively shallow depth of these wells is probably the main reason for their failure.