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HYDROLOGY AND WATER QUALITY EXISTING: Surface Water Flood hazard maps prepared by the Army Corps of Engineers indicate that the site is "Not prone to 100-year flood" [6]. Naturally, this assumes that levee failure does not occur. There is no evidence to suggest that levee failure is likely to occur; however, a portion of the levee between the Van Buskirk Golf Course and French Camp Slough has been identified as showing signs of levee deterioration [6, p. 2691. A more recent Sacramento - San Joaquin Delta Flood Insurance Study conducted by the Army Corps of Engineers has determined that levees protecting the site are stable and adequate. The unpublished, preliminary draft identifies the site as being within Zone B. The Corps of Engineers defines Zone B as: "areas between limits of the 100-year flood and 500-year flood; or, certain areas subject to 100-year flooding with average depths less than one foot; or, where the contributing drainage area is less than one square mile; or, areas protected by levees from the base flood." (Appendix C-24) . Currently, surface runoff flows generally north and west into a ditch which terminates at the San Joaquin River levee west of the site. There are a few localized depressions on the site where ponding occurs after episodes of heavy rainfall . Two municipal storm water pumping stations are located near the site (see map, page 3) . One is located southeast of the site on Denver Avenue and is the only means of removing storm water from the neighborhood. Stormwater drains to the pump sump then it is pumped southerly and is discharged into the San Joaquin River. Historically, the capacity of the pump has proven to be marginal or inadequate during heavy storm conditions (Duane Cox, telecon). The other pumping station is located on the golf course near the west end of Lot A. This station removes water which collects in the ditch in Lot A and discharges it into the San Joaquin River. Ground Water Ground water is contained in aquifers or water bearing strata with voids containing water. The replacement of ground water as it is depleted is referred to as aquifer recharge. Recharge is dependent upon surface infiltration rates, soil permeability, availability of surface water, and subsurface geologic formation. Aquifer recharge areas are those surface areas that have been identified as possessing the particular soils and subsurface materials with the characteristics that allow the passage of water into the water-bearing strata. The site has been identified as an area of "none to slight recharge" [6, p. 26]. During the subsurface exploration of the site by Geomechanics, Inc. , ground water was encountered at a depth of 13 feet [5]. 32