View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTGroundwater Recovery for Scenarios 2a and 2bScenario 2aScenario 2bLocation Well Pumpage Well PumpageCity Water Yard#20 (LAS)500 AFY (310 gpm)#20 (LAS)500 AFY (310 gpm)#21 (LAS)500 AFY (310 gpm)#21 (LAS)500 AFY (310 gpm)#22 (UAS)2,886 AFY (1,789 gpm)#22 (UAS)571 AFY (354 gpm)#23 (UAS)2,886 AFY (1,789 gpm)#23 (UAS)571 AFY (354 gpm)New 1 (UAS)2,886 AFY (1,789 gpm)New 1 (UAS)571 AFY (354 gpm)New 2 (UAS)2,886 AFY (1,789 gpm)New 2 (UAS)571 AFY (354 gpm)New 3 (UAS)2,886 AFY (1,789 gpm)New 3 (UAS)571 AFY (354 gpm)O-H System(All UAS Wells)Additional pumping is apportioned to each of the El Rio wells according to historicpumping in each of those wells.Scenario 2c. Scenario 2c consists of the same elements as Scenario 2a, except for thefollowing:• Groundwater Recharge. 3,086 AFY of recycled water, together with 3,086 AFY ofpotable water (to meet DHS requirements) for a total of 6,172 AFY, are injected at20 equally spaced injection wells completed in the LAS that would be located alongHueneme Road and Pacific Cost Highway as shown in Figure 4-3. It is assumed that thiswater is distributed equally over the 3-month winter season when irrigation demandsare lowest. These wells will act as a seawater intrusion barrier to create a focused rise ingroundwater elevations along the coast to reverse inward gradients and landwardgroundwater flow (seawater intrusion) in the LAS along the southern Oxnard Plain.• Groundwater Recovery. The additional 6,172 AFY of water, which was recharged at theinjection wells along the seawater intrusion barrier, is recovered by extracting thisamount of groundwater from wells at the City Water Yard (Nos. 20, 21, 22, and 23; plusthree new UAS wells) and from wells at the UWCD El Rio wellfield. The extraction ofthis 6,172 AFY of water is on top of the 19,286 AFY of water extracted for Scenario 2a, fora total amount of 25,458 AFY. As with Scenario 2a, it is assumed that this groundwater ispumped evenly on a continuous, year-round basis to help meet the potable demands ofthe City. It is assumed that 20 percent of this water is recovered at the UWCD El Riowellfield, and 80 percent is recovered from wells at the City Water Yard. The pumpageis apportioned as follows for this scenario:−−At the City Water Yard, the two LAS wells are increased to a maximum of 500 AFYeach, while the remainder of the increase at the water yard is apportioned equallyamong the two existing UAS wells and the three new UAS wells.The additional pumping is apportioned to each of the UAS El Rio wellfield wellsaccording to historic pumping in each of those wells. These added extractions wereapplied to the nine El Rio wells noted under the description for the Base Case.W112003002SCO LW1458.DOC/ 033390002 78