View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTProjected Water Demands and Supplies for City of Oxnard(AFY)2000 2005 2010 2015 2020Demand 25,966 31,081 35,730 40,380 44,565SuppliesCity Groundwater Allocation a 5,879 5,568 5,255 5,255 5,255UWCD Groundwater Suballocation 5,302 4,990 4,678 4,678 4,678CMWD Imported Water Supplies b 13,249 13,249 13,249 13,249 13,249Total Water Supplies c 24,430 23,807 23,182 23,182 23,182Additional Water Supplies Required d 1,536 7,274 12,548 17,198 21,383Supply Total 25,966 31,081 35,730 40,380 44,565a Assumes not additional allocation is granted.b Based on 90 percent of maximum demand from 1990-2000, consistent with proposed CMWD rate structure.c Total annual water allocation excluding groundwater credits.d Additional allocation needed to meet the projected demand.Approximately one-half of the current supply is from groundwater, and one-half is fromimported surface water. These water supply resources will not keep pace with theincreasing demand. The estimated additional supplies will steadily increase to an estimateddeficit of 21,383 AFY required to meet the estimated demand of 44,565 AFY in 2020. Thecurrent and future supplies, and estimated additional supplies required to meet the 2020demands of the City are illustrated in Figure 3-9. Significant limitations exist to meetingthese demands with current supply sources, which are described below.GroundwaterAs discussed above, FCGMA restricts the reliance of the City on local groundwater supplies,including both those developed from the City wells and those purchased from the UWCD.While the City can pump groundwater above its FCGMA allocation, it must pay asubstantial pumping assessment penalty to do so. Under the present FCGMA regulatorylimitations, the City is also required to reduce its groundwater use by an additional10 percent over the next decade (5 percent in 2005 and 10 percent in 2010). In recent years,the City has relied upon accumulated unpumped FCGMA groundwater allocation (credits)and additional purchases from CMWD to meet the growing demand of the City. However,once the FCGMA groundwater credits have been exhausted, the City would be required topay a pumping assessment penalty of $725 per acre-foot, in addition to the actual pumpingcharges, which in current dollars is somewhere between $850 and $1,000/acre-foot. Inaddition, pumping of groundwater exceeding FCGMA restrictions would contribute to thecontinuation or worsening of the effects of overdraft conditions of the Oxnard Plain andPleasant Valley aquifers. As described in Section 2.0, overdraft has historically resulted ingroundwater storage reductions, declining groundwater levels to below sea level, waterquality degradation, and ground subsidence.W112003002SCO LW1458.DOC/ 033390002 40