View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTRiver. Following discovery of seawater intrusion in the 1940s, additional facilities wereconstructed to move pumping away from the coastline and to deliver water to those areas.Today, spreading grounds to recharge groundwater consist of the Saticoy recharge ponds,El Rio recharge ponds, and the Noble Pit. Wellfields at the Saticoy and El Rio spreadinggrounds recover groundwater. The spreading operations have dramatically increased theyield of the Oxnard Forebay area and reduced overdraft conditions of the aquifersunderlying the Oxnard Plain. Approximately 21,000 AFY and 18,400 AFY of water wererecharged at the Saticoy and El Rio spreading grounds, respectively, during the 2000 wateryear.Planned Groundwater Recharge FacilitiesSeveral gravel pits along the Santa Clara River that have historically mined aggregate arenear the UWCD existing groundwater recharge facilities. In 1995, UWCD purchased theNoble Pit and began putting surplus water into it during and after heavy storms, increasinggroundwater recharge. UWCD is planning a project that would convert two additionalgravel pits, the Woosley and Hanson pits (formerly owned by S. P. Milling) that would beused to store river water diverted during peak Santa Clara River flows, when water is nowrejected to do its high silt load. After settling out, the water would be pumped back out ofthe pits for offsite groundwater recharge and direct agricultural irrigation. These pits arelocated within the RiverPark Project, a planned development with 2,900 homes plus retail,office buildings, hotel, and convention center on 700 acres.Saticoy WellfieldThe Saticoy wellfield, currently being constructed adjacent to the Saticoy SpreadingGrounds, is designed to reduce groundwater stored in the Forebay during the dry season,thus creating additional storage space in the Forebay for wet-season recharge. Pumpedwater will be delivered to both the Pleasant Valley pipeline and PTP for farmers to use inlieu of pumping their wells. These wells are designed to regulate storage in the Forebay, andwill be pumped mostly when water levels are higher. The amount of water to be pumpedwill vary with climatic conditions. It is anticipated that approximately 5,000 AFY will beextracted during normal and wet years, and that approximately 2,000 AFY will be extractedduring dry years. The wellfield will consist of four UAS wells, each anticipated to have acapacity of approximately 3,500 gpm and a sustained pumping rate of approximately2,000 to 2,500 gpm.El Rio WellfieldThe El Rio wellfield surrounds the El Rio recharge ponds and consists of eight wells locatedat the El Rio spreading grounds and three wells located along Rose Avenue. Pumped wateris delivered to the O-H pipeline system. Water produced by the wellfield is a blend ofrecharge water that has filtered down through the aquifer, and groundwater drawn laterallyfrom surrounding areas. The El Rio wellfield includes both UAS and LAS wells, allowing ablending of sources for water quality purposes. Nine wells are completed in the UAS, andtwo wells are completed in the LAS. The UAS wells each have a capacity of approximately4,000 gpm and can be pumped at sustained rates of approximately 2,000 to 2,500 gpm. TheLAS wells have lower capacities and can each be pumped at sustained rates ofapproximately 1,000 to 2,500 gpm.W112003002SCO LW1458.DOC/ 033390002 31