JUNE 2020 OF THE SANTA CLARA RIVER VALLEY AQUIFERS EAST SUBBASIN Anatomy of an aquifer An aquifer is an underground reservoir where water fills and moves between the voids in rocks, silt and other material. Many different types of sediments and rocks can form aquifers, including gravel, sandstone, and fractured limestone. Aquifers are fed by rain and runoff, which percolates downward. There are two main types of aquifers: unconfined and confined. Unconfined, or alluvial aquifers, lie below a permeable layer of soil. Confined aquifers occur beneath an impenetrable layer of rock or clay. RECHARGE AREA DISCHARGE AREA PUMPED WELL STREAM Unconfined Aquifer Confining Bed (aquitard) Confined Aquifer CENTURIES Confining Bed (aquitard) MILLENNIA Confined Aquifer Slowing the flow Natural groundwater filter Aquitards are geological formations of semi-permeable material, like silts and clays that separate one part of an aquifer from Aquifers naturally filter groundwater by another, limiting the ow of water between geological forcing it to pass through small pores formations. and between sediments, which helps to remove substances from the water. Find more information at scvgsa.org AQUIFERS OF THE SANTA CLARA RIVER VALLEY EAST SUBBASIN Groundwater in the Santa Clarita Valley SCV Water gets half of its total supply from two aquifers. The shallow alluvial aquifer lies beneath the Santa Clara River and its tributaries; the larger, deeper Saugus Formation aquifer sits beneath the entire Santa Clarita Valley. Of the 35,900 acre-feet of total groundwater pumped in the Santa Clarita Valley in 2018, about 26,450 acre-feet came from the alluvial aquifer and 9,450 acre-feet were pumped from the underlying Saugus Formation. Alluvial aquifer Saugus Formation aquifer The alluvial aquifer is replenished mainly by rainfall The Saugus Formation aquifer has a total capacity of and surface water runoff in the Santa Clara River and more than 6 million acre-feet. The deepest portion is its tributaries. The alluvial aquifer along the main stem filled with highly saline water, but the top portions of the river is also replenished from discharge of offer fresh water with a volume of about 1.4 million treated wastewater from the Saugus and Valencia acre-feet. Water Reclamation Plants. How much is an acre-foot of water? 1 acre-foot of water equals 325,851 gallons. It is the volume of water necessary to cover 1 acre of surface area to a depth of 1 foot. Feeding an aquifer Aquifers are fed by rainfall and Santa Clara River KERN COUNTY surface water runoff from rivers, Watershed streams and irrigation. SANTA Castaic Creek Pyramid n Runoff comes from the Santa o BARBARA Piru Creek y Lake n Lancaster a n C nyo COUNTY h Ca Clara River watershed, which has is e F k la k h its headwaters in Soledad t e e r e b C a o z it Sespe Creek li u Canyon and a drainage area of E q k Bouquet is e n c e Reservoir o Castaic n r y a C n r on a t y C several hundred square miles. Lake F n e e a lc n u u a q C D S u t o in a Acton The river drains in an east to B u M Lake g Ojai A west direction across the Piru Santa Clarita groundwater basin and continues Fillmore Soledad Canyon west across Ventura County and into A RIVER CLAR Santa Paula the Pacific Ocean. In general, the local San Gabriel Mountains VENTURA TA Simi Valley groundwater basin is oriented along the Ventura N COUNTY LOS ANGELES A COUNTY Santa Clara River. S The amount of groundwater in storage has varied Oxnard Burbank considerably over the past 50 to 60 years, depending on rainfall totals. The water is withdrawn by wells drilled into the ground. Find more information at scvgsa.org.