Irrigated agriculture is the dominant land use in the Cuyama Valley, with 20,000-25,000 acres devoted to active farming in any given year.  Current agriculture consists primarily of row crops rotated between root vegetables, alfalfa, and grains.  The largest crop by acreage is carrots, with an estimated 6,000 acres cultivated in 2008.  This represents approximately 17 percent of the statewide carrot production43.  Rotational fields are almost exclusively irrigated with overhead or center pivot sprinkler systems. Vineyards and orchards (pistachio, peach, and quince), totaling 400 acres, are irrigated with drip and micro-sprinkler irrigation systems and are mostly located near the town of Ventucopa, southeast of the primary agricultural zone.  The estimated total acreage of crops grown in the Cuyama Valley during the sampling years of 1977, 1985, 1996 and 2008 are below.  Figures for total water requirements of major crop classes were obtained from irrigation surveys conducted by San Luis Obispo County32.

Rural residential development consists of less than 200 farmsteads scattered across the privately owned portions of the valley.  The vast majority of privately owned land in the valley is assigned an agricultural land use classification, which limits the density of residential structures to one primary residence per 20 acres of irrigated land in San Luis Obispo County31 and a maximum of 1 residence per 40 acres of agricultural land in Santa Barbara County14.  Although scattered portions of the study area allow for settlements at this rate, much of the area in Santa Barbara County is zoned for one primary structure per 100 acres of farmed land.  Zoning ordinance in both counties allows for the construction of one accessory residential structure for every primary residence.

Gravel, sand and gypsum from alluvial deposits have proven to be a valuable resource for construction.  Three mines (GPS Mine, Lima Gypsum Mine, and Ozena Mine) are located on the upper Cuyama River in an area known to contain a high density of sensitive or endangered species.  A fourth mine, operated by the Alamo Rock Company, is located north of Twitchell Dam on Alamo Creek.  Plans for a fifth mine, the Diamond Rock Mine, are in progress13.

In-stream gravel and sand mining changes the sediment of the river bed, destroys habitat for species that utilize the river, and may result in fragmentation of the riparian corridor.  An aerial photograph of in-stream mining illustrates fragmentation of the river channel and riparian zone.  The recovery time of mined stream systems in arid environments is expected to exceed 20 years21.  The removal of aggregate from the river bed may also cause regional and localized geomorphic and hydrologic impacts to the area including increased total dissolved solid (TDS) levels in the groundwater and drawdown of the groundwater basin13.  Aggregate mining in the Cuyama Valley used an estimated 1,120 acre-feet/year in 199542.  The current combined water consumption of all Cuyama mining activities is unknown.  In addition to the direct loss of habitat and alterations to the sediment balance, increased truck traffic and nighttime lighting may also significantly impact species13.

The Diamond Rock Mine is a proposed sand and gravel mine to be located along the Cuyama River near the GPS Mine in Santa Barbara County.  An Environmental Impact Report (EIR) of the proposed mine was completed in 2007.  According to the EIR, the proposed Diamond Rock Mine will result in 27 acres of alluvial scrub habitat fragmentation in the riparian corridor, potentially impacting the following species: Blunt-nosed leopard lizard, San Joaquin kit fox, Loggerhead shrike (Lanius ludovicianus), and Lawrence’s goldfinch (Caduelis lawrencei) (County of Santa Barbara Planning and Development 2007).  Additionally, the Ozena Valley Ranch Mining Company has proposed a fifteen-acre expansion to the existing mining operations (Clerici 2007).

The 1989 California Geological Survey’s mineral land classification of Santa Barbara and San Luis Obispo Counties classified only the western portion of the study area near Twitchell Dam where the Alamo Rock Company is located.  This mine site is classified as likely to contain significant mineral deposits.  According to personal correspondence in January 2009 with John Clikenbeard of the California Geological Survey, an update of the aggregate classification maps that will include the entire Cuyama region is currently in progress.  An increase in aggregate mining activity could occur if the updated report indicates significant unexploited aggregate deposits in the area.

Petroluem Development

The Atlantic Richfield Oil Company began oil production in the early 1950s, with production peaking prior to 197716.  Currently, there are three oil fields located in the Cuyama Basin (Morales Canyon, Russell Ranch, and South Cuyama).

Sections of the Los Padres National Forest lie within the Cuyama Valley and adjoin it.  The Los Padres National Forest is the only California national forest with commercially developed oil and gas operations.  The leasing of land and construction of roads within the National Forest for oil or gas exploration is determined by National Forest management, and is constrained by the Oil and Gas Environmental Impact Statement38.  A 2005 Final Environmental Impact Statement indicated that an 80,258 acre area within the Los Padres National Forest, south of the current oil fields, is a High Oil and Gas Potential Area (HOGPA).  This area, known as South Cuyama, may be made available for oil and gas exploration.  Should the South Cuyama HOGPA be developed, potential impacts to species and habitat could occur39.

In 2006, the US Bureau of Land management announced its decision to auction off 34 parcels in Kern, Ventura, Santa Barbara, and San Luis Obispo counties for oil exploration and development as part of its quarterly oil and gas lease sales40.  Nine of those parcels are located in the valley and provide habitat for several endangered plants and animals, including the San Joaquin kit fox and the California jewel flower (Caulanthus californicus)40.  Although lessees would be subject to regulations aimed to protect endangered species40, the exploration and development of oil has the potential to reduce critical wildlife habitat.

Acreage for parcels proposed for auction are as follow (Parcel, Acres): 21, 1087; 22, 1800; 24, 1605; 25, 240; 26, 260; 27, 240; 28, 840; 36, 80; 37, 80. The comined total equals 8292 acres.

Renewable Energy Development

A California Energy Resource map created in 2004 depicts a portion of the Cuyama Valley as suitable for concentrated thermal solar development3.  Additionally, the Renewable Energy Transmission Initiative (RETI) Phase 1B planning document designates large portions of the study area as a potential Concentrated Renewable Energy Zone (CREZ) capable of generating 707 megawatts of thermal solar energy.  It is important to distinguish the proposed solar generation site in the Cuyama Valley from the “Cuyama” CREZ, which lies in the Carrizo Plain north of the study area.  The solar generating facility in the Cuyama Valley is named “Santa Barbara NE” and is intended to supplement large wind power installations in Los Padres National Forest and on the south coast near Gaviota.