The West Chocolate Mountains Solar Energy Zone (SEZ) is a designated leasing area (DLA) located in Imperial County, California within the boundaries of the California Desert Conservation Area (CDCA). The SEZ is located on BLM administered lands within the El Centro Field Office.
The Record of Decision (ROD) for the West Chocolate Mountains Renewable Energy Evaluation Area (REEA) Final Environmental Impact Statement and Proposed California Desert Conservation Area Plan Amendment established the 10,759 acre (43.5 km2) West Chocolate Mountains SEZ within the REEA. The REEA itself consists of approximately 64,000 acres (259 km2), of which 18, 765 acres (76 km2) is BLM-administered surface acreage.
The West Chocolate Mountains REEA is in western Imperial County within the Colorado Desert, approximately 90 miles east of San Diego. The Salton Sea is located to the west of the REAA, and the Chocolate Mountains Aerial Gunnery Range (CMAGR), which includes part of the West Chocolate Mountains, borders the REA on the east. A combination of BLM-administered land and private land is located to the north and south of the SEZ. The Coachella Canal runs along the northeastern border of the REEA and runs through the REEA on the southeast. The ROD requires that lands in the REEA that are east of the Coachella Canal will be limited in surface disturbance for solar development to less than 10 percent (706 acres [2.86km2]) of available BLM-administered lands.
Several hot springs, spas, and fish farms are located within the West Chocolate Mountains REEA and surrounding area. Slab City, a former military base, is located within the southern portion of the REEA and is the only population concentration within the REEA boundary. The Calipatria State Prison is located approximately 5 miles (8.1 km) south of the boundary of the West Chocolate Mountains REEA. The nearest airport is the Calipatria Municipal Airport, located 7 miles (11 km) to the west.
Since solar development could occur at various locations within the REEA, the entire REEA is described below.
The land use types occurring within the REEA include undeveloped and developed desert alluvial valleys, desert washes, and agricultural land. Creosote bush scrub is the most common plant community in the West Chocolate Mountains REEA, which is within the arid subtropical climate of the Colorado Desert ecoregion. The terrain is gently sloping from the Chocolate Mountains east and northeast of the REEA to the Salton Sea west and southwest of the REEA. Desert washes cross nearly the entire REEA, with Iris Wash being the largest and most pronounced.
The town of Niland is located 6 miles southwest of the SEZ and has a population of 1,290 residents. The town of Bombay Beach is in the northwest corner of the SEZ and has a population of 412 residents. The closest significant commercial land uses are located in El Centro, the county seat for Imperial County, approximately 30 miles south of the SEZ. El Centro has approximately 40,000 residents.
The West Chocolate Mountains REEA has existing infrastructure such as railroads, transmission lines, and major highways. It contains previously designated transmission corridors and meets other criteria found to be favorable for renewable energy development (for example, previous disturbance).
Regional access to the West Chocolate Mountains REEA is available via Interstate 8 to the south and Interstate 10 to the north. These interstate roadways connect to State Route 111 which directly crosses the SEZ north and south.
The ROD for the REEA indicates that solar facilities that require high water use (solar trough and power tower) would not be approved, nor would facilities including structures exceeding 200 feet in height.
There are currently five major transmission lines in Imperial Valley that connect to control areas outside of the Imperial Irrigation District (IID). Corridor M crosses the length of the REEA from the northwest to the southeast, and is adjacent to the East Highline Canal. There are existing utility ROWs within Corridor M, including a 230-kV transmission line.
In the Solar PEIS, the BLM committed to establishing a monitoring and adaptive management strategy for each solar energy zone (SEZ). Through these strategies, the BLM will take an active role in the collection of baseline data for the SEZs.
The BLM has not yet begun the monitoring and adaptive management strategy for the West Chocolate Mountains SEZ. However, the BLM has conducted a pilot monitoring and adaptive management strategy for the Riverside East SEZ. In May 2016, the BLM released the Riverside East Solar Energy Zone Long Term Monitoring Strategy Final Report. The monitoring strategy document (PDF, 16.6 MB) is now available.
In the Solar PEIS, the Bureau of Land Management (BLM) committed to establishing a solar regional mitigation strategy for each solar energy zone (SEZ). These regional mitigation strategies are expected to simplify and improve the mitigation process for future solar projects in SEZs.
The BLM has completed regional mitigation strategies for the Arizona SEZs, the Colorado SEZs, and the Dry Lake and Dry Lake Valley North SEZs in Nevada. The Desert Renewable Energy Conservation Plan (DRECP) Land Use Plan Amendment (finalized in September 2016) provides the mitigation strategy for renewable energy development throughout the southern California desert as a whole, including the California SEZs (Imperial East, Riverside East, and West Chocolate Mountains SEZs). Details of the strategy identified by the DRECP Land Use Plan Amendment are provided in the Final BLM DRECP Land Use Plan and Environmental Impact Statement, Volume VI.