The Project is a four-year pilot project that would include the installation and operation of 15 ground-based weather modification units throughout the Santa Ana River watershed to increase precipitation in the region. The Project would be operated for four years. Two types of ground-based cloud seeding methods would be used: North American Weather Consultants (NAWC) proprietary automated high output ground seeding (AHOGS) systems and ground-based cloud nuclei generators (CNGs). AHOGS are triggered by the Project meteorologist operating remotely; once triggered the units burn flares that rapidly release a concentrated amount of silver iodide (NAWC 2020). These generators are used for seeding convective bands with high concentrations of supercooled liquid water and strong vertical updrafts. CNGs are manually-operated systems that burn a solution of silver iodide and acetone to create a constant cloud of seeding material that provides broad coverage over mountainous terrain with strong orographic effects.
The project involves installation of 15 weather modification units in the Santa Ana River Watershed. These proposed locations have been chosen based on their upwind proximity to high precipitation target areas as follows:
• Northwest: The northwest target area bordering Los Angeles and San Bernardino Counties encompasses a portion of the Central Transverse Ranges, to the west of the Interstate (I)-15 freeway. Estimated average seasonal runoff: 25,000 acre-feet (AF). Four sites are proposed in this area, two sit just south of the Transverse Ranges on the Angeles National Forest just north of the 210 freeway, and two are located south of the 210 freeway.
• Northeast: The northeast target area target area in San Bernardino County encompasses the area of the Central Transverse Ranges east of I-15, extending down to I-10 north of Palm Springs. Estimated average seasonal runoff: 65,000 AF. Six sites are proposed within or just south of the Central Transverse Ranges on the San Bernardino National Forest.
• Southeast: The southeast target area includes the mountains in Riverside County centered just to the west and southwest of Palm Springs. Estimated average seasonal runoff: 10,000 AF. Three sites are located at the base of the San Jacinto Mountains.
• Southwest: The southwest target area includes the mountain range that lies on the border of Orange and Riverside counties. Estimated average seasonal runoff: 5,000 AF. Two sites are near the base of the Santa Ana Mountains.
List of Sites and Coordinates is below
Waterwise - CBWCD 34.078103, -117.704509
Upland - CBWCD 34.101183, -117.695932
SAWC-1 34.137955, -117.639953
SAWC-2 34.156470, -117.671847
EVWD 34.136848, -117.188404
Thousand Pines Christian Camp 34.249539, -117.278552
Sycamore Water Plant 34.186745, -117.309273
SBVWCD-1 34.070031, -117.114747
SBVWCD-2 34.107975, -117.099455
San Gorgonio Pass Water Agency 33.975799, -116.981613
EMWD - N 33.780236, -117.072465
EMWD - S 33.668970, -116.970352
Mary Lea Gardiner 33.536251, -116.805057
Irvine Ranch Water District 33.776528, -117.754128
El Toro Reservoir 33.6234824, -117.6697852
Notice of Completion
State Review Period Start
State Review Period End
State Reviewing Agencies
California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Habitat Conservation Planning (CDFW), California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW), California Department of Fish and Wildlife, South Coast Region 5 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Transportation, District 12 (DOT), California Department of Transportation, District 8 (DOT), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Santa Ana Region 8 (RWQCB), California State Lands Commission (SLC), Department of Toxic Substances Control, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality
Other (Weather Modification Project)
weather modification pilot project
Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Energy, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Schools/Universities, Solid Waste, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire
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