Programs from the drought-busting handbook practiced by Southern California water agencies include recycling water, building storm-water capture basins and offering cash rebates for replacing thirsty lawns with xeriscape landscaping.
With the grip from a second year of drought tightening, a regional water-planning agency in the Inland Empire is moving ahead for the first time in its history with a more controversial program: cloud seeding.
The Santa Ana Watershed Project Authority Commission has approved a four-year pilot cloud-seeding project in yet-to-be-determined locations in and near the mountains of San Bernardino, Riverside, Orange and a portion of Los Angeles counties, said Jeff Mosher, SAWPA general manager.
On Oct. 19, the commission’s board will vote on beginning the environmental review, which could take a few months. It will also determine the exact locations for cloud-seeding generators. The agency has committed about $400,000 and will seek a state grant for half — a combined process that may take about a year to complete, Mosher said.
A cloud-seeding program aimed at coaxing more rain out of the skies could launch in October or November 2022, depending on weather conditions, he said.
The objective is to augment the amount of rain and snowfall in the mountains that feed into the 2,560-square-miles of the Santa Ana River, from which about 6 million people get some if not all of their water. Storm-water runoff basins have already been built from the mouth of the river in Highland to the Prado Dam near Corona by the commission’s five member agencies: Eastern Municipal Water District, Inland Empire Utilities Agency, Orange County Water District, San Bernardino Valley Municipal Water District and Western Municipal Water District.
And more collection basins are planned — all in an effort to increase water supplies.
But if not enough rain falls, or mountain snowmelt is reduced to a trickle, capture basins will be underused or could go dry, reducing supplies. Other methods, such as recharging the underground aquifer, would also be limited, reducing water supplies for the five water agencies as well as many cities, such as Rialto and Riverside, that rely on pumping up water from local wells.
“We’ve invested in storm-water capture basins but they only work if we have storm water,” Mosher explained. Initial studies predict an increase of between 8% and 11% per year.
An 8% increase would generate 8,193 acre feet of water, more than 2.7 billion gallons, or enough for more than 16,000 households per year, when figuring 1 acre foot of water is used in indoor and outdoor uses for two households per year in Southern California.
“The idea would be to increase runoff into the Santa Ana River and its tributaries and then capture that behind the dams,” Mosher said. The biggest target is Seven Oaks Dam in Highland, near Redlands, which has the capacity for holding back more runoff for percolation into the water table.
How does it work
When cloud-seeding generators heat up, they send a plume of smoke containing microscopic crystals of silver iodide into the sky. These silver iodide particles attract super-cooled water droplets that instigate ice crystals. The crystals enlarge as more water freezes around their center and fall as snowflakes or hailstones. Some convert to raindrops, explained Garrett Cammans, president of North American Weather Consultants.
His company did a feasibility study for the Santa Ana Watershed authority’s project and determined that the mountains around the region and weather conditions make for a successful program. The company “concluded that the proposed program, as designed in this study, is technically feasible,” the report said.
The study suggests placing ground generators in four general locations: the mountains bordering Los Angeles and San Bernardino counties (from Montclair to Fontana); the mountains in San Bernardino County east of the 15 Freeway and extending to Palm Springs; the mountains in Riverside County west and southwest of Palm Springs; and the mountain ranges on the border of Orange and Riverside counties.
Mosher said the Inland Empire agency has never done cloud-seeding but has heard successful stories from other counties, namely Santa Barbara.
Becoming more popular
Cammans’ firm has been doing cloud seeding, known as weather modification, since the 1950s, he said. The company started in Altadena, an unincorporated community north of Pasadena at the base of the San Gabriel Mountains, and is now located in Sandy, Utah.
The company, with the website that says in big block letters “We Make It Rain,” has projects in Utah, Colorado and California. It has an ongoing cloud-seeding project in Santa Barbara County, Cammans said.
Interest in cloud seeding has grown during the last 10 years, he said. “I would say there is enhanced concern for the water resources that are available,” he added.
While climatologists talk about the southwestern United States mired in a 20-year drought, mostly due to climate change, rising temperatures and less snowfall, California has been plagued by a drought since 2020.
In July 2021, 85% of the state was facing extreme drought, with the Colorado River water source down considerably, according to state water agencies. Water levels at Lake Mead in Nevada continue to drop and were at 35% in August, the lowest since Hoover Dam was built in 1936. In mid-August the Metropolitan Water District of Southern California declared a “water supply alert” and began urging water conservation throughout Southern California.
Even with precipitation, bone-dry mountain areas can hold back runoff from reaching the river, as moisture soaks into the parched soil like a sponge, Mosher said.
Is it safe?
Cloud seeding would be halted if a storm was too big, for fear it would cause torrential rains and flooding. Also, scientists would avoid denuded areas scarred from previous wildfires to prevent rain from causing debris flows, according to the Santa Ana Watershed authority’s report.
Los Angeles County canceled a five-year contract with North American Weather Consultants after a brief stint with cloud seeding in the Pacoima, Tujunga and San Gabriel Mountains watershed areas when the San Gabriel Complex fire broke out in the eastern San Gabriel Valley foothills in June 2016, said Kerjon Lee, spokesman for the county’s Department of Public Works.
“We had a major fire event, we held off and didn’t do it anymore,” Lee said.
The company’s feasibility report for the Santa Ana Watershed mentioned an area left denuded by the Apple fire, near Cherry Valley south of Oak Glen, in 2020. But the study concluded the generators could be targeted away from such burn areas, “while avoiding burn scars, with relative ease.”
Jake Slemboski, 29, a resident of Rancho Cucamonga said he is concerned that not enough is known about the use of silver iodide.
“There have not been tons of studies to see if (silver iodide) would accumulate in the soil and if it would affect wildlife. It may not be safe,” he said.
Cammans said the amount of silver iodide after cloud seeding is imperceptible because concentrations are extremely low. Silver is “biologically inert” and iodine is a common food additive, often added to table salt, said.
“Silver and iodine are harmless to human life,” he added.
To learn more
• The Santa Ana Watershed Project Authority Commission will hold a webinar 1:30 p.m. to 3:30 p.m. Thursday, Oct. 14. The Zoom meeting will explain the process of cloud seeding.
• Go to the water agency’s website at sawpa.org and scroll down to “Latest Info.”