Water conservation

How to overcome drought? Inland Empire water agency wants to make it rain – press enterprise


The drought control manual programs practiced by the Southern California water agencies include recycling water, building stormwater catchment ponds, and offering replacement cash rebates. thirsty lawns by xeriscape landscaping.

In the grip of a second year of drought, an Inland Empire regional water planning agency is moving forward for the first time in its history with a more controversial agenda: cloud seeding.

  • Storm clouds fill the sky over the Beaumont as the Santa Ana Watershed Project Authority advances with cloud seeding over parts of the Inland Empire on Friday October 8, 2021 . (Photo by Terry Pierson, The Press-Enterprise / SCNG)

  • Storm clouds fill the skies over Redlands and the San Bernardino National Forest as the Santa Ana Watershed Project Authority advances with cloud seeding over parts of the Inland Empire Friday October 8, 2021 (Photo by Terry Pierson, The Press-Enterprise / SCNG)

  • Storm clouds fill the skies over Redlands and the San Bernardino National Forest as the Santa Ana Watershed Project Authority advances with cloud seeding over parts of the Inland Empire Friday October 8, 2021 (Photo by Terry Pierson, The Press-Enterprise / SCNG)

The Santa Ana Watershed Project Authority Commission has approved a cloud-seeding pilot project in yet-to-be determined locations in and near the San Bernardino, Riverside, Orange Mountains and parts of the counties from Los Angeles, said Jeff Mosher. , Managing Director of SAWPA.

On October 19, the commission’s board will vote on whether to start the environmental review, which could take a few months. It will also determine the exact locations of the cloud seeding generators. The agency has committed about $ 400,000 and will seek a state grant for half – a combined process that can take about a year, Mosher said.

A cloud seeding program aimed at attracting more rain into the sky could be launched in October or November 2022, depending on weather conditions, he said.

The goal is to increase the amount of rain and snow in the mountains that feed the 2,560 square miles of the Santa Ana River, from which about 6 million people get some if not all of their water. Stormwater runoff ponds have already been constructed from the mouth of the river in Highland to the Prado Dam near Corona by the five commission 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 other collection basins are planned, all with the aim of increasing the water supply.

But if it doesn’t rain enough or if mountain snowmelt is reduced to a trickle, catchment ponds will be underutilized or could dry up, reducing supplies. Other methods, such as recharging the underground aquifer, would also be limited, reducing the water supply to the five water agencies as well as many towns, such as Rialto and Riverside, which depend on pumping from the water supply. water from local wells.

“We’ve invested in stormwater catchment ponds, but they only work if we have stormwater,” Mosher explained. The first studies predict an increase of 8 to 11% per year.

An 8% increase would generate 8,193 acre feet of water, over 2.7 billion gallons, or enough for more than 16,000 households per year, considering that one acre foot of water is used at indoors and outdoors for two households per year in Southern California. .

“The idea would be to increase the runoff in the Santa Ana River and its tributaries and then capture it behind the dams,” Mosher said. The biggest target is the Seven Oaks Dam in Highland, near Redlands, which has the ability to retain more runoff for percolation into the water table.

How it works

A ground seeding generator is shown in use. Ground generators burn a 2% solution of silver iodide. As the generator burns, the silver iodide particles rise and enter the storm system, supported by the orographic lift. Once in the cloud, the silver iodide acts as a nucleating agent triggering the formation of additional snowflakes by attracting droplets of supercooled liquid water. (Courtesy of North American Weather Consultants)

As the cloud seeding generators heat up, they send a plume of smoke containing microscopic silver iodide crystals into the sky. These silver iodide particles attract supercooled water droplets which cause ice crystals. The crystals grow larger as the water freezes around their center and fall as snowflakes or hailstones. Some turn into raindrops, explained Garrett Cammans, president of North American Weather Consultants.

His company made a feasibility study for the Santa Ana Watershed Authority project and determined that the mountains around the area and the weather conditions make for a successful program. The company “has concluded that the proposed program, as designed in this study, is technically feasible,” the report said.

The study suggests placing generators on the ground in four general locations: the mountains bordering Los Angeles and San Bernardino counties (from Montclair to Fontana); the mountains of San Bernardino County east of Highway 15 and extending to Palm Springs; the mountains of 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 had never done cloud seeding, but had heard success stories from other counties, namely Santa Barbara.

Become more popular

Cammans’ business has been doing cloud seeding, known as weather modification, since the 1950s, he said. The business started in Altadena, an unincorporated community north of Pasadena at the foot of the San Gabriel Mountains, and is now located in Sandy, Utah.

The company, with the website that says in large print “We Make It Rain,” has projects in Utah, Colorado and California. He has a cloud seeding project underway in Santa Barbara County, Cammans said.

Interest in cloud seeding has increased over the past 10 years, he said. “I would say there is an increased concern for the available water resources,” he added.

While climatologists speak of the Southwestern United States mired in a 20-year drought, mostly due to climate change, rising temperatures and decreasing snowfall, California has been in the throes of drought ever since. 2020.

As of July 2021, 85% of the state was facing extreme drought as the Colorado River’s water source declined significantly, according to state water agencies. Water levels in Lake Mead in Nevada continue to decline and were at 35% in August, the lowest since the construction of the Hoover Dam in 1936. In mid-August, the The Metropolitan Water District of Southern California declared a “water supply alert” and began urging water conservation throughout Southern California.

Even with rainfall, parched mountainous areas can prevent 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 were too severe, lest it cause torrential rains and flooding. In addition, scientists would avoid bare areas marked by previous forest fires to prevent rain from causing debris flows, according to the report from the Santa Ana Watershed Authority.

Los Angeles County canceled a five-year contract with North American Weather Consultants after a brief period of cloud seeding in the Pacoima, Tujunga and San Gabriel mountain watersheds when the San Gabriel complex fire erupted in the eastern foothills of the San Gabriel Valley in June 2016, said Kerjon Lee, spokesperson for the county’s public works department.

“We had a major fire, we resisted and didn’t do it again,” Lee said.

Of the society feasibility report for the Santa Ana watershed mentioned an area left bare by the Apple fire, near Cherry Valley south of Oak Glen, in 2020. But the study concluded that the generators could be targeted away from these. burn areas, “while avoiding burn scars, with relative ease.”

Jake Slemboski, 29, a resident of Rancho Cucamonga expressed concern that not enough is known about the use of silver iodide.

“There haven’t been tons of studies to see if (silver iodide) would build up in the soil and if it would affect wildlife. It may not be sure, ”he said.

Cammans said the amount of silver iodide after cloud seeding is imperceptible because the 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 online seminar 1:30 p.m. to 3:30 p.m. Thursday, October 14. The Zoom meeting will explain the cloud seeding process.

• Go to the website of the water agency at sawpa.org and scroll to “Latest Information”.


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