As a follow-up to the Town Crier’s story about the Santa Ana Watershed Project Authority’s (SAWPA) plan to explore the use of a weather modification program to augment rainfall in Southern California, Idyllwild Water District (IWD) invited Mark Norton, SAWPA water resources and planning manager, to discuss the concept and pilot project at IWD’s Dec. 15 meeting.

Leo Havener, IWD general manager, introduced Norton, who attended and spoke via Zoom to the board and a few members of the public.

“I have some experience with this process,” Havener said during his introduction of Norton. “It’s like trying to squeeze a sponge to get all the water out.”

The intent of the weather modification, also known as cloud seeding, program being developed is to increase rain and snow fall, resulting in greater streamflow benefiting water consumers in Southern California, Norton said at the beginning. After describing the SAWPA composition of agencies, he explained how cloud seeding would work.

Cloud seeding is a chemical process intended to increase the amount of precipitation, including snow or rain, during the storm season. When a storm is approaching and over the target mountain range, silver iodide is fired into the atmosphere.

Releasing particles of silver iodide into clouds in the upper atmosphere increases the chances of a cloud’s ability to produce rain or snow by providing a substance on which the gaseous water molecules can adhere and condense on. This aids in forming snowflakes or raindrops.

The Southern California mountains are the target area for increasing precipitation. The San Jacinto Mountains are one of four areas identified. The others include the San Bernardino, Santa Ana and the San Gabriel mountains. The higher elevations are more likely to produce more rainfall.

Following Norton’s presentation, Dave Hunt, former IWD director, expressed his concerns about the process, including the danger of using silver iodide.

“The question is not that cloud seeding is harmful, but how harmful,” Hunt asserted. “UC Berkeley Office of Environment, Health and Safety rates silver iodide as a Class C, non-soluble, inorganic, hazardous chemical that pollutes water and soil. It has been found to be highly toxic to fish, livestock and humans.

“Deepwater Chemicals, a key manufacturer of silver iodide for weather modification, warns of potential health effects in their MSDS,” he added.

Norton pointed out that weather modification, or cloud seeding, is being done in many countries and 11 states including three other California counties — Santa Barbara, San Luis Obispo and Sacramento.

No effects of using silver iodide have been shown, he said. “There’s exposure to silver in tooth fillings and more iodine in table salt.”

Although little or less rainfall conditions are continuing, Norton said, cloud seeding is “not a huge drought buster.” But if successful, it would enhance water supplies.

Currently the SAWPA is conducting an environmental assessment and plans to begin a four-year pilot project late in 2022 or 2023 to assess its viability in Southern California.

Computer analyses, based on results in other areas and local weather patterns, including dry years, suggested rainfall would likely increase by 3.5 to 4.5%, the largest increase being in the San Jacinto Mountains.

Total resulting stream flow would likely increase by 8,200 acre feet (AF). The greatest projected increase was 13.7% and this was estimated to be in the San Jacinto watershed.

Annual cost is estimated to be slightly more than $200,000 or $25 per AF. The pilot program total costs would approach $900,000 and SAWPA plans to submit a grant request to the state for 50% of the total.

Consequently, it has been asking member agencies and others, such as IWD, who would benefit, to contribute to the costs. As part of the agenda, the board was to consider a $20,000 payment. Norton suggested it could be $5,000 over four years.

“We’re hoping you’re willing to put money on the table,” Norton told the board during the discussion. “The amount is not important. It’s just a commitment.”

“The program is in its infancy and still being studied,” said Director Peter Szabadi, who then recommended that the item be tabled for a later review.

Before the board’s vote, Hunt recommended to the board that “… they send a letter to SAWPA stating that we do not want this done in our area.”

Szabadi’s motion was approved 5-0.