New Mexico may turn to cloud seeding in attempt to improve snowfall

Nov. 20—As the drought drags on, New Mexico state officials want to pull snow from the skies using human intervention rather than relying on hope and prayer.

A Colorado company will employ a 75-year-old method known as cloud seeding in an area covering the Sangre de Cristo Mountains and six other counties with the aim of boosting precipitation and increasing the snowpack during a winter that is expected to again be drier than normal due to an El Niño weather pattern.

Western Weather Consultants has applied with the Interstate Stream Commission to set up seven machines that will release silver iodide vapor into the atmosphere during storms so the substance can be absorbed into some clouds, increasing ice crystals and producing more snow.

The company plans to conduct 200 hours of cloud seeding from Dec. 13 to Feb. 28. It will encompass parts of Santa Fe, Taos, Rio Arriba, Mora, San Miguel and Colfax counties.

The Roosevelt Soil and Water Conservation District in Eastern New Mexico is paying the company $55,000 for the work. It's using part of the $212,500 in weather modification funds it received from the state Department of Agriculture.

"There's no place in New Mexico that doesn't need more water," said Rick Ledbetter, treasurer for the district's board of directors.

Cloud seeding has been done sporadically in New Mexico in the decades since it was invented in a General Electric laboratory in 1946.

Although the period for public comment ends on Sunday, the commission will hold a hearing from 8 a.m. to noon Monday to give people another opportunity to weigh in.

How well cloud seeding works remains in question. Estimates vary depending on the time of year, the storms' direction and the water content in the clouds.

Eric Hjermstad, who co-owns Western Weather, said measuring results is an inexact science.

But data collected over the years and advances in technology peg the average increase in snow from cloud seeding at 3 percent to 8 percent over a season, Hjermstad said.

He added the company uses data sources such as SNOTEL, a federal sensor system that measures snowpack depth, to get an idea of how precipitation might have risen in areas where cloud seeding was done.

But even these metrics are not precise in pinning down the activity's impact on snowfall, he said.

"We're not creating purple snowflakes, so we can't go up and just measure how many purple snowflakes there were in an area," Hjermstad said.

Several years ago, the Wyoming Weather Modification Project led researchers to conclude that although they found no definitive answer on how effective cloud seeding could be, it worked under certain conditions.

Basic experiments conducted in the past 60 years, comparing snow on a mountain where clouds were seeded to one in which no seeding took place, consistently showed a 3 to 8 percent increase from seeding, Hjermstad said.

The amount of water that comes from bulking up the snowpack through cloud seeding can add up to thousands of acre-feet, with a cost of $3 to $7 per acre-foot.

An acre foot is roughly 326,000 gallons, enough to supply the average U.S. household for a year.

"It's a cheap way of getting water that typically wouldn't be there," Hjermstad said.

The plan calls for strategically placing seven machines, each with a different property owner, and training the owners how to operate them, he said.

A silver iodide solution is injected into a propane flame that vaporizes it. From there, it's released into the atmosphere.

Hjermstad said he and others in the company will track storm reports and other data, such as ice covering aircraft, to determine if conditions are right for a seeding in a particular area. Operators are told when to crank on a generator, he added.

Cloud seeding has raised concerns among some environmentalists who point to studies showing silver iodide in high enough quantities can harm microorganisms, fish and other wildlife. It also can contaminate water and soil.

A 2016 toxicological study suggested repeated cloud seedings in an area might cause enough of the substance to accumulate to be harmful to the ecosystem.

But Ledbetter said he has read through various studies that conclude seasonal cloud seeding doesn't leave enough residue to pose any environmental or health hazards.

"They said there is not a detectable increase," Ledbetter said.

He added cloud seeding has been done for many years in California with no reports of contamination and health problems, Ledbetter said. Given how environmentally conscious that state it is, he said there would've been bad publicity if cloud seeding proved harmful.

During the last legislative session, lawmakers expressed an interest in having this work done in the northern areas, partly to improve the snowpack in ski areas that depend on tourism, he said.

The Legislature then allocated money to the Agriculture Department for cloud seeding, for which he was grateful, Ledbetter said.

"We've been trying to get this going for five or six years," Ledbetter said.