High Tech Snowmaking Fills in for Mother Nature

04 February 2013
Published in Technology
Written by  Wina Sturgeon
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High Tech Snowmaking Fills in for Mother Nature Dylan Felton/Park City Mountain Resort

The snow at Utah ski resorts is plentiful this season, but a year ago it was not. The country’s snowfall at ski areas was down 41% and visits to Utah’s ski areas were down by 10%. To beat mother nature’s unpredictability, most Utah resorts have invested heavily in snowmaking.

Alex Divers, head snowmaker for Park City Mountain Resort, is one of their most valuable employees. Recent storms have allowed snowmaking to slack off, but during the early season, or seasons with sparse snow, making the stuff is constant labor. Divers explained, “There's no days off. Snowmaking runs 24 hours a day and moves really fast, so you can't be absent”. Even on snowy days, snowmakers fill in areas where skiers or snowboarders have scraped snow down to an icy base.

The job is demanding. Heavy snow guns have to be pulled by sled to the precise spot where snow is needed. Nozzles and fans must be manually adjusted in the freezing cold. Water must be cooled to the perfect temperature so that it explodes into snow when blown into the air. All this for the sake of skiable snow.

Science of snowmaking

Divers, his crew, and snowmakers at resorts along the Wasatch Front, are more than snow makers, they are snow scientists. But instead of a warm laboratory, their work is done in freezing temperatures.

"We can make 20 different kinds of snow, from a wet heavy snow to a light kind of powder. Wet snow is used for a base layer to blanket the whole run before we make skiable snow on top of it," says Snowbasin supervisor Cody Jones.

The ingredients of man-made snow are not just water and cold air. Water crystallization can only begin once snow particles have something to 'grab' onto. Some resorts nucleate snow crystals with "Snomax", a bacterial protein that allows crystallization to occur at warmer temperatures. Controversial because it comes from genetically modified bacteria, most Utah resorts load their guns with tiny particles of ice or dirt instead.

Snowmakers also know that successful snowmaking is inextricably tied to the weather. In a worst-case scenario, if the air is too humid and warm, water won’t cool to the freezing point, and the guns will shoot rain instead of snow.

Despite automated technologies, a snowmaker’s judgment is critical. "We still have to go out on a snowmobile to check the plume of every (operating) snow gun,” says Brian Dubuque, Snowbasin’s head snowmaker. “You grab a handful off the ground and kind of squeeze it in your hand, and if it's the density you want, you leave it, or you call back up to the control room and tell them to wet it up a little bit, or if it's too wet, you tell them to dry it up a little bit."

The effort can mean insurance for a ski area. Park City Mountain Resort estimated that just before Christmas, 2011 – peak season - 87% of its runs were open due to snowmaking.

High tech systems are an investment for the future

The biggest and most modern snowmaking system in the United States is at Snowbasin resort in Huntsville. It was built for the 2002 Salt Lake Olympics, and is still one of the most advanced in the world and is totally computerized. The system controls 540 snow guns fueled by15 miles of dual pipes buried underground, one pipe for highly pressurized air, the other for pre-cooled water.

"Our system is 100% automated. You tell it what kind of snow you want it to make, it finds the pressure inside the hydrant and makes the snow,” says Dubuque.

Within a huge mid-mountain building lies the heart of the operation, a control room that seems like something from a NASA lab. A multitude of gauges monitors the pressurized air, which leaves the pump at nearly a thousand PSI (pounds square inch), and regulates water temperature to within one-tenth of a degree. Computers make automated adjustments based on data from 100 weather stations throughout the mountain, changing the water temperature, or changing the mix of water and air to get the right snow consistency.

The technology behind snowmaking makes it one of, if not the biggest expenses at a resort. "It costs roughly $903 an acre foot---covering one acre with one foot of snow---and 95% of that is power costs. So if power costs go up, it gets more expensive for the resort," says Divers. That's not even counting the cost of the snowmaking guns, which can range from 25 to 75 thousand dollars.

Every Wasatch Front ski resort, except Powder Mountain, the highest elevation resort, has decided that the expense and effort of snowmaking are worth it.

Randy Doyle, general manager of Brighton resort in Little Cottonwood Canyon acknowledges that being able to make snow can mean survival for a winter resort. "If we didn't have snowmaking, we wouldn't have been able to open until much later."

With a warming planet and associated variable weather, snowmaking could be even more important for Utah ski resorts in the future.

Snowbasin snowmaker David Roberts directs
a crew member who is manually adjusting
snow gun nozzle angles.
Every green rectangle is a weather station,
every dot is a snowgun.

water coolers

snow gun nozzles
Tanks and pipes in the snowmaking building
allow water to be temperature adjusted to 
one-tenth of a degree.
A selection of snow gun nozzles.

 Photo credits: Wina Sturgeon

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