Snowpack news (Part 2): So far so good for Colorado Springs’ water supply

From The Colorado Springs Gazette (Ryan Maye Handy):

In mid-March, Dan Martin drove a snowcat 8 miles into the White River National Forest, headed for the place where Colorado Springs’ water supply begins. The cat lumbered along a forest service road at 10 mph, a road that Martin has driven every winter for nearly 20 years. A barbed wire fence lines the road, its wires half submerged in months of snow.

“There’s times when you can’t see this barbed wire fence,” Martin said. “To me, that’s a great year.”

Among other things, Martin measures snowpack for a living. But his time in Homestake Valley near Tennessee Pass has given him an extra snow sense. By barbed-wire fence standards, the water year for Colorado Springs is looking good.

After two years of low snowpack followed by a record-breaking year for snowfall, snowpack in Homestake Valley is solidly above average in 2015 – around 112 percent above average, based on a 30-year record. March is still winter in Colorado’s mountains, a crucial time for snowpack to keep building.

But snowpack levels are volatile – if snow doesn’t continue to fall in March and April, and if snowmelt begins too early, Colorado Springs, which gets much of its water from Homestake, could find itself facing a water deficit.

Martin monitors the snowpack closely for Colorado Springs Utilities to catch slight changes that could predict a good or bad water year.

Last winter was a record-breaking year of snowpack in Homestake Valley, but other years have been leaner. Sometimes the snow along the road is gone by spring’s end. Other times it lingers, soaking the valley until the end of summer.

“I’ve seen snow up here in August,” Martin said. “That’s probably 15 years ago, maybe. Sometimes it’s gone as soon as May. It depends on the snowpack.”

Snow in Colorado’s mountains is more than aesthetic and a blessing for ski resorts. For cities such as Colorado Springs and Aurora, snow in the White River Forest means water.

From January to April, Martin drives twice a month into Homestake Valley to take snowpack measurements, which help Utilities gauge its reservoir levels for the coming months. For Utilities customers, snowpack measurements determine watering restrictions come summer.

Water has around 200 miles to travel from Martin’s snowpack measuring tube to a faucet in Colorado Springs. It flows through Colorado River tributaries into three reservoirs, gets pumped over the mountains and is pulled pushed by gravity into Colorado Springs.

Aurora and Colorado Springs share the Homestake Water system, which conveys 70 percent of Colorado Springs’ water. Like water systems around the state, it depends heavily on winter and spring snowfall to fill its reservoirs every year.

Seeking snow

Mark Hanratty and Martin have measured snowpack for Colorado Springs and Aurora for more than a decade, and they return to the same spot every year in Homestake Valley to calculate the snow’s depth. They measure it in a drainage just off the forest service road, an area shaded by trees and where there is always snow.

“Anytime we come in here, we know we are going to have a lot of snow,” Hanratty said. The area’s wealth of moisture usually lingers for months after the mid-June snowmelt. “This is like the 9th green here in the summertime,” he added.

Mid-March is prime snow season for Colorado. The state typically receives most of its snow in March and April – no snow in late winter can signal a drought is in store.

“Springtime up here has nothing to do with when tulips and daffodils are coming up in your yard down there,” Hanratty said.

While March may leave Colorado Springs residents eager for warmth and greenery, Martin and Hanratty are praying for snow.

For their mid-March visit to the valley, Hanratty and Martin pulled their two snowcats into the drainage, covered by more than 3 feet of snow. Hanratty jumped out, sinking to his knees, with his 32-ounce aluminum snowpack measuring tube in hand. When stuck into the snow, the hollow metal tube measures the depth as well as its snowwater equivalent – there is about 1 inch of water to every foot of snow.

Hanratty tossed the tube into the snow – making sure that it was perfectly straight – and measured 47 inches of snow. The tube has to hit the dirt to get an accurate measurement. Hanratty weighed the tube and subtracted its weight from the total to come up with the snowwater equivalent of 18 ounces.

In layman’s terms, that puts the snowpack in Homestake Valley just above average. Later, a spreadsheet will translate the ounces into something more tangible – a water forecast for the upcoming summer.

While the tube measuring method might seem archaic, it is used around the West for measuring snowpack. Hanratty has no need for anything more high-tech and convenient, he said.

Crunching numbers

While Martin and Hanratty measure snowpack, Abby Ortega, a planner with Utilities, watches it through charts, graphs and data. But numbers are more than numbers to her, just as reservoirs aren’t quite as simple as they seem,

“Really I work on a spreadsheet all day,” she said. The spreadsheet tracks types of water. “You guys look at a reservoir and see a bucket of water. I see layers within that water.”

The layers depend on where the water came from, who owns it, and where it has to go. Built in the 1960s, Homestake Reservoir sits above 10,000 feet – it holds 43,000 acre-feet of water, and while it’s narrow, its depths reach 215 feet. In the winter, 4 feet of ice covers the reservoir. While good snow years come and go, there is always snow at Homestake in the winter, Hanratty said.

“The most snow I’ve seen up here was just over 7 feet,” he said.

The reservoir sits in an avalanche path – in the early 1990s, two years of avalanches destroyed an outlet hut along Homestake Dam. Some years, Utilities will hire contractors to trigger avalanches from the ridge above. Meanwhile, the hut was moved underground.

Homestake is where Colorado Springs’ water begins its journey eastward. After the reservoir, water is sent from Homestake to Turquoise Lake, then to Twin Lakes Reservoir.

Just north of Buena Vista, the Otero Pump Station pushes the water 750 feet over the mountains, and then it is pulled down the eastern side toward the Front Range. Half of the water goes to Spinney Mountain Reservoir, which feeds Aurora, while the rest travels down a pipeline to Rampart Reservoir.

Colorado Springs Utilities has been measuring snowpack in Homestake Valley since 1978, a much shorter span of time compared with the Natural Resources Conservation Service, which has been taking snow measurements around the West and in Colorado since 1935.

But the nearly 30-year span gives Utilities plenty of data to help forecast water levels for its reservoirs, which in turn determine water use for months and years. Monitoring snowpack levels in Colorado’s mountains is crucial for Front Range cities and for all of the 18 states downstream, to the east and the west, where Colorado’s rivers flow.

Four major rivers flow out of the state, including the Platte, the Arkansas and the Rio Grande, but the Colorado River, with its headwaters in Rocky Mountain National Park, is perhaps the most endangered. The river feeds California but it also provides water to the Arkansas River Basin, home to Colorado Springs, and feeds the reservoirs in the Homestake System.

Unlike other Front Range cities, such as Fort Collins, Colorado Springs is not near a major river, and relies instead on tributaries and recycled water to feed its water reserves, said Ortega. Having water storage is key to helping Utilities to weather a drought.

“If you can leverage those wet years with storage, you can ride through the dry years,” Ortega said.

Reservoirs are difficult to construct and even more difficult to get approved, since environmental regulations have tightened since the 1960s.

While Utilities may not add another reservoir, it is looking to the Southern Delivery System to offset stresses – population growth, drought and other system outages – on its existing system.

The Southern Delivery System is a regional project to bring Arkansas River water from the Pueblo Reservoir to Colorado Springs, Fountain, Security and Pueblo West. The project is expected to deliver water beginning in 2016.

“That pipeline is going to be our water supply,” Ortega said.

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