High snowpack a mixed bag for trans-mountain water diversions

by Nelson Harvey, Aspen Journalism

Some diverters ramping up withdrawals as others draw down

As this winter’s banner snowfall helps refill mountain reservoirs drained by the historic drought of 2012, it’s also allowing administrators of at least two major trans-mountain diversion water projects in the Roaring Fork watershed to plan for larger-than-normal diversions to the Front Range this year.

The Fryingpan-Arkansas Project is expected to divert 73,000 acre-feet of water in 2014 from the headwaters of the Fryingpan River above Ruedi Reservoir to the Arkansas River basin on the East Slope. One acre-foot is equivalent to 325,851 gallons, and over the last 12 years, the project has diverted an average of 54,000 acre-feet, making this year’s projected diversion 35 percent larger than average.

The Twin Lakes Reservoir and Canal Company, which manages a four-mile-long tunnel piping water from the headwaters of the Roaring Fork River on Independence Pass to the Arkansas River basin, is also tentatively planning to divert between 53,000 and 55,000 acre-feet of water this year. According to Kevin Lusk, the president of the company’s board of directors, that’s as much as 20 percent more water than the project’s average annual diversion of about 46,000 acre-feet, most of it destined for the cities of Colorado Springs and Pueblo.

But at least one other trans-mountain diverter — the Pueblo Board of Water Works — is actually planning to pipe less water to the East Slope this year through the Busk-Ivanhoe tunnel above the Fryingpan than usual, since above-average snowpack in the Arkansas River basin should help the city meet its water needs.

“It’s a lot less than we usually divert in the average year,” said Pueblo Water Resources Supervisor Ed Perko of the city’s planned 1,500 acre-feet diversion this year. Most years, Perko said, Pueblo diverts at least 2,500 acre-feet through the Busk-Ivanhoe tunnel.

“We have more snowpack,” Perko said, “so we need to divert less.”

Although peak runoff is likely weeks away, all three of the trans-mountain diversion projects in the Roaring Fork watershed are already piping water to the East Slope. On Sunday, a gauge at the Twin Lakes Tunnel’s entrance registered a flow of 22.3 cubic feet per second, or roughly 10,000 gallons per minute, heading into the tunnel. Similar gauges at the Boustead Tunnel (part of the Fryingpan-Arkansas project) and the Busk-Ivanhoe Tunnel registered flows on Sunday of 2.49 cfs and 1.43 cfs, respectively.

Boosting reservoirs, quelling early season fire danger


The ample water supplies that make historically large diversions possible also are aiding local reservoirs this year. Storage in the Colorado River basin’s reservoirs hovered around 93 percent of average on April 1, up from just 65 percent of average on the same date in 2013.

The storage picture is likely to improve even further in the coming months. Mage Hultstrand, a hydrologist for the National Resources Conservation Service, told a meeting of the Governor’s Water Availability Task Force in Denver this past Wednesday that snowpack in the Colorado River basin stood at 130 percent of average as of April 1. That early surplus means that the basin could still have an average water year even if it received just 83 percent of normal precipitation for the rest of 2014, Hultstrand said.

At last week’s task force meeting, officials charged with securing water for Front Range cities like Denver, Fort Collins and Colorado Springs said their own reservoirs already are between 80 and 90 percent full, even though peak spring runoff is likely more than a month away. The healthy storage numbers make it less likely — though not impossible — that Front Range cities will have to institute mandatory watering restrictions this summer like they did during the drought of 2012.

Despite the above-average snowpack still blanketing much of the state, drought conditions persist in parts of southern Colorado. Both the Rio Grande basin in southeastern Colorado and the San Juan basin in southwestern Colorado are drier than is typical at this time of year, according to the monthly Surface Water Supply Index tabulated by the Colorado Division of Water Resources.

Such dry conditions have prompted state fire officials to forecast that southern Colorado could see the highest rates of wildfire danger in the state during the summer season.

Rocco Snart, the acting section chief for the state division of fire prevention and control, told those present at the task force meeting on Wednesday that southeastern Colorado currently faces the highest wildfire risk of any area in the state, while risk in southwestern Colorado will likely ramp up in June and July.

“That does not mean that we can’t have large fires in the rest of the state,” Snart cautioned, noting that long-term climate forecasts call for above-average temperatures across much of Colorado this summer, but only average rates of precipitation.

Whether or not the healthy snowpack in the Colorado River basin will translate into a mellow fire season here largely depends on the weather between now and mid-summer, according to Doug Paul, a fire mitigation and education specialist with the federal Bureau of Land Management.

“When we have a normal or above normal snowpack, sometimes that can mean a less intense fire season, but if it warms up quite a bit we can get the runoff pretty quick, the snow cover leaves pretty quick, and we dry out the fuels pretty quick,” Paul said.

Whatever the intensity of the coming fire season, Snart said the state’s wildfire fighting efforts would be bolstered by lawmakers’ recent appropriation of $21 million to purchase four new single-engine air tankers for the statewide firefighting fleet. Tanker pilots will patrol the state during fire season, seeking to detect fires early and snuff them out.

As high runoff nears,
 Front Rangers fret about floods


As residents of southern Colorado contemplate a high-risk fire season, people along the Front Range have another sort of natural disaster on their minds this spring: floods. Last September, flash flooding destroyed and damaged homes, roads, bridges and other infrastructure in 20 Front Range counties. Now, concern is running high that when runoff courses down through stream and riverbeds that were rerouted by last year’s floods, a second round of flooding could result.

Many Front Range communities are racing to get ahead of the threat by stabilizing stream banks, shoring up roads and putting other watershed protections in place before spring runoff kicks into high gear next month.

Robert Glancy, a meteorologist with the National Weather Service, told last week’s task force meeting that recent bouts of warm weather in the central mountains have helped jump start the spring melting process, drawing down the snowpack and reducing the likely strength of future floods.

“I’m glad that we’re melting now, because it’s wearing down the snowpack,” Glancy said.

Still, he said substantial flood risk could persist if Colorado’s high altitudes see lots of rain in the next few months, because it could produce more runoff while also accelerating the speed of snowmelt in the high country.

Editor’s note: Aspen Journalism and the Aspen Daily News are collaborating on coverage of water and rivers. More at www.aspenjournalism.org.

nelson@nelsonharvey.com