by John Orr
La Niña, snowpack and runoff
The picture can change quickly when you’re watching the Colorado snowpack. On March 26 snowpack as a percent of average was declining in the Arkansas basin and San Luis Valley but by the end April things had improved considerably.
The winter was dominated by La Niña. Cool water in the eastern Pacific Ocean off South America often sets up very wet conditions in the northern Rockies and a drying out across the southern Rockies. That’s pretty much what happened this year.
Up until the gangbuster snowmakers of April the eastern San Juans, Sangre de Cristos and Wet Mountains all had below average snowpack.
The Rio Grande is in trouble from stem to stern due to drought and abnormally dry conditions from above Creede to the Gulf of Mexico. At the May meeting of the Rio Grand Roundtable, Colorado Division of Water Resources engineer Craig Cotten told the group, “We are looking at about a 75 percent of average year on both systems (Rio Grande and Conejos), roughly,” according to the Valley Courier.
Snowpack above Antero Reservoir in the South Platte Basin was below average until late April and May, and the Sangre de Cristos in the southern part of the San Luis Valley are very dry.
At the May 11 meeting of the Colorado Water Conservation Board’s Water Availability Task Force, the representative from Colorado Springs Utilities reported very dry conditions on south slope of Pikes Peak, “The system is going to struggle there,” she said.
It’s very different in Central Colorado. The snowpack at the headwaters of the Gunnison, Arkansas and Roaring Fork is well above average. On May 17 The Pueblo Chieftain reported that snowpack at the Roaring Fork Headwaters was 220% of average. That’s good news for the Upper Arkansas Valley in that there should be a sufficient supply through the Boustead Tunnel (Fryingpan-Arkansas Project) to keep flows up for the rafting season.
Snowpack across the northern mountains is record setting. Buffalo Pass and Cameron Pass both had record peaks this year.
This is all very typical for a La Niña year and this winter’s event was the strongest in 35 years, according to forecaster Klaus Wolter. It’s interesting that La Niña’s north/south divide is running through Colorado.
This is the time of year when irrigators, whitewater enthusiasts, flood response personnel and water suppliers all watch the stream gages to track runoff.
“Snowpack has remained at peak levels statewide for a full month longer than normal because of continuing snowstorms and late runoff,” according to The Pueblo Chieftain.
A good example is the gage on the East Fork of the Arkansas River at Leadville. The current value (May 18) is 33 cubic feet per second (cfs). The median value for the station on this date is 65cfs. So flows are roughly half of the median.
The creek should come up soon. The Leadville Herald-Democrat reports that Lake County had received 166.6 inches of snow by April 30.
On May 17 Bureau of Reclamation spokesperson Dan Crabtree reported via e-mail that they are having trouble calculating the peak operation through the Aspinall Unit (Blue Mesa, Crystal and Morrow Point dams) due to the late start to runoff and continuing storms over the headwaters.
The near term forecast for Colorado – according to the National Weather Service – is for continued below average temperatures across the state and good moisture across the northern mountains.
As we go to press the runoff is just starting up. When you read this the runoff should be well underway. Be careful out there. If you haven’t purchased flood insurance you’re probably out of luck. There is a 30 day waiting period for it to take effect.
Pueblo County commissioners deny zoning for nuclear power plant
An inscription on former U.S. Representative Wayne Aspinall’s memorial next to the Colorado River in Palisade reads, “In the West, when you touch water, you touch everything.” The quote is attributed to the water mover and shaker and he is spot-on when talking energy and water.
Normally a story out of Pueblo County wouldn’t be a subject for this column since geographically events below Cañon City are not on my beat. But this one turns out to be a water story and after all – as we’ve learned from recent events in Japan – anyone within 50 miles of a nuclear plant, like Cañon City would be, are in the evacuation zone if there is a meltdown.
At the end of April the Pueblo County Commissioners denied a zoning change request for a “clean energy park” just outside the city of Pueblo. The lynchpin project for the new park was going to be a nuclear power generation plant.
Pueblo attorney Don Banner’s timing could not have been any worse. The Japanese nuclear crisis started the Friday before the commissioners were to hold hearings on the zoning change.
Also, as the project sponsor, Banner never identified a source for the cooling water requirements for the plant.
After all was said and done the commissioners were unanimous in their decision. Commissioner Jeff Chostner attributed his decision to pressure on agricultural water and the availability of an emergency water supply. He told The Pueblo Chieftain, “And the last resort if we needed water for an emergency would be the Pueblo Reservoir. The county does not own a drop of that water.”
• Back in April students from the Colorado School of Mines were up near the Chalk Cliffs mapping the geologic structure of the basin at the northern end of the Rio Grande Rift, according to The Mountain Mail.
• In April, Trout Unlimited awarded the Collegiate Peaks chapter $4,500 to conduct planning for the restoration of the South Arkansas River.
• Denver Water is planning to draw down Antero Reservoir the first week of May to scope out the perpetually leaky dam.
• Governor Hickenlooper told the Colorado Ag Water Alliance at their May meeting, “My job is to see that we hold water up front and center to those in urban areas, so they realize how dependent we are on agriculture and the rural areas,” according to The Pueblo Chieftain.
John Orr follows Colorado Water issues at Coyote Gulch http://coyotegulch.net