NRCS: February Colorado Basin Outlook Report

A picture named snowpackcolorado02072011

Hot off the presses here’s the February Colorado Basin Outlook Report from the Natural Resources Conservation Service. Here’s the summary:


Colorado experienced a dry month during January, with extremely dry conditions in portions of southwestern Colorado. Snowpack percentages have decreased from those of a month ago in all basins of the state. Given the excellent start to the year, snowpack percentages still remain above average nearly statewide. January was the driest month of the water year with precipitation totals well below average in most basins. As expected, runoff forecasts have decreased from those issued a month ago. The state can now expect below average runoff this summer across all of the southern basins. While the water supply cushion we developed after the December storms has eroded, much of the central and northern basins can still expect near to above average spring runoff. Reservoir storage continues to track near average in most basins.


What a difference just a month makes. After experiencing abundant snowfall during late December, the western storm track left most of Colorado high and dry during January. The driest basins were in southern Colorado where the combined San Juan, Animas, Dolores, and San Miguel basins decreased by 38 percentage points from last month and are now standing at 106% of average. Snowpack statistics in the Gunnison basin closely followed, decreasing by 32 percentage points and is now 126% of average. The monthly decreases were large enough in the Rio Grande basin to decrease the percentages to below average levels, now at only 80% of average. Colorado’s statewide snowpack dropped significantly this month; down from the January 1 totals of 136% of average to 117% of average on February 1. Even after such a dry month, above average snowpack totals prevail across most of the state. The highest percents of average remain across northern Colorado, where percentages that exceed 130% of average can be found in the Colorado and North Platte basins. Colorado’s eastern basins faired the best during the dry January, with only slight decreases recorded in the Arkansas and South Platte basins. The best snowpack news for this month is the comparison to last year’s February 1 snowpack totals. This difference is most striking across the northern basins where percents of last year remain well above those of last year, and is an impressive 188% of last year in the Colorado Basin. While this expresses this year’s abundance, it also reflects last year’s dryness in this basin. Statewide snowpack totals are now at 137% of last year’s February 1 readings.


Monthly precipitation during the 2011 water year has been on a rollercoaster with wet months followed by dry months. Fortunately, statewide totals for the three months of October through December were all above average, leaving January’s totals as the only month with below average percentages. Monthly totals of only 23% of average were recorded during January in the Rio Grande Basin, which was the lowest basinwide percentage in the state. Only the South Platte Basin recorded an above average total for the month, at 106% of average. Statewide precipitation measured at SNOTEL sites across Colorado was only 73% of average in January. For the four months comprising the water year, percentages range from 133% of average in the Yampa, White and North Platte basins to only 85% of average in the Rio Grande Basin. Statewide water year totals decreased by 18 percentage points this month and are now at 121% of average. These readings remain well above last year at 137% of those totals.

Reservoir Storage

As is typical during mid-winter, reservoir storage changed only slightly during January. Storage volumes are near to above average in all basins, with the exceptions of the Yampa, Arkansas and Rio Grande. The lowest, in terms of percent of average, is the Rio Grande Basin which now stands at 79% of average. In terms of storage volume, the lowest departure from average storage is in the Arkansas Basin, currently storing 91% of average volumes, or a deficit of 50,000 acre-feet. Only the Rio Grande and Arkansas basins are storing significantly less than last year at this time, at 85% and 91% of last year’s storage, respectively. The highest storage volumes remain in the Colorado and Gunnison basins this month, at 112% and 109% of average, respectively. With statewide storage now at 103% of average, volumes have exceeded the average mark by 90,000 acre-feet. This year’s statewide storage remains at 100% of last year’s volumes on this same date. Assuming inflows this spring and summer remain at or above average this year, late summer water supplies should be adequate for most water users across the state.


As one would expect after such a dry month, runoff forecasts have decreased across Colorado. While at least the northern basins can continue to expect above average summer water supplies, the greatest concerns remain across the southern basins which now are expecting below average runoff. The lowest forecasts continue to be along those streams originating in the Sangre de Cristo Mountains, where volumes of only 40% to 80% are expected. This month also saw runoff forecasts decline sharply in the headwaters of the Rio Grande and San Juan Rivers. Flows on those rivers are now expected to be consistently below average for the 2011 runoff season. These basins will need a significant turnaround in weather patterns over the next few months in order to see improvements in this year’s water supply outlook. Meanwhile, across most of central and northern Colorado the water supplies remain quite favorable. Above average volumes are forecast throughout the Colorado, Yampa, White, North Platte and most of the South Platte basins in 2011. As usual, continued snowfall is critical for maintaining these expectations, so monitoring the snowpack will be critical through the remainder of the winter.

Colorado-Big Thompson Project udpate

A picture named coloradobigthompsonmap.jpg

From email from Reclamation (Kara Lamb):

[On February 3], we began running some more water into Pinewood Reservoir. We anticipate the water level in the reservoir will steadily increase over the weekend. The reservoir is currently an elevation of 6563–about 17 feet from completely full. By Monday, February 7, we anticipate the reservoir will be at an elevation of approximately 6567. A week from today, it should be closer to 6570.

More Colorado-Big Thompson project coverage here.

Green Mountain Reservoir update

A picture named greenmountainreservoir.jpg

From email from Reclamation (Kara Lamb):

Today, February 3 2011, we increased releases from Green Mountain Reservoir to the Lower Blue River in two increments of 25 cfs, one in the morning, one in early afternoon. As a result, the Lower Blue should now be running at about 175 cfs. Currently, Green Mountain Reservoir is at a water level elevation of about 7904–about 46 feet down from completely full. However, because of the above average snowpack in the Blue River basin, we have increased releases slightly to help with what we anticipate will be a large run-off. The reservoir elevation will drop very slowly at this release rate. I will keep you posted of additional changes, if any.

More Blue River watershed coverage here and here.

Aspinall Unit update

A picture named aspinallunitdescription.jpg

From email from Reclamation (Dan Crabtree):

The Colorado River Basin Forecast Center (Center) has issued the February 1st monthly runoff forecast for Blue Mesa Reservoir and the Gunnison Basin. As of February 1st, the Center is forecasting an April through July unregulated inflow to Blue Mesa Reservoir of 775,000 AF, which is 108% of average. Spring runoff is still a long way off and the forecast will likely change, but if the current forecast were to hold to May 1st, the Black Canyon Water Right 24 hour peak target flow would be 6,340 cfs. Reclamation’s current plans are to operate the Unit with the intent of allowing the target to be met.

In order to ensure adequate storage in Blue Mesa Reservoir to control runoff, Reclamation needs to begin increasing releases from the Aspinall Unit. Releases from Crystal Reservoir are 500 cfs. These releases will be increased by 300 cfs in two changes on Tuesday, February 8th.

In addition, the January 2011 Aspinall Operations Meeting summary and operations handout can be found at: There are several clickable links within the summary that can be used to access other presentations and handouts.

More Aspinall Unit coverage here.

Colorado dam update

A picture named tetondamfailurewikipediacommons.jpg

From The Denver Post (Bruce Finley):

A review of state dam safety records also shows that a breach at any of 21 “high hazard” dams today likely would kill people living or working nearby. Failures at another 33 deficient “significant hazard” dams would cause major property damage. But dam repairs can cost millions of dollars, and Colorado Department of Natural Resources officials say they lack funds to help owners make repairs…

Over the past five years, state water officials loaned dam owners $50.8 million to complete 35 dam rehabilitation projects. Lawmakers since 2009 have siphoned $120 million in state water-project funds to help deal with budget shortfalls. Now officials are bracing for cuts that they say will limit support for dam repairs…

There are more than 1,900 dams around the state, giving a capacity to store 7.5 million acre-feet of water. Those dams range from earthen berms built 100 years ago at isolated agricultural sites to the large urban-area structures constructed during the 1950s and 1960s to enable rapid population growth.

More than 50 major dams are located at federal facilities run by the Bureau of Reclamation. Federal engineers are investigating possible problems at six of those dams — Twin Lakes, Green Mountain, Granby, Mary’s Lake, Ruedi, and Ridgeway, said Bureau of Reclamation spokesman Peter Soeth…

The most problems have built up at dams that a dozen or so state inspectors oversee. The latest data indicate 176 dams are so deficient that restrictions were imposed to prevent blow-outs. That number is up 8 percent since 2009, when state inspectors deemed 163 dams deficient. The overall result is a loss of the capacity to store 117,000 acre-feet of water. By comparison, Chatfield Reservoir southwest of Denver stores 27,000 acre-feet of water. Denver Water’s Cheesman Reservoir holds about 75,000 acre-feet. “There’s no question, if we can use existing structures to beef up and support our water supply, that’s a better way to go,” said Alex Davis, assistant director of natural resources…

Dam and reservoir operators often lack the ability to deliver water to current water users. And lining up ownership rights for water to put in reservoirs — such as Parker’s massive new Rueter-Hess reservoir — has proved increasingly difficult…

It cost suburban water authorities and farmers $32.5 million to rehabilitate the ailing Standley reservoir dam where, if a breach had occurred, more than 100,000 west metro area residents would have faced harm.

More coverage from Bruce Finley writing for The Denver Post. From the article:

Colorado dam safety overseers say they face about a dozen security incidents each month at water storage facilities around the state. These range from reports of suspicious activity, such as a person spotted on a downstream face of a dam taking photos, to people threatening to blow up dams with explosives, said Mark Haynes, chief of dam safety in the Colorado Department of Natural Resources. “On a weekly basis, I get about three or four suspicious-activity reports,” Haynes said.

More infrastructure coverage here.

Snowpack news

A picture named snowpackcolorado02042011

From The Pueblo Chieftain:

A weather spotter in Trinidad said about a foot of snow fell Saturday and early Sunday. Streets were slippery early Sunday and residents across town were shoveling snow from sidewalks and driveways. About a foot of snow fell in Walsenburg and other parts of Huerfano County, too. A spotter near Cuchara and La Veta reported about 2 feet of snow. Residents there were plowing snow early in the morning…

In the Upper Arkansas River Valley, Canon City residents awoke to 3.5 inches of snow Sunday. A total of 5.5 inches of snow fell in Penrose. In Custer County, Wetmore residents reported 10 inches of snow. In Chaffee County, Monarch Mountain reported 10.5 inches of snow fell overnight.