Snowpack news

A picture named snowpackcolorado01122011

From The Mountain Mail (Paul Goetz):

Allen Green of the National Resources Conservation Service said Wednesday that by Jan. 5, statewide snowpack was 136 percent of average. He said that’s the highest Jan. 1 snowpack measured since 1997 when the state reported overall snowpack at 160 percent of average. Snowpack in the Arkansas River Basin was 105 percent of average while reservoir storage was 93 percent of average. Snotel sites maintained by the conservation service reported depths ranging from 30-45 inches in the Upper Arkansas River Basin. Water content ranged from 6.8-10.3 inches. Gunnison River Basin snowpack averaged 156 percent, Colorado River Basin was 147 percent, South Platte River Basin has 126 percent, North Platte Basin has 147 percent, Yampa and White river drainages show 145 percent. In addition, the Rio Grande drainage has 107 percent and the basin of the San Miguel, Dolores, Animas and San Juan rivers was 144 percent of average.

Meanwhile, many eyes are focused on the water level at Lake Mead. Here’s a report from the Las Vegas Sun (Dylan Scott):

Snow accumulation in the Colorado River Basin above Lake Powell in Utah is more than 30 percent above historical levels, the bureau estimated. If that number holds steady through the spring, Lake Powell’s depth could rise to 3,643 feet, a trigger point that would prompt the bureau to release at least an additional 3.13 million acre-feet of water into Lake Mead over the summer. As part of the Colorado River Compact, Lake Powell annually releases 8.23 million acre-feet of water into Lake Mead. According to agency statistics, if the higher threshold were reached at Lake Powell, a total of 11.36 million acre-feet of water or more would flow into Lake Mead by September. Andrew Munoz, spokesman for the Lake Mead National Recreation Area, said 100,000 acre-feet is equal to about 1 foot of elevation on the lake. If 3.13 million additional acre-feet of water was pumped into the lake at once, the surface level would rise more than 30 feet…

The Bureau of Reclamation projected a 76 percent chance that Lake Powell would reach the 3,643-feet threshold by April 1, the deadline for a decision to be made.

Click through for the photo slideshow showing the flooded town of St. Thomas. In the recent past the town was part of the lake bottom but these days it sits on the shore of the Colorado River.

From the Valley Courier (Ruth Heide):

Recent snowstorms brought the Rio Grande Basin (San Luis Valley) up to almost average levels of snowpack, Division of Water Resources Staffer Pat McDermott reported in the Rio Grande Roundtable meeting on Tuesday…

At the same time, precipitation has been down in recent years. Last year’s precipitation was only 6 inches, for example, more than an inch lower than the 7 1/4 inches average precipitation, and in 2008 the annual precipitation was only 5 1/2 inches…

As far as snowpack on January 11, the Upper Rio Grande Basin sat at 114 percent of normal, with some areas such as Wolf Creek much higher. Wolf Creek Summit’s SNOTEL site showed 136 percent of normal snowpack as of Tuesday, the Upper San Juan site 130 percent, Beartown 104 percent and Cumbres Trestle 131 percent…

The Valley’s east side, the Sangre de Cristo Mountain Range, was showing a different picture, however. McDermott pointed out that as of Tuesday, the Sangre de Cristo Mountain Range basinwide was showing only 62 percent of normal snowpack. The Culebra near San Luis, for example, was at 58 percent of normal. Medano Creek was sitting at 53 percent of normal, and North Costilla was 45 percent of normal. The highest snowpack in the Sangres was Ute Creek at 70 percent of normal…

The Rio Grande nearly “broke even” but ultimately appeared to have over-delivered about 300 acre feet, McDermott reported. That’s a pretty close call, considering the annual index supply on the Rio Grande totaled more than 539,000 acre feet. Of that, the river owed about 26 percent of the flow to downstream states New Mexico and Texas under its Rio Grande Compact agreement.

The Conejos River system over-delivered to downstream states by a much larger amount, about 2,300 acre feet, but part of that was by design, according to McDermott. He explained that because Colorado is storing water in the post-compact reservoir Platoro when it is not supposed to be (but cannot help doing so), it will basically trade its credit water from the Conejos River system with New Mexico and Texas to make up for the water it is storing in Platoro.

(When the Rio Grande Compact reservoirs in New Mexico reach a project storage level of less than 400,000 acre feet, post-compact reservoirs upstream are not allowed to store water, and that includes Platoro Reservoir. The reservoir storage in New Mexico is currently much lower than 400,000 acre feet. Because of current conditions at Platoro, however, the water cannot be released downstream.)

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