Another day another drop in statewide snowpack levels. Click on the thumbnail graphic for the statewide snowpack ogive from the Natural Resources Conservation Service. The NRCS calculates that Colorado would need precipitation at 903% of average to reach the average peak snowpack for the year. That probably won’t happen so everyone needs to start thinking about conservation, now. Storage should get the cities and many irrigators through this season but there may not be much runoff to store for next season. We could also see a early runoff peak that will pass by the direct irrigators before they need the water and reduced flows for whitewater fans.
Here’s a report from Bob Berwyn writing for the Summit County Citizens Voice. From the article:
…this month is tracking toward becoming the driest March on record for many locations, including Summit County, where the snowpack has dwindled to just 68 percent of average based on SNOTEL readings from most of the higher elevation sites, including Grizzly Peak, as well as Fremont and Hoosier passes. “The temperatures just keep getting warmer and the snow keeps disappearing,” said Blue River Basin water commissioner Troy Wineland, responsible for administering water rights in for ranchers and other users. The best thing Wineland could say was that the snowpack readings look a bit better than 1981, another notoriously dry year. But as of Wednesday, the numbers were looking ominously similar to 2002, which ended up as one of the driest years on record…
“In general, most of the water providers look to April 1 snowpack numbers to get an idea of what kind of runoff they’re going to have through the season,” said Scott Hummer, who preceded Wineland in the water commissioner post and now is a special project manager for the Colorado Water Trust. “It’s mirroring 2002 in some places, and the Upper Colorado is less than 2002 … In 2002 it was 33 percent below average, this year, it’s down to 40 percent below average,” he said. “The best thing that the state has going for it right … they’ve got enough water in storage, combined with what runoff is going to come this year, to make it through this year in pretty good shape,” he said, adding that water restrictions may be in store for some jurisdictions. “The one thing that I’ve noticed is that water is already starting to move,” he said, referring to the early runoff. “Many stream gages are already running way way above historic averages.”
Here’s a release from Denver Water (Stacy Chesney):
A relatively dry winter across Colorado and recent wildfires have some people asking about the water outlook for the summer.
“Spring in Colorado can be unpredictable, so it’s too early to say what our water outlook will be,” said Sally Covington, director of public affairs for Denver Water. “But we are concerned about how dry it’s been.”
As a result, Denver Water is asking customers to use only what they need as we move into spring.
“Customers’ continued conservation habits have made a huge difference in our water supply,” said Covington.
While Denver Water’s reservoir storage currently is above normal for this time of year due to 2011’s wet conditions and customers’ continued conservation habits, the utility asks customers to be mindful of the impact of dryness on supply availability, offering the following guidelines:
Check your sprinkler system for leaks — a lot of outdoor water use is wasted due to leaks in irrigation systems.
Hand-water your trees and shrubs.
Watering your lawn once a week or once every two weeks during this dry spell should suffice. To encourage deeper root growth and more drought-resistant lawns, water thoroughly once, rather than brief spritzes.
Associated Landscape Contractors of Colorado President Barry Wagner offers this advice: “It is crucial that homeowners check the amount of moisture in their soil before applying water to their grass. An easy way to test for soil moisture is to probe your lawn with a screwdriver. If it goes into the soil easily, that indicates sufficient moisture, but if the screwdriver can’t probe the soil, you want to apply water to that area.”
Denver Water always closely monitors area weather conditions and impacts on its water system this time of year.
“In 2002 we learned that reservoir storage is only one indicator of drought, and reservoir levels can drop quickly when we don’t get much snow and rain,” said Covington. “Droughts are always a reality in Colorado, which is why regardless of snowpack and reservoir levels, we ask customers to use water wisely.”
Following the drought that began in 2002, Denver Water nearly ran out of water in the north end of its system.
“The north end of our system, which is experiencing unusually dry conditions right now, is more susceptible to water supply problems during a dry year,” said Covington. “Without the blizzard of March 2003, we likely would have run out of water on that end. Earlier this winter we changed our operations and reduced the amount of water leaving the Moffat Treatment Plant — fed by Gross Reservoir, north of Boulder — to reserve more water in the north end of our system. We currently are in the permitting process to enlarge Gross Reservoir to help us avoid running out of water any given year and to help us put water where we need it.”
Here’s the executive summary from last week’s CWCB Water Availability Task Force Meeting (Veva Deheza/Kevin Rein):
Despite decent precipitation in February, the month of March has been warm and dry across most of the state. Little to no precipitation is forecast through the end of the month and some places, like Ft. Collins, are on track to have the driest March on record. All major basins of the state have seen a decline in snow water equivalent since March 1st, and all continue to be below normal. Severe drought conditions remain in southeastern Colorado, while lesser drought intensities have been introduced and expanded elsewhere in the state. Water providers are watching the situation in the mountains closely, but most feel they have sufficient storage at this time.
March temperatures, to date, have been 6 to 8 degrees above average for most of Colorado, with pockets on the northeastern plains experiencing temperatures 10 degrees above normal. The San Juan Mountains have been the coolest region of the state with near normal temperatures.
Typically by this time of the year Colorado has reached 92% of its average peak snow water equivalent for the season, however, to date the state has only achieved 67% of the peak and 72% of average statewide.
Reservoir storage remains above average in the Yampa/White, Gunnison, Colorado, South Platte Basins, and San Miguel/ Dolores/ Animas/ San Juan. Statewide, reservoir storage is 107% of average. The Rio Grande and the Arkansas River basins continue to be the regions with the lowest reservoir storage levels in the state at 69 and 98% of average, respectively.
As of March 20, 2012 US Drought Monitor, D1, moderate drought, conditions remain in the northern and central mountains, while D2, Severe drought, conditions remain over much of the southeast and south central portions of the state. D0, abnormally dry, conditions account for much of the rest of the impacted areas of the state. Expansion of D0 on the northeastern plains and an introduction of D2 in the Yampa/White river basin is expected within the next few weeks unless conditions drastically improve.
Surface Water Supply Index (SWSI) values range from -2.96 in the East Taylor Park sub-basin to +2.59 in the Big Thompson sub-basin of the South Platte. The remainder of the state is near normal, in part due to sufficient reservoir storage. The higher value in the Big Thompson is due to high storage levels and the fact that reservoirs in this basin are more heavily weighted. The Arkansas Headwaters, -2.22, is lower, due to operational drawdown of Homestake Reservoir. Other basins with a SWSI indicating moderate drought are the result of low stream flow forecasts. Streamflow forecasts have declined roughly 5-10% since March 1st and early runoff is expected.
La Niña conditions are weakening, which is somewhat typical for this time of year, but there is still a greater than 40% chance that this will be a three year La Niña event. Three year La Niña events have been associated with some of the driest periods on record for Colorado.
The long-term seasonal forecast for late spring (April-June) shows a tilt towards dryness covering much of the state, with the exception of the eastern plains which ‘lean’ towards near-normal moisture. This coupled with below average snowpack will likely result in earlier runoff. The best chance for increased moisture might derive from a sudden transition to El Niño, but there is only a 20% chance that this will occur.