A drop in drought intensity for Montezuma County, combined with mountain snowpack tracking near 100 percent of average, bodes well for the 2019 irrigation season.
The Four Corners has been the region hit hardest by drought nationwide, according to the U.S. Drought Monitor. Since April 2018, the area has had drought intensity at the D4 Exceptional Drought Category, the highest level.
But this week, a sign of relief appeared when a large area of Montezuma County dropped a level to the D3 Extreme Drought Category.
“A surplus of precipitation over the last 30 days” in Southwest Colorado was enough for a one category improvement, according to an assessment by the Climate Prediction Center of the National Weather Service.
Also, a seasonal U.S. Drought Outlook shows that through April, “drought remains but improves” in the Western Slope and Four Corners.
Cortez weather service observer Jim Andrus said Wednesday that precipitation in Cortez for December was 1.62 inches, or 207 percent of the average of .88 inches. January precipitation is at 1.82 inches, or 184 percent of the average .88 inches.
“We are in a very dynamic atmospheric pattern, with storms actively tracking across the area,” Andrus said. “Compare that to last year, when we were stuck under a high-pressure ridge and only had 8 inches of snow all year. This year, we have 28.2 inches of snowfall, which is 131 percent of normal.”
Mountain snowfall in the Dolores Basin, which feeds McPhee Reservoir in spring, is at 99 percent of average as of Jan. 22, according to data from Snotel measuring devices at El Diente, Lizard Head, Lone Cone and Scotch Creek. The Snotels are positioned between 9,000 and 11,000 feet in elevation.
“The recent snowfall has raised the odds of an average year, so if it keeps up, we will probably have a full supply,” said Ken Curtis, an engineer with the Dolores Water Conservancy District, which manages McPhee water supply.
In February, the district will begin to publish runoff forecasts from the Colorado River Basin Forecast Center. The medium runoff from the Dolores Basin into McPhee Reservoir is 250,000 acre-feet. Anything less would likely mean shortages because of low carryover in the reservoir, Curtis said.
Snowpack below 8,500 feet elevation appears higher than normal this year, he said, another good sign for the 2019 farming season.
To fine-tune runoff predictions, every year starting in February, the district sends snowmobiler Tad Wilbanks to take measurements of low-elevation snowpack below 9,000 feet, where there are no Snotels. Measurements are taken at Groundhog, along the Dolores-Norwood Road, Belmear Mountain, Cottonwood Road, Willow Divide, Salter Y and others. The district has 30 years of record on the low-elevation sites.
Conditions for cloud seeding have been good this year. More than a dozen stations throughout the basin release silver iodide into the atmosphere during certain conditions to draw out more moisture from storms. So far, about 10 storms have been cloud-seeded.
Curtis said the government shutdown has not had a big impact on management of McPhee operations. The U.S. Bureau of Reclamation – which owns and maintains McPhee Reservoir infrastructure, including the canals, pump stations and dam – is being funded, and the Cortez office is staffed.
McPhee managers have noticed a slight drop in communication from the Colorado River Basin Forecast Center, operated by National Oceanographic Atmospheric Administration.