Runoff from below-average snowpack is forecast to result in the lowest project irrigation supply in McPhee Reservoir history.
According to most probable forecast, Dolores River Basin snowmelt is expected to deliver 95,000 acre-feet of water to McPhee Reservoir, just 32% of the average 295,000 acre-feet average, reports the Colorado River Basin Forecast Center. The forecast could also continue to drop.
Full-service farmers of the Dolores Project are expected to receive just 1 inch per acre of irrigation water, or 4.5% of the 22 inches per acre provided when the reservoir fills, reports Ken Curtis, general manager for the Dolores Water Conservancy District that manages McPhee.
The forecast of 1 inch per acre is “the wost ever” for the Dolores Project, he said. The reservoir first filled in the late 1980s.
The previous worst irrigation seasons for McPhee Reservoir were in 2013 and 2002, when farmers received 6 inches per acre.
The amount of water predicted for this year is not enough for even one normal crop of alfalfa. With a full supply farmers typically get three to four crops of alfalfa per year. Farmers will be forced to consolidate crops into smaller acreage to produce anything on the limited water.
This year’s forecast shows McPhee Reservoir will fill less than 40% of its 229,000 acre-feet active capacity, according to forecast models. The reservoir had no significant carryover supply from last year’s water season.
Water shortages are across the board, except for domestic supplies for municipalities.
Ute Farm and Ranch on the Ute Mountain Ute Reservation is predicted to receive about 2,000 acre-feet, or 8.5% of the 23,300 acre-feet delivered when the reservoir has a full supply.
The water supply for downstream fish habitat dropped to less than 5,000 acre-feet of the 32,000 acre-feet provided when the reservoir fills.
Ashley Nielson, a senior hydrologist with the Colorado River Basin Forecast Center, said snowpack in the Dolores Basin took hits from multiple angles.
With the exception of a few good snowstorms, the basin experienced an extended dry period since April 2020, she said.
No monsoonal precipitation last summer dried out soils, which will cause snowmelt to be absorbed into the ground before it hits the river and McPhee.
Below-normal snowpack further suffered from warm weather and high winds in April, plus dust on snow that sped up evaporation.
April precipitation at the Lizard Head Pass Snotel is below normal, showing 0.2 inches, or 15% of the average 1.4 inches for the month.
Farmers and water managers have been tracking a startling drop in snowpack in the past few weeks.
On March 29, the Dolores Basin snowpack showed 83% of average for snow-water equivalent. On April 19, snowpack water equivalent had dropped to 32%.
“It disappeared fast, and it could still get drier,” Curtis said.
