From The Valley Courier (Ruth Heide):
Colorado Division of Water Resources Division 3 Engineer Craig Cotten explained that both the Rio Grande and Conejos River systems, which are under Rio Grande Compact obligations to New Mexico and Texas, are forecasted for above average flows . The snowpack in the Rio Grande Basin that encompasses the Valley is also above average.
More water is good news, Cotten said, but it also means more water must be sent down the river to meet the compact. He explained that the greater the flow, the higher the percentage that must be sent downriver.
That also means irrigators will see higher curtailments on the river systems affected by the compact, Cotten added.
Cotten updated the Rio Grande Roundtable members on the Valley’s river and snowpack status on Tuesday. His early forecast for the annual flow of the Rio Grande at Del Norte is 795,000 acre feet, 124 percent of the long-term average. That is higher than the Natural Resources Conservation Service’s (NRCS) current forecast, which is about 700,000 acre feet, Cotten said, but he believed the runoff would be higher.
He said his office is using multiple sources such as the NRCS and National Weather Service to develop forecasts.
If the forecast of 795,000 acre feet holds true on the Rio Grande, Colorado will be obligated to send 254,000 acre feet downstream to meet its compact obligations.
In order to do that, ditches along the Rio Grande would have to be curtailed by about 27 percent. In comparison, last year curtailments were at 12 percent at the beginning of the irrigation season, Cotten said.
Curtailments on the Conejos River system will be even higher, according to Cotten. He said the NRCS is currently forecasting an annual index flow of 420,000 acre feet, about 137 percent of the longterm average, which would require 206,000 acre feet to be sent downstream to meet compact obligations.
That would require a curtailment of 43 percent, Cotten explained…
As of Tuesday the snowpack in the Rio Grande Basin was 148 percent of average, Cotten said. Some of the snow measurement (SNOTEL) sites were well above that. For example, Costilla and Culebra Creeks’ SNOTEL sites were at 177-178 percent of average, and the Valley’s highest was Sangre de Cristo Creek at 184 percent.