The Rio Grande Basin has about another 70 days to get itself up to average peak levels for snowpack that would deliver a normal spring runoff year for San Luis Valley irrigators in 2024. Water from melting snow in the surrounding mountain ranges also irrigates farm fields in New Mexico and Texas through the Rio Grande Compact.
The snowpack levels and corresponding 2023 spring runoff was the focus of a presentation at the Rio Grande Water Conservation District’s quarterly meeting held on Tuesday, Jan. 16. Craig Cotten, Division 3 engineer for the Colorado Division of Water Resources, walked water managers through a series of slides showing the conditions of rivers and creeks all critical to Valley’s agricultural economy as well as Colorado’s ability to deliver water to the New Mexico state line for Rio Grande Compact obligations.
Here’s a breakdown of streamflows:
Rio Grande and Conejos River
These charts represent the two river systems tied to the Rio Grande Compact and the effect on stream flows from snow runoff during the spring of 2023. The winter of 2022-23 translated into significantly above-average runoff for several months and then by the first of July a drop in streamflows to below average on the Rio Grande and right at average to below on the Conejos River.
It’s the Rio Grande and Conejos that form the Rio Grande Compact between the states of Colorado, New Mexico and Texas. The annual spring runoff determines how much water Colorado delivers to the New Mexico state line to fulfill its compact obligation. From the 2023 runoff Colorado delivered 29 percent of the streamflow or 208,000 acre-feet of water from the Rio Grande, and 47 percent or around 200,000 acre-feet from the Conejos River.
Los Pinos River near Ortiz
Los Pinos is the main contributor to the San Antonio River, which is a main tributary to the Conejos. Los Pinos had significant above-average runoff that resulted in some flooding on the lower end of the San Antonio in the spring of 2023. With its tributaries, the Conejos River had 411,000 acre-feet or 137 percent of its long-term average in 2023. Again, 47 percent of that water had to be delivered to the New Mexico state line to meet Colorado’s Rio Grande Compact obligations.
Saguache Creek near Saguache
Saguache Creek forms from runoff coming off the San Juan Mountains. It had above-average spring streamflows like others, and ended up below-average when the normal summer rains did not materialize in 2023.
Trinchera Creek above Turner’s Ranch
Trinchera Creek presented the biggest challenges for irrigators in 2023 due to less snow on the Sangre de Cristos than on the San Juans. Trinchera Creek was significantly below average for most of the irrigation season.
Ute Creek near Fort Garland
Ute Creek too forms from the Sangres. Unlike the Trinchera Creek, it got to average and a bit above for the peak of the 2023 spring runoff and then dropped to below-average streamflows for the year.
Alamosa Creek above Terrace Reservoir
The highlight of the heavy snow from 2022-23 and the corresponding spring runoff was the spilling of Terrace Reservoir for the first time in 40 years. “That was really neat to see,” Cotten said.
Spring and summer 2024 forecasts
Looking to the 2024 spring runoff, current snowpack levels are at 71 percent of normal for the Rio Grande Basin and the lowest for any basin in Colorado by a significant amount. “We do still have some time to get up that average,” Cotten said. “If we can get some good snowstorms coming our way, hopefully we’ll be in decent shape for this year.”
Precipitation outlook through March shows potential for more snow that would help build up the snowpack for spring water. The spring months show an equal chance for precipitation and then below-average forecasts for the summer months. The temperature forecasts for the summer do not predict the same type of record-setting heat as the summer of 2023.