The health of our waters is the principal measure of how we live on the land — Luna Leopold
Irrigation season to begin March 16: Warmer weather brings early increased streamflows; March opened with record-setting temperatures — AlamosaCitizen.com #RioGrande #SanLuisValley
Potato truck Carmel district March 2026. Credit: The Citizen
An early start to the irrigation season in the San Luis Valley is coinciding with the arrival of spring’s first heat wave.
Craig Cotten, Division 3 engineer for Colorado Division of Water Resources, announced a staged approach to opening the water year for producers in the Upper Rio Grande Basin.
The water season will begin on March 16 for surface and groundwater irrigators in the Conejos River area (Water District 22), the Culebra Creek area (Water District 24), the Trinchera Creek area (Water District 35) and the La Jara Creek area. The irrigation season will begin on March 23 for all surface and groundwater irrigation structures in the Rio Grande area (Water District 20).
“I decided to start the irrigation season earlier than the presumptive April 1 date for many valley areas due to the very warm, dry spring and the low current snowpack. We are already seeing an increase in streamflows due to the warmer weather, and it is beneficial for water rights holders to be able to use this water while it is available,” Cotten said in an email exchange with Alamosa Citizen. [ed. emphasis mine]
On the Conejos River and Rio Grande, another reason is that Colorado is projected to meet its compact obligation without needing to deliver water during the irrigation season, Cotten said.
“In order to avoid a significant over-delivery of water to the stateline, I have decided to begin the irrigation season on these rivers prior to April 1.”
The coming week of March 16 could see record-setting temperatures to the official start of spring. The forecast calls for midweek daytime highs in the low- to mid-70s. March has seen 21 of its 31 days establish new record high temperatures since 2004, a heating trend that accentuates the warming winters and spring months.
This March opened with back-to-back days of new daily high records. More heat records could fall in the coming week. The irrigation season can’t open soon enough.
Upper Rio Grande SWE March 14, 2026. Note the early melt-out.
Chart showing water use trends in US and Mexico. Credit: Overconsumption gravely threatens water security in the binational Rio Grande-Bravo basin. Map via Springer Nature.
