The Irrigation Season indicator is a comparison of the length of the irrigation season compared to the average length for the period of record. A variable irrigation season can affect a rancher’s/farmer’s ability to anticipate operations, watering, herd rotation and other ranch management needs.

The irrigation season indicator is calculated using data from Colorado’s Decision Support System webtool. Water rights owners are required to report when they start and stop diverting water to the State of Colorado Division of Water Resources (DWR). Within the segment of interest, for diversion infrastructure such as ditches or pumps that have a continuous record of historical information, the number of days that water was diverted for irrigation use was tallied and averaged for the previous 5-year period as well as for the period of record (20-30 years, depending on the structure). The 5-year period average length of irrigation season within the segment is compared to the period of record average length of irrigation season.