These data are in support of report DS 456 (Arnold and others, 2009). 30 equal-area polygons generated using techniques described in Scott (1990). Polygons include areas overlying the High Plains Aquifer in Colorado having a depth to water less than 180 feet, a saturated thickness greater than 50 feet, and underlying irrigated agricultural lands. Described in Arnold and others (2009). Input saturated thickness and depth to water data from V.L. McGuire, written communication, 2008. Irrigated agricultural lands from Bauder and others (2004).