Agricultural land retirement is increasingly used to manage water resources. This study uses well-level enrollment data to explore the factors that influence landowner participation in the Colorado Republican River Conservation Reserve Enhancement Program. An empirical model of enrollment is informed by a theoretical model of participation that incorporates aquifer and soil characteristics in addition to financial incentives. Our results reveal that enrollment is predicted to increase by 0.087 percentage points with a $10 increase in the incentives offered. The probability of enrollment is also influenced by the aquifer's saturated thickness and the soil characteristics that impact land productivity.