A Nonlinear Mixed Integer Program Model for Evaluating Runoff Impoundments for Supplemental Irrigation

On‐farm runoff collection through small impoundments (ponds) is a potential irrigation water source. This study evaluates the economic feasibility of such impoundments for supplemental irrigation in the Blacklands region of Texas. This is done using a risk sensitive model which simultaneously considers water supply, irrigation system investment, irrigation scheduling, and crop mix selection. A two‐stage, mixed integer, nonlinear mathematical programming model under uncertainty, was used to formulate the problem and solved with Benders' decomposition. Pond‐based supplemental irrigation is found to be both risk reducing and net income increasing in the study area. The model results also show off‐farm water needs to be worth more than $100 per acre foot to make impoundments undesirable.