850,000+ monitoring wells providing depth-to-water measurements.
0-30ft excellent, 30-100ft good, 100-200ft moderate, 200-400ft marginal, 400ft+ infeasible.
$15-$500+ per acre-foot depending on depth. Corn needs 18-24 acre-inches, alfalfa 36-48 acre-inches.
Ogallala depletion trends, recharge rates, long-term water availability indicators.