Where groundwater is free to pump, each farmer has an incentive to draw water before others do, even when the shared aquifer is declining. A volumetric fee can discourage excessive use, but metering thousands of small wells is costly and may encourage tampering. Charging by irrigated acreage is easier, yet it does not reward efficient equipment. One district combined remote estimates of crop water demand with periodic meter checks and offered rebates for verified conservation. The hybrid system remains imperfect, especially for unusual crops, but it aligns charges more closely with use than acreage alone and costs less than continuous inspection. Which outline most accurately traces the passage's reasoning about groundwater pricing?