Governor Brownback's desire to conserve and extend the water resources of the Ogallala aquifer is laudable. As most people know, Ogallala groundwater is being "mined" as water extractions for agricultural irrigation outpace the natural rate of recharge. This longstanding policy makes sense, but it must be limited in two ways: first, by reducing the harm from one farmer's pumping on his neighbors; second, by limiting extractions today if it makes more sense to have water tomorrow.Note that Kansas already has a good system for managing groundwater.
Both of these goals can be reached with simple regulations, property rights and markets. The regulations would ensure that everyone's extractions are tracked; property rights would mean that extractions in one place are not allowed to outpace extractions in another place; markets would allow those who want to use more water to buy the right to pump more from those who have the right to extract but prefer to sell that right for money. It's possible to include other "features" in this system (water futures that would make it possible to pump less today and more tomorrow, for example), but these basic concepts are far easier to understand and operate than bureaucratic systems of command and control that try to make the best choice for everyone.
Let farmers choose what crops to grow, how much land to plant, and how much water to use. Just reduce the costs of those decisions on other farmers.