From High Plains Public Radio (Susan Stover):
Texas manages groundwater with the Rule of Capture. The groundwater belongs to the landowner without a defined limit. It’s sometimes known as the Law of the Biggest Pump.
Colorado and Kansas water law is based on prior appropriation, known as First in Time, First in Right. A water right owner can pump their permitted amount if it doesn’t impair a more senior right – a water right that was established earlier in time. When there isn’t enough water to meet all needs, the owners of senior water rights have priority. The priority system works well for streams. When stream flow is low, it is generally clear which upstream, junior users must be cut off to protect the more senior water rights.
For groundwater, it is more complex to identify which water wells are impairing a more senior water well. Groundwater often provides a baseflow to streams; when heavy groundwater pumping lowers the water table so there is no longer a connection to the stream and stream flow declines, is that impairment?
Colorado state law dealt with such concerns by defining “designated groundwater basins,” those in which groundwater contributes little to stream flow. The Ogallala aquifer lies in designated groundwater basins. This allows more groundwater to be pumped, which lowers the water table, but with less risk of impairing surface water rights.
In Kansas, action is taken when a junior water right well’s pumping directly impairs a senior water right well, whether it uses groundwater or surface water. However, no action is taken if problems are due to regional groundwater declines. Like Colorado, Kansas allows the decline of the Ogallala aquifer to get the economic benefit from the water.
Management of the Ogallala aquifer is a balance between protecting existing water right holders and conserving water for the future. Attitudes change over time on what is a proper balance. Much water law encouraged development of the aquifer and protects current users. Is that balance shifting more toward conserving and extending this resource further into the future?