9.2: Water Rights and Laws

From a legal perspective in the U.S., water may be classified as diffused surface water, water in well-defined surface channels, water in well-defined aquifers, and underground percolating water. Diffused surface water is precipitation spread across the landscape. Diffused surface water and underground percolating water, because of their diverse nature, are normally regulated by common or civil law. In most states diffused surface water is considered the property of the landowner, who may use it without regard to the water supply of others. In many states, particularly those in the east, the law of diffused surface water has addressed who is responsible for the damage caused by diffused surface water. In some western states, diffused surface water is treated the same as water in well-defined channels.

Surface Water

In the U.S., the right to use surface water in natural watercourses is governed by two different doctrines: riparian and prior appropriation. In different states these doctrines are recognized either separately or in combination. In the future, adjudicated water rights based on highest-value use will become increasingly important.

The riparian doctrine (National Agricultural Law Center, 2020) recognizes the right of an owner of riparian land to make reasonable use of the stream’s flow on the riparian land. Riparian land is contiguous to the stream or other body of surface water from which water is withdrawn. The right-of-land ownership includes the right of access to and use of the water. This right is not lost even if water is not used. Reasonable use of water generally implies that the landowner may use all the water needed for drinking, for household purposes, and for watering livestock. Where large herds of livestock are watered or where irrigation is practiced, the riparian owner is not permitted to exhaust the stream flow. Owners may only use their equitable share of the flow. This doctrine is used in many eastern states.

The doctrine of prior appropriation is based upon the priority of development and use. The first person to develop and put water to beneficial use has the right of continued use. The right of appropriation is generally acquired by filing a claim in accordance with state laws. If the use is beneficial, the appropriator has the right to all water required at the given time and place. This doctrine assumes that it is better to let individuals, prior in time, to take all the water rather than distribute inadequate amounts among all water users. Appropriated water rights are not limited to riparian land and may be lost by nonuse. This doctrine is recognized in most western states, although in some states it is in combination with the riparian doctrine. It is difficult to make generalizations because state laws on water rights differ on specific details and many change with time.

Today, almost all riparian states have moved towards allocating water through a permitting system. Using the same “reasonable use” criteria as common law, the states first determine whether a new use is reasonable. The permitting system allows the state to plan for and maximize water usage in the future. In many states, agricultural uses are exempt from permit requirements.

Some states, such as California and Oklahoma, have developed hybrid allocation systems. Hybrid systems combine aspects of both the riparian and the appropriation systems.

Ground Water

Most states in the U.S. have a different allocation system for groundwater than for surface water. Groundwater allocation systems often differentiate between on-tract and off-tract uses. On-tract use is where water is used on the tract where the well is located. Off-tract use is where water is transferred to another location.

Under the absolute dominion rule (National Agricultural Law Center, 2020 and Driscoll, 1986), a landowner may use as much groundwater as possible. The impact of the groundwater use on neighboring users is not taken into account. Although some states follow this doctrine with allowances for remedies for willful injury, most states have rejected this doctrine as malicious withdraws of water.

The correlative rights doctrine distributes water on an equitable basis among landowners and allows off-tract uses, although these are subordinate to on-tract uses. With the Correlative Rights Doctrine the landowners overlying the same aquifer are limited to a reasonable share of the aquifer supply.

Some of the western U.S. states apply the doctrine of prior appropriation (similar to its application to surface water), which gives the earlier water users priority over later users. The water use amount is limited to beneficial uses.

Another legal approach is to apply the rule of reasonable use. As the name implies the landowners have the right to use the groundwater beneath their land as long as it is deemed to be a reasonable and beneficial use.

In the U.S. these legal approaches, along with others, for groundwater use are applied on a state-to-state basis. For example, the State of Nebraska uses a unique blend of the Rule of Reasonable Use and the Correlative Rights Doctrine along with statutory preferences for use (Aiken, 1980).