Water Law: An Overview



Water is at the heart of agriculture. Without water, crops and livestock would not be able to survive. Water used in agricultural production can be sourced from surface waters, such as rivers, lakes, streams, and ponds, or from groundwater, such as an aquifer. Each state is able to allocate this important resource, with each state having its own regulatory system to allocate both the surface waters and groundwater in the state, with very little federal intervention.

Many important legal issues are presented by the use of water in agriculture. This reading room will deal with quantity issues, such as, allocation, irrigation, and other problems common to agriculture’s use of water. For quality issues involving water please see the Clean Water Act Reading RoomEnvironmental Law Reading Room, and Pesticides Reading Room. These reading rooms look closely at the quality issues in water.

Surface Waters

Allocation of surface waters is dependent on state law. Three different allocation systems have developed in the United States. The first is the riparian doctrine, which developed in the water-abundant eastern United States. The second is the system of prior appropriation, as developed in the western United States. Finally, a handful of states have adopted a hybrid system, which contains parts of both the prior appropriation and the riparian systems doctrines.


Riparianism limits the use of water to only those landowners with riparian land. In order to be classified as a riparian landowner, the landowner must own a parcel of land adjacent to a watercourse, such as streams, lakes, and ponds. The water may only be put to a reasonable use. The courts can enjoin landowners for unreasonable uses.

The riparian landowner has the right to make “reasonable use” of the watercourse. This means that the riparian landowner may make a reasonable use of the waters as long as that use does not interfere with the reasonable use of another downstream riparian landowner. Reasonableness is determined by comparing the proposed use with the other riparians’ uses. Any natural uses, such as water for drinking, watering livestock, or watering a garden, are considered reasonable under law. Artificial uses, such as those for irrigation or industry, are considered reasonable uses under most states’ laws.

Non-riparian landowners generally have no right to use water, although some riparian jurisdictions may allow it. A majority of jurisdictions require proof of actual harm from the use of water on non-riparian land. The minority follows the Restatement (Second) of Torts § 855, which allows for the reasonable use of water on non-riparian land only if the user also owns riparian land.

Under riparian rights, landowners do not have to use to keep the right. New uses may be started at any time as long as the new use is a reasonable one. Because the right is attached to the riparian land, non-use does not extinguish the right.

Today, almost all riparian states have moved towards allocating water through a permitting system, often called a “regulated riparian” system. Under the regulated riparian system,  a central state agency controls who may use the water, how much they can use, and when they can use it. Regulated riparianism departs from common law riparianism by looking at the projected use before any water is ever actually used. Using the same “reasonable use” criteria as common law, the states first determine if a new use is reasonable. This allows the state to take into account both the potential benefits to society and the compatibility with current uses before granting a new permit. In many cases, the permit is only required on consumptive uses and excludes non-consumptive uses, or uses that do not require a diversion or removal of water from the watercourse.

The permitting system allows the state to plan for and maximize water usage in the future. Even if a use is exempt from a permit, the user may still have to file a water use plan with the state in order to help with planning. However, the rules governing whether a use requires a permit vary from state to state. Further, in many states, agricultural uses are exempt from permit requirements.

Regulated riparian permits exist for a fixed period of years, unlike indefinite permits used in prior appropriation states. In times of water shortages, the state may adjust the the quantity of water use allowed and can require a pro rata reduction across the board or based on seniority of use. Permits may also prioritize permitted users over non-permitted users when non-permitted user withdrawals hurt permitted users. Additionally, riparian landowners who do not obtain a permit within the required statutory time period may see a reduction or a forfeiture of their common law riparian rights.

Prior Appropriation

The prior appropriation doctrine dates back to the miners who first settled the West and needed water to develop their mining claims. Because the land needed was not adjacent to a watercourse, the miners could not use the riparian system. Instead, the miners used the “first in time, first in right” a system, which was already being used to resolve disputes over water use. This led to the prior appropriation doctrine, where the first user had the right to continue using the water to the exclusion of the rights of those who came later.

The prior appropriation system is based on priority. The most senior appropriator has the highest priority and can defeat all other less senior appropriators in times of shortages. Unlike riparianism, there is no requirement that a senior appropriator use less water in times of a shortage. Water users can take in order of their respective priorities, with each user taking their full appropriative right until the water is gone.

The senior appropriator may enforce his rights by “calling the river.” This is a process that allows the senior appropriator to ensure the junior appropriators do not use water out of turn. The senior appropriator will either go to court or the state water agency to have their right enforced against a junior appropriator. If the senior appropriator’s water right would be lost through evaporation, instead, the senior only has a “futile call,” and the state will not enforce his right against the junior. The rationale behind this theory is that it is better for water to be used by the junior appropriator rather  than lost in transport to the senior appropriator.

The prior appropriation doctrine varies somewhat from state to state, although there are three general requirements: (1) the appropriator must intend to apply water to a beneficial use, (2) the water must be diverted from a natural course, and (3) the water must be applied to a beneficial use. A beneficial use is any use recognized by the state as being an appropriate use of water, such as domestic, municipal, agricultural, industrial and recreational uses. In all prior appropriative states, agricultural uses are considered beneficial uses. The beneficial use is the measure and limitation of the appropriative right Once water is put to a beneficial use, the right is perfected and has priority over later appropriators. The senior appropriator then has the right to use their original right, even if a “better’ use arises later.

In order to have a valid appropriation, an appropriator must show the necessary intent to make an appropriation. The intent necessary is usually just the intent to divert water and apply the water to a beneficial use. In states that require a permit, the application for the permit shows the objective evidence of the necessary intent. A valid appropriation will be given a priority date, or the date the water was first used. Some states have developed the doctrine of relation back that allows the appropriator to use the date that the intent was formed as the priority date.

Historically, the appropriator was required to divert, or build some form of a diversion, in order to provide notice that the water was appropriated. A diversion is typically any alteration to a portion or a stream’s entire natural course. In many cases, the capacity of the diversion could be used to determine the extent of the quantity of water appropriated. Today, most prior appropriation states have adopted a permit system that satisfies the notice requirement a diversion.

Hybrid Systems

Some states, such as California and Oklahoma, have developed hybrid allocation systems, which combine aspects of both the riparian and the appropriative rights systems. While there is no uniform system for all hybrid states, all hybrid systems contain elements of both riparian and prior appropriative rights.


Water used in agriculture can also come from underground aquifers. While many groundwater aquifers are connected to surface waters, most states have a different allocation system for groundwater. 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 pump is located. Off-tract use is where water is transferred to another location for use.

States often may not fall clearly within a particular doctrine, and may use components of two or more systems. For this reason, it is best to contact your state water agency to determine the allocation system that is used by your state. List of State Water Offices

Absolute Dominion Rule

Under the Absolute Dominion Rule, also called the “Absolute Ownership Rule” or the “English Rule,” a landowner may use as much ground water as possible. The rule does not take into account impacts on neighboring users, and, as a result, one owner could monopolize the entire aquifer without incurring liability. This doctrine creates an incentive to pump as much water as possible because of the lack of concern of incurring penalties from a neighboring user. Most states have rejected this doctrine, as malicious withdrawals of water could not be enjoined. The states that do continue to follow this doctrine allow for remedies for willful injury. States following this doctrine are Connecticut, Georgia, Indiana, Louisiana, Maine, Minnesota, Massachusetts, Mississippi, Rhode Island, Texas, and Vermont.

Correlative Rights Doctrine

The Correlative Rights Doctrine distributes water on an equitable basis among landowners and allows off-tract uses, although these uses are subordinate to on-tract uses. Like the Absolute Dominion Rule, the Correlative Rights Doctrine determines rights in groundwater based on ownership of land. The difference, however, is that landowners overlying the same aquifer are limited to a reasonable share of the aquifer’s total supply, rather than having an absolute right to groundwater or an unlimited right to pump.

This doctrine was first recognized in California in Katz v. Walkinshaw, 74 P. 766 (Cal. 1903). The court held that in times of shortages an overlying owner must limit withdrawals to a “fair and just proportion” of the underlying supply. Thus, when two users are both exporting water, the court would use the doctrine of prior appropriation. Finally, in disputes between an overlying landowner and an exporter, the overlying landowner receives a reasonable share of the water, even if the overlying owner is junior to the exporter. The states that apply this doctrine include: California, Minnesota, Iowa, Arkansas, Vermont, and Oklahoma. Nebraska follows a combination of this doctrine and the Reasonable Use doctrine.

Prior Appropriation

Many western states have adopted a prior appropriation doctrine for groundwater. Similar to the prior appropriative system for surface water, the first landowner to beneficially use or divert water from a groundwater source is given priority over later users. The right, similar to the surface water system, is limited to the amount that is put to a beneficial use. Many states, today, have replaced this doctrine with a permit system, similar to the surface water permit system. This doctrine is in use in Alaska, Colorado, Idaho, Kansas, Montana, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming.

Reasonable Use Rule

Some states have adopted the doctrine of reasonable use, or the American rule, which requires the water to be put to a reasonable use on the overlying tract of land and does not permit water to be taken to another tract. Reasonable use has been construed broadly, and almost any use is considered reasonable as long as the water is used on the overlying land. The rule is considered a modification of the Absolute Dominion Rule with exceptions for wasteful uses and off-tract uses. This system is used in Alabama, Arizona, Delaware, Illinois, Kentucky, Maryland, Michigan, Missouri, New Hampshire, New Jersey, New York, North Carolina, Oklahoma, Pennsylvania, Virginia, and West Virginia. Other states have adopted the reasonable use rule in conjunction with another groundwater rule. Florida has abolished all common law groundwater rights for a permit system, but uses this doctrine in granting permits. Wyoming uses the reasonable use doctrine along with the Prior Appropriative system for groundwater. Nebraska, additionally, uses the reasonable use doctrine along with the Correlative Rights Doctrine.

The Restatement (Second) of Torts Rule

Finally, Wisconsin and Ohio have adopted the Restatement (Second) of Torts approach, which utilizes a variety of factors to determine if a use of water is appropriate. The Restatement’s rule is seen as a merger of the Absolute Dominion Rule and the Reasonable Use rule. Section 858 of the Restatement (Second) of Torts states:

Liability for Use of Groundwater

(1) A proprietor of land or his grantee who withdraws groundwater from the land and uses it for a beneficial purpose is not subject to liability for interference with the use of water by another, unless

(a) the withdrawal of groundwater unreasonably causes harm to a proprietor of neighboring land through lowering the water table or reducing artesian pressure,

(b) the withdrawal of groundwater exceeds the proprietor’s reasonable share of the annual supply or total store of groundwater, or

(c) the withdrawal of the groundwater has a direct and substantial effect upon a watercourse or lake and unreasonably causes harm to a person entitled to the use of its water.

(2) The determination of liability under clauses (a), (b) and (c) of Subsection (1) is governed by the principles stated in §§ 850 to 857.

Federal Rights

The ability to fully develop state’s water resources, through irrigation of croplands or other projects, can be severely limited by federal reserved rights in water. The reserved rights doctrine reserves water rights for Native American reservations and public lands. The priority date is the date the reservation is created, and the quantity reserved is the amount necessary to fulfill the purpose of the reservation. For Native American tribes, the necessary use is the amount of water needed to irrigate all the tribe’s practicably irrigable acreage. This can be a significant amount of water and defeats junior appropriators’ claims.

Finally, under the McCarran Amendment, the federal government has waived sovereign immunity for the limited purpose of adjudicating western water rights. This Amendment authorizes the joinder of the United States in comprehensive stream adjudications, in both state courts and state water agencies. This Amendment has been construed to include the water rights of Native Americans to reduce the number of court proceedings to determine the same rights. The Amendment allows for the more efficient adjudication of water rights along streams in the Western States. For a list of general stream adjudications, see Dividing the Waters.

Reclamation Projects

In 1902, Congress passed the Reclamation Act (Act), which created the Bureau of Reclamation. The purpose of the Act was to provide irrigation water to the lands settled in the West, as well as to prevent land speculation in the West. The Act limited the use of Reclamation project water to 160 acres in single ownership. These reclamation projects helped to develop irrigation projects, which in turn helped to develop the arid West. The Act gives preference to irrigation over other uses, and priority is acquired under state law. The U.S. Supreme Court has held that water from reclamation projects must be distributed according to state law unless state law conflicts with a federal provision of the Act.

This overview was written with the help of Dean David H. Getches’ Water Law nutshell. David H. Getches, Water Law (3d. ed. 1997).