Imagine that a group of friends are camping in a hot and dry place with one container of water. The water is necessary for drinking, cooking, and washing. The group must decide the how much each person will receive and for what purposes the water will be used. The individual portion of water is called a water allotment. The laws that govern to whom water allotments are given, and for what purposes water allotments are used, are called water rights.
A water right is a use of water or a water source. Everyday, large nations and small communities alike must decide how to allocate their available sources of water. Negotiations similar to those in the camping example are conducted between individuals, cities, and countries to decide who has rights to water on a nation’s land or within its borders.
In the United States, all navigable waterways, waterways upon which vessels are able to travel, are considered public. No individual or business can own a river or large stream. Water rights permit use of the water without granting ownership of the waterway. Water rights distribute water in an organized manner, according to international agreements or national, state, and local laws.
Water rights allow communities, businesses, and individuals to use a certain amount of water (their allotment). Water rights may restrict where people obtain water, how much they use, and for what purpose they use the water. The goal of water rights is to ensure that many people have access to sources of fresh water and to ensure the sources are protected from pollution or overuse.
The two main sources of freshwater (non-salty water) on Earth are surface water and groundwater. Surface water is water found above ground. Rivers, lakes, streams, ponds, and wetlands are all sources of fresh surface water. Groundwater is freshwater that resides in rock and soil layers beneath Earth’s land surface. Surface and groundwater rights cover both the storage and active use of these waters.
Types of water rights
Just as water is used in different ways by nations, cities, businesses, and individuals, there are different kinds of water rights. These types of water rights are called doctrines. A doctrine is a set of basic rules that is the foundation for laws.
people to take, store, and use less water than areas with abundant rainfall and many streams.
Riparian doctrine. The riparian doctrine is most commonly used in places with abundant surface and groundwater supplies. Riparian rights are laws that grant individuals who own the land upon which a water source is located unlimited use of the water.
Even in places with a plentiful water supply, riparian water rights can cause conflicts. Examples of riparian doctrine conflicts include water sources located on the land of several individuals in conflict, and people who are granted riparian water rights and exhaust their source of water.
Reasonable use doctrine. The reasonable use doctrine is similar to the riparian doctrine. It tries to avoid the problems resulting from competition among owners or overuse of a water source. There are no limits on water use when the supply of water is abundant for landowners under a reasonable use doctrine.
However, reasonable use rights limit certain uses of water when water is scarce. Specific laws state how much water should be stored or used for certain purposes. Reasonable use laws consider environmental and human factors when deciding the most important uses for water.
For example, during a drought (an extended, but temporary period with less than normal rainfall) water rights under a reasonable use doctrine may limit the amount of water that can be used for watering plants, washing cars, or filling swimming pools.
Prior appropriation doctrine. Under the prior appropriation doctrine, the first person to use a water source and claim the water rights, has first use of the water when the supply is limited. The prior appropriation doctrine is also called “first in time, first in right.”
Usually, the person with the first right (prior appropriation) can use as much of the water as he needs. This may mean that to protect a source from overuse, other people will not be allowed to use the source. For example, cities or states may prohibit people from drilling wells into a source of groundwater if more water users would deplete the source.
The prior appropriation doctrine is the oldest type of individual water right. It also can cause many problems among landowners. Returning to the camping example, what if the oldest person in the group was permitted to use as much of the water as she wished? Would there be enough water for everyone else?
Combination of water rights. Some locations seek to balance water use with water conservation by combining water rights doctrines. Landowners may have rights to the water on their land, but the whole area surrounding and contributing to the water source is also protected. This area is called a watershed.
Watersheds are the areas of land drained by a river or stream. Watersheds are protected because use and abuse of water in a local stream watershed can affect other people’s use and enjoyment of the river into which it drains. For example, if a business has a water right over a stream and dumps chemicals into that stream, then those chemicals would eventually end up in the river.
The river water may become unsafe for drinking or kill plants and other wildlife. Draining and over-use of small, local water sources also can also influence larger watersheds. Due to the movement of water in watersheds, these effects can be felt hundreds of miles (kilometers) away and has made the combination of water rights doctrines necessary.
Areas that govern water usage with a combination of water rights doctrines may allow individuals and businesses to claim water rights under the prior appropriation doctrine when water is plentiful. When water is scarce governments may pass laws that limit water use and water storage.
This is called shortage sharing. People may be restricted from using certain water sources or using too much water. Laws may prohibit certain water uses, such as watering lawns or golf courses so that more water is available for irrigation (watering crops).
Ensuring a water supply
Because assessing the availability of water and assigning water rights is a complex issue, many national and local governments have developed special agencies that administer water rights. In local areas a water commissioner may oversee water rights and regulate water use.
National governments may also employ agents like water commissioners but also may have scientists who study, test, and monitor water sources. Sometimes, nations that share a surface water or groundwater source may form an agreement or treaty about how to best use and protect that water source.
In times of shortage some uses of water are preferred. Water rights help make sure that water is put to the best, most necessary uses, but that people have sufficient water. Drinking water and water for crop irrigation are favored uses when water supplies are low. Watering lawns, filling pools, and washing cars are disfavored. When water is abundant, water rights protect the water source while permitting free use of the water by many people.