Water rights are legal rights extended to users of a water source such as a spring, lake, or river. Legal systems for handling the administration of water rights vary around the world, and tend to become extremely complex when resources are limited and competition is high. Government agencies are typically responsible for apportioning water usage, although in some cases, water sources are privatized and the owners determine who can use the water and how. Globally, water rights became a serious issue in the late 20th century as the population increased and supplies of potable water became threatened in many areas.
People need access to water supplies for hygiene, cooking, agriculture, and manufacturing processes. In the development of water policy, all of these needs must be balanced to apportion the water fairly and reasonably. Generally, users are allotted a certain percentage of the water, and this may be adjusted in response to droughts and other changing weather conditions. Users may also lose their rights if they fail to exercise them.
Some regions attach water rights directly to land, ensuring that people who buy land also get water rights with it. In other cases, the rights to water and other resources are actually sold separately, and can complicate the deal considerably. People may be able to obtain a reasonable price for a home or lot, but be unable to do anything with it because they cannot reach an agreement to buy or lease the water rights associated with the property.
Right to water is generally recognized as a basic human right, but in some regions, water access is difficult. Polluted and otherwise contaminated water sources are a cause for concern, as is competition between differing users of a region's water. Regions with ample water supplies may sell their water to neighboring communities with more limited supplies. and fights can break out over water rights when a shared resource is involved, as seen in the Southwest of the United States with the Colorado River.
Development of environmental policy, such as water rights, usually includes input from a number of sources including residents, businesses, ecologists, and economists, all of whom may have information or insights related to the appropriate division of a resource. A big concern in this case is overallocation and subsequent shortages, especially in regions where weather patterns are irregular and basing water usage on a year with high rainfall could result in shortages during drought years, when there is not nearly as much water available.