Water law is the specialized area of legislation and statutes that govern the ownership, usage, and rights related to a body of water above or below ground in a region. These laws are, in many ways, similar to property or land laws that govern how terrestrial resources are owned and controlled by various groups and individuals. Certain aspects of water, however, differentiate such laws from those regarding land, such as how water can move and change based on seasons and location, as well as the fact that it can exist below ground. Water law is often established by countries and regions within a country, though large bodies of water can be governed by international laws as well.
Sometimes also called riparian law or riparian rights, water law typically deals with the control and usage of bodies of water. This is usually done by establishing how ownership, control, and usage of water are assigned and in this way it can be quite similar to property law. Some countries or states can use riparian rights to establish water usage for bodies of water such as rivers and lakes based on geographical location. This type of water law will typically allow those who live or own businesses along the coast of such water to use the water freely, so long as such usage does not diminish the quantity or quality of the water.
Water law becomes quite complicated because of this secondary stipulation. Property law is often fairly simple, at least in comparison, because someone may use the land he or she owns without necessarily affecting the land owned by someone else. Water, on the other hand, can potentially belong to a number of people living along the water, and underground water supplies may provide water to dozens or hundreds of individuals. Determining ownership and how these various individuals and companies can use available water typically results in complex water law regulations.
This is only made more complicated by the fact that water law regulations established by multiple regions or countries can affect a single body of water. A river flowing through and between five or six states can be affected by a number of individual state water laws, as well as federal water regulations. Water law pertaining to the use of oceans can be even more complex, since dozens of countries may potentially utilize such a body of water and have different laws regarding its use and maintenance. Due to these issues, international water laws, especially those dealing with conservation, have become increasingly important.