The framework that establishes Colorado water law was mandated in Colorado’s Constitution. It’s called the prior appropriation system, and it regulates river water rights in Colorado, including the use of surface water in rivers or tributary groundwater (also known as shallow groundwater, it is below the surface but still connected to a river system) connected to a river basin. Broken down, this means:
Prior: Water users with earlier river water rights decrees (senior rights) have better rights in times of short supply and can fill their water use needs before others (those with junior rights) can begin to use water. The term “first in time/first in right” is often a shortened way of describing the prior appropriation doctrine.
Appropriation: This occurs when a public agency, private person, or business puts water to a beneficial use according to law. River water rights can only be granted to previously unappropriated water. Before being allowed to put the water to beneficial use, the appropriator must have a plan to divert, store, or otherwise capture the water and possess and control it.
System: The system is a legal procedure by which water users can get a legal decree from the water courts for their river water rights. The court approval is called adjudication and it sets the priority date of the river water right, its source of supply, its amount, its point of diversion, its type, and its place of use. It also confirms that it won’t cause injury (cause river water rights holders to suffer loss of water during the time, place, and amount that they are entitled to use that water) to any existing river water rights holders. There are two types of prior appropriation river water rights. One enables the river water rights holder to take water directly from the river to its place of use and the second allows water to be stored in a reservoir for later use.
Usufructary Rights
In Colorado, river water rights fall under the category of property rights known as usufructary rights. Usufructary means having the right to use a resource without actually owning it. So while you may have river water rights to a certain amount of water in a certain river, you never actually own the water. According to Colorado law, the ownership of the water resource always remains in the public domain.
Usufructary rights have many facets. One of them is the idea of “use it or lose it,” which means if you don’t need to use all or part of your river water rights as decreed to you, the water goes to those who can put the water to beneficial use according to the priority dates established in their river water rights decrees.
But a river water rights holder may not take from the river any more water than is needed for beneficial use at the time the water is actually diverted, despite the amount that is allowed based on the river water rights decree. Diverting more than what is needed