This article provides an overview of Colorado's historical prior appropriation system of allocating water rights. The following is an excerpt from its introduction:

"Beneficial use and preservation are two primary public policies which guide western natural resource law; they are the two chambers of our western heart, the two lobes of our brain. Colorado water law establishes the right of water appropriation to serve public and private needs. New uses and changes in existing water rights continue to exist and evolve within the framework of the water law. The preservation interests are addressed primarily by state and federal land use law and environmental regulatory law, such as is evidenced by the acquisition of open space and parks by public entities, as well as federal land reservations for national parks, monuments, wilderness areas, and wildlife preserves.

Western prior appropriation water law is a property rights-based allocation and administration system, which promotes multiple use of a finite resource. The fundamental characteristics of this system guarantee security, assure reliability, and cultivate flexibility. Security resides in the system’s ability to identify and obtain protection for the right of use. Reliability springs from the system’s assurance that the right of use will continue to be recognized and enforced over time. Flexibility emanates from the fact that the right of use can be transferred to another, subject to the requirement that other appropriators not be injured by the change...Colorado water law illustrates the public interest at work through the interplay of two forces. On the one hand, individual and public entity initiative secure water supplies for beneficial use in a system of property rights creation. On the other hand is the enforcement of those rights, subject to local, state, and federal regulation aimed at meeting societal choices made by legislative means.

This article focuses on major historical and legal themes that emerge from Colorado’s water experience. It is accompanied by an appendix intended to highlight the major historic, statutory, and case law events that give structure to Colorado water law."