The Central Utah Project (CUP) is the largest and most complex water resources development project undertaken by the Bureau of Reclamation in the state of Utah. Reclamation-wide, the CUP is not the largest project, but the initial plans for the CUP were among the most complex, especially given the amount of water the project was originally intended to deliver.
The concept of a project for central Utah began with the Colorado River-Great Basin Project, initiated by Reclamation in 1939, that proposed delivery of one million acre-feet of water annually from the Green River in eastern Utah to the Great Basin (Wasatch Front). In 1945, the name "Central Utah Project" was given to an extended version of the plan that reduced exportation to 575,000 acre-feet of water. The project's first Definite Plan Report (DPR) in 1964 further reduced trans-basin diversion to 136,600 acre-feet and subsequent planning reduced the diversion even further to 101,900 acre-feet in a 1988 revision of the DPR. The Supplement to the 1988 DPR for the Bonneville Unit, approved in October 2004, provides the current design to complete the Central Utah Project and confirms the transmountain diversion of 101,900 acre-feet.
The CUP was officially authorized by Congress for construction in 1956 under provisions of the Colorado River Storage Project (CRSP) Act (43 USC 620). Because of its size and complexity, Reclamation divided the CUP into six units to facilitate planning and construction: Vernal, Jensen, Bonneville, Upalco, Ute Indian, and Uintah. The Vernal, Jensen, Bonneville, and Upalco Units were authorized by the 1956 CRSP Act. The Uintah and Ute Indian Unit were later authorized by the 1968 Colorado River Basin Project Act.
Over the decades since the CUP's authorization, the changing political climate, budget priorities, and emerging environmental concerns have resulted in many changes to the project. The Vernal and Jensen Units were completed; plans for the Upalco, Uintah, and Ute Indian Units were never realized with the Ute Indian Unit being de-authorized; the purpose and components of the Bonneville Unit evolved; and the passage of the Central Utah Project Completion Act (CUPCA) in 1992 altered the planning, oversight, and areas of responsibility for the Bonneville Unit.
CUPCA is federal legislation, Public Law 102-575, which became law October 30, 1992. CUPCA authorized additional funding for the project and transferred responsibility for planning, designing, and constructing the remaining CUP features to the Central Utah Water Conservancy District (CUWCD). CUPCA further authorized CUWCD to act as a federal agent for environmental compliance.
The largest unit of the CUP, the Bonneville Unit, collects and distributes water in both the Uintah Basin of eastern Utah and the Bonneville Basin of central Utah. The Bonneville Unit provides water for irrigation and municipal and industrial uses. In addition, Bonneville Unit systems provide water for maintenance of aquatic habitats in natural streams, open-water recreation, and flood control. For purposes of planning and construction, the Bonneville Unit itself was divided into component systems. Working together, the systems develop, store, and transport water resources for the benefit of the people of Utah.