Beginning in the Uinta Mountains, Bear River makes five state line crossings through three states: Utah, Wyoming, and Idaho, before flowing into Great Salt Lake, resulting in a multitude of political, institutional, and legal challenges in river management and regulation. At the start of the early 20th century, the river was regulated for hydropower by the diversion, conveyance, and storage of Bear River water into and out of Bear Lake by PacifiCorp and is considered one of the first multiple-use reclamation projects not financed by the federal government.
For over 110 years, regulation of Bear River has provided (1) stable water supply for over 150,000 acres of irrigated farmland downstream of Bear Lake, (2) extensive high-runoff management benefits, (3) generation of hydroelectric power, (4) recreation opportunities at Bear Lake and along the Bear River, and (5) habitat enhancements for fish and wildlife.
Similar to other semi-arid western watersheds, the hydrology of the Bear River watershed is defined by a series of wet-dry cycles. Figure 1 compares the elevations of Bear Lake to the Standardized Precipitation and Evapotranspiration Index (SPEI, Vicente-Serrano, 2010) for the period between 1903 and 2018. The SPEI provides a measure of how precipitation and potential evapotranspiration differ from normal conditions. A value greater than 0.8 indicates a wet period (see the blue line in Figure 1) and a value less than -0.8 indicates a drought year (see the brown line in Figure 1).
Legal and Institutional Background
The Dietrich Decree was established on July 14, 1920, to allow PacifiCorp to release water from Bear Lake “for the generation of electric power, and for such irrigation or other beneficial purposes, recognized by law, as the plaintiff (PacifiCorp) may devote or dedicate said released stored water, by use, sale, rental, or otherwise.” This right to store 5,500 cfs of water from the Bear River became controversial in compact negotiations because the right directly affected downstream rights. The Dietrich Decree gave PacifiCorp a priority right over most downstream users; additionally, upstream users could be affected, although they were not involved in the litigation.
The Kimball Decree was issued February 21, 1922 and also quantified and prioritized water rights in Utah. This decree also recognized PacifiCorp’s right to divert Bear River and Bear Lake/Mud Lake tributaries and to store the diverted water in Bear lake under the same quantities and priorities as the Dietrich Decree. The Kimball Decree was also silent on Bear lake elevations or volume storage allowed.
Bear River Compact
The Bear River Compact was signed by President Dwight D. Eisenhower on March 17, 1958. It included Utah, Wyoming and Idaho and divided the Bear River into the Upper, Central and Lower Divisions. It granted the three states storage rights above Bear lake amounting to 36,500 acre feet, subject to Bear Lake elevations 5,913.24 and 5,914.7 feet. Created an irrigation reserve elevation of 5,914.7 feet where no releases solely for power generation could occur below that elevation.
The Compact was revised in November 1997 to grant an additional 74,500 acre feet of storage, 35,000 acre feet each for Utah and Wyoming and 4,500 acre feet for Idaho with a depletion restriction of 28,000 acre feet above Bear Lake. The additional storage granted was subject to a Bear Lake elevation restriction of 5,911.0 feet. The Compact Commission modified the 5,911 Bear Lake elevation requirement to include storage in Mud Lake and its equivalent Bear Lake incremental elevation.
The Bear Lake Settlement Agreement was executed on April 10, 1995 by Last chance Canal Co., Cub River Canal Co., West Cache Canal Co., Idaho Pumpers Assn., Utah Pumpers Assn., Bear River Canal Co., Bear River Water Users Assn., Bear lake Watch, Emerald Beach, Bear lake East, Jim Kimball and PacifiCorp. It recognized PacifiCorp’s decreed rights to divert Bear River water and to store in Bear Lake between elevations 5,902 and 5,923.65 feet for irrigation, power and other beneficial uses. For the first time, the settlement agreement authorized an irrigation allocation schedule between elevations 5,914.7 and 5,902. The agreement did not grant storage volumes to individual irrigation companies in excess of the original storage contract amounts. Any unused storage allocation would be preserved for Bear Lake recovery for future use by the contract holders.
The Operations Agreement was made April 18, 2000, by PacifiCorp, Idaho, Utah and Wyoming, to assent to general operations of Bear Lake and hydroelectric dams downstream from Bear Lake. The parties agreed that Bear Lake would be operated primarily as a storage reservoir to satisfy existing contracts and for the flood control needs of the three States. Future operations would be constrained to not make deliveries exclusively for hydropower production.
Bear River Development
Planning and studies for the development or storage of the Bear River have been ongoing for several decades as outlined in the Bear River Development Act passed in 1991. Thanks primarily to conservation efforts, new technology and some water development projects, current projections indicate the water won’t be needed until 2045 to 2050. When the legislation was passed, the projected need was in 2015. Read More
History of the Bear River Compact by the Utah Division of Water Rights