Bighorn/Wind River Basin (Overview) HUC# 100800Basin Geography:This river basin mainstem is made up of the Wind and Bighorn Rivers. The Wind originates in the mountainous terrain between the Absaroka and Wind River Ranges and flows southeast through the Wind River Indian Reservation. A major Wind tributary is the Popo Agie River. At Riverton the river turns north and forms Boysen reservoir with a capacity of over 800,000 acre-ft. Once the river exits the Wind River Canyon near Thermopolis, it becomes the Bighorn which continues north and eventually enters Bighorn lake on the Montana/Wyoming border. Major Bighorn tributaries include the Greybull and Shoshone Rivers. The Little Bighorn River is also part of this hydrologic unit. It flows northeast from the east slope of the Bighorn mountains before entering Montana. This river eventually joins the mainstem Bighorn to the north. The Little Bighorn is administered by the State of Wyoming in conjunction with Water Division II to the east. Over 500,000 acres of land are irrigated in this arid basin with surface water. Suspended solids in the waters of the Wind/Bighorn and tributaries are a water quality concern and are due to base line and land use conditions. Human and livestock waste bacteria are also present in the River. Hydro-thermal resources are present on the Bighorn near Thermopolis. Alluvial, structural and sandstone aquifers support irrigation, livestock, domestic and industrial uses. Relevant Compacts and Decrees: The Yellowstone River Compact of 1950 allocated 80% of the Bighorn River flow to Wyoming. Pre-1950 rights are guaranteed in the compact. This arrangement indicates that there is significant available water for new consumptive uses in Wyoming, given that the Bighorn River discharges 3.9 million acre-ft of flow from Wyoming in an average year. However, federally reserved rights must be considered. These include water rights for the Wind River Indian Reservation as well as federal land agencies. In 1977, the State of Wyoming filed suit in federal court to settle the adjudication of the Bighorn. The Wind River Reservation has since been awarded over 500,000 acre-ft of reserved water rights. The adjudication is complicated and ongoing with many determinations still unsettled. The administration of reserved rights awarded to the Shoshone and Arapaho tribes will continue to be a future concern given the diversity of water rights holders in the basin. When the 1950 compact was negotiated, the Little Bighorn allocation was not agreed upon among the states. While general provisions of the compact are interpreted to cover this stream, no specific allocations of Little Bighorn flows were made in the Yellowstone River Compact. Sources: US Geological Survey. 1985. National Water Summary-Wyoming: Surface Water Resources, Water Supply Paper 2300. pp. 494. US Geological Survey. 1990. National Water Summary-Wyoming: Stream Water Quality, Water Supply Paper 2400. pp. 571-2. US Geological Survey. 1984. National Water Summary-Wyoming: Groundwater Resources, Water Supply Paper 2275. pp. 457. Wyoming Water Development Commission & Wyoming State Engineer's Office. 1996. Wyoming Water Planning: A Report for Updating the Process. Cheyenne, WY. pp.13-5 Wyoming Water Development Commission. 1990. Wyoming Water Atlas. University of Wyoming, Laramie. pp. 47.
Index of the Statewide Data Inventory | |||||