Юта штатындағы Сивер өзенінің сипаттамасы

River in central Utah, United States
The Sevier River drainage basin of covers more than 13 percent of Utah and includes parts of ten counties, of which the river flows through seven. The Sevier is the longest river entirely within the state of Utah.

The Sevier River is formed by the confluence of Minnie Creek and Tyler Creek in Long Valley in Kane County. The headwaters are at an elevation of 7310 feet (2228 m) between the Markagunt Plateau (on the west) and the Paunsaugunt Plateau. The river flows north through a wide valley into Garfield County passing Hatch and Panguitch. It then flows through the narrow, 5 mile (8 km) Circleville Canyon and enters Piute County at the town of Circleville, and is joined by the East Fork Sevier River at Kingston. Immediately north of Kingston, it is dammed to form Piute Reservoir. The Sevier continues north past Marysvale and through Marysvale Canyon (or Sevier Canyon) into Sevier County. At Sevier the river enters the agricultural Sevier Valley, a 50 mile (80 km) long basin between the Pavant Range on the west and the Sevier Plateau to the east. In the valley, the Sevier River flows generally northeast, passing the cities and towns of Sevier, Joseph, Elsinore, Monroe, Central Valley, Anabella, Richfield, Glenwood, Venice and Sigurd. Just north of Sigurd, the river is dammed to form Rocky Ford reservoir. The Sevier River then continues north passing the towns of Aurora, Salina and Redmond,

In Juab County the Yuba Dam forms Sevier Bridge Reservoir, which also extends into Sanpete County. Below the dam the river flows north then turns abruptly west through Leamington Canyon, between the Canyon Mountains and Gilson Mountains, into Millard County. The river flows southwest across the Sevier Desert, where it is used heavily for irrigation in the Delta area, and is dammed at the DMAD and Gunnison Bend reservoirs. The river is essentially dry for the last 30 mile (48 km) below Delta, through its confluence with the also dry Beaver River before reaching the intermittent Sevier Lake bed.

The Sevier River drainage basin is on the border of the Basin and Range Province and the Colorado Plateau; the north and west parts of the basin are defined by long linear mountain ranges such as the Pavant and Canyon Mountains. The lowest point is at Sevier Lake, 4524 feet (1379 m) above sea level. The basin experiences a continental climate ranging in character from semi arid to alpine. Precipitation – ranging from in the desert valleys to more than in the mountains Even before irrigation, however, not all of this water reached Sevier Lake due to large evaporation losses in the Sevier Desert. The Sevier River basin is bordered to the south by the drainage basins of Virgin River, Kanab Creek, Paria River, and Dirty Devil River, all tributaries of the Colorado River. To the east, it is bordered by the Price and San Rafael River basins, tributaries of the Green River, which flows into the Colorado River. On the north, it is bordered by the Utah Lake–Great Salt Lake basin, and to the west, it is bordered by the Great Salt Lake Desert basins. About 69 percent of the land is federally owned, much of that in national forest lands such as the Manti La Sal, Fishlake, Dixie, and Uinta National Forests. The basin also includes parts of Bryce Canyon National Park and Cedar Breaks National Monument. About 23 percent of the basin is privately owned and 8 percent is owned by the state of Utah. Groundwater basins occur mostly in the alluvial valleys and have been estimated to hold up to of water. Large mineral deposits occur in various areas of the basin, including coal in the Salina area, beryllium in the Delta area, and gypsum in the Richfield area. The dry Sevier Lake bed as well as deposits in the Redmond area, are a major source of salts, including halites and potassium sulfates. During the Pleistocene Ice Age and other preceding ice ages, the Sevier River flowed into Lake Bonneville, which covered more than of the eastern Great Basin. The Sevier Valley was underwater as far upstream as Richfield. As the lake receded with a drying climate at the end of the ice age, what is now the Sevier Desert became an independent lake, which drained into the Great Salt Lake via a now dry channel in Millard County north of Delta. As Sevier Lake shrank, the Sevier River formed a large delta at its mouth, hence the name of the modern town. Soils become progressively more alkaline and saline closer to Sevier Lake, the result of the river transporting minerals downstream over millennia as the lake receded. The upper reaches of the river and many mountain tributaries are home to cutthroat trout, brook trout and rainbow trout, of which cutthroat are the only native species. The deer population was nearly extirpated during the era of western settlement, although it has since recovered. The Fremont culture disappeared around 1300 AD, possibly due to an extended drought. and escaped to a stream they called Río Severo, Spanish for "violent". In 1821, the Sevier River basin became Mexican territory following the Mexican Revolution. Mountain man William H. Ashley explored the area in 1825 in search of beaver; the river was dubbed the "Ashley River" by Jedediah Smith in Ashley's honor. During the 1830s and 1840s the fur trade was in full force with thousands of beaver and otter taken from the Sevier River and its tributaries; most trappers were Native Americans although there were also many of British, French and Spanish origin. Despite the massacre, immigration continued with 30 Mormon families settling in the Richfield area in 1864, followed by 100 more the next year, further straining relations with the tribes. Between 1865 and 1872 more than 150 violent confrontations occurred between Mormon settlers and various Native American groups including the Utes, Paiutes, Apache and Navajo, a period now known as the Black Hawk War after Timpanogos chief Antonga Black Hawk. One of the bloodiest single episodes was the Circleville Massacre near the upper Sevier River, in which 26 Paiutes were killed by white settlers after an earlier attack by Ute warriors, despite the fact that the Paiutes and Utes were enemies. In total, at least 70 whites and an unknown number of Native Americans were killed. The Deseret Telegraph was extended from Salt Lake City as far as Monroe in 1872.

The first irrigation along the Sevier River was established in the spring of 1850, on the Sanpete County stretch of the river. Irrigation in Millard County began in 1859. Agriculture was made difficult by frequent flooding of the Sevier River. In June 1909 heavy snowmelt broke the Gunnison Bend Dam and flooded the town of Deseret under 3 feet (1 m) of water. It was not until about 1912 when the river was finally controlled by major reservoirs upstream. However, the river and lake can still fill after major floods. In the especially wet season of 1982–1983, the melting of a record snowpack overwhelmed the reservoir system which had not been designed for flood control. Bridges, roads and diversion structures were washed out, and the DMAD and Gunnison Bend dams were partially breached.

Along with agriculture, the Sevier basin has had a long history of mining and resource extraction, which continues in some areas of the basin today. Coal, rock salts and other minerals have been mined from the Salina area since the 1870s. In 1891 the Sevier Railroad, a branch of the Denver and Rio Grande Western Railroad (D&RGW), reached Salina, and the town soon became the shipping point for both coal and agricultural products from the Sevier Valley. Much of the coal mined in the area is nowadays shipped to the Intermountain Power Plant, which was completed near Delta in 1986. The 1,900 megawatt power station consumes two million tons of coal and draws of cooling water from the Sevier River each year. In 2017 the Intermountain Power Agency announced it would be converting the plant to natural gas operations. Gold was mined at several places along the river starting in the late 19th century. In 1896 the Sevier Railroad was extended to the gold mining area of Belknap and in 1900 tracks were laid through Marysvale Canyon to reach the diggings around Marysvale, with the line thereafter known as the "Marysvale Branch". The boom town of Kimberly in the Tushar Mountains was one of the largest gold mining camps in Utah. Other boom towns of the period included Bullion City, Webster and Alunite, the latter of which produced significant quantities of aluminum ore. Uranium was first discovered in Piute County in 1948. In the following decades, many former uranium miners died of emphysema or various forms of cancer. The state of Utah later spent $500,000 closing down two hundred mines in the district. There are 175 irrigation companies in the Sevier River basin, with 72 of them serving over each. Total water use in the basin is more than 1 million acre feet (1.2 billion m3) annually, with more than 60 percent dedicated to agriculture.

Piute Dam was constructed on the Upper Sevier River between 1908 and 1914, forming Piute Reservoir. The reservoir holds up to of water for use in the Sevier Valley. Water released from Piute Reservoir is diverted at the Sevier Valley Diversion Dam into the 65 mile (105 km) long Sevier Valley Piute Canal. It is one of the longest man made waterways in Utah, irrigating along the western side of the valley in Sevier and Sanpete Counties.

Parts of the Upper Sevier, and its higher tributaries and feeder lakes, are good trout waters, particularly in National Forest lands. The basin has native cutthroat trout, and many streams contain introduced brook, brown and rainbow trout. A 20 mile (32 km) stretch of the East Fork in Black Canyon, above Tropic Reservoir, is classified as a Blue Ribbon trout fishery. This stretch was restored by the Utah Division of Wildlife Resources between 1992 and 2006 due to damage from the 1983 flooding. Marysvale Canyon is also known for its trout during the non irrigation (low water) season, being located in the tailwater of Piute Dam. Fishing is generally poor downstream of Marysvale Canyon due to the warm silty water, numerous diversion structures and degradation of riparian habitat.