| Lac qui Parle River | |
| Map: | Lacqueparlerivermap.png |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Minnesota |
| Length: | 118.3miles[1] |
| Discharge1 Location: | Lac qui Parle Township[2] |
| Discharge1 Min: | 0cuft/s |
| Discharge1 Avg: | 157cuft/s[3] |
| Discharge1 Max: | 17100cuft/s |
| Source1: | Lake Hendricks |
| Source1 Location: | Hendricks, Lincoln County |
| Source1 Coordinates: | 44.5047°N -96.435°W[4] |
| Source1 Elevation: | 1755feet[5] |
| Mouth: | Minnesota River |
| Mouth Location: | Lac qui Parle State Park, Lac qui Parle County |
| Mouth Coordinates: | 45.0264°N -95.8803°W |
| Mouth Elevation: | 934feet |
| Basin Size: | 1156sqmi[6] |
| Tributaries Left: | West Branch Lac qui Parle River |
The Lac qui Parle River is a tributary of the Minnesota River, 118miles long, in southwestern Minnesota in the United States. A number of tributaries of the river, including its largest, the West Branch Lac qui Parle River, also flow in eastern South Dakota. Via the Minnesota River, the Lac qui Parle River is part of the watershed of the Mississippi River, draining an area of 1156sqmi in an agricultural region. Slightly more than two-thirds of the Lac qui Parle watershed is in Minnesota.[6]
The Native Dakota name for the river is "Watapan Intapa" which means "River at the Head", referencing that the Dakota considered the river the head of the Minnesota River. The French misinterpreted the name for Lac qui Parle Lake as also belonging to the Lac qui Parle River. The river was also called Beaver Creek by fur traders.[7] [8]
The source of the river is Lake Hendricks on the boundary of Lincoln County, Minnesota, and Brookings County, South Dakota. It issues from the lake in Hendricks, Minnesota, and flows northeastwardly through northwestern Lincoln County as an intermittent stream on the Coteau des Prairies, a morainic plateau dividing the Mississippi and Missouri River watersheds, into western Yellow Medicine County, where it flows off the Coteau, dropping 250feet in 8miles. Continuing northeastwardly through flat till plains with occasional willows and cottonwoods along its banks, the river flows into eastern Lac qui Parle County, passing to the east of Dawson. It flows into the Minnesota River just below Lac qui Parle Lake in Lac qui Parle State Park, approximately 10miles northwest of Montevideo, after flowing through a wooded valley in which it drops 210feet in 18miles. Lac qui Parle Lake was formed by a delta at the mouth of the Lac qui Parle River, and is maintained by a dam.[6] [9] [10]
The river's largest tributary, the West Branch Lac qui Parle River,[11] 103.2km (64.1miles) long,[12] rises on the coteau in eastern Deuel County, South Dakota, and flows initially northeastwardly as an intermittent stream, past Gary, South Dakota, then eastwardly through Lac qui Parle County, past Dawson. Other tributaries include two small trout streams: Canby Creek, 24miles long, which flows northeastwardly on the Coteau in western Yellow Medicine County, through Canby; and Tenmile Creek, 33miles long, which flows eastward and northwardy through Lac qui Parle County, through Boyd.[1] [9] [10] [13]
According to the Minnesota Pollution Control Agency, of the 806sqmi of the river's watershed in Minnesota, 79% of the land is used for agricultural cultivation, primarily corn and soybeans.[6] Water quality has degraded, with only 3% of the river being fully supportive of aquatic life. Eutrophication is one major reason for this.[14]
The river is also home to calcerous fen habitats, seven of which exist in the Lac qui Parle River Watershed.[15] Calcerous fens are calcium-rich peat wetlands which support endangered plants in Minnesota like the cut-leaf water parsnip and hairy fimbry.[16]
The Lac qui Parle River is used recreationally as a place for canoeing and kayaking.[17]
At the United States Geological Survey's stream gauge near the community of Lac qui Parle in Lac qui Parle Township, the annual mean flow of the river between 1910 and 2005 was 157 cubic feet per second (4 m³/s). The highest recorded flow during the period was 17,100 ft³/s (484 m³/s) on April 10, 1969. Readings of zero were recorded on numerous days during several years.[2]