The Otter Tail River Watershed represents an area of about 1,920 square miles, including areas of substantial portions of Otter Tail, Becker and Wilkin counties, and very small portions of Clay and Clearwater counties.

The watershed is a drainage basin of the Red River and the major tributaries of the watershed are the Ottertail and Pelican Rivers. Where the Otter Tail River joins the Bois de Sioux River is considered to be the headwaters of the Red River. The majority of the lakes in the Red River Basin are found in this watershed.

Three different ecoregions occur in the watershed. The southwest portion of the watershed - the mouth of the watershed, is located in the Red River Valley ecoregion. The northeast portion of the watershed - the headwaters of the watershed, is in the Northern Lakes and Forests ecoregion. The majority of the watershed found between these two areas is characterized by the North Central Hardwood Forest ecoregion. The eastern three-fourths of the watershed contains thousands of lakes and wetlands.

Much of the glacial deposits in the watershed are till, made up of clay, silt, sand and gravel. Also, in the east-central portion of the watershed, outwash, ice-contact, terrace and alluvium deposits made of mostly sand and gravel are plentiful. Glacial lake deposits of clay and silt are found at the mouth of the watershed. Soils vary widely from clayey soils of the lakeplain and black, limey and clayey soils at the mouth of the watershed; to black, loamy soils and sandy soils in the west central portion of the watershed; and rolling, wooded soils, sandy soils and loamy soils in the northeastern portion of the watershed.

Historically, watershed land cover was dominated by forest (50%), prairie/grassland (20%), and wetland (13%). Currently, land use is now dominated by cropland (43%), deciduous forest (20%), open water (14%), and wetland (13%), with the main conversion being of forested land to cropland. Land cover in the riparian areas of rivers (1,000 feet on either side of rivers) of the watershed is mainly wetland (37%), cultivated land (34%) and forest (15%). Primarily to accommodate agriculture, the mouth of the watershed is extensively drained.

The central, east and northeast portions of the watershed are underlain with a surficial aquifer. Large amounts of ground water are available from sand and gravel deposits throughout much of the watershed. The glacial lake plain and glacial till areas have more limited supplies. Except for the southwestern corner of the glacial lake plain, most of the watershed provides ground water recharge from precipitation. The same area is a discharge area to lakes and streams. Ground water is used primarily for irrigation, public water supplies and industrial uses, and averages 18,000 acre-feet per year.

The following charts show the assessments of water quality of streams in the watershed

Otter Tail Watershed Stream Water Quality Assessments:

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Of all of the watersheds in the Red River Basin, the Otter Tail River Watershed is one of the least impacted by flooding. Annual average flood damage (in 1996 dollars) in the watershed is estimated at $457,784 with 99% of the damages being rural. The watershed suffers 2.3% of flood damages occurring in the Red River Basin, outside of damages occurring along the main stem of the Red River.

The watershed does not have a watershed district to oversee water management for the entire watershed. However, the Pelican River Watershed District oversees the north-central portion of the watershed along the upper reaches of the Pelican River in the vicinity of Lakes Detroit, Sallie and Melissa; and the Cormorant Lakes Watershed district oversees water management activities in the Cormorant Lakes area, west of Detroit Lakes.

More Information

For questions about the Red River Basin information available on this page, contact Molly MacGregor at 218-846-0494.