Otter Tail River

Watershed at a Glance

The Otter Tail watershed encompasses three different ecoregions, covering 1,249,541 acres. 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. The watershed is a drainage basin of the Red River and the major tributaries of the watershed are the Otter Tail and Pelican Rivers. The headwaters of the Red River are considered to be where the Otter Tail River joins the Bois de Sioux River. The majority of the lakes in the greater Red River Basin are found in this watershed.

Assessment estimates indicate 2,241 farms in the watershed. Approximately 51% of the operations are less than 180 acres in size, 39% are from 180 to 1,000 acres in size, and 11% of the farms are equal to or greater than 1,000 acres in size.

Hydrologic Unit Code:09020103
Intensive monitoring start year:2016
Major lakesMajor rivers and streams
Otter Tail, Dead, Battle, Star, Detroit, Melissa, Sallie, Lida
Otter Tail River, Pelican, Bois de Sioux


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 the watershed is estimated at $457,784 (in 1996 dollars) with 99% of the damage being rural.

The main resource concerns in the watershed are wind and water soil erosion, wetland management, surface water quality, stormwater runoff, and wildlife habitat. Many of the resource concerns relate directly to changing land use and increased development in the region, resulting in fragmentation and increased sediment/pollutant (mercury, excess nutrients) loadings to surface waters. A significant portion of the land within this watershed is considered highly erodible, or potentially highly erodible. Land use within the watershed is largely agricultural, accounting for approximately 45% of the overall watershed acres. Development pressure is moderate to considerable in some areas, with occasional farms, timberland, and lakeshore being parceled out for recreation, lake, or country homes.

    What's being done

    Intensive watershed water quality monitoring was conducted in 2016. A monitoring and assessment report will be drafted in early 2018. A St. Clair Lake TMDL Report was completed in 2016 and is available below. The Lower Otter Tail restoration 319 project is in process (summer 2017). This project is designing channel restorations for approximately 20 river miles channelized in the 1960s as part of a flood reduction project. The idea is to improve water quality by reducing sediment associated with stream bank failure. The project will retain its flood damage reduction features. In June 2016 a group of 20 resource managers, local decision makers and land owners formed a civic engagement cohort. This group is led by staff from the U of M Extension Service. Members learned about skills training, leadership training and watershed science. They met monthly and completed formalized training in May 2017. Members will facilitate discussion and decision-making regarding water quality issues in the watershed. The group will meet annually each spring.

    Realtime flow monitoring was installed at three locations in the watershed. Those flows can be found on the MPCA/DNR cooperative stream gaging web page.

    Implementation plans

    Strategy reports

    What is a watershed?

    Illustration showing contour of land directing flow of water

    Learn the basics of a watershed.