The District was established as the Middle River Snake River Watershed District on August 28, 1970 with approximately 1,020 square miles in Marshall, Polk and Pennington Counties. The District is located in the Red River of the North basin. It was established in response to repeated flooding and inadequate drainage in the area. Starting in 1973, the District acquired jurisdiction of several drainage systems. In the 1990s to 2000, the District constructed 4 ditches. In 2010, the District acquired 2 more ditches. The total amount of ditch miles is nearly 340.
Seven ditches flow directly into the Red River of the North. These ditches have six ditches that flow into them. There are nine ditches that flow into the Snake River. The Middle River has four ditches that flow into it. The downstream portion of the Middle River is a channelized ditch which flows into the Snake River.
The District has ditches ranging from a 2 year, 5 year and an 8 year frequencies. The frequency refers to the conveyance ability to carry a specific runoff volume, without overflowing and will allow for the drainage of adjacent lands to prevent crop damage and avoid damage to the ditch’s infrastructure.
In 2002, the Board of Water & Soil Resources approved a petition to add the Tamarac River watershed to the District. The number of Managers was increased from 5 to 7. The name was changed to the Middle-Snake-Tamarac Rivers Watershed District and it increased in size to approximately 1,476 square miles. Portions of Kittson and Roseau counties are now included in the District too.
In 1983, the District constructed its first floodwater damage reduction impoundment, Angus Oslo #1, to temporarily store floodwater. The March Property was purchased along the Snake River in the early 1990s, southwest of March Siding. This site has not been developed into a storage area. In 2000, the second impoundment, Angus Oslo #4, was constructed. A PL-566 project to construct a Snake River diversion ditch around the town of Warren and an impoundment northeast of Radium were finalized in 2006. Then in 2010, the largest impoundment, Agassiz Valley, was constructed. In 2013, the newest impoundment Brandt Angus Coulee became operational. All of the impound locations have been towards the middle third of the District. The impoundments are operated in a way that they will be drained completely after a flood event. The partial exception is Agassiz Valley which has a summer low flow augmentation, which is to be drained by September 1st each year. All of the impoundments are considered empty at the end of the growing season.