| Percent samples with Dissolved Oxygen (DO) concentration less than 5 mg/L | |||||||
| Watershed | Mar-Apr | May-Jun | Jul-Aug | Sep-Oct | Winter | All Seasons | |
| Bois De Sioux | 2 | 2 | 17 | 0 | 8 | 6 | |
| Mustinka | 50 | 0 | 50 | 0 | 47 | 34 | |
| Otter Tail | 1 | 1 | 8 | 3 | 1 | 3 | |
| Upper Red | 1 | 2 | 9 | 3 | 2 | 4 | |
| Western Wild Rice | 0 | 5 | 0 | 14 | 0 | 4 | |
| Buffalo | 12 | 0 | 10 | 0 | 33 | 12 | |
| Elm-Marsh | 5 | 1 | 10 | 0 | 8 | 5 | |
| Eastern Wild Rice | 8 | 1 | 3 | 0 | 26 | 7 | |
| Goose | 10 | 2 | 10 | 6 | 9 | 7 | |
| Devils Lake | 6 | 6 | 19 | 16 | 25 | 11 | |
| Upper Sheyenne | 15 | 15 | 20 | 0 | 32 | 18 | |
| Middle Sheyenne | 14 | 2 | 9 | 0 | 15 | 9 | |
| Lower Sheyenne | 3 | 2 | 6 | 2 | 4 | 3 | |
| Maple | 6 | 0 | 0 | 0 | 0 | 3 | |
| Sandhill-Wilson | 15 | 7 | 15 | 8 | 25 | 15 | |
| Red Lakes | na | 100 | 33 | 43 | 52 | ||
| Red Lake | 0 | 1 | 4 | 0 | 4 | 2 | |
| Thief | na | na | na | na | na | na | |
| Clearwater | 9 | 5 | 20 | 9 | 25 | 14 | |
| Grand Marais - Red | 0 | 4 | 0 | 0 | 0 | 1 | |
| Turtle | 10 | 0 | 0 | 25 | 27 | 12 | |
| Forest | 10 | 0 | 0 | 0 | 4 | 2 | |
| Snake | 26 | 4 | 14 | 0 | 40 | 15 | |
| Park | 7 | 0 | 3 | 0 | 4 | 3 | |
| Lower Red | 1 | 1 | 5 | 0 | 1 | 2 | |
| Two Rivers | 0 | 5 | 6 | 0 | 5 | 3 | |
| Pembina | 1 | 0 | 1 | 0 | 7 | 2 | |
| Reseau | 21 | 5 | 8 | 0 | 42 | 18 | |