| Percent Samples with Total Phosphours Concentration more than 0.25 mg/L | |||||||
| Watershed | Mar-Apr | May-Jun | Jul-Aug | Sep-Oct | Winter | All Seasons | |
| Bois De Sioux | 47 | 38 | 75 | 37 | 16 | 41 | |
| Mustinka | 25 | 33 | 86 | 33 | 70 | 53 | |
| Otter Tail | 11 | 8 | 15 | 15 | 11 | 12 | |
| Upper Red | 38 | 36 | 49 | 24 | 25 | 34 | |
| Western Wild Rice | 57 | 45 | na | 33 | 0 | 48 | |
| Buffalo | 40 | 26 | 42 | 14 | 4 | 26 | |
| Elm-Marsh | 80 | 77 | 96 | 77 | 54 | 76 | |
| Eastern Wild Rice | 21 | 8 | 7 | 4 | 5 | 9 | |
| Goose | 50 | 6 | 58 | 26 | 24 | 32 | |
| Devils Lake | 59 | 44 | 83 | 78 | 58 | 60 | |
| Upper Sheyenne | na | na | na | na | na | na | |
| Middle Sheyenne | 55 | 22 | 48 | 18 | 12 | 33 | |
| Lower Sheyenne | 50 | 34 | 34 | 23 | 17 | 31 | |
| Maple | 64 | 9 | 67 | 0 | 0 | 43 | |
| Sandhill-Wilson | 75 | 60 | 60 | 64 | 43 | 59 | |
| Red Lakes | 9 | 2 | 4 | 10 | 29 | 7 | |
| Red Lake | 21 | 15 | 12 | 10 | 3 | 12 | |
| Thief | na | na | na | na | na | na | |
| Clearwater | 9 | 1 | 11 | 2 | 4 | 6 | |
| Grand Marais - Red | 57 | 64 | 68 | 26 | 33 | 49 | |
| Turtle | 25 | 5 | na | na | 0 | 12 | |
| Forest | 47 | 24 | 35 | 25 | 11 | 27 | |
| Snake | 67 | 52 | 65 | 47 | 50 | 56 | |
| Park | 45 | 32 | 50 | 31 | 24 | 36 | |
| Lower Red | 51 | 53 | 56 | 37 | 25 | 42 | |
| Two Rivers | 31 | 25 | 31 | 33 | 33 | 31 | |
| Pembina | 60 | 28 | 51 | 15 | 16 | 37 | |
| Reseau | 13 | 6 | 5 | 11 | 6 | 8 | |