Qacmainstfbk Lake is a 133,000-acre mesotrophic lake in Mercer County, North Dakota. Water quality is graded A based on 2 sampling years through 2020. The lake supports 1 documented fish species including Rainbow Trout. Compared to the 4 other monitored lakes in Mercer County, Qacmainstfbk Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, North Dakota DNR, last sampled 2020-10-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
No clarity data. Phosphorus level: 10 µg/L. Chlorophyll-a: 7 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 10 µg/L | A |
| Chlorophyll-a (Algae) | 7 µg/L | B |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | 6 ft |
| Surface Area | 133,000 acres |
| Shoreline Length | 0.5 mi |
Where to stay near Qacmainstfbk Lake
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Fish Species
Click a species to see every graded lake where it is documented.
Fishing Qacmainstfbk Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Source: USGS Nonindigenous Aquatic Species (NAS) Database. Hover a chip to see scientific name, ecological context, status, and first-observed year.
Location
County Ranking
Ranked #2 of 5 lakes in Mercer County
Nearby Lakes in Mercer County
Explore Qacmainstfbk Lake across LakeGrade
Fish species and top-graded lakes across North Dakota
Fish species and best lakes in Mercer County
Species activity outlook by water temperature and season
Where to stay at North Dakota's top lakes, each with its grade
Moderate nutrients, good water quality
North Dakota's cleanest and most-polluted lakes, ranked
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Other Grade A Lakes in North Dakota
Mesotrophic Lakes in North Dakota
Compare Qacmainstfbk Lake With Nearby Lakes
More records, surveys & data sources
Reservoir Info (USACE NID)
Qacmainstfbk Lake is a man-made reservoir impounded by the Garrison Dam (completed 1953), built primarily for hydroelectric on the MISSOURI RIVER; earth-type dam, 210 ft tall and 11,300 ft long.
- Surface area
- 133,000 ac
- Normal storage
- 18,500,000 ac-ft
- Max storage
- 26,000,000 ac-ft
- Drainage area
- 180,940 sq mi
- Hazard class
- High
- Owner
- USACE - Omaha District
All listed purposes: Hydroelectric;Irrigation;Navigation;Recreation;Flood Risk Reduction.
Source: USACE National Inventory of Dams, NID ID ND00145 · Operator website · Matched by proximity (0.09 km)
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Data Sources
Water quality data from the EPA Water Quality Portal
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Depth, fish, and access data from North Dakota Game & Fish
Most recent sample: 2020-10-22
Monitoring stations: 1