Blackbird Lake
Becker County, MinnesotaEutrophic
Blackbird Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Blackbird Lake sits at rank 69 of 102 in Becker County, in the lower half of the local distribution.
No invasive species are currently listed at Blackbird Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Blackbird Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Blackbird Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-26. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 7.5 ft. Phosphorus level: 29 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.5 ft | C |
| Phosphorus | 29 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 50 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.019 m/yr | 4 |
| Phosphorus | ↑ Improving | -3 µg/L/yr | 4 |
Location
County Ranking
Ranked #69 of 102 lakes in Becker County
Cleaner Lakes Within 30 Miles
Blackbird Lake holds Grade B. 5 nearby lakes hold higher grades.
- AIsland LakeBecker County · mi · Higher grade (B → A)
- AFlat LakeBecker County · mi · Higher grade (B → A)
- ATea Cracker LakeBecker County · mi · Higher grade (B → A)
- BJohnson LakeBecker County · mi · Higher overall water quality score
- BPine LakeBecker County · mi · Higher overall water quality score
Nearby Lakes in Becker County
More Minnesota Lake Rankings
Other Grade B Lakes in Minnesota
Eutrophic Lakes in Minnesota
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-26
Monitoring stations: 1