Helmer_nelson Pond Deep
Helmer_nelson Pond Deep in Cook County, Minnesota has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 2.9 µg/L.
- Clarity
- 2.5 ft
- Typical in August
- 68°F
- Type
- Eutrophic
- Trend
- ↓ Declining
Next lake in Cook County
Helmer_nelson Pond Deep is a productive, nutrient-rich eutrophic lake in Cook County, Minnesota. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Compared to the 43 other monitored lakes in Cook County, Helmer_nelson Pond Deep ranks #38 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-05-21. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 2.5 ft of visibility. Phosphorus level: 60 µg/L. Chlorophyll-a: 2.9 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 60 µg/L | Poor |
| Chlorophyll-a (Algae) | 2.9 µg/L | Good |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Helmer_nelson Pond Deep
Compare lakeside cabins, hotels, and vacation rentals near Helmer_nelson Pond Deep in Cook County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Water Temperature
Helmer_nelson Pond Deep typically sits around 68°F at the surface in August. Summer average is about 67°F. Usually warmest in Jul (about 70°F) and coldest in May (about 47°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 71 field readings (2011–2025) via the EPA Water Quality Portal. See the full Helmer_nelson Pond Deep water temperature breakdown →
Fishing Helmer_nelson Pond Deep
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -14.114 m/yr | 3 |
| Phosphorus | ↑ Improving | -8.73 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +4.56 µg/L/yr | 4 |
County Ranking
Ranked #38 of 44 lakes in Cook County
Nearby Lakes in Cook County
Frequently asked questions about Helmer_nelson Pond Deep
What is the water quality grade for Helmer_nelson Pond Deep?
- Helmer_nelson Pond Deep in Cook County, Minnesota has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 2.9 µg/L.
Is Helmer_nelson Pond Deep safe to swim in?
- Generally safe for swimming, moderate water quality. Helmer_nelson Pond Deep has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 2.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Helmer_nelson Pond Deep?
- Helmer_nelson Pond Deep typically sits around 68°F at the surface in August, from 71 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
Explore Helmer_nelson Pond Deep across LakeGrade
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Where this data comes from
31 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Grand Portage Reservation
GPC5_WQX31 samples · 2021–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 5310 C ~ Total Organic Carbon in Water- Ultraviolet Oxidation Method
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.