Upper Birch Lake
Upper Birch Lake in Isanti County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.8 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.3 µg/L.
- Clarity
- 10.8 ft
- Typical in August
- 77°F
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Isanti County
Upper Birch Lake is a cold, clear oligotrophic lake in Isanti County, Minnesota. Water quality is graded A based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 16 other monitored lakes in Isanti County, Upper Birch Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-05-22. 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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 10.8 ft. Phosphorus level: 9.5 µg/L. Chlorophyll-a: 2.3 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.8 ft | Not graded |
| Phosphorus | 9.5 µg/L | Good |
| Chlorophyll-a (Algae) | 2.3 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Upper Birch Lake
Compare lakeside cabins, hotels, and vacation rentals near Upper Birch Lake in Isanti 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.
Top-rated places to stay near Upper Birch Lake
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Water Temperature
Upper Birch Lake typically sits around 77°F at the surface in August. Summer average is about 77°F. Usually warmest in Jul (about 79°F) and coldest in May (about 66°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 21 field readings (2017–2024) via the EPA Water Quality Portal. See the full Upper Birch Lake water temperature breakdown →
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Upper Birch Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.587 m/yr | 6 |
| Phosphorus | ↓ Declining | +4.63 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.4 µg/L/yr | 6 |
EPA Impairment Status
Upper Birch Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN30-0004-00 · Official waterbody report · Matched by proximity (1.08 km)
County Ranking
Ranked #3 of 17 lakes in Isanti County
Nearby Lakes in Isanti County
Frequently asked questions about Upper Birch Lake
What is the water quality grade for Upper Birch Lake?
- Upper Birch Lake in Isanti County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.8 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.3 µg/L.
Is Upper Birch Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Upper Birch Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.3 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Upper Birch Lake?
- Upper Birch Lake typically sits around 77°F at the surface in August, from 21 EPA Water Quality Portal field readings (2017–2024). That is a typical value for the month, not a live reading.
How deep is Upper Birch Lake?
- The available depth estimate for Upper Birch Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown.
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Where this data comes from
34 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA34 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)