Swamp Lake
Swamp Lake in Chisago County, Minnesota has a water quality grade of C (Fair). Water clarity: 1.6 ft visibility. Phosphorus: 46 µg/L. Chlorophyll-a (algae): 6 µg/L.
- Clarity
- 1.6 ft
- Typical in August
- 75°F
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Chisago County
Swamp Lake is a productive, nutrient-rich eutrophic lake in Chisago County, Minnesota. Water quality is graded C based on 2 sampling years through 2025. 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 29 other monitored lakes in Chisago County, Swamp Lake ranks #16 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-09. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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 1.6 ft of visibility. Phosphorus level: 46 µg/L. Chlorophyll-a: 6 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | Not graded |
| Phosphorus | 46 µg/L | Poor |
| Chlorophyll-a (Algae) | 6 µg/L | Good |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Swamp Lake
Compare lakeside cabins, hotels, and vacation rentals near Swamp Lake in Chisago 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 Swamp Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Swamp Lake typically sits around 75°F at the surface in August. Summer average is about 73°F. Usually warmest in Aug (about 75°F) and coldest in May (about 65°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 37 field readings (2017–2025) via the EPA Water Quality Portal. See the full Swamp Lake water temperature breakdown →
Fishing Swamp Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.009 m/yr | 5 |
| Phosphorus | ↓ Declining | +21.2 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -0.93 µg/L/yr | 5 |
EPA Impairment Status
Swamp Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN13-0014-00 · Official waterbody report · Matched by proximity (2.65 km)
County Ranking
Ranked #16 of 30 lakes in Chisago County
Nearby Lakes With Higher Grades
Swamp Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Chisago County
Frequently asked questions about Swamp Lake
What is the water quality grade for Swamp Lake?
- Swamp Lake in Chisago County, Minnesota has a water quality grade of C (Fair). Water clarity: 1.6 ft visibility. Phosphorus: 46 µg/L. Chlorophyll-a (algae): 6 µg/L.
Is Swamp Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Swamp Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Swamp Lake?
- Swamp Lake typically sits around 75°F at the surface in August, from 37 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
Explore Swamp Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
76 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA76 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
- 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