Coldwater Lake
Isabella County, MichiganView mapDirections
EGLE publishes the water-quality measurements for Coldwater Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
Coldwater Lake in Isabella County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 1 µg/L.
Coldwater Lake is a cold, clear oligotrophic lake in Isabella County, Michigan. Overall water quality is improving over recent sampling years. The lake supports 1 documented fish species including Lake herring. Compared to the 1 other monitored lakes in Isabella County, Coldwater Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-14. Methodology: how these readings are compared.
If you are planning to stay, you can search lake houses and cabins around Coldwater Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Coldwater Lake is good for
From access and monitoring records, not editorial picks.
- Clear water11 ft of visibility
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Coldwater Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), oxygen depletion (low DO). Check local advisories before you swim.
Whether Coldwater Lake is safe to swim in today is a call for the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Coldwater Lake
These are the measurements EGLE publishes for Coldwater Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 11 ft. Phosphorus 16 µg/L. Chlorophyll-a 1 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 11ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 16µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Coldwater Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Coldwater Lake typically sits around 56°F at the surface in September. Summer average is about 54°F. Usually warmest in Aug (about 56°F) and coldest in May (about 51°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (51°F) to its warmest (56°F).
Typical surface water temperature by month, from 479 field readings (2021–2023) via the EPA Water Quality Portal. See the full Coldwater Lake water temperature breakdown →
Stays via Stay22
Stays near Coldwater Lake
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Top-rated places to stay near Coldwater Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Coldwater Lake
Water Quality Trend: Improving
Based on 5 years of monitoring (2018–2023).
Water clarity
Improving5 years
Phosphorus
Improving-0.47 µg/L/yr5 years
Chlorophyll-a
Stable0 µg/L/yr4 years
EPA Impairment Status
Coldwater Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MI040802020204-07 · Official waterbody report
Nearby Lakes in Isabella County
Frequently asked questions about Coldwater Lake
Where is Coldwater Lake?
- Coldwater Lake is a lake in Isabella County, Michigan. Its water-quality measurements are published by EGLE and shown on this page as reported.
What is the water quality of Coldwater Lake?
- Coldwater Lake in Isabella County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 1 µg/L.
Is Coldwater Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Coldwater Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), oxygen depletion (low DO). Check local advisories before you swim.
What is the water temperature of Coldwater Lake?
- Coldwater Lake typically sits around 56°F at the surface in September, from 479 EPA Water Quality Portal field readings (2021–2023). That is a typical value for the month, not a live reading.
What fish are in Coldwater Lake?
- Fish species found in Coldwater Lake include Lake herring. Coldwater Lake is located in Isabella County, Michigan.
Explore Coldwater Lake across LakeQuality
Fish species and the cleanest lakes across Michigan
Species activity outlook by water temperature and season
Where to stay at Michigan's top lakes, each with its readings
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Where this data comes from
70 measurements from 1 monitoring station, 2018–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS70 samples · 2018–2023
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database