Gage Lake
Cass County, MichiganView mapDirections
Nutrients and algae run above the regional average.
↑ up from F at the last regrade
- Eutrophic
- #9 of 10 in the county
Gage Lake in Cass County, Michigan has a water quality grade of D (Nutrient-rich). Phosphorus: 60 µg/L.
- Typical in September
- 67°F
- Type
- Eutrophic
- Phosphorus
- 60 µg/L
- Trend
- ↓ Declining
Stays via Stay22
Stays near Gage Lake
Compare lakeside cabins, hotels, and vacation rentals near Gage Lake in Cass County, Michigan — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Gage Lake are listed below.
Top-rated places to stay near Gage Lake
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Gage Lake is a productive, nutrient-rich eutrophic lake in Cass County, Michigan. Water quality is graded D based on 1 sampling years through 2025. Overall water quality is declining over recent sampling years. Compared to the 9 other monitored lakes in Cass County, Gage Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2025-10-20. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyElevated nutrients
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.
The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Phosphorus 60 µg/L. TSI 63. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 60 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Gage Lake typically sits around 67°F at the surface in September. Summer average is about 71°F. Usually warmest in Aug (about 73°F) and coldest in Feb (about 39°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 775 field readings (2013–2025) via the EPA Water Quality Portal. See the full Gage Lake water temperature breakdown →
Fishing Gage Lake
Water Quality Trend: ↓ Declining
Based on 9 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↓ Declining | +17.14 µg/L/yr | 9 |
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Gage Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 2 facilities have a reported Clean Water Act violation in the past three years.
- Dowagiac WwtpDowagiac · 4.2 mi away · NPDES MI0022837MajorRecent violation
- Alliance Cloud Services Llc-GwcuDowagiac · 2.5 mi away · NPDES MI0003069Recent violation
- Service Oil Co-DowagiacDowagiac · 3.8 mi away · NPDES MI0054488
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #9 of 10 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Gage Lake
Where is Gage Lake?
- Gage Lake is a lake in Cass County, Michigan. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Gage Lake?
- Gage Lake in Cass County, Michigan has a water quality grade of D (Nutrient-rich). Phosphorus: 60 µg/L.
Is Gage Lake safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Gage Lake?
- Gage Lake typically sits around 67°F at the surface in September, from 775 EPA Water Quality Portal field readings (2013–2025). That is a typical value for the month, not a live reading.
Explore Gage Lake across LakeQuality
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
424 measurements from 1 monitoring station, 2016–2025. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Pokagon Band of Potawatomi Indians, Michigan and Indiana (Tribal)
PBDNR424 samples · 2016–2025
Analytical methods
- 4500 P B ~ Phosphorus, sample preparation method
- 4500 P ~ Phosphorus in water and wastewater
- Total Phosphorus After Block Digestion
- Turbidity by Nephelometry
- Direct Measurement Method
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)