Osterhout Lake
Allegan County, MichiganView mapDirections
EGLE publishes the water-quality measurements for Osterhout Lake. Here is what has been measured.
- Mesotrophic
- Limited data
Osterhout Lake in Allegan County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.8 µg/L.
Osterhout Lake is a mesotrophic lake in Allegan County, Michigan. Overall water quality is declining over recent sampling years. Compared to the 4 other monitored lakes in Allegan County, Osterhout Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-21. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Osterhout 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 Osterhout Lake
These are the measurements EGLE publishes for Osterhout Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9 ft. Phosphorus 14 µg/L. Chlorophyll-a 2.8 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 14µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.8µg/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. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Osterhout Lake
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Fishing Osterhout Lake
Water Quality Trend: Worsening
Based on 7 years of monitoring (2016–2023).
Water clarity
Improving6 years
Phosphorus
Worsening+1.25 µg/L/yr7 years
Chlorophyll-a
Worsening+0.7 µg/L/yr2 years
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Osterhout Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Pullman Industries Inc.Pullman · 3.5 mi away · NPDES MIG250128Recent violation
- Antioch Packing HouseAntioch · 4.6 mi away · NPDES IL0067733
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.
Nearby Lakes in Allegan County
Frequently asked questions about Osterhout Lake
Where is Osterhout Lake?
- Osterhout Lake is a lake in Allegan County, Michigan. Its water-quality measurements are published by EGLE and shown on this page as reported.
What is the water quality of Osterhout Lake?
- Osterhout Lake in Allegan County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.8 µg/L.
Is Osterhout Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
109 measurements from 1 monitoring station, 2016–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS109 samples · 2016–2023
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)