Ottawa Reservoir
Putnam County, OhioView mapDirections
Ohio EPA publishes the water-quality measurements for Ottawa Reservoir. Here is what has been measured.
- Eutrophic
- Limited data
Ottawa Reservoir in Putnam County, Ohio has water-quality measurements published by Ohio EPA, shown here as reported. Phosphorus: 74.9 µg/L.
Ottawa Reservoir is a productive, nutrient-rich eutrophic lake in Putnam County, Ohio.
Source: EPA Water Quality Portal sampling records, Ohio EPA, last sampled 2024-09-18. 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 Ottawa Reservoir is safe to swim in today is a call for the Ohio Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Ottawa Reservoir
These are the measurements Ohio EPA publishes for Ottawa Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 74.9 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 74.9µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 66 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
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Stays near Ottawa Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Ottawa Reservoir in Putnam County, Ohio — 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Ottawa Reservoir are listed below.
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Fishing Ottawa Reservoir
Nearby Lakes in Putnam County
Frequently asked questions about Ottawa Reservoir
Where is Ottawa Reservoir?
- Ottawa Reservoir is a lake in Putnam County, Ohio. Its water-quality measurements are published by Ohio EPA and shown on this page as reported.
What is the water quality of Ottawa Reservoir?
- Ottawa Reservoir in Putnam County, Ohio has water-quality measurements published by Ohio EPA, shown here as reported. Phosphorus: 74.9 µg/L.
Is Ottawa Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Ottawa Reservoir across LakeQuality
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Where this data comes from
10 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Division of Surface water (Ohio)
21OHIO_WQX10 samples · 2024
Analytical methods
- Total Phosphorus After Block Digestion
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.