Morrow County, Ohio · Water Quality Report Card
Amann Reservoir
Amann Reservoir in Morrow County, Ohio has a water quality grade of D (Poor). Phosphorus: 241 µg/L.
- Type
- Hypereutrophic
Amann Reservoir is a highly nutrient-loaded hypereutrophic lake in Morrow County, Ohio. Water quality is graded D based on 1 sampling years through 2024. Compared to the 1 other monitored lakes in Morrow County, Amann Reservoir ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Ohio EPA, last sampled 2024-10-02. Grade methodology: LakeGrade methodology.
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Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D (Poor)
No clarity data. Phosphorus level: 241 µg/L. Trophic State Index: 83.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 241 µg/L | Poor |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 83 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Amann Reservoir
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Fishing Amann Reservoir
Location
County Ranking
Ranked #1 of 2 lakes in Morrow County
Nearby Lakes in Morrow County
Explore Amann Reservoir across LakeGrade
More Ohio Lake Rankings
Other Grade D Lakes in Ohio
Hypereutrophic Lakes in Ohio
More records, surveys & data sources
EPA Impairment Status
Amann Reservoir 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 OH050600010801 · Official waterbody report · Matched by proximity (2.65 km)
Where this data comes from
7 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_WQX7 samples · 2024
Analytical methods
- Total Phosphorus After Block Digestion
Monitoring station identifiers (1)
Grade thresholds come from the U.S. EPA National Lakes Assessment 2022 Technical Support Document (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated.
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2024-10-02
Monitoring stations: 1