渡之瀬ダム貯水池
渡之瀬ダム貯水池 in Hiroshima, Japan has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 16.5 µg/L.
Why 渡之瀬ダム貯水池 has no A–F grade
渡之瀬ダム貯水池 in Japan is published with the authority's own measurements, not a LakeQuality letter. official authority class; not a LakeQuality A–F letter Sampling here has recorded phosphorus, but not water clarity and algae (chlorophyll-a).
A letter on the LakeQuality scale would be an invention, not an official class. Everything below that has been measured is still reported on this page.
Monitoring: the Ministry of the Environment (Japan).
渡之瀬ダム貯水池 is a lake in Hiroshima County, Japan.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2021-07-01. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for 渡之瀬ダム貯水池
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 16.5 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 16.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near 渡之瀬ダム貯水池
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Fishing 渡之瀬ダム貯水池
Frequently asked questions about 渡之瀬ダム貯水池
What is the water quality of 渡之瀬ダム貯水池?
- 渡之瀬ダム貯水池 in Hiroshima, Japan has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 16.5 µg/L.
Is 渡之瀬ダム貯水池 safe to swim in?
- 渡之瀬ダム貯水池 has official nutrient and clarity measurements, not a bacteria swim class and not a safety clearance. Algal blooms, currents, and depth are not covered. Always check local notices before swimming.
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Where this data comes from
6 measurements from 1 monitoring station, 2016–2021. Retrieved from Japan MOE public water-body monitoring (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Ministry of the Environment (Japan)
moe-jp6 samples · 2016–2021
Analytical methods
- MOE public water body monitoring (kosui, lakes)
Monitoring station identifiers (1)
3420060
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See methodology and data sources.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2021-07-01
Monitoring stations: 1