みどり湖
みどり湖 in Nagano, Japan has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 26 µg/L.
Why みどり湖 has no A–F grade
みどり湖 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).
みどり湖 is a lake in Nagano County, Japan.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-07-01. 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 みどり湖
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 26 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 26 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near みどり湖
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Fishing みどり湖
Frequently asked questions about みどり湖
What is the water quality of みどり湖?
- みどり湖 in Nagano, Japan has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 26 µg/L.
Is みどり湖 safe to swim in?
- みどり湖 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, 2019–2024. 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 · 2019–2024
Analytical methods
- MOE public water body monitoring (kosui, lakes)
Monitoring station identifiers (1)
2020140
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: 2024-07-01
Monitoring stations: 1