Retenue de Villerest
Retenue de Villerest in Unknown, France has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 89 µg/L.
Why Retenue de Villerest has no A–F grade
Retenue de Villerest in France 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 French water agencies, via UNEP GEMS/Water.
Retenue de Villerest is a lake in Unknown County, France.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-10-20. 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 Retenue de Villerest
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 89 µg/L. Trophic State Index: 69.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 89 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 69 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Retenue de Villerest
Compare lakeside cabins, hotels, and vacation rentals near Retenue de Villerest in Unknown, France — 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.
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Fishing Retenue de Villerest
Frequently asked questions about Retenue de Villerest
What is the water quality of Retenue de Villerest?
- Retenue de Villerest in Unknown, France has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 89 µg/L.
Is Retenue de Villerest safe to swim in?
- Retenue de Villerest 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
32 measurements from 1 monitoring station, 2019–2022. Retrieved from UNEP GEMS/Water GFQA (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- European Environment Agency
europeanenvironmentagenc32 samples · —
Analytical methods
- GEMStat OPEN / CC BY 4.0
Monitoring station identifiers (1)
FRA00077
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: 2022-10-20
Monitoring stations: 1