Barrage de Saint-Jean
Barrage de Saint-Jean in Gers, France has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 0.2 m visibility. Phosphorus: 57 µg/L. Chlorophyll-a (algae): 11 µg/L.
- Clarity
- 0.2 m
Why Barrage de Saint-Jean has no A–F grade
Barrage de Saint-Jean 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 water clarity, phosphorus 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.
Barrage de Saint-Jean is a lake in Gers County, France.
Source: the French water agencies, via UNEP GEMS/Water — not the EPA Water Quality Portal, last sampled 2022-10-03. 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 Barrage de Saint-Jean
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 0.7 ft of visibility. Phosphorus level: 57 µg/L. Chlorophyll-a: 11 µg/L. Trophic State Index: 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.2 m | Not graded |
| Phosphorus | 57 µg/L | Not graded |
| Chlorophyll-a (Algae) | 11 µg/L | Not graded |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Barrage de Saint-Jean
Compare lakeside cabins, hotels, and vacation rentals near Barrage de Saint-Jean in Gers, 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 Barrage de Saint-Jean
Frequently asked questions about Barrage de Saint-Jean
What is the water quality of Barrage de Saint-Jean?
- Barrage de Saint-Jean in Gers, France has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 0.2 m visibility. Phosphorus: 57 µg/L. Chlorophyll-a (algae): 11 µg/L.
Is Barrage de Saint-Jean safe to swim in?
- Barrage de Saint-Jean 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
34 measurements from 1 monitoring station, 2019–2022. Retrieved from UNEP GEMS/Water GFQA (not the EPA Water Quality Portal) on 2026-08-20.
Collected and reported by
- Office français de la biodiversité (Hub'Eau)
hubeau-fr34 samples · —
Analytical methods
- Hub'Eau / Naïades plans d'eau
Monitoring station identifiers (1)
Q2205013
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See how grades are calculated and data sources.