Where is Etang de la Forge?

Etang de la Forge is a lake in Ille-et-Vilaine, France. This page reports official water-quality measurements, shown as reported.

Is Etang de la Forge safe to swim in?

Etang de la Forge 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.

Etang de la Forge

Ille-et-Vilaine, FranceView map Directions

Eau France publishes the water-quality measurements for Etang de la Forge. Here is what has been measured.

Clarity

0.6 m

Murkier than most

Secchi · sampled 2023

Phosphorus

195 µg/L

More phosphorus than most

Measured by Eau France

Chlorophyll-a

21.7 µg/L

More algae than most

Measured by Eau France

Limited data

See the measurements Directions Where to stay

Etang de la Forge in Ille-et-Vilaine, France has official water-quality measurements, shown as reported. Water clarity: 0.6 m visibility. Phosphorus: 195 µg/L. Chlorophyll-a (algae): 21.7 µg/L.

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How Etang de la Forge is classified

Etang de la Forge in France is published with the authority's own measurements and class. The measurements here are published by the agency that samples the lake, as reported. Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).

LakeQuality publishes no grade of its own beside it. Everything below thathas been measured is reported on this page.

Monitoring: the French water agencies, via UNEP GEMS/Water.

Etang de la Forge is a lake in Ille-et-Vilaine County, France.

Source: the French water agencies, via UNEP GEMS/Water — not the EPA Water Quality Portal, last sampled 2023-09-20. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Etang de la Forge is safe to swim in today is a call for the French water agencies, via UNEP GEMS/Water and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Etang de la Forge

These are the measurements Eau France publishes for Etang de la Forge. More on the source.

Very murky, less than 2 ft of visibility. Phosphorus 195 µg/L. Chlorophyll-a 21.7 µg/L. TSI 69.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	0.6m	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	195µg/L	Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.
Chlorophyll-a (algae)	21.7µg/L	Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water.
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	69	Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic

High nutrients, frequent algae, reduced clarity

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Answers come straight from the public measurements and survey records on this page.

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Stays near Etang de la Forge

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Fishing Etang de la Forge

→ Etang de la Forge fishing regulations (limits, seasons, special rules)

Frequently asked questions about Etang de la Forge

Where is Etang de la Forge?: Etang de la Forge is a lake in Ille-et-Vilaine, France. This page reports official water-quality measurements, shown as reported.
What is the water quality of Etang de la Forge?: Etang de la Forge in Ille-et-Vilaine, France has official water-quality measurements, shown as reported. Water clarity: 0.6 m visibility. Phosphorus: 195 µg/L. Chlorophyll-a (algae): 21.7 µg/L.
Is Etang de la Forge safe to swim in?: Etang de la Forge 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, 2017–2023. 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-fr32 samples · —

Analytical methods

Hub'Eau / Naïades plans d'eau

Monitoring station identifiers (1)

J760510

Authority classifications are shown as the authority published them. See where the data comes from and data sources.