Where is Lac de Sède?

Lac de Sède is a lake in Haute-Garonne, France. This page reports official water-quality measurements, shown as reported.

Is Lac de Sède safe to swim in?

Lac de Sède 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.

Lac de Sède

Haute-Garonne, FranceView map Directions

Eau France publishes the water-quality measurements for Lac de Sède. Here is what has been measured.

Clarity

5.8 m

Clearer than most

Secchi · sampled 2022

Chlorophyll-a

1.5 µg/L

Less algae than most

Measured by Eau France

Limited data

See the measurements Directions Where to stay

Lac de Sède in Haute-Garonne, France has official water-quality measurements, shown as reported. Water clarity: 5.8 m visibility. Chlorophyll-a (algae): 1.5 µg/L.

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How Lac de Sède is classified

Lac de Sède 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 and algae (chlorophyll-a), but not phosphorus.

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.

Lac de Sède is a lake in Haute-Garonne County, France.

Source: the French water agencies, via UNEP GEMS/Water — not the EPA Water Quality Portal, last sampled 2022-10-26. Methodology: how these readings are compared.

What Lac de Sède is good for

From access and monitoring records, not editorial picks.

Clear water18.9 ft of visibility

Swimming conditions

No reading

Limited data

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

Whether Lac de Sède 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 Lac de Sède

These are the measurements Eau France publishes for Lac de Sède. More on the source.

Crystal clear, you can see 18.9 ft down. Chlorophyll-a 1.5 µg/L. TSI 35.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	5.75m	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus		No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.
Chlorophyll-a (algae)	1.5µg/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.	35	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Low nutrients, clear water. No reading is a swimming clearance.

Ask about Lac de Sède

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

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Stays near Lac de Sède

Compare lakeside cabins, hotels, and vacation rentals near Lac de Sède in Haute-Garonne, 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.

Top-rated places to stay near Lac de Sède

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Fishing Lac de Sède

→ Lac de Sède fishing regulations (limits, seasons, special rules)

Frequently asked questions about Lac de Sède

Where is Lac de Sède?: Lac de Sède is a lake in Haute-Garonne, France. This page reports official water-quality measurements, shown as reported.
What is the water quality of Lac de Sède?: Lac de Sède in Haute-Garonne, France has official water-quality measurements, shown as reported. Water clarity: 5.8 m visibility. Chlorophyll-a (algae): 1.5 µg/L.
Is Lac de Sède safe to swim in?: Lac de Sède 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

10 measurements from 1 monitoring station, 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-fr10 samples · —

Analytical methods

Hub'Eau / Naïades plans d'eau

Monitoring station identifiers (1)

O0205043

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