Where is Suuri Tetrijärvi?

Suuri Tetrijärvi is a lake in Ilomantsi, Finland. This page reports official water-quality measurements, shown as reported.

Is Suuri Tetrijärvi safe to swim in?

Suuri Tetrijärvi 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.

How deep is Suuri Tetrijärvi?

Suuri Tetrijärvi has a maximum depth of 29.9 feet.

Suuri Tetrijärvi

Ilomantsi, FinlandView map Directions

Syke publishes the water-quality measurements for Suuri Tetrijärvi. Here is what has been measured.

Clarity

2.8 m

Clearer than most

Secchi · sampled 2026

Phosphorus

7.7 µg/L

Less phosphorus than most

Measured by Syke

Chlorophyll-a

2.5 µg/L

Less algae than most

Measured by Syke

Max depth

9.1 m

Bathymetric survey

30 ft max depth
Limited data

See the measurements Directions Where to stay

Suuri Tetrijärvi in Ilomantsi, Finland has official water-quality measurements, shown as reported. Water clarity: 2.8 m visibility. Phosphorus: 7.7 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 29.9 ft.

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How Suuri Tetrijärvi is classified

Suuri Tetrijärvi in Finland 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 Finnish Environment Institute (Syke) and the ELY Centres.

Suuri Tetrijärvi is a lake in Ilomantsi County, Finland with a maximum depth of 30 feet.

Source: the Finnish Environment Institute (Syke) and the ELY Centres — not the EPA Water Quality Portal, last sampled 2026-06-25. 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 Suuri Tetrijärvi is safe to swim in today is a call for the Finnish Environment Institute (Syke) and the ELY Centres and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Suuri Tetrijärvi

These are the measurements Syke publishes for Suuri Tetrijärvi. More on the source.

Moderate clarity, visible to about 9.2 ft. Phosphorus 7.7 µg/L. Chlorophyll-a 2.5 µg/L. TSI 39.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	2.8m	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	7.7µg/L	Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.
Chlorophyll-a (algae)	2.5µg/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.	39	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

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

Ask about Suuri Tetrijärvi

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

Lake Details

Max depth

9.1 m

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Fishing Suuri Tetrijärvi

→ Suuri Tetrijärvi fishing regulations (limits, seasons, special rules)

Frequently asked questions about Suuri Tetrijärvi

Where is Suuri Tetrijärvi?: Suuri Tetrijärvi is a lake in Ilomantsi, Finland. This page reports official water-quality measurements, shown as reported.
What is the water quality of Suuri Tetrijärvi?: Suuri Tetrijärvi in Ilomantsi, Finland has official water-quality measurements, shown as reported. Water clarity: 2.8 m visibility. Phosphorus: 7.7 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 29.9 ft.
Is Suuri Tetrijärvi safe to swim in?: Suuri Tetrijärvi 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.
How deep is Suuri Tetrijärvi?: Suuri Tetrijärvi has a maximum depth of 29.9 feet.

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Where this data comes from

13 measurements from 1 monitoring station, 2020–2026. Retrieved from Syke VESLA (not the EPA Water Quality Portal) on 2026-08-16.

Collected and reported by

Finnish Environment Institute (Syke) and ELY Centressyke-vesla13 samples · 2020–2026

Analytical methods

SYKE VESLA

Monitoring station identifiers (1)

23964

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