Where is Sonnanjärvi?

Sonnanjärvi is a lake in Kouvola, Finland. This page reports official water-quality measurements, shown as reported.

Is Sonnanjärvi safe to swim in?

Sonnanjärvi 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 Sonnanjärvi?

Sonnanjärvi has a maximum depth of 82 feet.

Sonnanjärvi

Kouvola, FinlandView map Directions

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

Clarity

4.1 m

Clearer than most

Secchi · sampled 2022

Phosphorus

3.9 µg/L

Less phosphorus than most

Measured by Syke

Chlorophyll-a

3.1 µg/L

Less algae than most

Measured by Syke

Max depth

25 m

Bathymetric survey

82 ft max depth
Limited data

See the measurements Directions Where to stay

Sonnanjärvi in Kouvola, Finland has official water-quality measurements, shown as reported. Water clarity: 4.1 m visibility. Phosphorus: 3.9 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 82 ft.

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How Sonnanjärvi is classified

Sonnanjärvi 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.

Sonnanjärvi is a lake in Kouvola County, Finland with a maximum depth of 82 feet.

Source: the Finnish Environment Institute (Syke) and the ELY Centres — not the EPA Water Quality Portal, last sampled 2022-08-25. Methodology: how these readings are compared.

What Sonnanjärvi is good for

From access and monitoring records, not editorial picks.

Clear water13.3 ft of visibility
Deep water82 ft surveyed max depth

Swimming conditions

No reading

Limited data

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

Whether Sonnanjärvi 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 Sonnanjärvi

These are the measurements Syke publishes for Sonnanjärvi. More on the source.

Good clarity, visible to about 13.3 ft. Phosphorus 3.9 µg/L. Chlorophyll-a 3.1 µg/L. TSI 35.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	4.05m	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	3.9µg/L	Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.
Chlorophyll-a (algae)	3.1µg/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 Sonnanjärvi

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

Lake Details

Max depth

25 m

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Stays near Sonnanjärvi

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Fishing Sonnanjärvi

→ Sonnanjärvi fishing regulations (limits, seasons, special rules)

Frequently asked questions about Sonnanjärvi

Where is Sonnanjärvi?: Sonnanjärvi is a lake in Kouvola, Finland. This page reports official water-quality measurements, shown as reported.
What is the water quality of Sonnanjärvi?: Sonnanjärvi in Kouvola, Finland has official water-quality measurements, shown as reported. Water clarity: 4.1 m visibility. Phosphorus: 3.9 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 82 ft.
Is Sonnanjärvi safe to swim in?: Sonnanjärvi 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 Sonnanjärvi?: Sonnanjärvi has a maximum depth of 82 feet.

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Where this data comes from

10 measurements from 1 monitoring station, 2016–2022. 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-vesla10 samples · 2016–2022

Analytical methods

SYKE VESLA

Monitoring station identifiers (1)

12072

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