Where is Heranen Lake?

Heranen Lake is a lake in Joensuu, Finland. This page reports official water-quality measurements, shown as reported.

Is Heranen Lake safe to swim in?

Heranen Lake 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 Heranen Lake?

Heranen Lake has a maximum depth of 38.7 feet.

Heranen Lake

Joensuu, FinlandView map Directions

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

Clarity

2.3 m

Clearer than most

Secchi · sampled 2024

Phosphorus

4.5 µg/L

Less phosphorus than most

Measured by Syke

Chlorophyll-a

2.5 µg/L

Less algae than most

Measured by Syke

Max depth

11.8 m

Bathymetric survey

39 ft max depth
Limited data

See the measurements Directions Where to stay

Heranen Lake in Joensuu, Finland has official water-quality measurements, shown as reported. Water clarity: 2.3 m visibility. Phosphorus: 4.5 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 38.7 ft.

Loading map…

How Heranen Lake is classified

Heranen Lake 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.

Heranen Lake is a lake in Joensuu County, Finland with a maximum depth of 39 feet.

Source: the Finnish Environment Institute (Syke) and the ELY Centres — not the EPA Water Quality Portal, last sampled 2024-08-08. Methodology: how these readings are compared.

What Heranen Lake is good for

From access and monitoring records, not editorial picks.

Deep water38.7 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 Heranen Lake 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.

Get alerts for Heranen Lake →

Water quality measurements for Heranen Lake

These are the measurements Syke publishes for Heranen Lake. More on the source.

Moderate clarity, visible to about 7.4 ft. Phosphorus 4.5 µg/L. Chlorophyll-a 2.5 µg/L. TSI 38.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	2.25m	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	4.5µg/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.	38	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

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

Ask about Heranen Lake

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

Lake Details

Max depth

11.8 m

Stays via Stay22

Stays near Heranen Lake

Compare lakeside cabins, hotels, and vacation rentals near Heranen Lake in Joensuu, Finland — 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 Heranen Lake

Prices for Oct 2–4, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Follow Heranen Lake’s readings

Email me when new measurements post for this lake. Updates stay free.

Or email

Fishing Heranen Lake

→ Heranen Lake fishing regulations (limits, seasons, special rules)

Frequently asked questions about Heranen Lake

Where is Heranen Lake?: Heranen Lake is a lake in Joensuu, Finland. This page reports official water-quality measurements, shown as reported.
What is the water quality of Heranen Lake?: Heranen Lake in Joensuu, Finland has official water-quality measurements, shown as reported. Water clarity: 2.3 m visibility. Phosphorus: 4.5 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 38.7 ft.
Is Heranen Lake safe to swim in?: Heranen Lake 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 Heranen Lake?: Heranen Lake has a maximum depth of 38.7 feet.

Explore Heranen Lake across LakeQuality

Lake Fishing Forecast

Species activity outlook by water temperature and season

More lakes in Finland

Lakes in Finland

Official water quality for lakes in Finland

Lake water quality by country

EU bathing ratings and named-lake measurements

Where this data comes from

5 measurements from 1 monitoring station, 2024. 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-vesla5 samples · 2024

Analytical methods

SYKE VESLA

Monitoring station identifiers (1)

21817

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