Why rank lakes by phosphorus?

Phosphorus is usually what limits how much algae a lake can grow, so it is the earliest signal that a lake is under nutrient pressure. It is also the measurement these agencies publish most consistently, which makes it the fairest way to compare lakes across a country.

Is a low-phosphorus lake safe to swim in?

Not necessarily. A lightly loaded lake can still carry bacteria, a seasonal algal bloom, or contaminants that a nutrient reading does not cover. Check the local authority notice for the day you plan to go.

What is a typical phosphorus level in Estonia?

The median measured lake in Estonia reads 32 µg/L of total phosphorus. Lakes below roughly 10 µg/L are considered nutrient-poor and usually run clear; above about 30 µg/L a lake is generally nutrient-rich and more likely to green up in summer.

Cleanest lakes in Estonia

Cleanest lakes in Estonia: 101 named lakes have an official total-phosphorus reading. The 20 below carry the lowest nutrient load — a measurement, not a LakeQuality A–F grade.

Lake map

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Lowest phosphorus readings in Estonia

Phosphorus is the nutrient that feeds algae growth, so the lakes at the top of this table are the least loaded ones the Estonia monitoring programme has measured. The median measured lake in Estonia reads 32 µg/L.

Lake	Place	Total phosphorus	Chlorophyll-a	Secchi	Year
Sinijärv	Lääne-Viru	10 µg/L	1.0 µg/L	6.3 m	2024
Karujärv	Saare	11 µg/L	1.5 µg/L	4.6 m	2024
Rummu Järv	Harju	11 µg/L	1.0 µg/L	8.8 m	2024
Hindaste Järv	Lääne	12 µg/L	1.7 µg/L	0.6 m	2021
Ahnejärv	Ida-Viru	13 µg/L	4.1 µg/L	3.0 m	2025
Valgejärv	Ida-Viru	13 µg/L	2.5 µg/L	1.9 m	2025
Kooru Järv	Saare	15 µg/L	1.5 µg/L	0.8 m	2025
Saadjärv	Tartu	16 µg/L	1.8 µg/L	4.8 m	2016
Konsu Järv	Ida-Viru	18 µg/L	3.4 µg/L	2.4 m	2025
Aidu Järv	Ida-Viru	20 µg/L	—	—	2021
Järise Järv	Saare	20 µg/L	4.3 µg/L	0.8 m	2024
Männiku Järv	Harju	20 µg/L	3.6 µg/L	3.0 m	2024
Mustanina Karjäär Lake	Ida-Viru	20 µg/L	—	—	2020
Suurjärv	Võru	20 µg/L	3.4 µg/L	2.9 m	2025
Valgõjärv	Põlva	20 µg/L	4.8 µg/L	4.1 m	2025
Hino Järv	Võru	21 µg/L	7.1 µg/L	2.5 m	2023
Pabra Järv	Võru	22 µg/L	3.6 µg/L	1.6 m	2022
Tõhela Järv	Pärnu	22 µg/L	2.0 µg/L	0.9 m	2023
Veskijärv	Lääne	22 µg/L	5.9 µg/L	0.9 m	2021
Jõksi Järv	Põlva	22 µg/L	3.4 µg/L	2.0 m	2025

Showing 20 of 101 named lakes. Open a county or place page for the rest.

Frequently asked questions

Which lakes in Estonia are the cleanest?: 101 named lakes in Estonia have an official total-phosphorus reading. This page ranks the 20 lowest. Phosphorus is the nutrient that feeds algae growth, so a low reading means a lightly loaded lake — it is not a swim-safety class and not a LakeQuality A–F grade.
Why rank lakes by phosphorus?: Phosphorus is usually what limits how much algae a lake can grow, so it is the earliest signal that a lake is under nutrient pressure. It is also the measurement these agencies publish most consistently, which makes it the fairest way to compare lakes across a country.
Is a low-phosphorus lake safe to swim in?: Not necessarily. A lightly loaded lake can still carry bacteria, a seasonal algal bloom, or contaminants that a nutrient reading does not cover. Check the local authority notice for the day you plan to go.
What is a typical phosphorus level in Estonia?: The median measured lake in Estonia reads 32 µg/L of total phosphorus. Lakes below roughly 10 µg/L are considered nutrient-poor and usually run clear; above about 30 µg/L a lake is generally nutrient-rich and more likely to green up in summer.