Which lakes in Bulgaria are the clearest?

11 named lakes in Bulgaria have an official Secchi depth. This page ranks the 11 deepest readings. Secchi is a clarity measurement, not a swim-safety class and not a LakeQuality A–F grade.

Is clear water the same as clean water?

No. Secchi measures how far a disk stays visible. A clear lake can still have bacteria, toxins, or contaminants this catalog does not grade. Open a lake page for the authority's values.

Clearest lakes in Bulgaria

Clearest lakes in Bulgaria: 11 named lakes have an official Secchi depth. The 11 below are ranked by that reading — water clarity, not a LakeQuality A–F grade.

Lake map

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Highest Secchi readings in Bulgaria

Lake	Place	Total phosphorus	Chlorophyll-a	Secchi	Year
Dam Dospat	—	21 µg/L	—	4.5 m	2023
Dam Studen Kladenec	—	48 µg/L	—	4.5 m	2022
Tsonevo Dam	—	22 µg/L	—	4.0 m	2023
Dam Ivaiilovgrad	—	48 µg/L	4.9 µg/L	3.5 m	2023
Dam Ogosta	—	53 µg/L	11 µg/L	3.4 m	2023
Dam Kardjali	—	45 µg/L	—	3.3 m	2023
Dam Aleksandar Stamboliyski	—	46 µg/L	2.6 µg/L	3.0 m	2022
Dam Batak	—	32 µg/L	3.0 µg/L	2.9 m	2023
Dam Jrebchevo	—	27 µg/L	—	2.5 m	2023
Dam Topolnica	—	42 µg/L	7.4 µg/L	2.3 m	2023
Dam Koprinka	—	36 µg/L	15 µg/L	2.2 m	2023

Frequently asked questions

Which lakes in Bulgaria are the clearest?: 11 named lakes in Bulgaria have an official Secchi depth. This page ranks the 11 deepest readings. Secchi is a clarity measurement, not a swim-safety class and not a LakeQuality A–F grade.
Is clear water the same as clean water?: No. Secchi measures how far a disk stays visible. A clear lake can still have bacteria, toxins, or contaminants this catalog does not grade. Open a lake page for the authority's values.