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LakeQuality

Lake map

Map shows 12 lakes with coordinates

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Named lakes

LakePlaceTotal phosphorusChlorophyll-aSecchiYear
下久保ダム貯水池Gunma14 µg/L—3.0 m2025
奈良俣ダム貯水池Gunma4.0 µg/L—5.5 m2024
尾瀬沼Gunma6.0 µg/L—3.7 m2024
桐生川ダム貯水池Gunma15 µg/L—2.8 m2025
榛名湖Gunma9.0 µg/L—5.2 m2024
相俣ダム貯水池Gunma7.0 µg/L—3.0 m2025
矢木沢ダム貯水池Gunma6.0 µg/L—5.5 m2024
草木ダム貯水池Gunma10 µg/L—4.0 m2025
薗原ダム貯水池Gunma20 µg/L—2.1 m2024
藤原ダム貯水池Gunma7.0 µg/L—4.0 m2025
赤城大沼Gunma17 µg/L—3.8 m2024
須田貝ダム貯水池Gunma7.0 µg/L—3.7 m2024

Frequently asked questions

How many named lakes are in Gunma?
12 named lakes in Gunma, Japan, have official phosphorus and Secchi, 2024–2025. Values are the authority's measurements, shown as reported.
Where do the Gunma readings come from?
Gunma pages show official phosphorus, chlorophyll-a, and Secchi from the publishing authority, with the year each was taken.

Official surface phosphorus, chlorophyll-a, and/or Secchi. Not a LakeQuality A–F grade — the authority does not publish a letter on this scale.