赤城大沼
Gunma, JapanView mapDirections
MOE publishes the water-quality measurements for 赤城大沼. Here is what has been measured.
- Limited data
赤城大沼 in Gunma, Japan has official water-quality measurements, shown as reported. Water clarity: 3.8 m visibility. Phosphorus: 17 µg/L.
How 赤城大沼 is classified
赤城大沼 in Japan 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 and phosphorus, but not algae (chlorophyll-a).
LakeQuality publishes no grade of its own beside it. Everything below thathas been measured is reported on this page.
Monitoring: the Ministry of the Environment (Japan).
赤城大沼 is a lake in Gunma County, Japan.
Source: the Ministry of the Environment (Japan) — not the EPA Water Quality Portal, last sampled 2024-10-15. Methodology: how these readings are compared.
What 赤城大沼 is good for
From access and monitoring records, not editorial picks.
- Clear water12.3 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether 赤城大沼 is safe to swim in today is a call for the Ministry of the Environment (Japan) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for 赤城大沼
These are the measurements MOE publishes for 赤城大沼. More on the source.
Good clarity, visible to about 12.3 ft. Phosphorus 17 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.75m | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 17µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | No reading 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. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
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Frequently asked questions about 赤城大沼
Where is 赤城大沼?
- 赤城大沼 is a lake in Gunma, Japan. This page reports official water-quality measurements, shown as reported.
What is the water quality of 赤城大沼?
- 赤城大沼 in Gunma, Japan has official water-quality measurements, shown as reported. Water clarity: 3.8 m visibility. Phosphorus: 17 µg/L.
Is 赤城大沼 safe to swim in?
- 赤城大沼 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.
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More lakes in Japan
Where this data comes from
27 measurements from 1 monitoring station, 2016–2024. Retrieved from Japan MOE public water-body monitoring (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Ministry of the Environment (Japan)
moe-jp27 samples · 2016–2024
Analytical methods
- MOE public water body monitoring (kosui, lakes)
Monitoring station identifiers (1)
1020080
Authority classifications are shown as the authority published them. See where the data comes from and data sources.