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河口湖

Yamanashi, JapanView mapDirections

MOE publishes the water-quality measurements for 河口湖. Here is what has been measured.

Clarity
3.5 m
Typical for Japan
Secchi · sampled 2025
Phosphorus
12 µg/L
Typical for Japan
Measured by MOE
  • Limited data

河口湖 in Yamanashi, Japan has official water-quality measurements, shown as reported. Water clarity: 3.5 m visibility. Phosphorus: 12 µg/L.

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How 河口湖 is classified

河口湖 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).

河口湖 is a lake in Yamanashi County, Japan.

Source: the Ministry of the Environment (Japan) — not the EPA Water Quality Portal, last sampled 2025-03-15. Methodology: how these readings are compared.

What 河口湖 is good for

From access and monitoring records, not editorial picks.

  • Clear water11.5 ft of visibility

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether 河口湖 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.

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Water quality measurements for 河口湖

These are the measurements MOE publishes for 河口湖. More on the source.

Good clarity, visible to about 11.5 ft. Phosphorus 12 µg/L. TSI 41.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)3.5mMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus12µg/LMeasured, 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.41Mesotrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Moderate nutrients, good water quality

Ask about 河口湖

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

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Stays near 河口湖

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Fishing 河口湖

Frequently asked questions about 河口湖

Where is 河口湖?

河口湖 is a lake in Yamanashi, Japan. This page reports official water-quality measurements, shown as reported.

What is the water quality of 河口湖?

河口湖 in Yamanashi, Japan has official water-quality measurements, shown as reported. Water clarity: 3.5 m visibility. Phosphorus: 12 µg/L.

Measurements on this page ↑

Is 河口湖 safe to swim in?

河口湖 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.

Swimming on this page ↑

Where this data comes from

90 measurements from 2 monitoring stations, 2016–2025. 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-jp90 samples · 2016–2025

Analytical methods

  • MOE public water body monitoring (kosui, lakes)
Monitoring station identifiers (2)
  • 1920020
  • 1920030

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