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LakeQuality

Lough Rea

Galway, IrelandView mapDirections

EPA Ireland publishes the water-quality measurements for Lough Rea. Here is what has been measured.

Phosphorus
12 µg/L
Less phosphorus than most
Measured by EPA Ireland
Chlorophyll-a
2.5 µg/L
Typical for Ireland
Measured by EPA Ireland
  • Limited data

Lough Rea in Galway, Ireland has official water-quality measurements, shown as reported. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 2.5 µg/L.

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How Lough Rea is classified

Lough Rea in Ireland 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 phosphorus and algae (chlorophyll-a), but not water clarity.

LakeQuality publishes no grade of its own beside it. Everything below thathas been measured is reported on this page.

Monitoring: the Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland.

Lough Rea is a lake in Galway County, Ireland.

Source: the Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland — not the EPA Water Quality Portal, last sampled 2023-10-09. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

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

Whether Lough Rea is safe to swim in today is a call for the Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Lough Rea

These are the measurements EPA Ireland publishes for Lough Rea. More on the source.

No clarity data. Phosphorus 12 µg/L. Chlorophyll-a 2.5 µg/L. TSI 40.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)No reading

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)2.5µg/LMeasured, not scored

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.40Oligotrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Low nutrients, clear water. No reading is a swimming clearance.

Ask about Lough Rea

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

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Stays near Lough Rea

Compare lakeside cabins, hotels, and vacation rentals near Lough Rea in Galway, Ireland — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

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Fishing Lough Rea

Frequently asked questions about Lough Rea

Where is Lough Rea?

Lough Rea is a lake in Galway, Ireland. This page reports official water-quality measurements, shown as reported.

What is the water quality of Lough Rea?

Lough Rea in Galway, Ireland has official water-quality measurements, shown as reported. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 2.5 µg/L.

Measurements on this page ↑

Is Lough Rea safe to swim in?

Lough Rea 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

125 measurements from 2 monitoring stations, 2016–2023. Retrieved from UNEP GEMS/Water GFQA (not the EPA Water Quality Portal) on 2026-08-16.

Collected and reported by

  • European Environment Agencyeuropeanenvironmentagenc125 samples · —

Analytical methods

  • GEMStat OPEN / CC BY 4.0
  • EPA Ireland WFD lake waterbodies CC BY 4.0
Monitoring station identifiers (2)
  • IRL00105
  • IRL00401

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