Lough Neagh
Northern Ireland, Northern IrelandView mapDirections
NIEA publishes the water-quality measurements for Lough Neagh. Here is what has been measured.
- Limited data
Lough Neagh in Northern Ireland, Northern Ireland has official water-quality measurements, shown as reported. Phosphorus: 140 µg/L.
How Lough Neagh is classified
Lough Neagh in Northern 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, but not water clarity and algae (chlorophyll-a).
LakeQuality publishes no grade of its own beside it. Everything below thathas been measured is reported on this page.
Monitoring: the Northern Ireland Environment Agency (DAERA).
Lough Neagh is a lake in Northern Ireland County, Northern Ireland.
Source: the Northern Ireland Environment Agency (DAERA) — not the EPA Water Quality Portal, last sampled 2022-12-01. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Lough Neagh is safe to swim in today is a call for the Northern Ireland Environment Agency (DAERA) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lough Neagh
These are the measurements NIEA publishes for Lough Neagh. More on the source.
No clarity data. Phosphorus 140 µg/L. TSI 75.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 140µg/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. | 75 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lough Neagh
Answers come straight from the public measurements and survey records on this page.
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Fishing Lough Neagh
Frequently asked questions about Lough Neagh
Where is Lough Neagh?
- Lough Neagh is a lake in Northern Ireland, Northern Ireland. This page reports official water-quality measurements, shown as reported.
What is the water quality of Lough Neagh?
- Lough Neagh in Northern Ireland, Northern Ireland has official water-quality measurements, shown as reported. Phosphorus: 140 µg/L.
Is Lough Neagh safe to swim in?
- Lough Neagh 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.
Explore Lough Neagh across LakeQuality
More lakes in Northern Ireland
Where this data comes from
102 measurements from 4 monitoring stations, 2016–2022. Retrieved from the Northern Ireland Environment Agency (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Department of Agriculture, Environment and Rural Affairs (Northern Ireland)
daera-ni102 samples · 2016–2022
Analytical methods
- DAERA NIEA lake nutrient monitoring
Monitoring station identifiers (4)
10395103991040211024
Authority classifications are shown as the authority published them. See where the data comes from and data sources.