Skip to main content
LakeQuality

Lough Melvin

Northern Ireland, Northern IrelandView mapDirections

NIEA publishes the water-quality measurements for Lough Melvin. Here is what has been measured.

Phosphorus
40 µg/L
Measured by NIEA
  • Limited data

Lough Melvin in Northern Ireland, Northern Ireland has official water-quality measurements, shown as reported. Phosphorus: 40 µg/L.

Loading map…

How Lough Melvin is classified

Lough Melvin 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 Melvin is a lake in Northern Ireland County, Northern Ireland.

Source: the Northern Ireland Environment Agency (DAERA) — not the EPA Water Quality Portal, last sampled 2024-11-25. 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 Melvin 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.

Get alerts for Lough Melvin →

Water quality measurements for Lough Melvin

These are the measurements NIEA publishes for Lough Melvin. More on the source.

No clarity data. Phosphorus 40 µg/L. TSI 57.

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 phosphorus40µg/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.57Eutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

High nutrients, frequent algae, reduced clarity

Ask about Lough Melvin

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

Stays via Stay22

Stays near Lough Melvin

Compare lakeside cabins, hotels, and vacation rentals near Lough Melvin in Northern Ireland, Northern 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.

Top-rated places to stay near Lough Melvin

Prices for Oct 2–4, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Follow Lough Melvin’s readings

Email me when new measurements post for this lake. Updates stay free.


Or email

Fishing Lough Melvin

Frequently asked questions about Lough Melvin

Where is Lough Melvin?

Lough Melvin 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 Melvin?

Lough Melvin in Northern Ireland, Northern Ireland has official water-quality measurements, shown as reported. Phosphorus: 40 µg/L.

Measurements on this page ↑

Is Lough Melvin safe to swim in?

Lough Melvin 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

122 measurements from 3 monitoring stations, 2016–2024. 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-ni122 samples · 2016–2024

Analytical methods

  • DAERA NIEA lake nutrient monitoring
Monitoring station identifiers (3)
  • 10655
  • 10656
  • 11508

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