Lably
Skip to content

Lough Neagh

Freshwater lake in Northern Ireland

  • 13 min read
  • 5 chapters
Date: 2018-06-30 Sensor: MSI on Sentinel-2B Resolution: 10m RGB Composites: True color, Band 4-3-2
Copernicus Sentinel-2, ESA · CC BY-SA 3.0 igo

Related on Lably

Through Fresh water, Eutrophication and Water treatment

Its main inflows are the Upper River Bann and Blackwater, and its main outflow is the Lower Bann. There are several small islands, including Ram's Island, Coney Island and Derrywarragh Island. The lake bed is owned by the 12th Earl of Shaftesbury and the lake is managed by Lough Neagh Partnership. Its name comes from Irish Loch nEachach , meaning "Eachaidh's lake".

From 2023 blue-green algae has polluted the lough.

Geography

With an area of 148 square miles (383 km2), it is the British Isles' largest lake by area and is ranked 34th in the list of largest lakes of Europe. Located 20 miles (32 km) west of Belfast, it is about 19 miles (31 km) long and 9 miles (14 km) wide. It is very shallow around the margins and the average depth in the main body of the lake is about 30 feet (9 m), although at its deepest the lough is about 80 feet (24 m) deep.

Geology

Geologically the Lough Neagh Basin is a depression, built from many tectonic events dating back as far as 400 million years ago. These tectonic events are responsible for a NE-SW bedrock structure which has controlled many subsequent events. During the Paleozoic era, the Lough Neagh Basin was a depositional graben.

Hydrology

Of the 1,760-square-mile (4,550 km2) catchment area, around 9% lies in the Republic of Ireland and 91% in Northern Ireland; altogether 43% of the land area of Northern Ireland is drained into the lough, which itself flows out northwards to the sea via the River Bann. As one of its sources is the Upper Bann, the Lough can itself be considered as part of the Bann. Lough Neagh is fed by many tributaries including the rivers Main (34 mi, 55 km), Six Mile Water (21 mi, 34 km), Upper Bann (40 mi, 64 km), Blackwater (57 mi, 92 km), Ballinderry (29 mi, 47 km) and Moyola (31 mi, 50 km)

The water in the lough has been monitored extensively since 1974 and has undergone considerable eutrophication and toxic algal blooms. According to a 2016 study, it "has become much enriched as a result of anthropogenic eutrophication, most of which occurred in the last century... Despite the recent changes in nutrient loading the lake is still currently classed as hypereutrophic". Each summer since 2023, toxic algal blooms, mostly caused by agricultural run-off, have spread across the lake (see section algal bloom crises below).

Islands and peninsulas

  • Coney Island
  • Croaghan Island
  • Derrywarragh Island
  • Gartree Point
  • Kinnegoe (peninsula)
  • Kinturk (peninsula)
  • Oxford Island (peninsula)
  • Padian
  • Ram's Island
  • Tolans Flat
  • Traad (peninsula)

Towns and villages

Towns and villages near the Lough include Craigavon, Antrim, Crumlin, Randalstown, Toomebridge, Ballyronan, Ballinderry, Moortown, Ardboe, Brockagh, Maghery, Lurgan and Magherafelt.

Counties

Five of the six counties of Northern Ireland have shores on the Lough (only Fermanagh does not), and its area is split among them. The counties are listed clockwise:

  1. Antrim (eastern side and northern shore of the lake)
  2. Down (small part in the south-east)
  3. Armagh (south)
  4. Tyrone (west)
  5. Londonderry (northern part of west shore)

Local government districts

The area of the lake is split between four local government districts of Northern Ireland, which are listed clockwise:

  • 3 Antrim and Newtownabbey, in the north-east
  • 4 Lisburn and Castlereagh, in the east
  • 6 Armagh, Banbridge and Craigavon, in the south
  • 9 Mid Ulster, in the west

Sign in to keep reading

4 more chapters are free with a Lably account.

More in Physical geography