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Lough Neagh and Its Catchment

Understanding the vital water system that sustains nature, communities, and industry across Northern Ireland.

Catchment Overview

Lough Neagh, the largest freshwater lough in the UK and Ireland, sits at the heart of Northern Ireland. Its vast catchment area spans multiple counties, making it one of the most significant hydrological systems in the region.

Water from across the landscape drains into the Lough through an extensive network of rivers and tributaries, playing a crucial role in water supply, agriculture, fisheries, and recreation.

Managing this resource sustainably is essential for maintaining water quality, supporting local communities, and protecting the surrounding environment

Ecosystem Services and Human Use

The Lough Neagh catchment plays a fundamental role in both environmental sustainability and the local economy:

  • Water Supply – Provides drinking water for nearly 40% of Northern Ireland’s population.
  • Agriculture – The surrounding land supports dairy, beef, and sheep farming.
  • Fisheries – Home to a long established eel and fishery industry.
  • Tourism & Recreation – Boating, angling, birdwatching, and nature conservation bring economic and social benefits.

The Rivers Feeding Lough Neagh

Six major rivers and a number of smaller rivers drain into Lough Neagh, supplying fresh water and sustaining its ecosystem:

  • River Blackwater – Originates in County Monaghan, flowing through counties Armagh and Tyrone.
  • River Ballinderry – Rises in the Sperrin Mountains and flows into the western shore.
  • Upper Bann River – Begins in the Mourne Mountains and enters from the southeast.
  • Six Mile Water – Starts in County Antrim and flows into the northeastern shore.
  • River Main – Originates in County Antrim and drains into the northern part ofthe Lough.
  • River Moyola – Rises in the Sperrin Mountains and feeds the northwest of the Lough.

Lough Neagh has only one river flowing out – the Lower Bann, which carries water northward to the Atlantic Ocean.

Environmental Challenges

Despite its importance, the Lough Neagh catchment faces several environmental pressures:

  • Phosphates & Nitrates Run-off – Excess nutrients from slurry and sewage processing contribute to algal blooms.
  • Pollution – Industrial and domestic wastewater impact water quality.
  • Invasive Species – The spread of zebra mussels disrupts native ecosystems.
  • Climate Change – Changing rainfall patterns and rising temperatures affect water levels and aquatic life
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