We rely on a vast network of drainage and flood defence infrastructure including: rivers, culverts and weirs; sewers, wastewater treatment works and pumping stations; road gullies and drainage pipes; waterways and canals; lakes, loughs and reservoirs; green infrastructure (parks and open spaces; and coastal and river flood defences. The graphic below provides examples of some of the existing infrastructure throughout Northern Ireland.
When it rains, some of the water naturally seeps into the earth or makes its way directly to a watercourse. The rest finds its way via a network of underground pipes into rivers and estuaries and eventually out to sea. Some of this water is carried by separate storm drains and pipes and some flows into the sewers and is carried along with sewage to a wastewater treatment works.