Northumbrian Water Limited is a water company in the United Kingdom, providing mains water and sewerage services in the English counties of Northumberland, Tyne and Wear, Durham and parts of North Yorkshire, and also supplying water as Essex and Suffolk Water. It is a wholly-owned subsidiary of Northumbrian Water Group.

Northumbrian Water’s operations cover an area of 9,400 km2 and extend from the urban conurbations of Tyneside, Wearside and Teesside to the sparsely populated rural districts of Durham and Northumberland. A small area around Hartlepool is excluded from NW’s water supply licence; this area is supplied by Hartlepool Water, a water-only company.

The total population served by NW is 2.7m people using:

• 44 impounding reservoirs
• 57 water treatment works
• 344 water pumping stations
• 338 water service reservoirs
• 25,545 km of water mains
• 418 sewage treatment works
• 765 sewage pumping stations
• 29,724 km of sewers (including the transfer of 13,510 km of private drains and sewers on 1 October 2011)