Public water supply and sanitation in the United Kingdom are characterized by universal access and generally good service quality.

Unlike many other developed countries, the United Kingdom features diverse institutional arrangements across its constituent parts: (England and Wales; Scotland; and Northern Ireland).

[4] The recurrence of water poisoning, and large public health crises were a part of people's ordinary existence until scientific advances of the 19th century.

Following the Great Stink of 1858, where the River Thames had become so bad smelling that it offended the Queen and forced Parliament to relocate, Joseph Bazalgette began to build the London sewerage system.

c. 90), local government began building drains, sewers, and piping clean water to households.

c. 93) provided model constitutions for the growing number of private and local government water companies.

[12] The majority of the UK's abstraction of surface water is from reservoirs, where rainwater is transported via rivers and streams and contained in an artificial or natural lake until it is required.

[15] While the UK has the fortune of substantial rainfall, climate damage means water resources are under pressure, and less predictable than before.

[20] In Scotland, it was thought that competition in sewer and water services could pose a public health risk.

Ofwat (technically called the Water Services Regulation Authority) has at least three members appointed the Secretary of State,[23] and is meant to "protect the interests of consumers, wherever appropriate by promoting effective competition" and yet ensure companies have a "reasonable returns on their capital",[24] rather than simply act in the public interest.

[28] As real competition in natural monopolies always appeared unlikely, Ofwat has always set upper limits to prices, historically for 5-year periods.

[48][49][50] Total employment by UK water companies amounted to 41,000 full-time equivalent jobs in 2012/13, according to an analysis by the consulting firm Deloitte.

[51] According to a 2006 survey by NUS Consulting the average water tariff (price) without sewerage in the UK for large consumers was the equivalent of US$1.90 per cubic metre.

The Fairness on Tap coalition (including National Trust, Waterwise, WWF and RSPB) is calling for the government to set out a strategy to install water meters in at least 80% of England where there is the greatest pressure on the freshwater environment and people's pockets, by 2020.

[54] In July 2011, the think tank Policy Exchange reported a significant decline in river quality due to abstraction carried out by water companies.

[55] In 2009, an investigation conducted by the BBC's Panorama concluded that the operation of more than 20,000 combined sewer overflow pipes (CSO) was leading to the routine spillage of untreated wastes around Britain's coastline, potentially leading to very dirty water around some of the most popular beaches in the UK.