<P> Water supply and sanitation in London is provided by a number of private companies . The regional water strategy for London is produced by the Greater London Authority . Much of the water supply and sewerage system was constructed during the Victorian era . Greater London is located within the Thames River Basin District . </P> <P> Water supply by population </P> <P> London has well developed water supply infrastructure . Most drinking water consumed in London comes from the River Thames and the River Lee . Approximately 70% of all water supplied to London is taken from the Thames upstream of Teddington Weir . </P> <P> Greater London is currently supplied by four companies: Thames Water (76% of population), Affinity Water (14%), Essex and Suffolk Water (6.6%) and Sutton and East Surrey Water (3.4%). </P>

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