 Further demand prompted new conduits and sources, particularly in the 150 years to 1900 as the Agricultural and Industrial Revolution caused a boom in London's population and housing.A crisis point was reached in the mid 19th century with biology proving outbreaks of cholera and other disease arose from commercial extraction of water from the Tideway, where the city once had its main filter beds and purification buildings.The Metropolis Water Act 1852 allowed all water extractors three years to find wells or non-tidal sources.