Question: In what year was the River Lea constructed as part of the London water supply infrastructure?

Context paragraphs:
Water supply and sanitation in Algeria: Drinking water supply and sanitation in Algeria is characterized by achievements and challenges.  Among the achievements is a substantial increase in the amount of drinking water supplied from reservoirs, long-distance water transfers and desalination at a low price to consumers, thanks to the country's substantial oil and gas revenues.  These measures increased per capita water supply despite a rapidly increasing population.  Another achievement is the transition from intermittent to continuous water supply in the capital Algiers in 2011, along with considerable improvements in wastewater treatment resulting in better water quality at beaches.  These achievements were made possible through a public-private partnership with a private French water company.  The number of wastewater treatment plants throughout the country increased rapidly from only 18 in 2000 to 113 in 2011, with 96 more under construction.  However, there are also many challenges.  One of them is poor service quality in many cities outside Algiers with 78% of urban residents suffering from intermittent water supply.  Another challenge is the pollution of water resources.  There has also been insufficient progress concerning reuse of treated water, a government priority in this dry country.

London water supply infrastructure: London's water supply infrastructure has developed over the centuries in line with the expansion of London.  For much of London's history, private companies supplied fresh water to various parts of London from wells, the River Thames and in the three centuries after the construction in 1613 of the New River, the River Lea, which has springs that divert alongside Hertford at an elevation of 40 metres AOD.  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.

Microcredit for water supply and sanitation: Microcredit for water supply and sanitation is the application of microcredit to provide loans to small enterprises and households in order to increase access to an improved water source and sanitation in developing countries.  While most investments in water supply and sanitation infrastructure are financed by the public sector, current investment levels are insufficient to achieve universal access.  Commercial credit to public utilities is limited by low tariffs and insufficient cost recovery.  Microcredits are a complementary or alternative approach to allow the poor to gain access to water supply and sanitation.

Thames Water Ring Main: The Thames Water Ring Main (TWRM) (formerly the London Water Ring Main/LWRM) is a major part of London's water supply infrastructure, approximately 80 km of mostly 2.54 m concrete pipelines to transfer potable water from water treatment works (WTWs) in the Thames and River Lea catchments for distribution within London.

River Lea: The River Lea in England originates in Marsh Farm, Leagrave, Luton in the Chiltern Hills and flows generally southeast, east, and then south through east London where it meets the River Thames, the last section being known as Bow Creek.  It is one of the largest rivers in London and the easternmost major tributary of the Thames.  Its valley creates a long chain of marshy ground along its lower length, much of which has been used for gravel and mineral extraction, reservoirs and industry.  Much of the river has been canalised to provide a navigable route for boats into eastern Hertfordshire, known as the Lee Navigation.  While the lower Lea remains somewhat polluted, its upper stretch and tributaries, classified as chalk streams, are a major source of drinking water for London.  A diversion known as the New River, opened in 1613, abstracts clean water away from the lower stretch of the river for drinking.  Its origins in the Chilterns contribute to the extreme hardness (high mineral content) of London tap water.

Mount Evelyn Aqueduct: Mt Evelyn Aqueduct was a former feature of the Melbourne water supply infrastructure that was built by the Melbourne and Metropolitan Board of Works The O'Shannassy Water Supply (designs prepared 1910-1911).  Where the aqueduct crossed the lower lying areas around Wandin and approaching Mount Evelyn, it was in steel or wood-stave piping, converting to open concrete-lined channel when the higher levels were reached.  It went through the township of Mount Evelyn in open channel (except for a short distance adjacent to the railway line) winding around the local contours to just above what is now Johns Crescent, then part of the ‘Pine Mont Estate.’

Lea Valley: The Lea Valley, the valley of the River Lea, has been used as a transport corridor, a source of sand and gravel, an industrial area, a water supply for London, and a recreational area.  The London 2012 Summer Olympics were based in Stratford, in the Lower Lea Valley.

Berg River Dam: The Berg River Dam is a 68 m high dam on the Berg River in South Africa.  It is the centerpiece of the Berg Water Project (BWP) which is designed to capture the winter rainfall and store it for supply to Cape Town during the dry summer months.  The project in turn forms an important part of the Western Cape Water Supply System (WCWSS), an intricate system of dams and bulk water infrastructure that provides water to more than 3 million people.  At the inauguration of the dam in 2009, then President of South Africa Kgalema Motlanthe called the project "a good example of how public infrastructure projects can be used to contribute meaningfully to poverty eradication and to foster social empowerment of the people."  The Berg River Dam was the first dam in South Africa to be designed and constructed, and is due to be operated, in accordance with the guidelines of the World Commission on Dams.  It has been completed on time and within budget.  The Berg River basin and the adjacent metropolitan area of Cape Town are of particular importance to the Western Cape region because, although the basin generates only about 3% of the country's water resources, it is home to about 8% of South Africa's population, and produces about 12% of GDP.

Water supply and sanitation in Belgium: Water supply and sanitation in Belgium is provided by a large variety of organizations: Most of the 589 municipalities of Belgium have delegated the responsibility for water supply and sanitation to regional or inter-municipal utilities.  There are more than 62 water supply utilities, including 2 regional, 30 inter-municipal and 30 municipal utilities.  Another 100 mostly small municipalities provide services directly without having a legally of financially separate entity for water supply.  Water is not scarce in Belgium and water supply is generally continuous and of good quality.  However, wastewater treatment has long lagged behind and Brussels only achieved full treatment of its wastewater in 2007.  In 2004 the European Court of Justice ruled condemning Belgium's failure to comply with the EU wastewater directive, and the ruling has not been fully complied with so far.  Wallonia satisfies 55% of the national needs in drinking water while it counts only 37% of the population.  Flanders and Brussels are dependent on drinking water from Wallonia, at a level of 40% and 98% respectively.

Water Board (South Africa): Water Boards play a key role in the South African water sector.  They operate dams, bulk water supply infrastructure, some retail infrastructure and some wastewater systems.  Some also provide technical assistance to municipalities.  Through their role in the operation of dams they also play an important role in water resources management.  The Water Boards report to the Department of Water Affairs (DWA).  There are 13 Water Boards in South Africa (see list below), together indirectly serving more than 24 million people in 90 municipalities in 2005, or about half the population of South Africa.

Supporting paragraphs: London water supply infrastructure River Lea
Answer: 1613