Neither New nor a River

The New River (YMGW passim) was constructed between 1609 and 1613 to carry fresh spring water to London from Hertfordshire, and is still in use by Thames Water as a source of drinking water. Chadwell Spring, rising in a circular basin 30 yards wide and known as the 'banjo,' was the New River's original source, and yields up to just shy of a million gallons per day. The nearby Marble Gauge, of 1770, used to regulate the amount of water taken from the River Lea, but is now bypassed by pipes. The intake from the river is now regulated a little further to the north, at New Gauge.