Middlesex lies entirely within the Thames river basin. It is alive with rivers and streams, was formerly dotted with wells and spas (pronounced and sometimes spelt ‘spaws’) and the availability of water determined the very shape of London . The 12th century chronicler, William Fitz Stephen, a monk former clerk of Thomas Becket (and witness to his murder), describes the numerous little tributaries of the Thames as places ‘whose waters are sweet salubrious and clear’ where ‘watermills turned by the current make a pleasing sound’. In central London these have disappeared underground (the Tyburn, Fleet, Walbrook, Counter’s Creek, Westbourne, Stamford Brook); even so it’s fun to follow their course especially with the help of this amazing new book.
London’s clay is famous. What is less well known is that this clay is covered in many places by gravel washed down by the river, and that it’s only these places that, in the absence of mains water or conduits of some kind, are suitable for housing. In his address to the Geological Society in 1872, Professor Joseph Prestwich demonstrated how the earliest settlements in and around London were dependent on the local geology and hydrology.
‘The London Clay, which occupies so wide an area, is covered to a large extent by the valley gravels and here and there in the North of London by an outlying hill of Bagshot Sand. Wells sunks through those sandy and gravelly deposits were always supplied with water, which was held up by the impervious London Clay.
‘Hence the bare London Clay was unoccupied until the New River and other waterworks did away with the necessity for well; and the clay districts of Holloway, Camden Town, Regent’s Park, St John’s Wood, Westbourne Park and Notting Hill received town populations much later than Stepney, Hackney, Islington, Paddington, Kensington, Chelsea and Camberwell, which were situated on gravel.’
We can still walk along much of the length of the New River, which was the main source of clean water for London after it was built, from 1609 onwards, by the Welshman Hugh Myddelton, a wealthy London goldsmith and member of parliament. Less famous artificial watercourses are the Duke of Northumberland’s River and the Longford River in Isleworth.
Middlesex lies between the Colne in the west and the Lea in the east. But don’t overlook the Crane, Yeading Brook, the Silk Stream, the Brent, the Dollis, and the Lea with its tributaries the Moselle, Salmon’s Brook and Pymme’s Brook. And the Thames has come back to life; it’s again one of Britain’s most important fish nurseries, with spawning grounds for sea bass, grey mullet, sea lamprey, flounder and smelt.