"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
.. .
The river Lea runs past the bottom of my hill north of Luton town
centre,
about 4 or 5 km (or 10km depending on which stream you follow) from
its source. So it's not very big, but it carries an awful lot of urban
water
away when it rains and usually floods the A6 after a 30mm downpour.
It first dried out in mid-August, ran for three days after 11mm fell
on
22nd August, and for a week after the recent rains which totalled
about 30mm. But it's gone again now. I remember the river being
dry briefly in 1997, 1976, 1964, and I'm told it was in 1959 too.
But never in mid-November.

This is a good indicator of how far the water table in the chalk of
the
Chiltern Hills must have dropped ... especially notable because it
follows the unprecedentedly high water table of 2001, and also
bearing in mind that much less water is extracted from the chalk via
artesian wells these days compared with 30 or 40 years ago.

Philip Eden

The River Ver still seems to be flowing quite well near its source and
is in much better condition than it was several years ago (1997) when it
dried up as far as St Albans; this is probably a result of less water
abstraction at the Friars Wash pumping station which has been of
enormous benefit to the river.

Unlike the River Lea the Ver gets all of its water from springs; I
assume that the Lea is flowing well downstream of the sewage works
discharge (it may be fully treated but its origin can easily be
detected).

Alan