Mercian, thanks for the very interesting link to the web-site about Ted Wright - quite a hero, I will go back to it and read again.

Fascinating subject, water-sheds and which little streams feed into larger rivers. When you start looking into it, it gives a wonderful sense of connectiveness. In the ever expanding town where I live (Swindon) there are some ancient willows growing on a section of the central reservation of the main duel carriageway out to Junction 15 of the M4. When I asked around a bit, it turned out that these trees grew alongside a small river (probably the river Cole) which in turn formed a natural boundary to some farm-land (needless to say no longer there). When the road was widened into a duel carriageway the river was culverted underground and diverted - but the willows still remain as a clue to its presence.

tjj

Thinking about journeys by river in prehistory... The river Chew makes it way past Stanton Drew Circle, and winds on to meet the Avon at Keynsham which then meanders past Bath, continuing the circuit round; the Avon is joined at Midford by Midford Brook, and into Midford Brook a mile or so later Wellow Brook merges. Now Wellow Brook flows past Stoney Littleton longbarrow - so did the ammonite stone of SL get transported down the Avon, Midford and Wellow Brook from Keynsham where ammonites can be found?
I remember the river Marden at Calne, you could walk through the fields to a weir, or at least a concrete slide, children used to swim there till one day someone got drowned....