[citation needed] The Ver is a chalk stream, which is partly a seasonal winterbourne north of Redbourn.

Although these abated temporarily after the closure of one of the pumping stations, as of 2005[update] the upstream part of the river dries up completely during the summer, and the rest of the river may suffer the same fate within a few years; compared to the current situation with the "great flow of water" that was reported to exist in 1885, with a depth of 12 ft (3.7 m) at Dolittle Mill on the Redbourn Road .

The Romans built the city of Verulamium alongside the Ver at a time when it was navigable, expressing their preference for building in valleys rather than on hills.

The ford alongside the current bridge, which is known to have existed for 2,000 years and is traditionally believed to be Alban's crossing point on his way to his execution, was substantially restored in 2001 by local residents' associations.

The river south of Redbourn has been the site of several watermills down the centuries, mainly for grinding corn but also put to such diverse uses as paper making, fulling cloth, silk spinning and diamond lapping.