The River Ver is one of many chalk streams and rivers in the south of England suffering from low flows. It drains from the Chiltern Hills and runs south through Markyate, Redbourn, St Albans and Park Street for 20 km, to join the River Colne near Bricket Wood, which in turn runs into the River Thames west of London. It was once famous for its sparkling spring water. Trout, eels and crayfish were caught in abundance, and watercress was farmed widely.