Water on the Downs
The rain which falls onto the Downs is part of a water cycle, providing vast quantities of pure water which is pumped out by the Water Companies to surrounding towns and villages for their use. Having a good supply of pure water to the area is crucial to the people and animals living there, so it is important to be aware of the threats to both the pumped water and the rivers which cut through the hills of the Downs.
The porous chalk of the Downs
Aquifers
An aquifer is a rock that has fissures (little cracks) and tiny holes called pores which can hold water like a sponge. Rain soaks into these pores instead of lying on the surface. In the South Downs, there are two major aquifers; the Chalk and the Lower Greensand. They provide over 75% of the public water supply in this area. The Chalk is the more important of the two with the Brighton Chalk Block one of the most important aquifers in England and Wales. Rainfall is higher (about 1000 mm a year) on the relatively high Downs compared to the surrounding low lying land (about 500 mm a year).
Did you know?
Rainwater is naturally soft. As it seeps through the Chalk, it picks up calcium. This makes the water hard, which creates lime scale that builds up in pipes, kettles and washing machines.
Did you know?
The water on earth today is the same water that was here when the earth was formed and when dinosaurs lived. We keep using the same water over and over.
