Water Extraction Flashcards
Size of River Kennet Catchment area
12,000km2
What happened to the flows after extraction exceeded recharge
10% reduction in flows of river. springs and seepages dried up, as water table lowered
Aquifer definition
A permeable/porous rock containing groundwater that can be extracted for public use by a well or borehole
Artesian Basin definition
An aquifer trapped between 2 layers of impermeable rock and as the upper sedimentary rocks create Artesian pressure the water can flow up by its own pressure when tapped
Example of Artesian Basin
London
Rocks in London Artesian Basin
Chalk aquifer between clay
What happened in 19th century to the London Basin
Over extraction led to a significant 90m fall in the water table
What happened in the 20th century to the London Basin
Allowed to recover and water table rose. Started to threaten houses in 1990s so was tapped