catchment The area from which a surface watercourse or a groundwater system derives its water. Catchments are separated by divides. A surface catchment area may overlie an aquifer system, but may be unconnected with the aquifer rock itself if there are intervening impermeable aquicludes. In US usage a catchment is often termed a ‘watershed’; in Britain the term ‘drainage basin’ is commonly used.

catchment The area from which a surface watercourse or a groundwater system derives its water. Catchments are separated by divides. A surface catchment area may overlie an aquifer system, but may be unconnected with the aquifer rock itself if there are intervening impermeable aquicludes. In US usage, a catchment is often termed a ‘watershed’.

catch·ment / ˈkachmənt; ˈkech-/ • n. the action of collecting water, esp. the collection of rainfall over a natural drainage area.

catchment area (kach-mĕnt) n. the geographic area from which a hospital can expect to receive patients and on which (in Britain) the designated population of the hospital is based.