Water Abstraction

Abstraction involves taking water, via pipe, from the sea, using it for an industrial process and then returning it to the sea. Most abstracted water is used for cooling. There is a limit placed on the temperature at which water can be returned. The majority of coastal water abstractions, by volume, are for power stations, the remainder are for use by the fish processing and manufacturing industries. Cooling water used by ships is not included here.

A large power station may abstract up to 200m 3/second or more during peak load for cooling from either coastal or estuarine waters. In most cases non-evaporative cooling is used where the steam turbine exhausts are cooled via the main condensers before the water is discharged back to the sea. Evaporative cooling is often used by power stations located inland which use cooling towers to recycle the water.

Other uses include the operation of fish farms and fish processing factories, manufacture of food, wood and chemical products, agriculture, marine animal sanctuaries and navigation abstractions to maintain water levels in impounded docks. Use is also made by the construction industry (for use as a raw material) and by the defence industry.