Water extraction
Water extraction (also known as water withdrawal, water abstraction, and water intake) is the process of taking water from any source, either temporarily or permanently, for flood control or to obtain water for, for example, irrigation.[1][2] The extracted water could also be used as drinking water after suitable treatment.
Depending on the environmental legislation in the country, controls may be placed on extraction to limit the amount of water that can be removed. The over-extraction of water can lead to dry rivers or declining groundwater levels.[3]
The science of hydrogeology is used to determine safe water extraction levels. Water can go through dams that are used to regulate or stop water from coming though, creating hydroelectricity.
Effects of overextraction
Saltwater intrusion
Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences. Saltwater intrusion can naturally occur in coastal aquifers, owing to the hydraulic connection between groundwater and seawater. Because saline water has a higher mineral content than freshwater, it is denser and has a higher water pressure. As a result, saltwater can push inland beneath the freshwater.[4] In other topologies, submarine groundwater discharge can push fresh water into saltwater.
Certain human activities, especially groundwater pumping from coastal freshwater wells, have increased saltwater intrusion in many coastal areas. Water extraction drops the level of fresh groundwater, reducing its water pressure and allowing saltwater to flow further inland. Other contributors to saltwater intrusion include navigation channels or agricultural and drainage channels, which provide conduits for saltwater to move inland. Sea level rise caused by climate change also contributes to saltwater intrusion.[5] Saltwater intrusion can also be worsened by extreme events like hurricane storm surges.[6]References
- "What is Water Extraction & Why is it Necessary". BMS CAT. 2021-07-28. Retrieved 2021-11-08.
- Rooks, Jeff (2020-02-22). "Water Extraction | What is Water Extraction & How it Fits in Water Cleanup". Restoration Local. Retrieved 2021-11-08.
- "Over-extraction and pollution of water sources". WIN - Water Integrity Network. 2015-12-01. Retrieved 2021-11-08.
- Johnson, Teddy (2007). "Battling Seawater Intrusion in the Central & West Coast Basins" (PDF). Water Replenishment District of Southern California. Archived from the original (PDF) on 2012-09-08. Retrieved 2012-10-08.
- Barlow, Paul M. (2003). "Ground Water in Freshwater-Saltwater Environments of the Atlantic Coast". USGS. Retrieved 2009-03-21.
- "CWPtionary Saltwater Intrusion yes". LaCoast.gov. 1996. Retrieved 2009-03-21.