Study Finds Coastal Groundwater More Vulnerable to Water Draw-offs than Climate Change

Study Finds Coastal Groundwater More Vulnerable to Water Draw-offs than Climate Change

By Dan DeBaun

Climate change has the potential to impact humans in a variety of ways, but the impact on water availability – both for irrigation and drinking water – is without doubt one of the biggest concerns. Similarly, sea level rise is an important factor in coastal areas, not only because it poses a risk of inundation to low-lying areas, but it also poses a threat of saltwater intrusion into underground aquifers.

However, according to a recent study published online in Nature Climate Change by a team of Canadian geoscientists, coastal groundwater sources used to supply drinking water are facing a greater threat from human activity than from climate change.

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Grant Ferguson from the Department of Civil and Geological Engineering at the University of Saskatchewan University and Tom Gleeson, a geoscientist from the Civil Engineering department at McGrill University analyzed data collected from more than 1400 coastal aquifers. They found that the majority of coastal aquifers are not affected by rising sea levels – the exception being aquifers situated in flat coastal plains that can easily be inundated by rising sea water, however, these are rare in the US.

What they found more of a concern, is water extraction from coastal aquifers for irrigation, domestic use, and for drinking water, as this appears to have a greater impact on these aquifers.

“The bulk of the research in recent years has focused on climate change effects on coastal groundwater but increases in water demand could be more important,” explains Ferguson. “This is particularly true in growing coastal cities and towns where groundwater is often an important water supply.”

Aquifers consist of geological formations, such as gravel or sand, which are saturated with water. Wells withdraw freshwater from these underground aquifers, which are then replenished by surface water sources supplied by rain and melted ice or snow. However, coastal aquifers are bordered by seawater on one side, and this can begin to migrate into the groundwater – including surrounding wells – if excessive amounts of fresh water are drawn off. While a rise in sea levels can also cause salt water to intrude into these coastal aquifers, up until now only issues related to water draw-offs have been recorded in Canada.

“Coastal aquifers are very vulnerable to increased water demand so we have real policy opportunities,” says Gleeson. “We can reduce consumption of groundwater in coastal areas or manage groundwater use wisely.”

Approximately one billion people reside in coastal areas around the world, many of whom depend entirely on groundwater. In Canada alone, roughly 25% of the population relies on groundwater, with some areas almost totally dependent on this resource for irrigation, drinking water, and domestic household use. It is therefore critical that we manage this essential resource wisely to prevent saltwater intrusion, which will only be exacerbated further with rising sea levels.

Dan DeBaun

Dan DeBaun

Dan DeBaun is the owner and operator of Big Berkey Water Filters. Prior to Berkey, Dan was an asset manager for a major telecommunications company. He graduated from Rutgers with an undergraduate degree in industrial engineering, followed by an MBA in finance from Rutgers as well. Dan enjoys biohacking, exercising, meditation, beach life, and spending time with family and friends.

~ The Owner of Big Berkey Water Filters

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