A threatened groundwater source

(Dan here…one of David Zetland’s students Lenaide writes on groundwater…a reminder of what also matters during this heated political climate, and from a younger generation)

A threatened groundwater source

Lenaide writes*

Imagine living in a city located on top of the largest groundwater source and longest river in France, but to also have both of these sources be under the threat of scarcity. That it is the current state of Beaugency, France.

Beaugency has two water sources: the Beauce aquifer, which I will focus on in this blogpost and the Loire river, which I will only briefly mention at the end.

The aquifer, covering about 10 000 km2, is referred to as the water tower of the department, as it provides water to about 1 million inhabitants. Since the beginning of the 1990s, special attention for its care and sustainable use has been given to it as there was a major drought, forcing regulations to be put in place. However, these did not last, and thirty years later here we are with falling water levels and deteriorating water quality .

The aquifer provides drinking water for citizens and water for irrigation (mostly) and industrial uses. (For more info on the extraction, specific uses, and historical regulations imposed check out this website.)

 

Figure 1

Climate and agriculture threaten the Beauce groundwater.

 

The region Centre-Val de Loire (where Beaugency is located) is known for its lack of rain. Since the aquifer recharges with winter rains, a lack of rain impedes replenishment. Strong winds also reduce water supply by increasing evapotranspiration (see this PDF for more details).

Climate change changed rainfall occurrence and intensity. Altered and unreliable rainfall makes replenishment inconsistent. Average temperatures have also increased, and in the summer, there have been droughts leading to strict regulations.

The second problem I will mention is linked with agriculture. There has been an increase in population, meaning that more production is needed to meet the demand and needs of the people. Because of this increase in demand on irrigation systems, more water is used, adding to pressures from increased domestic use from the aquifer.

Additionally, there is a major problem regarding pesticide/herbicide aquatic pollution. In 2015, over half of all the groundwater sources tested in the region surrounding Beaugency had traces of either pesticides or herbicides. Some levels are dangerous, especially from forbidden herbicides (see this PDF for more info).

Finally, the river Loire is also under stress due to the same reasons affecting  the aquifer. Climate change causing extreme heat events and reducing the amount of rain which leads to a reduction of the flow which can lead to future shortages, and reduces the efficiency of the nuclear powerplant relying on the river flow. Agricultural runoff laden with more pesticides and herbicides also pollutes the river, leading to health concerns.

Bottom line: The increased intensity of climate change impacts, ever-growing population demanding more food, and poor management of water resources puts both the aquifer and the river under major threat. Action is needed to protect them.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice