Drought and water tables

The Le Teich bird reserve is on the west coast of France near Bordeaux. It lies in salt marshes on a partially enclosed tidal bay. In the 1990's there were a number of drought years and in the reserve the fresh water was so depleted that there was an intrusion of saline water into the freshwater aquifer. The top image was taken in 2002 and even the shallow rooted alders (Alnus glutinosa) have died while salt tolerant invasive alien saltbush (Baccharis halimifolia) thrives and flowers. This not only affects plants but also all forms of animal life whose habitats have been changed. The image at bottom was taken in 2015, freshwater has returned to the water table, native trees are thriving and the Saltbush is eradicated. Often this problem is exacerbated when water abstraction for domestic and industrial use is greater than natural replacement.