The desalination plan provide water when the groundwater reservoirs are too low to fulfill freshwater demand. The brine slowly go down through geological layer

The desalination plan provide water when the groundwater reservoirs are too low to fulfill freshwater demand. The brine slowly go down through geological layers. After 5 years it reaches groundwater reservoir. 20-50 years later, the regions become famous for its fun pod racing and for its numerous ghost cities around the old plain.