THE SOUTHERN HILLS AQUIFER SYSTEM IN SOUTHEAST LOUISIANA
IN BATON ROUGE AND SALTWATER ENCROACHMENT
At Baton Rouge, the Southern Hills Aquifer System comprises ten sands named after their depths (in feet) at a spot near the State Capitol, close to the Mississippi River. These are the “400-ft,” “600-ft,” “800-ft,” “1,000-ft,” “1,200-ft,” “1,500-ft,” “1,700-ft,” “2,000-ft,” “2,400-ft,” and “2,800-ft” sands. Altogether, these sands provide a prolific amount of groundwater that has been utilized extensively since the early 1900s both for public supply, or “drinking water,” as well as for industrial needs because of its high quality.
As the city’s
population and heavy industrial base expanded in the middle
decades of the 20th century, groundwater use increased.
Since the 1960s, East Baton Rouge Parish (EBR) consistently
has ranked as one of the top four largest consumers of
groundwater in the State of Louisiana, and has been among
the top three since the 1990s. Today, only Jefferson Davis
and Acadia Parishes, in the heart of Louisiana’s
water-intensive rice and crawfish industries, pump
groundwater nearly as much as or more than EBR.
These large volume groundwater
withdrawals have caused saltwater from the south to encroach
into the freshwater sands at Baton Rouge. Groundwater
investigations in the 1960s first delineated this
freshwater/saltwater interface near the Baton Rouge fault.
The fault, which runs parallel to the Interstate 10 corridor
before continuing on to the east-southeast, has served in
the past to keep saltwater at bay. Heavy pumping has been
pulling saltwater across this barrier, though, for several
For more educational information about groundwater use and management in Baton Rouge, please visit the Louisiana Office of Conservation’s Water-Wise in BR website.