River barges are filled with water from an upstream location and transported down river to be offloaded to onsite reservoirs at requesting water treatment facilities. The initial bargeload of 500,000 gallons arrived at the Port Sulphur Water Treatment Facility at approximately 7:00 pm Sunday, October 1, 2023. This water can be mixed with water at the intake to dilute salinity content to levels safe for water treatment. Additional barges will be delivered as the need for upriver fresh water occurs. USACE anticipates delivering water to the Port Sulphur and Pointe A La Hache facilities during the following week.
The amount of water barged daily will depend on the amount required by a requesting facility at any given time. USACE is currently acquiring the capability of delivering 36 million gallons of water per day in the event additional facilities are impacted by the saltwater intrusion in the Mississippi River.
In addition to barged water, USACE continues work to increase the height of the underwater sill initially constructed in July at river mile 63.8. Augmentation of the sill began Sunday Sept. 24, 2023 and is anticipated to take approximately 24 days to complete.
The intrusion of salt water into the river is a naturally occurring phenomenon because the bottom of the riverbed between Natchez, Miss., and the Gulf of Mexico is below sea level. Denser salt water moves upriver along the bottom of the river beneath the less dense fresh water flowing downstream. Under normal conditions, the downstream flow of the river prevents significant upriver progression of the salt water. However, in times of extreme low volume water flow, such as what has been occurring this year, unimpeded salt water can travel upriver and threaten municipal drinking water and industrial water supplies. An underwater sill was constructed on four previous occasions in 1988, 1999, 2012 and last year in 2022.
Video and imagery of the process are available on the New Orleans District Flickr site: https://www.flickr.com/photos/teamneworleans/albums/72177720311632338
Release no. 23-036