The U.S. Army Corps of Engineers has announced that the construction of the saltwater sill will be required again this year, with the latest measurement confirming the saltwater sill had reached Mile 29.9 Above Head of Passes. The long-range forecast indicates the Carrollton Gage will fall to 2.4 feet on September 21 (2024). The construction of the saltwater sill has been required each of the last two years, while the sill augmented had to be augmented with a different design to include a navigation notch in 2023. The saltwater sill’s construction will be in the vicinity of Mile 64 Above Head of Passes (AHP).
The following information was released by the USACE this morning and then cleared for distribution to industry contacts this afternoon:
“We are tracking advancement of saltwater in the Mississippi River due to extreme low water. The toe of the saltwater wedge was measured at mile 34.5 AHP on 23 Aug and is expected to continue progressing upriver. The most recent river forecast and salinity measurements indicate that construction of an underwater sill at approximately mile 64 AHP is required. A bid opening for the sill contract is scheduled for this Thurs, 29 Aug. Following contract award, we will coordinate a meeting with you to discuss navigational considerations for sill construction. We expect dredging operations and channel restrictions to be similar to prior construction effortsbut will not know for sure until a dredging contractor is onboard.”