A swelling of the Mississippi River’s upper basin is now making its way south, forcing the U.S. Army Corps of Engineers to initiate flood defense measures across Louisiana—including a Stage 1 Flood Fight in New Orleans set to begin this week and the potential partial opening of the Bonnet Carré Spillway, which has not been opened since 2020.
Between April 2 and 6, areas of Kentucky, Arkansas, and Tennessee were inundated with more than a foot of rain. Benton, Kentucky, recorded nearly 16 inches, while Memphis and Hot Springs saw totals exceeding 12 inches. Though the storms never touched Louisiana directly, the Mississippi River’s vast watershed is designed to carry runoff from 32 states—meaning floodwaters are now surging toward the Gulf.
Rickey Boyette, U.S. Army Corps of Engineers, Mississippi Valley Division, New Orleans District, Chief of Public Affairs, has stated that this week they will begin Flood Fight Stage 1.
A Flood Fight is the U.S. Army Corps of Engineers’ official response to rising river levels that pose a potential threat to levees and surrounding infrastructure.
It’s not an emergency declaration but a structured monitoring and readiness plan.
Once activated, it increases the frequency and depth of levee inspections, enforces stricter rules on nearby activity, and triggers coordination between federal, state, and local stakeholders.
There are two key levels:
- Phase 1 (Heightened Awareness) – Begins when the river reaches 11 ft at the New Orleans gauge.
- Phase 2 (High Alert) – Triggered at 15 ft, when the river is directly pressing against the levee system.
As the river gauge at New Orleans hits 11 feet, the Corps will activate Stage 1 protocols: levee inspections will occur twice weekly along every 1 mile of the levee. During these inspections there is also a lookout for construction within 1,500 feet of the levee—including utility work, boring, and foundation-laying— which under Stage 1 must halt unless expressly approved. These steps aim to detect and prevent threats like sand boils and seepage that could undermine the flood control system.
Alongside the Mississippi, officials are also monitoring the Atchafalaya River, which branches off from the Mississippi north of Baton Rouge and flows through south-central Louisiana. St. Martin Parish President Pete Delcambre has given updates on proactive measures being taken. "We are closing the Bayou Chene portal to alleviate some of the pressure from the backflow waters." He also states, "we have bagged 6000 sandbags" in anticipation of residents needing them. They are currently still in an active waiting and planning phase.
More updates will be available on this situation in the coming days.
The Morganza Spillway, used only in major flood events, diverts water from the Mississippi into the Atchafalaya Basin to relieve pressure downstream. Current forecasts indicate the river flow can be managed without having to open the Morganza Spillway.
The current forecast shows the river cresting near 16.5 feet—just shy of Stage 2, which would trigger daily inspections and a full stop on all subsurface construction, even if previously permitted. It's been noted by Ricky Boyette that the forecast has changed slightly, daily. For example, the duration of the 16.5 feet has decreased in amount of time anticipated at that level.
The potential of partially opening the Bonnet Carré is still on the table, but isn't guaranteed to be necessary at this time. There is the goal of maintaining the volume of water passing through New Orleans at 1.25 million cubic feet per second. To continue this as water levels rise above a certain stage, the Corps may partially open the Bonnet Carré Spillway. This critical relief valve diverts water into Lake Pontchartrain to ease pressure on levees downstream.
However, opening the spillway isn’t a decision made lightly. The Corps follows a multi-step review process:
- Forecast models predict a threshold breach. The Corps uses official NWS River forecasting.
- Actual river observations must reach threshold criteria.
- The Corps will work with the New Orleans District and consults with local, state, and federal stakeholders.
- A recommendation is made to the Commanding General of the Mississippi Valley Division.
- If approved, public notifications and press briefings are issued before the spillway is opened incrementally.
Boyette says, "The environmental impact is something we take into consideration when making these decisions.”
When opened, the spillway flushes a mix of freshwater and sediment into Lake Pontchartrain, disrupting salinity levels. This can stress oyster beds and shrimp populations, and the influx of nutrient-rich water can trigger algae blooms—especially if the water lingers.
Residents across south Louisiana are urged to follow updates from the Corps and local emergency management offices as water levels evolve over the coming days. More information on flood stages, levee inspections, and spillway operations is available at www.mvn.usace.army.mil and KATC will be following the story as it progresses.
