What the Morganza Spillway Does

The Morganza Spillway is a massive flood-control structure on the Atchafalaya River in Pointe Coupee Parish, about 20 miles south of Simmesport. When the Mississippi River rises above a certain level—typically around 61.5 feet at the Red River Landing gauge—the U.S. Army Corps of Engineers can open the spillway's gates to divert water away from populated areas downstream and into the Atchafalaya Basin. The spillway has never been opened since its completion in 1973 until 2011, when it was opened to prevent catastrophic flooding in Baton Rouge and New Orleans.

For anglers, the spillway matters because it fundamentally changes water levels, flow rates, and fish behavior across a massive area. When gates open, the Atchafalaya River swells dramatically, flooding backwater areas and creating temporary channels through the basin. This affects where fish move, how they feed, and whether certain areas are even fishable.

Key Takeaways

  • The Morganza Spillway diverts Mississippi River water into the Atchafalaya Basin during extreme floods, changing water levels and fish location across the entire region.
  • When the spillway opens, backwater areas flood, current speeds increase, and fish move to deeper channels and structure—traditional shallow-water spots become unfishable.
  • The spillway opening is announced by the Army Corps of Engineers and typically lasts weeks to months depending on how fast the Mississippi River recedes.
  • Bass, catfish, and crappie respond predictably to spillway openings by moving to deeper water and current breaks, which changes where and how you should fish.
  • Check the Army Corps of Engineers' Vicksburg District website for real-time spillway gate status and river stage forecasts before planning a trip.

How the Spillway Affects Water Levels and Current

When the spillway gates open, water volume in the Atchafalaya River increases dramatically—sometimes doubling or tripling the normal flow. This surge pushes water into areas that are normally shallow or dry, flooding cypress swamps, backwater lakes, and low-lying terrain across the basin. The water level can rise 3 to 6 feet or more in connected areas within hours of the gates opening.

The increased current also changes how water moves through channels and around structure. Normally slack backwater areas develop strong current, and main-channel current becomes almost unmanageable. Shallow flats that hold fish during normal conditions become too deep and swift to fish effectively. Fish respond by moving to deeper holes, behind fallen trees, and into areas where current breaks—places where they can hold position without fighting the flow.

Where Fish Move When the Spillway Opens

Bass, catfish, and crappie all shift their location when spillway gates open. Bass move from shallow flats and cypress knees into deeper channels and around submerged structure like fallen trees and root systems. They position themselves on the downstream side of obstacles where current breaks, allowing them to feed without exhausting themselves fighting the flow. Deep holes and channel ledges become the primary holding areas.

Catfish move to the deepest available water and concentrate in areas with strong current, where they can intercept food washed downstream. Crappie move from shallow brush into deeper channels and around pilings or structure that provides current relief. The key pattern is consistent: fish abandon shallow, slack-water areas and move to depth and structure where they can survive the increased current.

Fishing success during spillway openings often requires moving away from your normal spots and focusing on deeper channels, bridge pilings, and areas where current slows. Drifting live bait or using heavy jigs in deep water often outperforms the shallow-water techniques that work during normal conditions.

How Long the Spillway Stays Open

The duration of a spillway opening depends entirely on how fast the Mississippi River recedes. The 2011 opening lasted about 13 days, but the Army Corps of Engineers monitors river stages constantly and can keep gates open longer if the Mississippi remains high. There is no fixed schedule—the spillway opens only when necessary and closes as soon as river levels drop below the trigger point.

During an opening, the Army Corps of Engineers issues daily updates on gate positions and river stage forecasts. These forecasts typically project 5 to 10 days ahead and help predict when the spillway might close. If you are planning a fishing trip during a spillway event, check the forecast before you go—conditions can change rapidly, and a spillway closure can shift fish location back to normal patterns within days.

Finding Real-Time Spillway Status and River Data

The U.S. Army Corps of Engineers, Vicksburg District, maintains the official spillway status and publishes it on their website. You can find current gate positions, river stage readings at multiple locations, and 5-to-10-day forecasts. The National Weather Service also publishes river stage forecasts for the Atchafalaya and Mississippi rivers, which help predict spillway operations.

Local fishing guides and tackle shops in Pointe Coupee Parish monitor spillway status closely because it affects their business. Calling a guide or local shop before a trip is often faster than searching online—they know current conditions and can tell you whether fishing is worth the trip or whether you should wait for the spillway to close.

Fishing Strategy During Spillway Operations

The most productive approach during a spillway opening is to abandon shallow-water patterns and focus on deep channels, current breaks, and structure. Use heavier jigs, live bait, and slower presentations that work in deeper water and stronger current. Drifting is often more effective than casting because it allows you to cover deep water efficiently and present bait in the current where fish are feeding.

Target areas where current slows—behind pilings, around fallen trees, in deep holes, and along channel ledges. Fish will be concentrated in these spots rather than spread across shallow flats. The spillway opening essentially compresses the fishery into smaller, deeper areas, which can actually make fishing more predictable once you locate the right structure.

Be aware that spillway openings can make some areas completely unfishable. Shallow-draft boats may not be able to navigate swollen backwater areas, and current in main channels can be dangerous. Always check conditions and use caution—spillway openings are flood events, and water conditions can be hazardous.

What Happens After the Spillway Closes

When river stages drop and the Army Corps closes the spillway gates, water levels in the Atchafalaya Basin recede over days to weeks. Fish gradually move back to their normal patterns—from deep channels back to shallow flats, cypress knees, and backwater areas. This transition period can be excellent for fishing because fish are moving and feeding actively as they relocate.

The return to normal conditions is not instantaneous. Water levels may remain elevated for several days after gate closure, and current may still be stronger than normal. Fish behavior during this transition is often more aggressive than during the spillway opening itself, making it a good time to fish if you can time your trip right.

Frequently Asked Questions

How often does the Morganza Spillway open?

The spillway has opened only once since 1973—in May 2011 during an extreme Mississippi River flood. It is designed for rare, catastrophic flood events. Most years it does not open at all, so spillway openings are exceptional circumstances rather than regular occurrences.

Can I fish during a spillway opening?

Yes, but conditions are challenging. Water levels are high, current is strong, and shallow-water areas are flooded. Fishing is possible in deeper channels and around structure, but it requires different techniques than normal conditions. Some areas may be unsafe or unfishable due to current and water level.

Where do I learn about the spillway is open right now?

The U.S. Army Corps of Engineers, Vicksburg District, publishes current spillway status and river data on their website. The National Weather Service also provides river stage forecasts. Local fishing guides and tackle shops in the area monitor conditions and can tell you whether the spillway is currently operating.

How does the spillway opening affect catfish fishing?

Catfish move to deeper water and concentrate in areas with strong current during spillway openings. They feed actively on food washed downstream, so live bait drifted in deep channels and around structure is often productive. The increased current actually concentrates catfish in predictable locations.

Will the spillway opening ruin my fishing trip?

It changes fishing conditions significantly, but it does not necessarily ruin a trip. Fish are still present and still feeding—they are just in different locations and require different techniques. If you are flexible and willing to adapt to deeper water and stronger current, a spillway opening can still produce good fishing.