he Birds Point-New Madrid floodway is 

designed to prevent the MR&T project 

design flood from exceeding the design 

elevation on the Mississippi River levees in the 

vicinity of the confluence of the Mississippi and 

Ohio rivers. The floodway not only protects 

Cairo, Ill., but also 2.5 million acres of land in 

Missouri, Arkansas, Kentucky and 

Tennessee. The floodway is 

bounded on the east by the 56-mile

-long frontline MR&T levee that 

generally runs along the 

Mississippi River between Birds 

Point, Mo., and New Madrid, Mo. 

On the west, the floodway 

boundary is defined by 36-milelong setback levee. The frontline 

and setback levees end without 

connecting near New Madrid, 

leaving a 1,500-foot gap that 

serves as an outlet for interior 

drainage. This gap also permits 

backwater flooding in the lower 

portion of the floodway. The area 

within the floodway comprises 

approximately 133,000 acres. 

The frontline levee includes 

three crevasse sites (upper, middle 

and lower) that introduce 

floodwaters into the floodway 

upon activation. The 11-mile long 

upper crevasse site consists of 

approximately 8.5 miles of 

fuseplug levee standing two feet 

lower than the frontline levee. The 

fuseplug levee is lower than 

surrounding levees because it is 

designed to overtop to relieve 

pressure on the nearby levees in 

the system. The remaining 2.5 miles of the 

upper crevasse site are constructed to the same 

height as the frontline levee, but they contain 

imbedded polyethylene pipes that can be filled 

by pumping liquid blasting through preemplaced access wells installed in the levee. 

Upon activation, the liquid blasting agent is 

exploded to remove approximately seven feet 

from the top of the levee to allow floodwaters to 

enter the floodway. The middle crevasse site is a 

5,500-foot-long section of levee that also 

contains imbedded pipes and is activated in 

similar fashion to the upper crevasse site. 

This site is used to both introduce 

floodwaters upon floodway activation and to 

drain the floodway after the flood crest passes. 

The 5-mile-long lower crevasse consists of 

approximately 3.5 miles of lowered fuseplug 

levee for overtopping and 1.5 miles of raised 

Birds Point-New Madrid Floodway 

T 
2

sections of levee that that are 

imbedded with pipes. The lower 

crevasse site also acts as an inflow 

and outflow location. 

Under project design flood 

conditions, the floodway can pass up 

to 550,000 cfs from the Mississippi 

River and provide up to 7 feet of 

stage lowering in the vicinity of 

Cairo, with smaller reductions above 

Cairo and through the floodway 

reach. Because timely operation of 

the floodway is critical to ensure it 

performs as designed, the operations 

plan includes a timeline with trigger 

stages for preparation of the inflow 

crevasse. According to the tenets of 

the plan, preparations for artificial 

crevassing should be completed by 

the time the river stage reaches 60 

feet at the Cairo gage. 

The operational plan allows for 

the leeway to activate the floodway 

when stages reach at least 58 feet on 

the Cairo gage, if warranted by the 

conditions of the MR&T levee system 

in the vicinity. The operation of the 

floodway is directed by the president 

of the Mississippi River Commission 

after consultation with the Chief of Engineers. 

History of the Floodway 

The Birds Point-New Madrid floodway 

proved controversial almost from its 

conceptualization prior to the 1928 Flood 

Control Act. In the aftermath of the devastating 

1927 flood, President Calvin Coolidge 

instructed the Mississippi River Commission 

and the Corps of Engineers to develop 

comprehensive plans to prevent a similar 

tragedy from happening again. The resultant 

commission plan, with an estimated cost of a 

then-staggering $882 million, recommended 

the inclusion of four floodways to allow room 

for the river to expand and to relieve pressure 

on surrounding levees in the system. The 

proposed floodways, however, were all situated 

below the mouth of the Arkansas River. From 

Cape Girardeau, Mo., to the mouth of the 

Arkansas River, the commission recommended 

stronger and higher levees that would be set 

back from the existing levee system at places 

where the confined channel was too narrow to 

handle the maximum probable flood. To 

provide protection for Cairo, at that time a 

lavish and bustling river town with a 

population exceeding 15,000, the commission 

recommended raising the level of levee 

protection to 70.4 feet on the Cairo gage. 

Birds Point-New Madrid Floodway 
3

Birds Point-New Madrid Floodway 

The plan submitted by Maj. Gen. Edgar 

Jadwin, the Chief of Engineers, differed from 

the commission plan in a number of respects 

and had an estimated cost of 

only $296 million—a number 

that was well-received by the 

fiscal conservatism of the 

Coolidge administration. One 

of the more noticeable 

engineering differences 

involved Jadwin’s proposal for 

the construction of the Birds 

Point-New Madrid floodway, 

which he believed was less 

expensive and less dangerous 

than the commission 

recommendation for higher 

and stronger levees to protect 

Cairo. The initial floodway 

operations plan did not rely on 

explosive detonation. Instead, 

the plan called for the existing 

Mississippi River levee 

between Birds Point and New 

Madrid to remain in place, but 

approximately 10 miles were to 

be cut down or degraded by 3 

feet. The height of the degraded 

levee would correspond to a 

gage reading of 55 feet on the 

Cairo gage. This cut-down 

section of levee represented the 

fuseplug – a levee designed to 

overtop and crevasse as a means 

of triggering the activation of 

the floodway. The setback levee 

to the west was intended to 

confine the floodwaters 

introduced into the floodway. 

By Jadwin’s estimation, the 

floodway would undergo 

operation approximately once every ten years. 

A review of the transcripts of the hearings 

held by the House Committee on Flood Control 

reveals that many residents from within the 

alluvial valley favored the Mississippi River 

Commission plan over the Jadwin plan. 

Obviously, interests in southeast Missouri who 

owned land within Jadwin’s proposed Birds 

Point-New Madrid floodway 

were among those who 

favored the commission plan. 

The inclusion of floodways in 

the general flood protection 

scheme marked a necessary 

turnaround in the engineering 

policy practiced prior to the 

1927 flood. The flood had 

forced that change, but even 

in the wake of its widespread 

devastation a controversy 

emerged over the reality of 

actually implementing the 

floodways. Residents within 

the floodways were illprepared for that reality, 

which assured that private 

land once protected by levees 

would now be subject to 

inundation to reduce flood 

stages elsewhere in the valley. 

Under the Jadwin plan, the 

Birds Point-New Madrid 

floodway was designed to do 

just that. Opposition to the 

floodway was best expressed by 

Missouri congressman Dewey 

Short when he proclaimed to 

the House Committee on Flood 

Control that his constituents “do 

not want to see southeast 

Missouri made the dumping 

ground to protect Cairo, much 

as we love Cairo.” 

The 1928 Flood Control Act 

ultimately adopted the 

engineering features of the Jadwin plan. On 

December 11, 1928, Coolidge approved the 

federal acquisition of land and flowage rights—

a one-time indemnity paid landowners to flood 

their land during the operation of the floodway. 

The president also authorized the purchase of a 

Maj. Gen. Edgar Jadwin 
4

strip of land immediately adjacent to the 

fuseplug levee at a price capped at two times 

the 1928 assessed value of the land, but 

stipulated that the fuseplug levee could not be 

constructed until at least 50 percent of the 

flowage rights had been secured. 

Construction was scheduled to commence in 

the summer of 1929, but George W. Kirk, who 

owned land in the floodway, filed a lawsuit 

seeking an injunction to stop the awarding of 

contracts. In the lawsuit (Kirk v Good), Kirk 

maintained that because of the floodway, he 

would be unable to sell his property or use it as 

security to obtain loans. Judge Charles B. Davis 

of the Federal District Court of Missouri denied 

the injunction on the grounds that the damages 

Kirk would sustain would be “mere 

consequential damages such as the construction 

of any major public work is likely to entail.” If 

damages were to be realized through the 

operation of the floodway, the landowner had 

“complete and adequate remedy” for 

compensation under the provisions of the1928 

Flood Control Act. 

Following the dismissal of the case, 

construction of the setback levee commenced 

October 21, 1929, as did improvements to 

carry the drainage intercepted by that levee. 

This work was completed by the end of October 

1932. For all intents and purposes, the 

floodway was operational. The only remaining 

work involved degrading the fuseplug levee to a 

height corresponding to 55 feet on the Cairo 

gage. The levee had not been degraded because 

the federal government had reached agreement 

to purchase only 44 percent of 

the necessary flowage easements 

within the floodway. By 1936, the 

Corps of Engineers had obtained 

approximately 77 percent of the 

flowage rights, surpassing the 

mandated 50 percent necessary to 

degrade the fuseplug levee. A 

federal judge, however, 

threatened to issue an injunction 

if the Corps of Engineers 

attempted to degrade the levee 

prior to obtaining all flowage 

easements. It was not until 

January 1942—fourteen years 

after the passage of the 1928 

Flood Control Act—that the 

federal government completed 

Birds Point-New Madrid Floodway 

1937 levee 

blast 
5

Birds Point-New Madrid Floodway 

the acquisition of flowage rights on the 

necessary 106,858 acres within the floodway at 

a total cost of $2,385,546 or approximately $22 

per acre. 

The Great Flood of 1937 along the Ohio and 

Mississippi valleys provided the first significant 

test for the Birds Point-New Madrid floodway. 

The flood emanated from the Ohio River and 

reached a record maximum discharge of 

1,850,000 cfs at Cairo. While the Mississippi 

River above Cairo was at a low stage, the 

combined flows surpassed the highest flood 

stages ever experienced between Cairo and 

Helena, Ark. As the flood stage exceeded 56 feet 

on the Cairo gage January 23, Brig. Gen. Harley 

Ferguson, the president of the Mississippi River 

Commission, approved the operation of the 

floodway. The following day, the Memphis 

District dispatched Major R.D. Burdick to 

oversee the activation of the floodway. 

The Corps of Engineers intended for the 

floodway to activate when the river, after 

exceeding 55 feet on the Cairo gage, would 

overtop and naturally crevasse the fuseplug 

section of the frontline. However, the fuseplug 

section still had not been degraded by the 

necessary 3 feet because of the federal court’s 

threat of an injunction. Moreover, the frontline 

levee was one of the strongest in the system, 

leading Burdick and his team of engineers to 

fear that it would act as a spillway and not 

crevasse quickly enough to lower stages at 

Cairo before the river overtopped the floodwall 

there. Consequently, with floodwater already 

spilling over the frontline levee through 

groupings of natural crevasses near river mile 

18 and river mile 30, personnel from the 

Memphis District attempted to breach the levee 

with picks and shovels. These efforts failed to 

produce the desired result. On January 24, 

preparations were made to open the levee with 

dynamite placed into freshly augured holes. 

The following day, Burdick’s team detonated the 

explosives, opening two sections of the levee 

aggregating 120 feet in width and sending 

1937 flood aftermath 
6

Birds Point-New Madrid Floodway 

about 30,000 cfs of floodwaters coursing 

through the floodway. By January 27, the 

crevasses had an aggregate length of only 

1,000 feet, well short of the intended 10-

mile long fuseplug site envisioned under 

the Jadwin plan. As such Burdick 

estimated that the floodway discharge 

only reached 150,000 cfs of the 550,000 

cfs design capacity. 

After the artificial crevasses were 

executed, Burdick noted that the stage at 

Cairo fell only about 4.5 inches, from 

58.7 feet to 58.3 feet, before resuming its 

ascent as the Ohio River crest had not yet 

reached Cairo. On February 3, the river 

crested on the Cairo gage at 59.5 feet. By that 

time, the length of the crevasses had grown to 

9,200 and passed, by the commission’s 

estimation, approximately 450,000 cfs. Despite 

the flawed activation, Burdick concluded that 

the floodway reduced the crest at Cairo by 3.5 

feet. 

By May 1937, the commission had closed all 

the openings in the frontline levee with an 

interim levee and restored the levee to its 

former section and grade with the exception of 

crevasses at the lower end of the floodway. In 

spite of heavy damage to buildings in the 

floodway, the inhabitants moved back after the 

1937 flood and planters were able to yield an 

excellent crop during the 1937 growing season. 

By 1938, the levee was restored to its former 

section and grade. 

The operation of the floodway demonstrated 

the reality of the engineering plan which had, 

up to that point, only existed on paper. Maj. 

Gen. Edward Markham, the Chief of Engineers, 

highlighted the difficult reality of floodway 

activation when he wrote to Congress, “I am 

now of the opinion that no plan is satisfactory 

which is based upon deliberately turning 

floodwaters upon homes and property of 

people, even though the right to do so may have 

been paid for in advance.” In the 

decades following the 1937 flood, 

the Corps of Engineers and 

Mississippi River Commission 

initiated reservoir projects and 

levee modifications that raised the 

level of protection in the confluence 

area and reduced the frequency of 

operation of the Birds Point-New 

Madrid floodway. The flood control 

acts of 1938, 1944 and 1946 

authorized dozens of reservoirs in 

the Missouri, Upper Mississippi and 

Ohio basins that, once constructed, 

played a significant role in 

managing floodwater throughout 

Lake Barkley 

Kentucky Lake 
7

Birds Point-New Madrid Floodway 

the drainage basins above the confluence area. 

Perhaps the most important of these reservoirs 

were Kentucky Lake on the Tennessee River and 

Lake Barkley on the Cumberland River. Though 

the two reservoirs are not features of the MR&T 

project, both are operated to reduce flood stages 

to safeguard the levee system in the vicinity of 

Cairo and to reduce the frequency of operation 

of the floodway. By the late 1950s, the 

Mississippi River Commission estimated that the 

reservoirs in the greater Mississippi drainage 

basin, once completed, would reduce the 

expected frequency of operation to once every 

17 years. 

The 1965 Flood Control Act authorized a 

plan by the Mississippi River Commission to 

raise the frontline levee at the floodway to a 

grade corresponding to 62 feet on the Cairo 

gage and the fuseplug sections to a grade 

corresponding to 60 feet. The levee 

improvements enhanced the level of protection 

within the floodway by reducing the expected 

frequency of its operation to once every 80 

years. While the floodway would not be placed 

into operation by overtopping until a flood 

stage of 60 feet was predicted, the act stipulated 

that the Mississippi River Commission, if 

necessary, maintained the right to operate the 

floodway through artificial crevasses at the 

fuseplug sections or elsewhere on the frontline 

levee when stages reached 58 feet on the Cairo 

gage and a stage higher than 60 feet was 

predicted. 

Following the passage of the 1965 Act, the 

Mississippi River Commission further modified 

the plan for operating the Birds Point-New 

Madrid floodway. The new plan raised the 

fuseplug sections to a height corresponding to 

60.5 feet on the Cairo gage, raised the frontline 

levee to 62.5 feet and raised the setback levee to 

a height of 65.5 feet. The plan called for the 

operation of the floodway through explosives 

detonation only at the upper fuseplug section 

when stages reached 58 feet at Cairo with a 

forecast of stages to exceed 60 feet. 

Cape Girardeau, Mo. 

Arnold, Mo. 

Grafton, Ill. 

1973 flood 
8

Birds Point-New Madrid Floodway 

These changes necessitated a round of 

modified easement acquisition that conformed 

to the new plan of operation and reserved for 

the federal government the right to operate the 

floodway by artificial crevassing. The easement 

also reserved to the owners the right to 

compensation if operation of the floodway 

resulted in “excessive deposits of sand and 

gravel” upon the land.

Following the floods of 1973, 1975 and 

1979, all of which raised the specter of 

activation, the Mississippi River Commission 

revised its operational plan further after 

concluding that the activation of the floodway 

would be more safe and effective if artificial 

crevasses, including the use of explosives, were 

not limited to the upper fuseplug section. 

The new plan of operation included artificial 

crevasses at four locations along the frontline 

levee: two at the upper fuseplug section, one at 

the lower fuseplug section and one in the 

frontline levee opposite Hickman, Ky. To assure 

the artificial crevasses came at the precise time 

to protect against the project design flood, the 

commission made provisions for the use of 

explosives if necessary. 

The Mississippi River Commission and the 

Corps of Engineers, though, soon realized that 

neither possessed sufficient property rights to 

enable personnel to access the levee to place 

explosive materials as prescribed in the 

modified plan. The original and modified 

easements obtained under the authority of the 

1928 and 1965 flood control acts covered only 

those lands between the landside toe of the 

frontline levee and the riverside toe of the 

setback levee. The easements did not extend to 

and Barkley lakes. Although the floodway was 

not operated, the district court’s injunction 

remained intact. The federal government 

appealed the case to the 8th U.S. Circuit Court of 

Appeals. On April 15, 1984, the appellate court 

reversed the district court’s decision by finding 

that the plan to operate the floodway was not 

1983 flood at Cairo, Ill. 
9

Birds Point-New Madrid Floodway 

“arbitrary, capricious or an abuse of 

discretion.” The court also questioned 

Wangelin’s authority to review the case at all by 

finding that the decision to operate the 

floodway “is one committed to agency 

discretion by law...and is unreviewable.” 

Lastly, the court ruled that the district court had 

erred in instructing the federal government to 

deposit the $10.4 million as compensation. 

After the flood, the Mississippi River 

Commission tweaked the operational plan again 

in 1986 in an effort to reduce preparatory 

actions and to delay the operation of the 

floodway until later in the project design flood 

curve. Elements of the plan included raising 2.5 

miles of the upper fuseplug section and 1.5 

miles of the lower fuseplug, and imbedding the 

raised sections with polyethylene pipe that 

could be filled with blasting agent in less than a 

day. The explosives could also be removed 

safely in the event that river stages did not 

necessitate the operation of the floodway. The 

timetable for the new operational plan was 

based on the river elevations projected in the 

design hydrograph for floods approaching the 

project design flood. When stages reached 56 

feet on the Cairo gage, a tow with the 

components for the blasting agent and 

necessary equipment would depart the Ensley 

Engineer Yard. Preparation of the inflow 

crevasse would begin when stages reached 59 

feet and would be completed by the time the 

river reached 60 feet. Artificial crevassing of 

the levee would commence upon the command 

of the Mississippi River Commission president 

prior to river stages reaching 61 feet on the 

Cairo gage with additional stage increases 

forecasted. It must be noted that under the 

operating plan, the federal government 

reserved the right to activate the floodway 

when stages reached or exceeded 58 feet on the 

Cairo gage. 

Despite the increase in the level of 

protection and the reduced frequency of 

operation brought about by reservoir 

construction, residents within the floodway 

pushed for its outright abandonment. In 1987, 

Missouri congressman William Emerson 

prodded the House Committee on Public Works 

and Transportation to pass a resolution that 

directed the Corps of Engineers to determine 

feasible alternatives to operating the floodway. 

This resulted in a 1990 reconnaissance study 

that investigated several alternatives to include 

purchasing the land within the 

floodway; constructing 

permanent auxiliary channels 

in the floodway to confine 

floodwaters diverted into the 

area, rather than allow them to 

overflow the entire floodway; 

realigning and setting back the 

frontline levee at five locations 

2011 flood - Mississippi 

River levee between 

Baton Rouge and New 

Orleans, La. 
10

Birds Point-New Madrid Floodway 

to provide a wider floodplain; 

executing a cutoff at Bessie Bend 

to increase the slope and lower 

flood stages upstream of the bend 

throughout the floodway reach; 

and a plan of natural overtopping 

of the frontline levee. The study 

concluded that several of the 

alternatives were feasible from an 

engineering viewpoint, but were 

not justified economically. The 

study further concluded that the 

plan of natural overtopping of the 

frontline levee without artificial 

crevasses would serve as an 

alternative to the 1986 plan of 

operation and would provide a 

higher level of protection for the 

lands within the floodway. This 

alternative would require raising 

the upper fuseplug section to 

height corresponding to 64.5 feet on the Cairo 

gage, while leaving the elevation of the lower 

fuseplug section unchanged. 

The reconnaissance study served as the basis 

for an engineering review of the potential 

impacts the natural overtopping plan would 

have on the levees along both banks of the 

Mississippi and Ohio rivers. Published in 1991 

by the Memphis District, in coordination with 

the Louisville District, the engineering review 

determined that the implementation of the 

modified plan required improvements to 

existing levees and floodwalls and alterations to 

existing pumping stations and culverts in both 

districts at a cost of $140 million—$100 million 

in the Memphis District and $40 

million in the Louisville District. In 

April 1992, the Mississippi River 

Commission endorsed the modified 

plan and requested that the district 

furnish copies to local and 

congressional interests because the 

2011 flood - preparing to load levee 

pipes with liquid blasting agent. 

2011 flood - ????? 
11

Birds Point-New Madrid Floodway 

implementation of the plan 

would require 

congressional 

authorization. Through 

2011 such congressional 

authorization had not been 

secured, and the 1986 plan 

of operation remained in 

effect. 

In the spring of 2011, 

the lower Mississippi River 

experienced record-setting 

flood stages that ultimately 

prompted the second ever 

activation of the Birds Point

-New Madrid floodway. On 

April 25, the stage at Cairo 

reached 55 feet with a 

forecasted crest stage of 60 

feet. Maj. Gen. Michael Walsh, president of the 

Mississippi River Commission, directed the 

Memphis District to begin preparing the 

floodway in the event that rising river stages 

necessitating filling the pipes in the frontline 

levee with liquid blasting agent. The following 

day, the state of Missouri filed a temporary 

restraining order with the federal courts. The 

plaintiffs argued that floodwaters passing 

through the floodway would cause pollutants to 

enter Missouri’s waters, violating Missouri’s 

Clean Water Act, and also that using explosives 

to activate the floodway represented and 

arbitrary and capricious action. Judge Stephen 

Limbaugh denied the order on the grounds that 

the U.S. Court of Appeals’ decision after the 

1983 flood had already established that the 

Corps of Engineers’ right to activate the 

floodway is authorized by 

Congress and unreviewable 

and, moreover, activation 

would not violate the 

Missouri Clean Water Act. 

The appellate courts and the 

U.S. Supreme Court upheld 

the decision. 

2011 flood - blast for 

middle crevasse at Birds 

Point-New Madrid 

floodway 

 

2011 flood - loading levee pipes with liquid blasting agent. 
12

Birds Point-New Madrid Floodway 

As work crews prepared the floodway for 

possible pumping operations, water control 

managers in the Ohio basin reduced releases 

from Kentucky and Barkley lakes to slow the 

rate of rise at Cairo. With the forecasted crest 

stabilized at 60.5 feet (just inches below the 

activation trigger point under the operations 

plan) and with the region experiencing several 

consecutive days with no rainfall, Walsh 

delayed issuing orders to commence pumping 

operations even though the stage at Cairo 

climbed above 59 feet and a massive sand boil 

had developed near the city’s floodwall. 

Unfortunately, heavy rains returned on the 

evening of April 30. 

The river quickly established a new record 

stage on the Cairo gage, surpassing the old 

record set in 1937. At around 3 p.m. May 1, as 

the river hit 60 feet at Cairo and the National 

Weather Service issued a new forecast crest of 

61.5 feet, Walsh issued the order to commence 

pumping operations, although he still held out 

hope that activation would not be necessary. 

Heavy lightning, however, prevented the work 

crews from accessing the levee and pumping 

the liquid blasting agent. Finally in the early 

morning hours of May 2 as the Cairo gage 

reach nearly 61 feet (forecast crest of 63 feet 

for May 5), the lightning abated and work 

crews began pumping operations. 

As pumping operations commenced, the 

floodway preparation task force experienced 

several problems, including a bad mixing unit 

on one the two barges and a spur levee that 

denied the barges access to a portion of the 

upper inflow crevasse site. Facing time 

constraints and a rising river, the task force, at 

the request of Maj. Gen. Walsh, developed and 

implemented an accelerated operations plan 

that called for preparing only 9,000 feet of the 

levee with explosives, 

rather than the 11,100 feet 

prescribed in the operations 

plan. At approximately 10 

p.m. May 2, Maj. Gen. 

Walsh issued the order to 

activate the floodway. The 

Cairo gage read 61.72 feet. 

Within an hour the river at 

the Cairo gage, which had 

been rising one-half of an 

inch per hour, dropped by 

one-half of a foot. By May 

5, when the forecasted river 

crest was to reach 63 feet 

on the Cairo gage, the gage 

read 59.65 feet, 

approximately 3.5 feet 

lower than projected. After 

the floodway was activated, 

the task force had to quickly 

move to the lower end of the floodway to open 

the lower inflow/outflow crevasse. The crevasse 

was opened by May 3, but because of a 

perceived limited supply of liquid blasting 

agent, only five of the six lines were filled and 

the levee was only partially opened. On May 5, 

the middle inflow/outflow crevasse site was 

opened, but because the task force had to use an 

alternative explosive that was not as effective, 

only 500 feet of the designed 5,500 feet were 

opened during the initial activation. 

2011 flood - upper levee crevasse. 
13

Birds Point-New Madrid Floodway 

Although the floodway succeeded in 

significantly reducing stages, the operation did 

not go according to the operations plan. For 

instance, actual loading of the pipes imbedded 

in the inflow crevasse did not begin until the 

stage at Cairo had surpassed 60 feet, the level at 

which loading was intended to be completed. In 

addition, the order to activate was not given 

until after the Cairo gage exceed 61 feet by 

more than 8 inches. Furthermore, the 

accelerated plan resulted in the intentional 

crevassing of only a portion of the upper 

crevasse site. Consequently, the floodway was 

able to pass just over 400,000 cfs rather than 

the full design flow of 550,000 cfs. 

In the aftermath of the floodway’s activation, 

the timely reconstruction of the three crevasse 

sites was essential for farmers to proceed with 

planting during the 2011 growing season. 

While it would take nearly a year-and-a-half to 

return the levee at the upper crevasse site to 

62.5 feet, residents wanted a temporary levee to 

provide adequate protection so that farming 

operations could safely resume. By mid-June 

2011, work began closing all three of the 

crevasses, repairing scour holes and 

constructing the levees to a target elevation of 

51 feet. The initial work was limited in scope 

and intended to provide adequate protection for 

the 2011 growing season and to provide a 

stable platform for future system restore 

operations. By November 2012, all three 

crevasse sites were completed to full width and 

a height of 55 feet. By early January 2013, both 

the middle and upper crevasse sites had been 

fully restored and provided a level of protection 

equivalent to 62.5 feet on the Cairo gage, and 

the lower crevasse had been restored to a height 

equivalent to 58 feet. The restoration of the 

lower crevasse to a height equivalent to 62.5 

feet on the Cairo gage was completed in the 

summer of 2014. 

In the aftermath of the 2011 flood, the 

Corps of Engineers tweaked the floodway 

operation plan to incorporate the lessons 

learned during the most recent activation. The 

revised plan addressed the use of an alternate 

commercial explosive and more clearly detailed 

the decision criteria and trigger points for 

activation. The updated plan also addressed post

-operation reconstruction plans.

2011 flood - aerial view of 

Cairo, Ill., and floodway. 
uthorized by the 1936 Flood Control 

Act, the Morganza floodway is designed 

to relieve pressure on the levee system 

along the critical Baton Rouge to New Orleans 

corridor by providing a major diversion of 

floodwaters from the Mississippi River to the 

Atchafalaya basin. The floodway is operated 

when Mississippi River flows below the 

floodway are projected to exceed 1.5 million cfs 

or when stages are forecasted to encroach upon 

freeboard requirements on the levee along the 

Baton Rouge to New Orleans corridor. 

Floodwaters are introduced into the floodway 

via a 3,906-foot long 

controlled spillway located 

on the right descending 

bank of the Mississippi 

River just north of the city 

of Morganza, Louisiana. 

The 125-gate spillway is 

designed to divert up to 

600,000 cfs from 

Mississippi River during 

project design flood 

conditions. Floodwaters 

entering the floodway are 

contained between an 

upper guide levee 

extending from the 

Mississippi River levee to 

the Atchafalaya River levee 

and a lower guide levee 

extending from just above 

the city of Morganza to 

just past the town of Lottie. 

Since its completion in 

1954, the Morganza 

floodway has only seen activation during the 

1973 and 2011 floods. 

Prior to the Mississippi River and Tributaries 

(MR&T) project, federal flood control policy 

was one of confinement by levees. The 1927 

flood, however, completely overwhelmed the 

levee system and devastated the lower 

Mississippi River valley, showing the 

inadequacy of the “levees-only” policy. The 

flood was the catalyst for the comprehensive 

MR&T project authorized by the 1928 Flood 

Control Act. The project was developed 

specifically to provide protection from the 

project design flood by raising and 

strengthening levees and constructing 

floodways to relieve pressure on the mainstem 

levee system by providing room for the river to 

expand. The original plan called for five 

floodways, two of which – the East and West 

Atchafalaya floodways – were in the 

Atchafalaya River basin. 

While feasible from an engineering 

standpoint, the floodways proved difficult to 

implement and provoked intense opposition, 

particularly from landowners within the 

floodways. This opposition led to delays in 

construction. Many landowners in Louisiana 

were ill-prepared for the reality that their 

lands, once protected by levees, would now be 

subject to periodic inundation to benefit private 

Morganza Floodway History 

By Brian Rentfro 

A 
2

landowners elsewhere in the valley without 

federal compensation for their land rights. 

Section 4 of the 1928 Flood Control Act 

obligated the federal government to 

compensate landowners within the floodways 

who would be subjected “to additional 

destructive floodwaters that will pass by reason 

of diversion” from the Mississippi River. 

However, President Calvin Coolidge did not 

approve the federal 

acquisition of flowage 

rights for the Louisiana 

floodways on the 

grounds that the Boeuf 

and Atchafalaya basin 

floodways were natural 

floodways and would 

not be subjected to 

additional floodwaters 

because they would be 

receiving the same level 

of protection as before. 

Landowners also 

opposed the use of 

fuseplug levees as a 

means to floodway 

activation. Fuseplugs –

sections of levee that 

are designed to overtop 

and crevasse –

represented an untried 

theory that opponents 

considered dangerous. 

The most common 

criticisms involved the uncertainly of where the 

levee would crevasse and the possible damage 

caused by the uncontrolled kinetic energy of 

floodwaters coursing through the floodway. 

In June 1932, the Mississippi River 

Commission began work on an experimental 

program designed to increase the carrying 

capacity of the channel and lower the flood line 

on the Mississippi River between the mouth of 

the Arkansas River and Old River. The program 

was based largely on cutting off numerous 

river bends and using corrective dredging 

techniques to realign the channel, thereby 

increasing the river’s velocity and scouring the 

riverbed deeper to increase the cross section of 

the channel. By 1935, the commission had 

facilitated eight cutoffs which, when combined 

with corrective dredging measures, allowed the 

Mississippi to carry more water at lower stages. 

The initial success of the program allowed the 

Mississippi River Commission to propose 

modifications to the 

MR&T project, 

including replacement 

of the East Atchafalaya 

floodway with the 

smaller Morganza 

floodway, which would 

be regulated by a 

controlled spillway 

situated directly on the 

Mississippi River. The 

commission also 

proposed federal 

compensation for land 

rights within the 

floodways. 

The proposed Morganza 

floodway offered several 

advantages over the East 

Atchafalaya floodway. 

First, the floodway 

would use a controlled 

spillway in place of the 

unproven and 

unpredictable fuseplug levee. Under the 

previous plan, which included fuseplug levees 

for the East and West Atchafalaya floodways, 

the commission speculated that both fuseplug 

levees would be operated during project design 

flood conditions. However, during smaller 

floods it was possible that only one of the two 

floodways would face operation. Which one 

would be activated depended on chance. To 

remove this uncertainty, the commission 

recommended a controlled intake directly on 

the Mississippi River near Morganza, a location 

where levees had historically crevassed. In 

Morganza Floodway History 
3

Morganza Floodway History 

addition to providing greater predictability, the 

controlled intake directly on the Mississippi 

could better assure the integrity of the flood 

control system from Old River to the Gulf of 

Mexico. Moving the intake offered the further 

advantage of saving approximately 100 square 

miles of rich farmland formerly located within 

the east 

Atchafalaya 

floodway in 

northern Point 

Coupee Parish 

from inundation 

in the event of 

opening the 

Morganza 

spillway. The 

Mississippi River 

Commission also 

believed that the 

diversion of 

excess flows 

through the 

Morganza 

floodway, 

combined with 

the increased 

carrying capacity 

of the 

Atchafalaya, 

would improve 

conditions in the 

Red River 

backwater area 

and lessen the 

likelihood of 

triggering the 

activation of the 

West Atchafalaya 

floodway. 

The proposed engineering features of the 

plan drew wide support, with the Louisiana 

Board of State Engineers calling it “as near 

being a perfect plan, consistent with justifiable 

outlay and funds, as it is possible to conceive.” 

Congress authorized the recommendations of 

the plan in the 1936 Flood Control Act. While 

engineers were conducting design studies on 

the Morganza spillway structure, the Corps of 

Engineers began purchasing easements for the 

floodway, constructing levees and relocating 

highways and railroads. By the end of 1940, 

construction was complete on the upper and 

lower guide 

levees. By mid1940, the Corps 

of Engineers had 

received offers to 

sell 

comprehensive 

easements on 80 

percent of the 

total land value 

for the floodway 

and had 

completed 

payment on 50 

percent of these. 

The general plan 

for the spillway 

was based on the 

1935 Mississippi 

River Commission 

report and a more 

comprehensive 

1948 report 

detailing the 

design criteria of 

the project. Actual 

construction of 

the spillway 

began in 1949 

and was 

completed by 

1954. 

The completed spillway was 3,906 feet long, 

with 125 gated openings, each of which was 28 

feet 3 inches wide and separated by 36-inch 

wide piers with a weir crest of 37.5 feet. The 

top of the gates stood at an elevation of 60 feet. 

The operational plan called for activation of the 
4

floodway when the discharge at Tarbert 

Landing was forecasted to reach or exceed 1.5 

million cfs, which in 1950 corresponded to a 

stage of 56 feet at the spillway. This was 

supposed to allow four feet of leeway, or 

freeboard, before the spillway’s gates would 

overtop. The spillway’s vertical lift gates are 

opened by two gantry cranes that move along 

the structure and raise the gates by lowering lift 

beams equipped with pins into the two lifting 

eyes. The pins attach to the lifting eyes and raise 

the gates. Aligning 

the pins into the 

lifting eyes requires 

visual assistance 

and confirmation. 

Because of the 

method of 

operation, having 

the necessary 

freeboard to operate 

the structure before 

it overtopped is 

essential. With the 

structure 

completed, it would 

take nearly two 

decades before it 

would face its first 

significant test. 

In 1973, a major 

flood struck the lower Mississippi River valley. 

During the flood, significant scouring occurred 

in the inflow channel of the Old River control 

structure, causing the south guide wall of the 

structure to collapse and compromising the 

integrity of the entire structure. To lower flood 

stages and relieve pressure on the Old River 

control structure, the Corps of Engineers 

initially opened 42 of the Morganza spillway’s 

125 gates. Because of adverse affects on wildlife 

and a malfunction at the Point Coupee Drainage 

Structure which prevented one of the gates 

from closing, the spillway bays had to be closed 

for two days. When the New Orleans District 

began re-opening the bays, they opened just ten 

initially and then opened two a day until a total 

of 20 bays were opened. The purpose of this 

slow opening was to reduce adverse affects on 

wildlife and to reduce scouring below the 

spillway. The flood crested at 1,498,000 cfs at 

the Tarbert Landing gage before beginning to 

subside in mid-May. The primary problems the 

Morganza spillway experienced during its 

operation was the development of scour holes 

below the stilling basin and damage to the 

stilling basin caused by displaced derrick 

stones. Engineers 

addressed these 

problems by placing 

concrete pads in the 

outflow channel to 

reduce future 

scouring. 

Another major flood 

struck the lower 

Mississippi in 1983. 

Although the 

Morganza floodway 

was not activated, 

the north end of the 

spillway 

experienced major 

seepage problems. A 

scour hole 

developed under the 

north abutment pier 

on the inflow side of the structure. Engineers 

repaired the structure by placing a six-foot 

deep clay blanket on the forebay side of the 

structure extending from the north abutment to 

the wing wall and from the curtain wall 

extending out about 130 feet. Engineers also 

constructed a permanent seepage cutoff with 

sheet pile in front of the approach piers and the 

abutment pier on both ends of the structure. 

Engineers also constructed a concrete apron 

behind the seepage cutoff extending to the 

curtain wall. 

The 1973 exposed a potential problem 

involving the operation of the Morganza 

Morganza Floodway History 
5

Morganza Floodway History 

spillway. Rating curves developed after the 

flood indicated a progressive deterioration of 

the discharge capacity of the Mississippi 

between Old River and the floodway, possibly 

due to the changes in the dynamics of the river 

created by the Old River Control Complex. In 

other words, higher stages than expected for a 

given flow had materialized. An analysis of the 

MR&T project just after the 1973 flood 

indicated a 15 percent decrease in the capacity 

of the channel, causing stages near Tarbert 

Landing to be up to an estimated 1.7 feet 

higher at a given flow than they were in 1950. 

The phenomenon 

occurred again 

during subsequent 

floods. During 1973 

flood, a discharge of 

1,335,000 cfs at 

Tarbert Landing 

produced a stage of 

52 feet at the 

Morganza spillway, 

but during the 2008 

flood, the same rate 

of flow produced a 

stage of 54 feet at 

the spillway. During 

the 2011 flood, the 

same rate of flow 

produced a stage of 

55 feet. Because the 

discharge was not 

correlating to the 

expected stage, 

engineers 

recognized the strong possibility that the river 

could overtop the gates at the Morganza 

spillway before reaching the 1.5 million cfs 

discharge trigger. 

The obvious deterioration of the channel 

between the Old River Control Complex and the 

Morganza floodway presented numerous 

challenges for the operation of the floodway 

during the 2011 flood. With the top of the 

spillway’s gates standing at 60 feet, there was 

supposed to be approximately four feet of 

freeboard once the river reached the 1.5 million 

cfs discharge trigger for operating the 

floodway. . However, even though stages at the 

spillway continued to rise above 56 feet, 

discharge at Tarbert Landing had not yet 

reached 1.5 million cfs, which led to the 

possibility that the gates would be overtopped 

prior to the discharge reaching 1.5 million cfs. 

If this occurred, it would be difficult for the 

gantry crane operators to align the pins with 

the lifting eyes to lift the gates. Another problem 

was that since the Morganza spillway was 

designed under the 

assumption that the 

gates would rise 

prior to river stages 

reaching 56 feet, all 

tables, graphs, and 

data in the water 

control manual 

ended at that stage. 

Thus, rating curves 

and various 

equations used by the 

New Orleans 

District’s hydraulic 

engineers to 

extrapolate stages 

were not as precise 

as needed, posing an 

incredible challenge 

for the district. 

With the trigger 

stage of 1.5 million 

cfs at Tarbert Landing forecasted for May 14, 

2011, Col. Edward Fleming, the New Orleans 

District Commander, requested that Maj. Gen. 

Michael Walsh, President of the Mississippi 

River Commission, approve slowly opening the 

structure starting on May 11. Fleming based his 

request on the experience the district had 

gained during the 1973 flood as well as on the 

operational guidelines of the Water Control 

Manual. However, having made the agonizing 

decision to activate the Birds Point-New Madrid 
6

Morganza Floodway History 

floodway just over a week earlier, Walsh 

wanted to avoid activating the Morganza 

floodway if possible and was poised to follow 

the operational trigger point of 1.5 million cfs 

at Tarbert Landing as spelled out in the 

approved water control manual. The 

deterioration of the channel also made Walsh’s 

decision even more difficult, as higher than 

expected stages were occurring at a given 

discharge. For example, when the discharge at 

Tarbert Landing reached 1.5 million cfs, the 

stage at that gage was 62.3 feet, 4.2 feet higher 

than the same stage during the 1973 flood. 

With the stage 

rapidly rising and 

the discharge 

forecasted to 

reach 1.5 million 

cfs by May 15, the 

New Orleans 

District informed 

Walsh that if the 

structure was not 

opened soon, the 

district would be 

forced to further 

deviate through 

the Old River 

Control Complex 

to prevent the 

spillway from 

overtopping. On 

May 14, with the 

stage less than a 

foot away from 

overtopping the structure and the discharge still 

below 1.5 million cfs, Walsh gave the order to 

open the spillway. Two gates bays were opened 

on May 15, with 17 gate bays being opened by 

May 18, with peak flows reaching 180,000 cfs. 

Operation of the floodway damaged several 

areas of the spillway. In part due to the high 

head differential under which the spillway was 

initially operated, the structure suffered 

significant scouring in its tailbay beyond the 

limits of the scour protection, along the stilling 

basin end sill wall, and in the concrete plunge 

pond. If allowed to continue unimpeded, this 

scouring could have affected the structure’s 

integrity. Additionally, some of the stone from 

the scour protection area adjacent to the stilling 

basin was washed out and displaced. The 

floodway’s lower guide levee had scour damage 

in low sections and other scour areas developed 

along the forebay levee slopes. 

The 2011 flood revealed several deficiencies 

in the operation of the Morganza floodway, the 

most pressing of which was that the operational 

trigger was tied to 

a defined river 

discharge rather 

than a river stage. 

Due to this 

operational 

deficiency and the 

deterioration of the 

channel, 

floodwaters nearly 

overtopped the 

spillway before 

river discharge 

reached the 1.5 

million cfs level 

that dictates 

floodway 

operation. Due to 

the continuing 

deterioration of the 

channel, the 

discharge 

threshold for operation of the floodway is 

increasingly associated with stages that are very 

close to the top of the spillway. Further 

deterioration of the channel could lead to the 

operational discharge trigger occurring at a 

stage exceeding the spillways elevation. Moving 

forward, engineers are addressing the 

deterioration of the Mississippi channel 

between the Morganza floodway and the Old 

River Control Complex and reevaluating the 

operational plans for activation of the floodway.