As a civil engineer with the U.S. Army Corps of Engineers, Victor Gervais was in charge of Hannibal's flood wall construction and witnessed its success during the Great Flood of 1993, shortly after the levee was completed.
As a civil engineer with the U.S. Army Corps of Engineers, Victor Gervais was in charge of Hannibal’s flood wall construction and witnessed its success during the Great Flood of 1993, shortly after the levee was completed.
Gervais is now a professor of Construction, Engineering and Management (CEM) at Purdue University in West Lafayette, Ind., explaining, “I used to do Heavy, Civil, Marine Construction, and now I teach it.”
Gervais agreed to share the story of his involvement in the flood wall by responding to the following questions.
Courier-Post: How did you feel when the flood began?
Victor Gervais: It was a very satisfying feeling to see the long overdue levee protection system do the job it was designed for. My understanding is that a levee was talked about for decades before this project was approved and authorized.
Was this the first time you had seen immediate results of this type of project?
Yes. That’s the thing about a levee system, it just sits there for years until called into service by Mother Nature’s floods. It was quite amazing, because we had just completed the levee a few months before the 1993 flood which was one of the largest on record. Perfect timing for the new project.
What was most rewarding about saving downtown Hannibal?
1. Of course, protection of downtown and Mark Twain’s home, etc.
2. Great satisfaction, because the Hannibal residents were not sure the levee would do its job.
3. My sister-in-law, Pat Waelder, owner of the Hickory Stick, could finally relax during floods. She had been flooded out numerous times over the decades and had losses and hardships. She was wondering if the building could withstand any more floods.
This flood was unusual because it stayed for more than 54 days, instead of receding. Were you still in this area during the flood?
I was in the area for most of the flood. We were in the planning process to move my Corps office from Quincy to Ottawa, Ill., when the flood hit.
Did you keep track of the flood level, and were you concerned the water would top the wall?
My Quincy office was turned into the Flood Area Office headquarters during the initial flood fighting, until the rains subsided. I was there but was not directly involved with flood monitoring or the flood fighting efforts. A flood team from Rock Island was set up in my office. I did, however, keep close track of the water levels and the performance of the new levee and pumping system. About overtopping – there was no way to tell at the time. I knew the levee would perform as designed even with an additional few feet of top elevation from sandbags. It was up to Mother Nature as to whether or not we got more than a 500 Year Flood, which is what the levee was designed for.
When did the river level require more sandbags to be added to the flood wall?
When the river elevation crest was predicted to be within about two feet from the top elevation of the levee. It was a prudent precaution for potentially higher river elevations.
How close was the water to the top of the levee?
Within about two feet, roughly what was predicted.
Gervais describes construction of the $7 million flood wall
Can you outline how it was built?
The footprint where the levee was to be built was excavated down about six feet to remove any buried objects and construct an impervious clay foundation. Then the levee was built up to the design top elevation. Removable closure structures were constructed for street and railroad passage through the levee. A pump station was built to catch the interior storm water (water trapped by the levee) and pump it over the levee during a flood.
How long did construction take?
About two years. The contractor was Bleigh Construction — a local Hannibal contractor. Great contractor. Easy to work with and built a great structure.
What is its material?
The main levee is clay. Closure structures were on steel sheet piling foundations with concrete walls on top of the sheet piling. Structural steel removable gates were built for each closure structure. A ponding area for collecting interior storm water was excavated and an automated pump station was built to pump the water over the levee through large pipes embedded in the levee.
Was the clay available here?
The clay was local material from a borrow site a couple miles west of Hannibal along U.S. 36.
Were the levees built at the same time or which was constructed first?
Stage I, along the Mississippi, was built first. Stage II, along Bear Creek was built second.
What was most difficult about construction?
We really did not have any problems. A potential problem would have been a flood during construction — which we did not have, thankfully.
Was it easier here than in other places?
It was fairly normal except we needed extra precautions because of the proximity of the downtown and Mark Twain areas, and the many curious visitors as well as curious local residents.
Was it landscaped before the flood?
Landscaping was part of the original contracts and was completed before the flood.
When and/or why did you become a professor instead of a construction engineer?
I retired from the Corps after working on locks and dams and building levees for 31 years. Two years after that, I decided to teach young engineers about heavy/civil construction. I always show my new students the Hannibal levee. The pictures included here are part of my Powerpoint presentation.
Have you been back to Hannibal to see the changes in downtown?
I haven’t been back for years, but my wife has to see Pat (Waelder). I get the lowdown on all the great changes that would not have been possible without the protection from the levee system. I’m very proud to have been part of constructing it.