Concerns about the rise in the Mississippi River and the possible “solutions” to the current test of the river levee system have dominated state news over the past week.
John Barry is a member of the Southeast Louisiana Flood Protection Authority and has written several books most notably Rising Tide, which chronicles the Great Flood of 1927.
The flood control commission member/author was kind enough to field some questions about the rise in the Mississippi River’s water level, where the water is coming from and the safety of the New Orleans area during this tense situation.
POI: How does the current rise in the Mississippi River compare with that of the Great Flood of 1927?
JB: It's actually considerably less on the lower portion of the Mississippi River. A great deal of the water is coming down is from the Ohio River. In 1927 the Arkansas River added an enormous amount-- currently it's less than 20% that.
POI: Why has there been a delay in the opening of the Morganza Spillway?
JB: I believe they were waiting for the trigger of over 1.5 million cfs to reach there.
POI: Where has all of the water come from, especially since Louisiana has been in the midst of a dry spell?
JB: Mostly from the Ohio River Basin.
POI: So heavy rains in Pittsburgh and Cincinnati affect the river here?
POI: Has the sudden rise in the Mississippi River created a need for the creation of additional outlets for the river water or does the current spillway system suffice?
JB: No, the current levee and spillway system is adequate.
POI: Speaking of spillways, who has the authority to open them: the local levee boards, the state or the federal government?
JB: The federal government.
POI: What area of the state is of the greatest concern right now with the sudden rise in the river level?
JB: The people most threatened are those that will be affected by the opening of the Morganza Spillway, especially those outside Morgan City.
POI: Is the New Orleans area in serious danger with the rising river level?
JB: Actually New Orleans is the safest area because of all of the diversions that can steer the water away from it.
POI: Let’s assume the worst happens. How would officials cope with the collapse of a section of the Mississippi River levee?
JB: They probably couldn’t. Closing a crevasse would be a nearly impossible task with a tiny sliver of opportunity to close a breach. That said once a breach got rolling, it could flow for weeks creating an enormous disaster.
POI: What effect will the opening of the Bonnet Carré spillway have on Lake Pontchartrain?
JB: Mostly the proliferation of algae blooms, changes in the lake’s salinity and fish populations. However the lake will recover rapidly.
POI: What effects will the opening of the Morganza Spillway have on south Louisiana communities?
JB: It would be hard for me to paint a scenario.
POI: How predictable is a crest in the Mississippi River?
JB: The Army Corps of Engineers has good estimates based upon when the crest passes each point along the river. When the level begins to drop, the decline will be slow. A river flood crest is not like one big wave; it's gradual.