While record rains roil the depths of the Mississippi River and drive it from its banks, commotion over a deliberate levee breach by the U.S. Army Corps of Engineers threatens to muddy debate over the basic wisdom of living and doing business in a floodplain.

The corps' Maj. Gen. Michael Walsh, who also serves as president of the Mississippi River Commission, made the tough decision to breach the Birds Point levee Monday—despite public outcry and an unsuccessful lawsuit by the State of Missouri. The breach sent about 550,000 cubic feet of water per second into the already flooded 130,000-acre Birds Point-New Madrid Floodway. About 90 houses and acres of farmland were affected. A subsequent breach was made further south, near New Madrid, Missouri, on Tuesday and a third was planned for Thursday, according to the Southeast Missourian.

“These are people’s homes, their livelihoods,” Russ Davis, chief of the corps’ operations division, told the New York Times days before the levee was breached. “We really don’t want to do this.”

But a historic 61-foot crest of the river near Cairo, Illinois—which stands on the bank opposite the intentionally breached levee—became enough of a threat that officials had no choice but to activate the floodway. Although many news reports have painted Walsh's decision as a choice to drown rich Missouri farmland to save the poor and fading town of Cairo, in actuality, the entire levee system as far south as Louisiana was in jeopardy. Two other floodways in Louisiana might need to be opened before the end of the week, according to the Missourian.

“The sacrifice that these people are making is for the greater good,” the corps’ Jim Pogue is quoted as saying by CNN. “Their sacrifices are going to benefit hundreds of thousands of people all through this region. It's not just Cairo. It's people all through this part of the country.”

Those affected are understandably distraught and much has been made of their plight. Less attention, however, has been focused on the risks they took by living in the floodplain to begin with. While it may seem obvious that areas designated as floodways are meant to be flooded, the concept and the reality can be harder to reconcile, especially when long periods pass between operation.

In the case of the Birds Point levee, the last forced breach of the levee was in 1937 with another close call in 1950, according to a Mississippi River Commission information paper on the floodway. Apparently that was enough time for some area residents to fail to take precautions for the inevitable. Some, like Larry and Cathy Allred, who just built a new house in floodway, were unable to purchase insurance because of the risk. Others inherited property in the area after the record 1927 flood inspired the federal government to build the floodway system. For those owners, the right of the Army Corps to operate the floodway has always been at issue.

While floodplain managers, emergency officials, and environmental agencies have long opined against floodplain development, tax-starved municipalities—the same ones residents trust to protect community interests—often allow it. And those official blessings can create a cavalier attitude toward flood risk.

“In some cases the [100-year flood] standard has actually increased flood risk,” wrote Rising Tide author John Barry in the Wall Street Journal recently. “Developers push for levee construction, a levee gets built, homeowners move in thinking they're safe and don't buy flood insurance, since it's not required. Then a flood wipes them out.”

Although developer profits aren’t an issue in the case of the Birds Point floodway, the lure of extremely fertile, yet comparatively inexpensive farmland provided the same type of incentive to live under the threat of flood. It’s that willingness, perhaps even more so than a deliberate levee breach, that’s the real tragedy and one that’s bound to be repeated. Regardless of which side of the levee one lives one, eventually the water will flow your direction. “Once again this shows that conflict arises when humans start manipulating natural river systems,” Larry Larson, executive director of the Association of State Floodplain Managers, wrote in an e-mail Friday. “Water in the system must go somewhere—if it can’t spread out and store a portion of that water until the flood passes, the level in the river will go higher to build more energy…. The water must go somewhere and often is pushed onto someone else.”