Flooding in New Orleans during Hurricane Katrina

Flooding in New Orleans during Hurricane Katrina was not simply a rising-water emergency: it became a test of whether residents, hospitals, and public agencies could move people and preserve essential services as the city’s defenses failed. The water advanced into streets and buildings, while transport bottlenecks and vulnerable infrastructure narrowed the options available to people who could not leave on their own. At Memorial Medical Center, floodwater helped bring down a backup-power system whose most vulnerable components had been identified before the storm.

Evacuation and Unequal Exposure

At around ten in the morning, Mayor Ray Nagin ordered an immediate evacuation. The order came after hours of delay as officials considered logistical and legal questions. Yet the command to leave did not mean that everyone had a way out. Many residents had no car or other means of transport; officials knew that the city’s arrangements to move them had serious gaps, including too few drivers, while people evacuating on their own were already caught in traffic on the interstate.

The New Orleans Superdome was designated as a shelter of last resort, and shuttle buses were meant to take people there. Nagin specifically urged people with medical conditions, including those receiving dialysis, to go to the stadium, but did not explain what assistance they could expect. Tourists stranded by canceled flights and people in hospitals, nursing homes, and the parish jail also remained within the evacuation problem: the order exempted essential hotel and sheriff’s office workers, and hospitals and their staff were exempted because officials feared that injured people would otherwise have nowhere to go.

The transport system was already under strain as the storm approached. Dispatchers at Acadian Ambulance were overwhelmed by requests to move patients from hospitals, nursing homes, and homes. Many of the roughly two dozen ambulances made available were stuck on the congested interstate. Some began taking patients to the Superdome rather than trying to carry them out of the region. At Chalmette Medical Center, the first group of critically ill patients was evacuated, but ambulances did not return. Elsewhere, administrators seeking to move nine of their sickest patients west faced a choice between arranging an urgent, costly airlift and risking a long trip through clogged roads. The flood emergency therefore fell hardest on people whose health, circumstances, or lack of transport made independent evacuation impossible.

Water Reaches Memorial

A National Guardsman told Memorial plant operations director Eric Yancovich that the levees had been breached and that the hospital should prepare for fifteen feet of water. Yancovich initially doubted the warning, then asked the soldier to accompany him to the command center rather than bring the news inside alone. By then, the hospital’s exposure was not an unforeseen technical mystery. Yancovich had previously sketched the elevations of hospital entrances and outdoor equipment against Magnolia Street. His calculations indicated that less than four feet of street flooding could carry water over the loading dock and into the building.

The generators themselves stood on the second floor, but parts of the emergency power distribution system did not: some switches and related equipment were below ground or only inches to a few feet above it. Yancovich had warned that limited flooding could disable much of the medical center and expected patients might have to be moved to the newer Clara Wing, where he believed the electrical circuitry was better protected. Some measures had been taken, including adding floodgates and raising a vent for the underground diesel tanks. More extensive changes, such as elevating transfer switches and pumps for medical air and suction, had not been approved; a partial estimate for electrical work exceeded a quarter of a million dollars.

As floodwater reached the hospital’s surroundings, it emerged through sewer vents and advanced up Claiborne Avenue. People inside watched the water move toward the building with debris in its path. For ICU nurse Cathy Green, the information that the water came from Lake Pontchartrain, rather than the Mississippi River, clarified the scale and direction of the danger: the water had reached an avenue many blocks from the lakefront. The scene changed her understanding of the crisis from a threat that might still pass to a flood already advancing into the city.

The Hospital’s Power System Fails

The flood exposed a mismatch between the hospital’s emergency plans and the conditions they were meant to address. Memorial’s plans treated hurricanes, floods, power loss, and evacuation as major hazards, but did not adequately join those contingencies together: the hurricane plan did not anticipate flooding, the flooding plan did not anticipate evacuation, and the evacuation plan did not account for losing power or communications. The backup generators were expected to support the hospital for at least three days, but by the time they failed they had already been running for two. They were powerful machines, each rated at 750 kilowatts, but the system depended on electrical components and connections vulnerable to water.

Maintenance staff tried to keep the generators running without an on-site generator mechanic. When one engine stopped, workers added water to its radiator and restarted it. Later, they tried to address low oil pressure and bring the engines back with fresh diesel. As sections of the hospital lost power, workers in boots entered knee-deep basement water to investigate and reroute electrical loads. About a third of the automatic transfer switches were at a low level and appeared likely to be submerged. A bypass connection temporarily shifted the load, but a gauge indicated that the working generator was drawing too much current, raising the risk of a short circuit. Workers shut off branch circuits and attempted to salvage parts from a failed generator, but could not repair it.

At about two in the morning on Wednesday, August 31, nearly forty-eight hours after Katrina made landfall near New Orleans, the last backup generator surged and stopped. The blackout was not an isolated equipment failure: flood exposure, the arrangement of the electrical system, limited capacity for prolonged operation, and the lack of spare parts combined to defeat the hospital’s emergency power. Earlier, outside on the emergency-room ramp, a fuel truck had approached along the shallower side of Napoleon Avenue but turned away at Magnolia Street, apparently unable to proceed without flooding. In the basement, water passed through breached window seals and through cracks around doors despite plywood barriers and duct tape. Staff had to move supplies out of the basement a second time after bringing them back following the storm’s initial threat; pets that had been moved downstairs were again taken upward, toward the parking garage.

Continuing Consequences

The water around Memorial eventually stabilized at roughly five to six feet, rather than reaching the fifteen feet feared during the emergency. That lower level did not mean that the crisis had passed. An outpatient made it through the flood to the hospital for a scheduled chemotherapy appointment, only to be told that treatment could not be given. A man from the neighborhood waded to Memorial because he was overdue for dialysis, illustrating how a flooded city could turn access to routine but essential treatment into a life-threatening problem.

Accounts of the disaster place the flooding within a wider chain of failures and unevenly distributed risks. More than a thousand people died immediately in New Orleans, many in medical facilities and many others poor or elderly; additional people suffered and died afterward amid stress and disrupted health care. The identified contributing factors included the delayed evacuation order, insufficient buses and drivers, uncoordinated rescue efforts, poor communications, and hospitals and nursing homes that had not evacuated before the storm or invested in backup power and water systems capable of withstanding a prolonged emergency. Floodwater made those weaknesses consequential at once: it blocked roads, complicated rescue, and reached equipment on which hospitals depended.

The flooding thus exposed two connected vulnerabilities. At the city scale, an evacuation order could not protect people who lacked transportation or whose medical needs made travel difficult. Inside Memorial, a generator located above ground could not keep the hospital operating when vulnerable switches and distribution equipment were exposed below it. In both cases, safety depended on systems beyond any one person’s control—and on preparations that had not matched the danger that arrived.