May 10, 2010
By Brad Schrade and Anne Paine
The (Nashville) Tennessean
NASHVILLE — When Mike Ezell left his overnight shift commanding the Old Hickory Dam on the morning of May 1, the lake was resting normally, at 444 feet above sea level, just as it had been when he started his shift 12 hours before.
Photo: Trent Burian, 12, looks over downtown Nashville from the pedestrian bridge. (By John Partipilo, The (Nashville) Tennessean)
By the afternoon, the rains that had swept in from the west intensified, and creeks and tributaries throughout middle Tennessee were spilling over their banks.
"I knew it was going to be bad, but I didn't have any idea how," said Ezell, a powerhouse shift manager with the Army Corps of Engineers.
By May 2, water was ripping through the heart of Nashville. The Gaylord Opryland Resort & Convention Center had evacuated 1,500 guests. Water was quickly rising into downtown streets, and Nashville-area residents scrambled to survive the flash floods.
The epic rainfall, along with calculations and decisions made by a series of agencies, including the Corps of Engineers, during last week's historic floods, plays a central role in understanding how this disaster was able to wreak so much havoc across the region.
Residents, business owners and elected officials raised questions about the Corps of Engineers' management of the emergency. Sen. Lamar Alexander, R-Tenn., has promised a Senate committee hearing to understand what happened. Gaylord Entertainment Chairman and CEO Colin Reed said he continues to agonize over why emergency personnel had told him the Cumberland would stay below protective levees around the hotel, while his security staff witnessed a more urgent situation.
Corps of Engineers officials say their actions to manage the flow of water during the 48-hour storm helped to curtail the damage. Flooding takes top priority, and protection of the dams to prevent whole communities from being crushed by the walls of water behind them is part of that, Lt. Col. Anthony P. Mitchell said.
"There were a number of lives saved, and a considerable amount of damage that was minimized," Mitchell said.
Photo: The Cumberland River floods outside of its river banks in Nashville. (By Jeff Gentner, Getty)
The Tennessean examined corps maps, flood models, dam-release data and lake-level reports to piece together the events that saw the greatest flood here since a series of dams was built in the 1950s, '60s and '70s along the 687-mile Cumberland River.
No Disaster Expected
Two to 4 inches of rain was forecast for the Nashville area May 1 and May 2 as the Corps of Engineers' chief water manager for the Cumberland River, Bob Sneed, and his wife set out April 30 for a weekend retreat. This early forecast was nowhere near the more than 17 inches of rain that eventually fell.
Carol LeStourgeon, one of Sneed's assistants, was scheduled to run the water management office that Saturday, May 1. The office is where decisions are made on how much water to release and keep in each of the Cumberland's 10 dams.
The federal dams balance a variety of competing water interests, including barge traffic, drinking-water systems, lakefront homes and power plants.
Even though the weekend's rain forecast meant small tributaries and creeks could fill up, the Cumberland was expected to handle the additional water.
On the Saturday morning before the worst of the flooding, Sneed started receiving phone calls from LeStourgeon, each one warning of worsening conditions. "The river was getting juiced — primed," Sneed said. "There was a lot of water coming through the system." He decided to head back to Nashville.
Photo: Jim Hutchenson stands in his front yard with debris from his flood-damaged home in Nashville. (By Jeff Roberson, AP)
The National Weather Service issued flood warnings for middle Tennessee that afternoon. Mill Creek, which feeds into the Cumberland River, had become so flooded that its waters engulfed Interstate 24, pushing cars and buildings along the roadway.
At 1 p.m. that day, authorities at Old Hickory Lake decided to open the dam's spill gates to relieve the growing lake levels, Corps of Engineers records show.
"At that time on Saturday morning, we still didn't have a forecast that looked like anything that followed," Sneed said.
By 7 p.m., the Cumberland River in downtown Nashville had risen more than 10 feet.
Lake Overwhelmed
At Old Hickory, where Ezell manned the control room, the Corps of Engineers made adjustments to the floodgates 10 times from noon May 1 to 7 a.m. May 2 as they struggled to manage the massive amounts of water flowing into the lake.
By 6:30 a.m. May 2, the river in downtown Nashville had risen 10 feet higher, and it was just 3 feet below the 40-foot flood stage, according to corps records.
"The lake elevation went up faster than it ever has since I've been here," Ezell said.
Photo: Heaps of damaged drywall, insulation and furniture are piled up outside of a Bellevue, Tenn., home after the Harpeth River flooded the Riverwalk neighborhood. (By Alan Poizner for USA Today)
At midnight Sunday, Ezell heard the scream of the waters flowing through the spill gates at Old Hickory.
"When the gates are open like we had them open right at the dam, it's real violent," said Ezell. He said he was concerned about what was happening downstream but believed there was no other choice but to release water from Old Hickory.
"You're talking about controlled releases versus uncontrolled releases," said the corps' Mitchell. "You run a serious threat to the population when you have uncontrolled releases."
"The amount of rain was far more than what was forecasted, and it landed in areas that weren't really equipped to hold that," he said.
http://www.usatoday.com/weather/floods/2010-05-09-nashville-flood_N.htm