Canal’s failure put Columbians ‘less than a day away’ from losing water supply
The soft-spoken engineer from rural Newberry County took the helm of Columbia’s drinking water system because he wanted less stress on his family life. Eight weeks later, an epic rain nearly broke the capital city’s water supply.
Clint Shealy accepted the job and a cut in pay to put an end to long hours as a consultant and to see his wife and kids more. Then the heavens opened.
The flood of October 2015 was the greatest crisis in the history of Columbia’s water department. It tested the endurance Shealy developed as a triathlete, stressed his even-keeled personality, and threatened fresh water for 188,000 customers stretching to lower Richland County.
By the time the weekend deluge ended, two feet of rain flooded the metropolitan area, taking nine lives in Richland County and causing at least half a billion dollars in damage.
Customers suffered through days of interrupted water service. The nearly 200-year-old Columbia Canal wall gave way. The city issued its first system-wide, boil-water advisory. Repairs to the canal — far from finished — are expected to cost about $100 million.
It could have been even worse.
“If the plans hadn’t been effective,” Shealy said, referring to the work of city workers and private contractors in the days surrounding the historic flood, “we were less than a day away from being unable to deliver water to our customers.
“But the plans worked.”
The rain comes
Weather forecasts for the weekend of Oct. 2 warned of a 100-year rain event. Few people beyond meteorologists understood what that might look like.
The storm turned out to be 10 times worse than predicted – a once-in-a-millennium event.
Shealy felt prepared, however. On the Thursday before the storm, the small staff at Columbia’s downtown water treatment plant began treating and topping off storage tanks that hold water-purification chemicals. Friday also was spent preparing the plant for the onslaught.
“We were ready,” said Shealy, then 46. “Plenty of water. Plenty of chemicals. Plenty of fuel to run backup generators to power the plant.”
During daylight on Saturday, the rain was not fearsome. Had forecasters over-hyped the threat?
“We were all sitting around in different places watching the radar. It looked like a huge red spot heading toward Columbia,” said Joey Jaco, the city’s utilities director. “We thought maybe this won’t hit us as bad.
“We were wrong.”
By midnight Saturday, the levels of the Broad and Congaree rivers had risen 3 feet. In the next 12 hours, they rose another 9 feet. The Broad, the chief source of water for the canal, was clogged with trees, limbs and other junk. The dirty water picked up speed as it rushed downstream, toward the Columbia Canal that dates to the 1820s.
The canal once served as a shipping lane for cargo. A hydroelectric plant was added in the 1890s and, until the flood, continued to supply electricty to South Carolina Electric & Gas Co.’s power grid.
The canal also is the water source for a treatment plant equipped with a 60-million-gallon reservoir that helps provide water for drinking, eating and bathing. Storm water jeopardized all of that.
Shealy and his small crew of seven faced several threats, starting with controlling the flow of water into the canal at the 11 jammed head gates.
“We could slow it, but we could not shut if off,” Shealy said of the surging water at the gates. “If we could have stopped it, that would have been a great benefit.’’
Consequently, the canal water level swelled as quickly as the Broad, which runs alongside it until the river converges with the Saluda — the site of the treatment plant — to form the Congaree River. There, yet another stress on the plant emerged later, when SCE&G would release up to 375,000 gallons per minute from Lake Murray to relieve pressure on its dam.
Elsewhere, aging water lines in the city were bursting under the pressure of the mounting flood. City workers had difficulty reaching them because flooding made many roads impassable.
Those problems intensified Sunday.
As the downpour worsened Saturday night, workers at Lockhart Power Co., the company that runs the city’s century-old hydroelectric plant near EdVenture Children’s Museum, were glued to their monitors. Earlier, employees had patrolled the canal dike on foot and reported to Shealy that rising water levels had forced the shutdown of the hydro plant and that water from the canal was washing over the top of the dike.
The levee was still holding.
For now.
Rising waters, stresses everywhere
River water was so dirty and contaminated by Sunday that city decided to add unprecedented amount of chemicals to meet safe-water standards — four times the normal amount at one point, Shealy said.
Most of Sunday was spent trying to keep water flowing to downtown customers.
Those served by a newer plant at Lake Murray – customers in Irmo, Chapin, and a northern strip of the city that stretches into the Northeast Columbia suburbs – were not yet feeling the full impact at their taps. So workers began channeling as much treated water as they could from the lake plant to the downtown plant.
But there was a problem with that approach: The plants aren’t directly connected, and diverting too much water from the network linking them would cause sharp drops in water pressure for customers along the northern tier.
Meanwhile, more water lines ruptured, including in an 18-inch pipe that spilled as much as 20 million gallons per day into already soggy soil. Then, two primary downtown water tanks, in the Wales Garden and Melrose Heights neighborhoods, were drained by the broken lines and public demand.
“That was the artery that was severed,” said Columbia water engineer Jason Shaw of the 18-inch line.
At its worst on Sunday afternoon, the plant was plagued with as many as 17 line breaks, which drained so much water that the plant struggled to keep delivering water to taps.
“We had to stop the hemorrhaging,” Shealy said. “... We ramped up production from 30 million (gallons daily) to 55 million, and the tanks continued to fail. By midafternoon, we really didn’t have much water in the downtown system.”
Late Sunday and into Monday morning, the two water tanks were completely drained, though others around the city were operational, said Shealy and chief water plant engineer Jon Sherer.
Despite those troubles, “The majority of our customers just had low pressure,” Jaco said.
But Sunday afternoon brought yet another challenge.
At about 1:30 p.m., the city decided to evacuate the treatment plant after SCE&G notified the city it was opening the Lake Murray floodgates. That would pour torrents into the Saluda — the river that joins the Broad at the water treatment plant.
The plant, though evacuated for two hours, did not flood, Shealy said. But the convergence of problems prompted city leaders to issue a first-ever boil water advisory for all 375,000 customers of Columbia’s water system.
The ‘holy (expletive)’ moment
About 1:30 a.m. Monday, monitors in the downtown treatment plant showed a sudden 8-foot drop in the bloated canal’s water level. That was quickly followed by a call from a worried Lockhart employee: The dike was breached.
Water ripped a 60-foot gash near the hydro plant. The breach was just upstream of the spot where the stone foundation of an earlier hydro dam was buried beneath the dike. City officials had no idea the foundation of the old dam was even there.
In the first couple of hours after the dike gave way, 150 million gallons of canal water rushed into the Congaree River — the equivalent of 2,270 Olympic-size pools, Sherer said. Put another way, the water treatment plant lost enough water in two hours to supply the entire city for five days.
Jaco was summoned to the plant about 2 a.m. His first thought when he saw the gaping hole was, “It was a holy (pause) moment,” he said, withholding the profanity.
The canal is the chief supplier of water for the treatment plant. If the water depth in the canal could not be maintained, the entire plant and his thousands of customers were at risk of running dry.
“We knew we couldn’t fix this,” Jaco said of the hole, “so we had to look at options to protect our water source. We had to dam the canal (as a stopgap).”
Building a 200-foot boulder dam across the canal between the plant and the ruptured dike was a herculean task. It took a week to place 50,000 tons of granite because a network of power lines and low highway overpasses made it difficult to get equipment into place. Heavy equipment was needed to move those heavy rocks, and some bridges to the dike simply could not bear the weight.
A National Guard Chinook helicopter was brought in to lower a crane into place.
In the middle of the mess, state National Guard troops were summoned to help unjam the canal entrance at the head gates. Soldiers created a sandbag assembly line across the top of the head gates. They dropped 50-pound bags in an attempt to stem the flow into the canal.
It didn’t work.
The granite boulders for the temporary dam came from the nearby Vulcan Materials Co. quarry in Olympia. By Tuesday morning, Vulcan had become an round-the-clock operation loading rock from its four Columbia-area granite quarries, said Vulcan’s Bob Johnson, who oversaw the task.
That was no easy task, either: Rainfall had filled the quarry bottom with 70 feet of water, Johnson said.
Convoys of trucks snaked their way out of the quarry, to be escorted sometimes by police or fire trucks. About 2,000 truckloads went to the canal, he said.
“We started rockin’ and rollin’ – no pun intended,” Johnson said.
Loads of granite began inching across the canal toward the damaged dike. But as the boulder dam grew longer, the rising force of the canal water flowing through a ever-narrower gap caused a second, though less serious collapse of the dike.
“Probably the worst time was when we were building the dam out and we lost more embankment,” Shealy said, nothing concerns other collapses might follow. “It became apparent that we could lose the canal.”
Pumps and hoses to the rescue
As Monday blurred into Tuesday and Wednesday, city leaders decided to open eight bottled-water distribution centers.
Repairs to water lines allowed the Wales Garden and Melrose water tanks to refill to normal levels.
But the level in the canal had dropped so much that intake pumps struggled to draw enough water for the plant for to continue to operate. By Thursday, the water was so low in spots that Sherer “could see rock.”
So, one more challenged had emerged: Siphoning enough river water to keep the plant running and its 60-million gallon reservoir from dwindling.
Four temporary pumps supplied by contractors began drawing water from the canal at depths below the water intakes that normally supply the plant. Within the next few days, a network of 15 pumps carrying 45 million gallons daily through about a mile of hoses drew both raw water from the Broad River. In addition, treated drinking water from plants in neighboring cities of Cayce and West Columbia was fed to the Columbia plant.
“The most challenging moment for our water supply was probably Friday, Oct. 9,” Shealy said. “The water had receded in the canal. The water level in the reservoir was down to the lowest it had ever been. Our gauge wasn’t able to read it. It was critical.
“At that point, we were putting in 12 million (gallons) and pushing out 30 million,” he said. “It was like dying a slow death.”
By Sunday morning, Oct. 11, 30 million gallons a day was flowing into the plant and city officials were announcing its water supply was stabilizing and safe water advisories were being replaced by water conservation notices.
As he drove home for the first time in days, Shealy reflected on all those who labored on the monumental task.
“We were all exhausted. Thinking back about the emotions we had lived through, you felt like you could breathe a little easier,” he said. “It was like a physical weight had been lifted off our shoulders.
“I had a really, really good night’s sleep.”
This story was originally published September 28, 2016 at 2:52 PM with the headline "Canal’s failure put Columbians ‘less than a day away’ from losing water supply."