Disastrous dams leave a mark on the Midlands

Published: Oct. 29, 2015 at 7:38 PM EDT|Updated: Nov. 9, 2015 at 4:14 AM EST
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COLUMBIA, SC (WIS) - After this year's devastating floods, the state may take action soon to deal with possible safety issues at almost a dozen dams, whether the dams' owners ask for it or not.

DHEC now says its inspectors have issued emergency orders for 75 dams across the state and gave the owners until Monday to respond and start action, like letting water out of them. Ten still haven't responded, and DHEC may now hire contractors on its own to deal with them.

Mobile users, tap here to see flooding photos from across South Carolina.

WIS took a look at the inspection reports on some of the dams that failed, causing disastrous flooding in the Midlands. The reports' findings on the dams' condition was not a solid predictor of what would happen to them.

Disastrous Dams

"We've cried a few tears, and we are just trying to get everything together again, said homeowner Susan Hare.

Newlyweds Susan and Kevin Hare are trying to pick up the pieces after their Columbia neighborhood flooded, with an added twist.

Those were our trees," Kevin Hare said.

A huge chunk of their property itself was simply washed away, leaving just a jagged cliff and empty space when the Rockyford Lake emptied on them as dam after dam upstream collapsed.

"The flood came, which I know is an act of God," Susan said. "But I mean, we had reported this for quite a bit and people were just arguing about who's going to pay for it. … We are starting to talk with lawyers."

Former federal prosecutor Pete Strom is a lawyer, and he's talking legal action following the flood earlier this month.

"I think everybody is still in shock," Strom said.

Strom's house flooded as the water inundated subdivisions around Lake Katharine and in his own neighborhood of Kings Grant, flooding he blames on the failure of the Semmes Lake Dam on Fort Jackson.

"And every one of these dams, you're going to find, probably, negligence in the way it was designed and or negligence in the way it was maintained," Strom said.

S.C. Department of Health and Environmental Control passes the blame for the failed dams in the state.

"Well, I think we can look at Mother Nature being very terrible to us the last couple of weeks," said DHEC spokesman Robert Yanity. "The amount of rainfall we saw just was more than the dams could handle."

DHEC monitors and inspects 2,370 dams across the state, including dozens of them which failed during the October floods. Many of those dams are privately owned and DHEC inspection reports from those dams reveal a mixed bag of maintenance judged "adequate" and "inadequate," and dams in very different conditions, including some with problems dating back years.

In Lexington, a chain reaction failure on Twelve Mile Creek wreaked havoc when the Lexington Mill Pond Dam ruptured and washed over U.S. 1. Up the creek, an inspection in July of the Gibson Pond Dam noted cracks in the spillway and debris blocking it. In the floods, that dam collapsed.

Farther upstream, an inspection in June 2014 at the Barr Lake dam found animal burrows, erosion and cracks sufficient to question its integrity.  The dam was judged in "poor" condition. That dam collapsed.

The Lexington Mill Pond Dam itself was flagged for a sinkhole.  That dam was being repaired and the pond had been drained at the time of the flooding rains. It was still overwhelmed and failed when the two upstream dams let loose.

However, a 2013 inspection report on Cary's Lake in Columbia found no significant problems and ruled the dam in "good" condition. It ended up damaged – spewing the flood downstream into Forest Acres.

Dam owners are supposed to have emergency action plans filed with DHEC, so federal, state and local responders can access them in emergency situations. DHEC says it won't release those plans because of security concerns.

Meanwhile those 75 dams hit with emergency orders include three dams in Kershaw County, four in Lexington County and 19 in Richland County. Ironically, the safety and integrity of dams is the focus of a research project already underway at USC.

Dams research

USC Civil Engineering Professor Hanif Chaudhry says a system of dams throughout a creek system needs to be run like a "system," all of them managed with an eye towards their impact on the whole watershed. Chaudhry and his team of graduate students are in the middle of a project for the National Science Foundation, modeling the effects of flooding from levee breaches and dam failures.

In the lab, numerous simulations show what inevitably happens when water overwhelms a dam like the network of earthen dikes all over Midlands waterways. Chaudhry says some of the inspection reports show disturbingly slow response to dams with problems.

"Something should have been done. You shouldn't have to wait a year. There should be specified times when it is inspected," Chaudhry said regarding a preliminary inspection report from DHEC on a failed dam.

Chaudhry says a truly adequate regimen of inspections and maintenance would require a substantial investment, perhaps a good deal more than the state has been investing.

"All this last couple of decades of no government. No government. How much money you saved? And how much will they be putting in? What is the lesson there? And it is a lesson to us as voters," Chaudhry said.

As flood recovery got underway, Gov. Nikki Haley announced an exhaustive program of inspections on more than 600 dams across the state. DHEC has also contracted H.D.R. Engineering to help devise a new strategy for overseeing dams and making sure they're properly maintained and their operations coordinated.

"Change is coming," Yanity said. "You're going to see us take a very critical look at ourselves with the help of outside partners to make sure that we are ensuring we are moving forward and anticipating those things that we never thought we had to anticipate before."

Chaudhry says after 18 years living on a Midlands lake, even he had no idea it could be this bad.

"Saying it's a 1,000 year storm doesn't mean it will happen after 999 years. No. It could happen next year," Chaudhry said.

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