The state is preparing to tell about 100 dam owners they need to fix problems discovered in the earthen structures after Hurricane Matthew battered eastern South Carolina 10 days ago.
Regulators with the S.C. Department of Health and Environmental Control expect to begin sending out letters this week requesting that property owners make repairs or upgrade their dams as part of an agency effort to improve safety.
At least 25 dams broke during the storm, but many others need attention, officials said Monday. After Matthew blasted South Carolina Oct. 8, the department sent teams into the field to determine the extent of the damage to dams.
All told, DHEC conducted 469 “visual inspections’’ of dams, mostly in the Pee Dee region east of Columbia, after the storm. About one-quarter of those reviews will result in letters requiring improvements to dams, agency spokeswoman Jennifer Read said.
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“It looks like we are going to send out 115’’ letters as a result of the hurricane, DHEC water bureau chief David Baize said.
Improvements include removing trees that could eat holes in dams, or cleaning out spillways to make sure water can pass through during heavy rain. Spillways act like bathtub drains so that water in ponds or lakes doesn’t get too high. If spillways are clogged with trees, water can back up in lakes and put more pressure on dams.
In addition to the more than 100 letters to be sent out, DHEC has issued more than 20 emergency orders to property owners whose dams are considered in most immediate need of attention. The orders are telling owners to make basic repairs because their dams are unsafe.
DHEC’s investigation of failed and battered dams follows more than a year of agency emphasis on improving its dam safety program, which until a few years ago was one of the most poorly funded in the country. The department in the past year has more than doubled its budget and staff needed to oversee dams.
In 2015, more than 50 state regulated dams broke when a historic flood hammered Columbia and parts of eastern South Carolina with more than 2 feet of rain in one weekend. The dam breaks — most in the Columbia area — added to flooding downstream, where millions of dollars worth of residential and commercial property was damaged, according to court records.
Following the 2015 flood, state and federal regulators assessed more than 600 dams, ordering emergency repairs on many of the structures that did not break.
Now, the agency is dealing with its second major dam crisis in a year, this time in the Pee Dee region of the state near Florence and Darlington.
Some of the dams that broke or were severely damaged this year had been examined by DHEC after the big flood in 2015, DHEC officials acknowledge.
Agency officials say that while they have put more resources and energy into the dam safety effort since last year, it was difficult to resolve all of the problems with shaky dams in one year. That’s why it’s no surprise that some of the dams that were examined last year failed during the recent hurricane, officials said.
David Wilson, who is spearheading a DHEC effort to tighten the state’s dam safety laws, said stronger rules could eventually limit the number of dam breaks that occur when major storms blow through South Carolina.
New rules being discussed in the Legislature would require property owners to examine their own dams annually and report what they saw to DHEC. They also would have to bring in professional engineers to conduct detailed inspections every five to 10 years for dams with the greatest potential to result in injury or damage property if they broke. That would be in addition to inspections DHEC already conducts every two to three years.
Baize said the department is still investigating this year’s hurricane aftermath and may find other dams that are in poor shape or which have broken.
“It wouldn’t surprise me; some of these areas are hard to get to,’’ Baize said. “Undoubtedly, we’ll find more. We had folks going through heroic efforts to get to places to look at them.’’