Dam failure maps will remain public, EMA director says

The Army Corps of Engineers doesn’t want Columbia County residents to have access to maps showing which neighborhoods would flood in the unlikely event that Thurmond Dam would fail – but local authorities intend to keep the information available anyway.

Citing national security concerns, the corps asked county officials last summer to remove inundation maps from its 93-page “Emergency Evacuation Plan for Dam Failure & Flooding,” which is available on the county’s Web site.

The corps also notified the county it will be required to sign agreements to keep future updated versions of the inundation maps private. Those updates could be issued as early as 2012.

Although the older maps, created in 2005, were removed from the emergency plan as the corps requested, the same data will remain available in a different location – through the county’s online tax maps, which include an optional overlay to display dam failure inundation areas.

“As the EMA director, it is my duty to inform our citizens about the hazards and risks, including if their home is in the inundation area, advise how they will be warned, and what actions to take in the extremely unlikely event of a dam failure,” the emergency services director Pam Tucker said.

She conveyed those concerns in September to Donald L. Smith, the corps’ Charleston and Savannah districts Dam and Bridge Safety Program manager, and asked him to reconsider the corps’ insistence that the information be kept from the public.

“I haven’t heard anything since that meeting in early September, but we are moving ahead with our job of taking care of our citizens,” she said.

The existing data will remain available until updated maps are issued, she said, and the updates that show new residential areas built since 2005 will also be public – unless the county is required to sign a nondisclosure clause.

“If a nondisclosure statement is included when the updated 2012 maps are completed, we will just overlay GIS data onto the existing inundation area map to add properties built since the previous update in 2005, and it will be public,” she said.

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