Raleigh officials are monitoring city dams and water levels in local lakes, but a majority of the dams in Wake County and the Triangle are in the hands of private land owners.
The North Carolina Department of Environmental Quality issued an “urgent message” to dam owners on the state’s website leading up to contact by Hurricane Florence.
“Due to the current forecast and uncertainties regarding the track of Hurricane Florence, we are recommending that prudent action be taken regarding lowering operating levels in reservoirs,” according to the message.
Representatives from the department couldn’t be reached for comment.
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The message urged dam owners to lower reservoirs at a rate of one foot per day unless it was unsafe to do so. Those were the precautions that the city of Raleigh took at Lake Johnson, Lake Wheeler and Lake Benson.
“We are monitoring lake levels in real time from the city’s emergency operations center to identify any concerns as early as possible and mitigate and/or respond as needed,” said Wayne Miles, the city’s stormwater program manager.
The U.S. Army Corps of Engineers does not draw down Falls, Jordan and other lakes in the state ahead of storms because even with advances in forecasting it doesn’t know how much rain will fall upstream, said spokeswoman Lisa Parker. The Corps is now releasing the minimal amount of water to keep rivers healthy, Parker said, and after the storm it will minimize releases to areas that are experiencing flooding downstream.
Raleigh officials are also monitoring rainfall throughout other dams and lake systems managed by the city.
Dams are inspected by the state and given a condition assessment that can range from “satisfactory,” which is the best, to “unsatisfactory.” The dams at Lake Wheeler and Lake Benson have been labeled “satisfactory” while Lake Johnson is labeled the second highest, which is “fair.”
Of the more than 700 dams in the Triangle, nearly 40 of them received an “unsatisfactory” or “poor” condition rating during their last inspection. And 20 of those are also considered a “high” hazard structure, which means it poses a high risk to people downstream who could be injured or to property that could be destroyed if there was a dam failure. The data available on the state’s website is current as of July and it’s unclear if improvements have been made to some of those dams.
The dams at Raleigh’s lakes are all considered “high hazard” dams because of their proximity to people and property.
Dam failures are uncommon but they can occur during storms. And some property owners may not be aware they are required to maintain and repair the dams on their properties.
There are 20 dams in the Triangle that are rated “poor” or “unsatisfactory” and are considered a “high” hazard structure. And while dam owners are supposed to have an emergency action plan in place to notify residents if there is a failure, only two of those 20 dams with a “high” hazard rating and which are deemed “unsatisfactory” or “poor” have such a plan.
At least 17 dams in North Carolina failed during or in the aftermath of Hurricane Matthew and 40 dams failed during Hurricane Floyd, according to The News & Observer.
Richard Stradling contributed to this report.