By Tameka Kenan-Norman, City of Rocky Mount
On Friday afternoon, October 14, 2016, City Manager Charles Penny informed the mayor and members of the City Council of a mechanical hydraulic malfunction at the Tar River Water Supply Reservoir.
Due to the volume of flood water associated with Hurricane Matthew, the southernmost gate drifted below its normal position of 125 feet to a level of 122 feet. The situation could not be identified previously due to the volume of water coming through the reservoir as a result of Hurricane Matthew. Once identified, staff tried to manually correct the situation and was unable to do so until approximately 6:30 p.m. on Friday evening, Oct. 14, 2016. The gate was raised when the volume of water subsided and the hydraulic controls were able to overcome the upstream water pressure.
Flood waters associated with Hurricane Matthew caused the water in the reservoir rose to a maximum recorded elevation of 127.58 feet, which exceeds the height of the dam by 2 feet 7 inches. On Thursday morning, October 13, 2016, the reading was 126.67 feet. On Friday morning, October 14, 2016, the reading was 126.5 feet. Later that day, at 12pm, the reading was 124.33 feet which allowed staff to observe the gate had drifted approximately three feet below its normal position.
The reservoir has two hydraulic gates. The northern gate was not affected by the storm. On September 23, 2016, staff identified a problem with the southern gate and a contractor was on site on September 26, 2016. The parts were ordered on that date and delivered on September 30, 2016.
“The situation with the gate could not have occurred at a worse time and was exacerbated by the volume of water from Hurricane Matthew,” said Penny.
Given the impact of Hurricane Matthew on the hydraulic controls at the dam, Penny has directed the Public Works & Water Resources Department to engage a consultant experienced with dam inspection to review the conditions at the Tar River Water Supply Reservoir and provide a report within the next 90 days regarding the condition of the dam and recommendations to minimize the likelihood of a similar malfunction in the future. Input from the Army Corps of Engineers will also be requested. The repair will be scheduled once voluntary water conservation ends and during a low flow/low demand period, typically occurring in late December or early January.
“At this time, we understand that notification at this point may raise more questions than we are able to answer,” said Mayor David Combs. “However, we thought it would be in the public’s best interest to notify everyone of this situation. Our thoughts and prayers remain with all citizens in Rocky Mount and eastern North Carolina, and we are continuing to monitor the reservoir daily.”