Author: Josh Kastrinsky
North Carolina’s Dam Safety Program recently received the Southeast Regional Award from the Association of Dam Safety Officials for its work protecting North Carolinians.
The Dam Safety Program, part of DEQ’s Division of Energy, Mineral, and Land Resources, received the award as part of the Association of State Dam Safety Officials’ (ASDSO) annual conference, held in Baltimore in August. North Carolina’s program “has initiated several innovative projects to provide for the safety of dams, reduction of risks, and benefits for the state,” according to ASDSO. That work includes:
- Hydrologic and hydraulic studies for overtopping on 530 large and very large dams in three river-basins that have seen multiple Probable Maximum Precipitation (PMP) events since 2016: the Neuse, Lumber and Cape Fear River basins. In that year, Hurricane Matthew caused record rainfall in 17 of North Carolina’s counties, with as much as 18 inches of rain falling within a 36-hour period. Two years later, Hurricane Florence doubled that rainfall level in some areas, within the same period of time. Using updated figures that account for a changing climate, the Dam Safety Program hopes to account for these increasingly frequent events to help dam owners protect downstream communities. These studies are expected be available in 2023.
- Development of Semi-Quantitative Risk Analysis (SQRA) & Risk-Informed Inspection Report Form using available apps and common software programs: this internal process is the foundation of the state’s Semi Quantitative Risk Assessment method and will feed the Program’s Facility Access Management Application (FAMA) map.
- Development of an FAMA mapping WebApp including every dam in the North Carolina inventory (more than 6,000 dams): each point on the map will have data that incorporates the most recent inspection and other site-specific details. Based on predicted storm paths and rainfall amount, the Program can filter at-risk dams by various attributes as systems approach and work with dam owners to make preparations.
- Implementation of Dam Watch, a real-time web-based tool to assist in dam infrastructure monitoring, including work beyond the minimum design-based information feeds: the program has worked with North Carolina Emergency Management to facilitate the installation of 81 water-level sensors and has uploaded 530 overtopping studies, further enhancing the monitoring. They aim to install a total of 132 sensors on publicly owned high hazard potential dams. The system was first used this year.
- Implementation of a new PMP study for North Carolina: thanks to recently obtained funding, the new study will consider the impacts of climate change, provide up-to-date information for the design and safety of dams, and assist with the planning and design of all infrastructure throughout the state. The study is currently underway.
Part environmental protection and part emergency management, the Dam Safety Program provides oversight of more than 3,000 dams statewide, including certification and inspection to reduce the risk of failure. The program works to prevent property damage, personal injury and loss of life, and loss of reservoir storage, and to ensure maintenance of minimum flows of adequate quantity and quality below dams.
North Carolina has about 6,100 dams, one of the largest inventories in the country. About 2,700 of these dams are under state jurisdiction, while others fall under the jurisdiction of federal agencies or are small enough to fall below regulatory thresholds.
DamWatch was used in advance of Hurricane Ian in September 2022. Though the storm did not see any substantial impacts on dams across the state, it gave the Program an opportunity to test capabilities before the system officially went live in October.
The Dam Safety Program also contributed toward the City of Asheville’s North Fork Spillway and Embankment Improvements Project, which received an ASDSO award for National Rehabilitation Project of the Year in 2021.