CS31C - Concurrent Session 31C: Building a municipal dam safety program and restoration case studies on dam embankments in Charlotte, NC.

Abstract Description: The City of Charlotte (city) is the largest city in North Carolina and the 15th largest in the country. The city began implementing surface water quality improvement projects and other surface water quality protection tools decades ago. Many of these projects included enhancements to ponds and earthen dam embankments. As such City of Charlotte Storm Water services (Storm Water) began implementing dam safety protocols to meet regulatory standards from the North Carolina Department of Environmental Quality (NCDEQ) Division of Energy, Mineral, and Land Resources (DEMLR) State Dam Safety Program.

In 2021, Storm Water’s Dam Safety Program was re-developed to better meet regulatory standards. Currently, Storm Water manages 35 earthen dam embankments, 17 which are regulated, and 10 of which are high-hazard impounding structures. Many of these dams are privately owned and have shared maintenance responsibilities through established easements. The updated program ensures that dams are inspected and maintained from a reactive, routine, and proactive standpoint. In addition, the program currently has 7 dams under engineering evaluation for minor or major repairs.

The first part of the presentation will highlight the development of Storm Water’s Dam Safety Program, our 7 main initiatives, and share insights from our comprehensive peer review. The second part of the presentation will focus on a repair case study for two high-hazard earthen dam embankments, Linda Lake dam and Oakwood Dam. We will discuss the phases of inspection, evaluation, and implementation in order to repair damaged valve stems, sinking stormwater drainage infrastructure, buried spillway drainage outlets, and excessive outfall sedimentation. We will also discuss the various challenges associated with these privately owned dams and lessons learned when planning and implementing these types of projects.