The city of Norfolk, one of the most flood-prone areas around the Bay, has been actively implementing anti-flooding measures. Recently, these efforts faced a real-world test with the high tides from Hurricane Erin and this month’s coastal flooding. Norfolk is a low-lying city uniquely vulnerable to both sinking land and rising water levels, prompting the need for innovative solutions to reduce the frequency of street flooding.
In coastal cities like Norfolk, storm drain systems are a significant component of the flood management strategy. These drains often channel water directly into nearby rivers like the Elizabeth and Lafayette. High tides can cause river water to flow back through these storm drains, resulting in tidal flooding—a situation that can occur even on clear, sunny days. Rain exacerbates the issue, particularly when storm drains are already full from the backflow, leaving no room for rainwater to drain, thus contributing to street flooding.
Christopher Epes, the Project Manager for one of Norfolk’s flood mitigation initiatives, emphasizes that while total elimination of flooding isn’t feasible, significant mitigation is possible. One of his key projects is situated at the intersection of Walnut Hill and Sylvan streets, a historically marsh-filled area prone to flooding even during regular high tides. The project includes rebuilding and extending a berm and upgrading the drainage system. This newly constructed berm is 130 feet long and 4 feet high, built with interlocking concrete sections that provide a stable foundation and are reinforced with a 700-foot cable.
The incorporation of a flapper valve in the drainage system is designed to curb backflow. The valve closes when river levels are high, reducing water backflow into the streets and reopens to allow drainage as the tide recedes. Additionally, 200 feet of wetlands have been restored as part of the project.
Although the system has shown improvements in mitigating flooding, with water levels visibly controlled from Hurricane Erin and recent coastal lows, it’s not entirely foolproof. Valves can be susceptible to debris or marine life like oysters and require regular maintenance. Any significant debris can potentially undermine the system’s efficacy, underscoring the importance of clear storm drains—encouraged by the city to prevent blockages from yard waste.
Overall, while Norfolk’s new system has not completely eliminated flooding, it represents a significant improvement, making streets like Walnut Hill passable during severe weather and high tides. This project highlights the importance of innovative solutions in urban flood mitigation and the ongoing work required to manage natural challenges effectively. More information and updates on Norfolk’s efforts can be found at norfolk.gov/1055/Flooding-Awareness-Mitigation.