By Greg Mantell
The town near North Carolina’s capital has several streams and waterways that are susceptible to flooding. To assess flood risk and improve public health, the town recently implemented the AWARE Flood System to alert officials to flood risks and develop basin models that mitigate water pollution.
In 2021, the FBI declared Cary, North Carolina — the seventh most populous city in the state — to be the safest mid-sized city in the United States. The FBI’s survey, however, only pertained to crime. It did not account for the dangers posed by flooding and severe storms, which can put residents’ lives in jeopardy.
Cary features a number of streams and waterways that diverge from the Neuse and Cape Fear River Basins. These river basins present a severe flooding risk for the town, particularly during the annual hurricane season when heavy winds and precipitation can overrun riverbanks and produce runoff. The Neuse and Cape Fear Rivers have also been plagued by wastewater and pollutants that pose even greater dangers to public health.
To protect its residents, Cary officials needed a flood-monitoring tool that could not only alert first responders to possible flooding, but also record water level data to develop inundation maps and improve public health.
The town ultimately found a perfect solution in the AWARE Flood System, a low-cost, highly accurate flood-monitoring tool that can connect multiple types of sensors and autonomously report water level data. This system continuously reports data in practically real time using a solar-powered communications node, which can be positioned near streams and waterways without requiring any connection to a power source.
The flood-monitoring system employed by Cary uses both in-stream water pressure gauges and tipping bucket rain gauges. The AWARE Flood System was designed to connect a variety of sensors to capture a complete picture of flood risk in the area. The data collected by these in-stream sensors and rain gauges can also help city officials develop basin models, complete stormwater planning, and make floodplain improvements.
The AWARE Flood System ensures that water level and precipitation data can be sent to any Internet of Things (IoT) connected device, including mobile phones and tablets. This IoT technology and data analysis are part of the Smart and Connected Cities Program that supports data-driven solutions intended to enhance the quality of life in cities like Cary. It is currently being implemented in several cities across the eastern United States, including several communities in North Carolina.
The AWARE Flood System has already demonstrated its feasibility in North Carolina’s largest city, Charlotte. The city instituted a pilot program of low-cost flood sensors to supplement the stream gauges that recorded water level data. At the time, the City of Charlotte only had 50 stream gauges to monitor nearly 370 miles of streams. They sought a cost-effective solution like the AWARE Flood System that could endure severe weather events like hurricanes and send flood alerts over a cellular network.
Over the course of its year-long deployment, the AWARE Flood System exceeded the City of Charlotte’s expectations in terms of accuracy, compatibility, and reliability. The system provided accurate water level data that was commensurate with their legacy stream gauges. It also worked with their flood-monitoring software thanks to a direct-to-IP approach and TCP/IP socket. This feature makes it compatible with a variety of flood-monitoring software tools. Additionally, the system reliably transmitted data throughout adverse weather and day/night conditions. This network also helped the city develop inundation maps and move residents and businesses from flood-prone areas, saving Charlotte stormwater services an estimated $10.5 million in 2020 alone.
The AWARE Flood System is now fully integrated into North Carolina’s Flood Inundation Mapping and Alert Network (FIMAN). Cary also provides a portal that is open to the public and features interactive maps and real-time water level and rain gauge data. The data from the AWARE Flood System helps optimize the city’s operations at its wastewater treatment facility and improve Cary’s public health and safety.