Real-time Monitoring Aims to Foil Flash Flood Fiascos

Smart IoT-enabled flood monitoring systems allow state and local authorities to respond to localized flooding incidents and better predict future events, potentially reducing property damage and saving lives.

Image credit: Green Stream

Floods are the most common natural disaster in the United States and account for 90 percent of all declared national disasters. In an average year, 95 people perish as a result of flooding, making it the second most deadly weather-related form of death after heat waves. In addition to the human toll, flooding is costly. In 2019, floods were responsible for $3.75 billion in damaged property and crops in the U.S.

While much of that stems from hurricanes, local floods resulting from slow-moving thunderstorms also are dangerous and deadly. According to the National Weather Service, nearly half of all flash flood fatalities occur in a vehicle, and two feet of water provides enough buoyancy to make an SUV float away. Providing local and state governments with tools to warn citizens of current or impending floods is critical to public safety.

Measuring from the Ground Up

On the task is Green Stream Technologies. The company developed a flood monitoring solution to give emergency management teams real-time information to protect citizens. Green Stream’s ruggedized flood sensors use ultrasonic technology to monitor water levels by measuring the distance between the water surface to the sensor. Sensors can be located above a lake, river, or other body of water, and also on dry land that is prone to flooding, such as an underpass.

The sensors capture data every six minutes and measure the depth of the water as it rises and recedes. The information is sent to the Green Stream Wireless Gateway, which communicates with backend servers via WiFi or cellular connections. It is designed to feed into Green Stream’s cloud-based servers but can be configured to support other servers.

Flood monitoring data is available on the cloud, where clients can view it on a computer or smartphone app. Green Stream’s dashboard visually displays the water level, making it easy to see when and where flooding occurs, along with signal strength and power levels. The company maintains a dashboard for some locations that is accessible to the general public.

Flood sensor attached to pole near field

Image credit: Green Stream

Green Stream is part of the Wireless Research Center in Wake Forest, NC, and is a member of the RIoT Accelerator Program for startup companies. Future plans include developing sensors to measure rainfall and groundwater saturation.

Flood Monitoring from a Different Angle

Rather than measure the water levels from the ground up, rain gauges measure precipitation from the skies. Used in conjunction with other weather sensors, cities gain a broader view of potential flood conditions. The Advanced Flood Warning and Environmental Awareness (AFWEAR) project is a collaborative effort in Northern California between the city of Rohnert Park, the city of Santa Rosa, and Sonoma County.

AFWEAR is a network of real-time sensors deployed throughout Rohnert Park, CA, at the base of Sonoma Mountain in Sonoma County, CA, with the goals of warning the community of potential road hazards due to flooding and improving city-wide flood response times. AFWEAR is a pilot program under the NIST-sponsored Global Cities Team Challenge, which encourages smart city development.

The AFWEAR team is using environmental sensors and watershed modeling and assessment tools to help city planners better understand and respond to water-related events. The sensors connect to servers via WiFI or GSM and can be accessed by researchers, city planners, and citizens. The team hopes to reduce property damage by 15 percent and warn cities and community members of flood events up to six hours before they occur.

As cities gain more information, and more quickly, they will be better prepared to protect people and property when precipitation packs a punch.