Hurricane Florence smashed into North Carolina on September 14, 2018. Although upon landfall it registered as only a Category 1 storm (winds clocking between 74-95 miles per hour), it brought with it an 11-foot storm surge. As the tempest stalled over the state, it dumped well-over 30 inches of rain in some areas. The flooding was devastating, dozens of people perished in the storm, and early estimates put the financial losses in the billions.
Historically, flooding is the most destructive natural disaster in this country. Facing this ever-growing threat, many wonder, “What can be done to protect life and property, reduce insurance claims, as well as help communities become more resilient?”
To mitigate the impact of flood disasters, the Department of Homeland Security (DHS) Science and Technology Directorate (S&T) has initiated multiple projects across the nation through its Flood Apex Program. One of the projects involves partnering with five communities around the country to test and evaluate low-cost Internet of Things (IoT) flood sensors.
According to Dr. David Alexander, DHS S&T Flood Apex Program Director, “The goal is to provide a bridge between industry and local governments, while simultaneously performing real-world research and development.”
S&T Technology Innovation and Partnership
As part of a pilot, S&T selected three small business industry partners. The companies were each tasked with designing, developing and providing 100 flood sensors that would be deployed to five communities. The devices are to be clustered in flood-prone areas, near existing U.S. Geological Survey (USGS), state or county flood sensors. Dr. Alexander explained that “By co-locating the new devices in these watershed areas, S&T is able to measure the performance of the competing company’s gauges against one another and against a higher-order, scientific grade control gauge (the USGS sensor).”
The IoT flood sensors were designed to provide a low-cost, highly reliable, modular, wireless sensor network and notification system that can be deployed for years at a time with little/no maintenance. The sensors have a variety of communications capabilities, energy harvesting and recharge, imagery collection, triggered reporting and data transmissions, as well as durable form factors for harsh environments.
More than 80 percent of the devices have been deployed across the five partner communities, with the remaining two installations to be completed by mid-November.
Advantages for Communities
One of the communities selected for the pilot was Mecklenburg County, N.C.
Although far from the coastline, Mecklenburg (home to the city of Charlotte) has a history of severe riverine flooding. Downtown Charlotte is perched safely atop a hill; however, the surrounding neighborhoods and business corridors are older and lie within the floodplain. The outlying areas are also prone to severe flash floods that can strike with little warning.
“The county was an enthusiastic partner,” said Dave Canaan, Mecklenburg County Water & Land Resources Director, “We saw the advantages of potentially expanding our flood risk management capabilities.”
The function of the existing USGS sensors in Mecklenburg County is to collect flood data for floodplain mapping and to act as the backbone for the Flood Information and Notification System (FINS). There are 14 automated FINS field sites that rely on USGS gauges to alert the Charlotte Fire Department and other agencies of potential flooding.
The new flood sensors are constructed to be affordable, accurate and able to provide actionable real-time data to authorities. They sense water depth and can wirelessly transmit this data using IoT technology to cloud-based services. With this timely information, emergency managers can coordinate alerts, warnings and notifications and their response to time sensitive incidents like flash flooding.
Currently, most of the existing USGS sensors are focused on larger creeks, but authorities want to add additional sensors that monitor the riverine tributaries to provide greater additional insights to potential flooding. Even though FINS is a dense network of stream and rainfall gauges, county staff still have gaps in their understanding of flood patterns through some watersheds. The objective with the strategic placement of these new flood sensors is to close those gaps and assist emergency managers with their situational awareness of the county’s dynamic floodplains.
In the future, localities want to be able to communicate directly with the public in real-time. Information from flood sensors and other devices may be transmitted to people at risk via their cell phones or even smart homes. An example of this connectivity would be if flooding has caused dangerous, fast moving or deep water ahead of motorists. The individuals could be sent notifications to their mobile devices with a “Turn Around Don’t Drown” warning. These alerts could be transmitted well before the drivers come in contact with floodwaters.
Advantages for S&T
Alexander believes all parties will benefit, “S&T sees the placement of these cutting-edge sensors in communities as both a great opportunity for R&D as well as valuable relationship-building. For some municipalities, this will be the first time they have worked with DHS.”
The program also assists in widening S&T’s footprint with their industry partners. By helping the performers with the development of innovative low-cost alternatives to existing devices (that can eventually be made commercially available across the country) S&T is helping to open new markets to their industry business partners.
Advantages for All
S&T programs such as these also provide their private sector industry partners invaluable field data. The performance of their products is tested and evaluated by potential state and local government community clients. The companies are free to use the performance analysis to inform the next iteration of their devices and to publish the real-world test data when they bring their product to market.
Flood sensors are just one small part of S&T’s comprehensive Flood Apex Program. Through a variety of programs and partnerships (focused on risk assessment, reduction and mitigation) S&T hopes to save lives, property and reduce insurance claims. The test and evaluation of next generation low-cost IoT flood sensors in Mecklenburg County is one of the ways that S&T is helping to save lives and achieve the goal of more resilient communities.
