Dozens of sensors that detect floodwaters and sewer backups are being installed across Chicago in an effort to limit storm damage in the wake of heavy flooding this summer that’s damaged hundreds of homes.
The sensors, which are being deployed over the next 18 months, use sonar technology to detect when water levels rise and create real-time flood maps for different city agencies.
“Ultimately, the goal is to make sure the residents of our city are safer, faster,” said Nina Idemudia, chief executive of Chicago-based Center for Neighborhood Technology. “It can also help determine where money goes and where improvements are made.”
The telecommunications giant Verizon and the Michigan-based tech startup Hyfi are providing the technology for free through next year. The city will then have the option to keep the network for $1,495 per sensor, or less than $75,000 per year.
Ten of the solar-powered sensors had already been deployed by Monday, but the installation of the other 40 sensors has been held up because permits haven’t been obtained to put them in place. No timeline was given for the installation.
The wireless, cylindrical sensors sit above the water — in cases on bridges, above roadways or in sewer drains — and send sound pulses to measure its depth, much like boats and submarines do to detect objects around them in the water.
Idemudia said the goal is to coordinate resources and immediate flood responses to keep residents safe. Her nonprofit is helping coordinate the project and working on data collection.
Eventually, she thinks a data set could be built to guide future infrastructure work. Hyfi has plans to try to add the data to the city’s Office of Emergency Management and Communication alert system for localized warnings, although that hasn’t happened yet.
The Chicago Department of Water Management said it would be using the data from nine new sewer-based sensors to cross-reference with its own to find problem areas in the sewer system, largely in Chatham and on the West Side.
In July, more than 100 homes were considered destroyed in Cook County due to flooding from storms; 544 reported major damage; and another 1,451 had minor damage, according to a flood assessment survey of Chicago and Cook County residents.
Another pilot of the sensors in New Orleans saw faster alert times in the midst of Hurricane Francine, said Brandon Wong, chief executive of Hyfi. The technology pinged emergency workers, sometimes faster than sheltering residents were able to call 911, he said.
Eventually, Hyfi wants to predict floods by combining the sensor and flood data with forecasting.
“Chicago is a lot of more localized urban flooding, which is a significant challenge in itself,” Wong said. “In other cities like New Orleans, they detected flooding an average of an hour ahead of 911 calls.”
Though Chicago isn’t facing hurricanes, a combination of an aging sewer system, more intense storms and a lack of natural areas to soak up rain have exacerbated existing flooding issues.
Some neighborhoods are more affected than others. As a result, Austin and Chatham are set to receive many of the new sensors, largely to watch for sewer overflow, with 13 and 10 planned for installation, respectively.
Thousands of flood disaster relief claims were filed in Chatham from 2010 to 2020 — in addition to hundreds of private claims and dozens of National Flood Insurance Program claims, according to data compiled by the Center for Neighborhood Technology.
A study from the group found that 13 of the city’s nearly 60 ZIP codes made up more than 75% of flood-based insurance claims between 2007 and 2016.
Idemudia said not much has changed since.
“Our most vulnerable communities are the ones on the South and West sides,” Idemudia said. “We want to make sure, when they’re handing their homes down to their grandkids, they won’t be facing the same issues.”
The 27 other sensors will target street flooding and will be scattered across the city — from Edgewater to the north and as far south as the East Side. Input from community meetings in Belmont Cragin and Chatham helped determine where to place them. Another community meeting, hosted by the North River Commission is set for Sept. 10, in Albany Park.
The Grassroots Empowerment Mission helped organize last month’s meeting in Belmont Cragin, which drew about 80 residents who shared their experiences with flooding. They said it was difficult to get around after the storms and complained about the cost of repairing flooded basements.
Jeremy Cuebas, executive director of the Belmont Cragin group, said getting community input was vital.
“Something that kept coming to the surface was response time,” Cuebas said. “Flooding occurs when pipes are backed up and water has nowhere to go. … [Even] an hour could be someone’s basement that could be saved.”
