NORFOLK – Last month, Jim Gray was heading out of state to visit some friends when he pulled his phone out of his pocket to check the tide levels back home. He had a feeling it was flooding, and as it turns out, he was right.
After a friend confirmed his suspicions, Gray knew that his months of hard work had paid off.
But how did Gray, who was more than 400 miles away at the time, know that it was flooding near Christ and St. Luke’s Church on West Olney Road?
Gray is the president and CEO of Green Stream Technologies, a startup eco-technology firm in Norfolk, that, using sensors developed by Gray, tracks flooding data throughout the Ghent neighborhood in six locations.
The primary sensor is attached to the underside of the Hague footbridge, with five nearby sensors placed on light posts near intersections from Stockley Gardens to St. Paul’s Boulevard.
“The Hague is really ground zero with respect to flooding,” Gray said, explaining the location of the first set of sensors. “And it’s not just the Hague that overflows, but the area surrounding it.”
When tides are high, the neighborhood which is less than 15 feet above sea level, floods regularly. If it rains, matters are only made worse.
When the drainage pipes throughout the Hague are backed up from flood water, it causes a chain reaction in several problematic intersections – for example, in front of Christ and St. Luke’s at the intersection of Boissevain Avenue and Stockley Gardens.
Each device uses what Gray calls an ultrasonic sensor that works in a similar manner to sonar. Every six minutes, a pulse is sent out from the bottom of the sensor. By measuring the return time, Gray said they can accurately predict rising water levels and.
That data is sent from each sensor to a nearby gateway using cell service towers, which is then pushed to Green Stream’s cloud platform.
Gray said they plan to share the information with residents via an online dashboard – and eventually a mobile app – so that flooded intersections are no longer an unwelcome surprise while driving through town.
Once a mobile app is developed, the data will be accessible from anywhere, which will help residents better plan their commutes to and from their homes.
Eventually, Gray said, the information would ideally be shared with traffic-based app Waze so that drivers already on the roads would be notified of impassable streets and intersections. The sensors not only measure rising water levels but also information equally as vital, especially for motorists in low-lying cars: water depth.
Nearly every time city roadways flood, cars are left behind by motorists who tried to brave the flood said Karen Lindquist, Gray’s business partner.
“What we’re really hoping is that we can help residents avoid that potential loss, which can be devastating.”
While researching intersections for sensor placement, Gray said he frequently saw drivers brace themselves before proceeding through water-covered roads.
For now, the six sensors will monitor the neighborhood, but Gray said they hope to build their network with more sensors across the city. Roadways and neighborhoods along the Lafayette and Elizabeth Rivers are being eyed as potential locations to serve a larger population.
“We’re coming to this realization that sea level rise discussion is around maps and technology terms,” Gray said, “but the public just wants to know the basics and in plain, understandable language. And that’s what we’re going to give them.”
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