Drapkin had partnered with numerous experts to develop rain and flood monitoring techniques that could be used by community members. Experts included meteorologists from the National Weather Service, modelers from the Lower Mississippi River Forecast Center, water architects and green infrastructure engineers, who provided feedback on their methods and data quality. Volunteers from the American Geophysical Union’s Thriving Earth Exchange (TEX) also made site visits to the flooding hotspots to get detailed GPS measurements.
Residents of the waterlogged neighborhood who decided to participate became weather stewards. ISeeChange provided them with rain gauges, and they carefully monitored rainfall and flooding on their block.
Bell says, “The corner that I live on, pretty much every time it rains, floods. Our corner is the worst corner in the neighborhood for some reason.” She describes the water that accumulates there as brown, mucky and filled with trash. Once a dirty diaper even washed up onto her lawn. Although it was a clear and sunny day when Drapkin knocked on Bell’s door, there were still remnants of flooding from rain that fell a couple of days earlier.
After speaking with Drapkin, Bell began uploading images of flooding around her house to the ISeeChange social media platform. “The biggest thing I realized is that it doesn’t really matter how much rain falls – it matters how fast it falls,” says Bell. “If we get half an inch over 30 minutes, my street is going to be flooded. If we get a half an inch over the course of a day, it’s going to be fine.”
By recording her observations, she began to notice another important flooding factor: the amount of time the water lingered in the streets. She began including time stamps on her posts, which led to ISeeChange documenting flood duration in addition to rain intensity.
The rainfall and flooding data collected by Bell and the other residents of Gentilly yielded a highly detailed map of flooding in the neighborhood, which engineers contracted by the city are now incorporating into their plans. The data captures not just flooding location and extent, but social aspects, such as when transportation routes gets disrupted or when playgrounds become too dangerous for children to play in.
In 2018, the international engineering and planning firm, Stantec Consulting Services, Inc., was awarded a contract to improve the quality of life and infrastructure of the Gentilly neighborhood. As the engineers began putting together designs for the City’s Gentilly Resilience District, they reached out to Drapkin. “We saw a lot of value in having her network of people provide us with real-time data regarding flooding, and regarding their concerns,” says Dan Grandal, a vice-president of Stantec. “We’re able to use that data to validate results from our hydraulic models.”
The company is in the process of designing a new green infrastructure project for the neighborhood, called Blue & Green Corridors. The project is supported by $141 million in funding awarded to New Orleans by the U.S. Department of Housing and Urban Developmentthrough the National Disaster Resilience Competition.Blue & Green Corridors is currently in the design phase, which will be completed in early 2020, and construction will start shortly thereafter. The project will involve new recreational waterways and green infrastructure, such as landscaped areas and other innovative solutions designed to soak up excess water. Importantly, it will include water storage facilities, which will help mitigate flooding during intense rainfall events and manage stormwater.
Grandal says, “This project provides flood mitigation and neighborhood improvements that will help to bring up the property values and encourage people to develop vacant lots. That fear of flooding, especially in New Orleans, can make a neighborhood undesirable.”
While many neighborhoods in New Orleans have a long history of flooding, the effects are likely to be amplified by climate change. As the Fourth National Climate Assessment notes, “Extreme rainfall events have increased in frequency and intensity in the Southeast, and there ishigh confidencethey will continue to increase in the future.The region, as a whole, has experienced increases in the number of days with more than 3 inches of precipitation and a 16% increase in observed 5-year maximum daily precipitation.”
The report notes that projections under a higher emissions scenario, in which emissions continue to rise throughout the 21st century, show that the number of heavy rainfall events could double in the region by 2100, and the amount of rain falling on the heaviest precipitation days will likely increase by about 20%.
Another major issue facing New Orleans – and all of the Southeastern U.S. – is a higher incidence of heat waves. According to the Fourth National Climate Assessment, “61% of major Southeast cities are exhibiting some aspects of worsening heat waves, which is a higher percentage than any other region of the country. Theurban heat island effect(cities that are warmer than surrounding rural areas, especially at night) adds to the impact of heat waves in cities.
“The number of days with high minimum temperatures (nighttime temperatures that stay above 75°F) has been increasing across the Southeast, and this trend is projected to intensify, with some areas experiencing more than 100 additional warm nights per year by the end of the century.”
ISeeChange and Stantec are also working to help neighborhoods in New Orleans adjust to these worsening heat waves. Similar to the rain gauge project, ISeeChange began installing heat sensors in New Orleans in April 2019. These sensors help pinpoint areas that are particularly prone to the heat island effect, but also monitor the neighborhood over time, as the Blue & Green Corridors project is implemented and additional green infrastructure is added. The heat sensors – already installed on some utility poles throughout the nearby neighborhood of St. Bernard, will help quantify the impact of planting more trees, for example. The low-cost sensors, designed by a tech company called MCCI, collect and transmit real-time data using low-power radio frequencies. Using the data from these sensors, ISeeChange, with its Thriving Earth Exchange partners at Georgia Tech and MCCI, will be developing a protocol for measuring the impact of green infrastructure. Lastly, the New Orleans Department of Homeland Security, Emergency Preparedness (NOLA Ready) and ISeeChange will be developing a localized heat alert system.
