Peschel Leading Smart Cities on Green Storm Water Infrastructure
By Mike Koon
The streets of Chicago are getting smarter, literally, through a UI LABS City Digital project being led by Civil and Environmental Engineering Research Assistant Professor Joshua Peschel. As part of a unique interdisciplinary effort, including personnel from the University of Illinois, Argonne National Laboratory, and the City of Chicago, along with UI LABS’s corporate partners, Peschel and his team are developing the next generation of sensing and sense-making tools for green storm water infrastructure.
The Smart Green Infrastructure Monitoring project is one of two pilot projects announced last fall by City Digital, a Chicago-based consortium focused on data-driven urban innovation with the built environment. It was also one of a handful of projects nationwide highlighted by the White House at its Smart Cities Forum.
Green infrastructure, which includes elements such as porous asphalt and infiltration bump outs brings into engineering design vegetation, soils, and natural processes to manage water and create healthier urban environments. Peschel’s project will measure the health, performance, and effectiveness of green infrastructure in the City of Chicago by deploying new low-cost sensors and innovative software tools across five pilot urban streetscapes.
The goal of each streetscape design is to reduce the amount of flooding by reducing the amount of water flowing into conveyance systems that later requires energy for downstream treatment. While typically water runs off and goes immediately to the storm sewer, Peschel’s team is aiming to improve these green systems in which water permeates through special surfaces and is stored a few feet below the surface. This serves two purposes. First, the use of permeable pavers or roadways allows the water to soak in and be held onto, helping prevent water from backing up and flooding. It also means storm water is less likely to contribute to overflows that might lead to wastewater discharge to the environment.
“We turn streets into sponges,” Peschel explains. “We can hold onto the storm water underneath the streets and slowly let it be taken up by vegetation or trickle out. Combined sewer systems, present in Chicago and over 700 cities across the United States, have both waste streams from buildings and flows from parking lots and streets. Under dry conditions, the two combine in order to be treated. However, under really wet conditions, you can get overflows that can end up in the Chicago River or Lake Michigan. In other words, when we think about excess water, we need to not only think about street flooding and basement flooding, but also ways to prevent combined sewer overflow.”
Using infiltration bump outs, curbs that curve out reducing traffic from four lanes to two at some intersections, would allow for the presence of a green space or what Peschel calls “green bathtubs” with the added benefit of a safer, more pleasant place for pedestrians. The other type of streetscape being tested is planting a series of trees along graded sidewalks, which routes water along those interconnected green spaces instead of immediately down the drains. This green network along the street could also help reduce the urban heat island effect, where the presence of asphalt and concrete make cities hotter than the adjoining undeveloped areas.
City Digital’s pilot experiments are supported by a commitment from the City of Chicago to open its assets and infrastructure for technology experimentation to drive innovation and change. Each pilot’s completion plan includes a pathway to commercialization so that successful pilots can be extended throughout Chicago and to other cities nationally and globally almost immediately.
UI LABS provides a neutral environment for companies, cities and universities to jointly identify and solve large infrastructure challenges and then commercialize those solutions broadly.
Microsoft, who has a strong focus on cloud-computing and ubiquitous sensing, is a key corporate collaborator in this project. Peschel is working closely with Spyros Sakellariadis, Principal Program Manager of MS Applied Technologies in the Azure Machine Learning Team, to develop the smart infrastructure analytics toolset in the cloud for civil and environmental engineers.
In addition to its effectiveness, these methods are also about one-tenth of the cost. That means if a city like Philadelphia spends $10 billion on tunnels for its combined sewer system, it can instead spend $1 billion for green infrastructure for the same effect.
“The traditional way of monitoring storm water infrastructure, if done at all, is with expensive measurements that are often very sparse in space and time”, Peschel said. “This project seeks to fill the data gaps by adding unique measurement techniques to provide a lifecycle analysis, which explains the environmental impact, as well as the lifecycle costing to help those in public policy arenas have clearer information available to make decisions and address problems that, quite frankly, are not going away.”
At top: (left) One of the streetscapes being designed and studied by the Smart Cities project is one with infiltration planters, image courtesy of U.S. Environmental Protection Agency; (right) Joshua Peschel