Foreclosed homes: Stormwater management's secret weapon?
Will razing abandoned properties in flood-ravaged neighborhoods stop flooding in the basements of homes that people live in?
Overgrown vacant lots and foreclosed homes — you know, those blighted bank-owned properties that serve as magnets for disease-carrying insects and/or indoor pot growers — are being considered in a handful of Midwestern cities as a means of protection against storm-related municipal sewer backups that wreak havoc upon happily occupied homes.
In attempt to improve its increasingly overwhelmed stormwater management system, the City of Milwaukee, a city that's no stranger to outside-the-box civic solutions, recently released a 20-page feasibility study revolving around the idea of converting the basements of long-abandoned homes into underground stormwater cisterns —"BaseTerns," if you will. Runoff from heavy rainstorms would be diverted to the holding tanks and be kept there until rains cease and the risk of sewer backups and localized flooding has passed. To be clear, any aboveground structures on the lots would be demolished; only the cellar-turned-cistern would be retained. Community gardens (irrigated with reclaimed rainwater, naturally) could potentially replace the razed homes making for an intriguing mash-up of urban agriculture, blight-remediation and stormwater management.
As detailed by NPR, Milwaukee, like many other cities, has a combined sewer system that handles both domestic waste and storm runoff. During and after heavy rainstorms, basements are sometimes left with a particularly nasty remainder: a soupy and stinky mix of raw sewage and rainwater that bubbles up through floor drains when the system is overstressed.
Eric Shambarger, deputy director of Milwaukee’s Office of Environmental Sustainability, conceived The BaseTern concept after noticing that much of the city’s most severe basement flooding happens to occur in close proximity to a large number of foreclosed homes in a north-central section of the city. Many of these beyond-repair homes —"blighted houses that cannot be economically saved" — are in the process of being demolished by the city with plans to, among other things, transform the vacant lots into small-scale urban farms.
Shambarger explains to NPR: "If we are going to demolish the house anyway and there's going to be a vacant lot there, why not keep the basement portion of it? Let's get water into those basements, and in the process keep other basements dry. We are making good use of a hole in the ground that somebody put there for us."
In his introduction to the HTNB Corp-conducted "Vacant Basements for Stormwater Management Feasibility Study," Shambarger specifically mentions the flood-related damage resulting from potent storms that rocked the Milwaukee area in 2008, 2009 and 2010. In 2010 alone, the city’s call center fielded 11,600 reports of flooded basements. City officials are bracing themselves for even more sewage backups and stormwater-related headaches in the coming years: "… with climate change, extreme weather appears to be becoming a new normal for our region."