By Terry Schwarz
Surplus real estate is a common characteristic of legacy cities. Population decline and the ongoing effects of the foreclosure crisis have led to an unprecedented number of vacant and abandoned buildings, which in turn has given rise to the large-scale demolition programs underway in Cleveland, Detroit, Buffalo, and many other legacy cities. In the wake of demolition efforts, cities need to take a thoughtful approach to the management and reuse of vacant land, given that much of this land is unlikely to be redeveloped in the foreseeable future.
Detroit has over 100,000 vacant lots within city limits. Philadelphia has approximately 40,000 vacant lots. In Cleveland, the current count stands at about 21,000. Community gardens, greening projects, side yard expansions, and infill development are the most frequent responses to urban vacancy, but these strategies only address a small percentage of the large and growing inventories of vacant land in legacy cities.
Some cities have developed broad strategies for dealing with population loss and urban vacancy. The Youngstown 2010 Plan, Re-imagining a More Sustainable Cleveland, and Detroit Future City each provide a strategic framework for vacant land reuse at the citywide scale, with varying degrees of specificity. These three cities, among others, have also launched pilot projects at the parcel scale to introduce green space uses into depopulating neighborhoods.
However, inbetween high-level city-wide strategies and small-scale interventions for individual sites, there is a need to address vacancy in a more coordinated way at the neighborhood scale, where inter-related actions can produce a network of greening and redevelopment uses with additive benefits. When exploring options for vacant land, natural boundaries are often more relevant than political subdivisions. Nature’s equivalent of a “neighborhood” is a sub-watershed.
As defined by the EPA, a watershed is the area of land where all of the water that is under it or drains off of it goes into the same place. Sub-watersheds are smaller drainage areas (or catchments) within a larger watershed. For example, Greater Cleveland has five major watersheds which drain to Lake Erie. Within these larger watersheds, there are numerous sub-watersheds that drain to smaller tributaries or culverts as water makes its way to the lake.
Thinking about vacant land at the scale of a sub-watershed enables us to see how greening and redevelopment strategies for individual vacant parcels can impact economic, ecological, and human health outcomes at the scale of a neighborhood, city or region. Planning at the sub-watershed scale enables us to make better choices about where to concentrate infill development and where to set aside vacant land for permanent green space and green infrastructure uses.
To illustrate this point, we can look at the Dugway Brook, one of Cleveland’s many sub-watersheds. An initial overlay shows all existing green spaces with the sub-watershed. The next overlay adds vacant lots in ecologically useful locations, which in this case means sites that align with culverts (buried creeks) that feed into Dugway Brook. These sites can be aggregated into greenways that allow for natural infiltration of stormwater and create a public amenity. Finally, we can overlay the areas within the sub-watershed that offer the best potential for future infill development.
Planning at the sub-watershed scale is a way to explore the aggregate effects of many, small-scale interventions on the long-term regeneration of legacy cities. For example, can numerous parcel- and neighborhood-scale tree planting efforts achieve city-wide and regional impacts in terms of improved air quality and a reduction of urban heat island effects? Could hundreds (or thousands) of small-scale green infrastructure installations have a measurable effect on water quality, the health of the Great Lakes, and combined sewer overflows? Can scattered site food production (community gardens, urban farms, etc.) have an impact on food security issues at the city-wide or regional scale?
If we examine these issues at the sub-watershed scale, we can assess whether many small actions will add up to large-scale outcomes. And whether there are thresholds or tipping points at which urban systems begin to shift to more sustainable states.
Terry Schwarz is the Director of Kent State University’s Cleveland Urban Design Collaborative (CUDC). Her work at the CUDC includes neighborhood and campus planning, commercial and residential design guidelines, stormwater management and green infrastructure strategies. Terry launched the CUDC’s Shrinking Cities Institute and established Pop Up City, a temporary use initiative for vacant and underutilized sites in Cleveland.