Housing location in a Philadelphia metro watershed: Can profitable be green?

The objective of this paper was to examine the profit levels, energy use and environmental impacts of two residential development scenarios in a watershed in the Philadelphia region under two zoning assumptions. The two scenarios were based on economic suitability and environmental suitability. A key question was whether these occurred together in the Pennypack Creek Watershed. Suitability analyses in ArcGIS using criteria for profit and for local sustainability parsed out two sets of developable areas. Buildouts to satisfy 2035 population projections in these areas using CommunityViz software were based on actual municipal zoning ordinances. In a unified zoning scheme created by the authors, a density-adjusted number of housing units are placed watershed-wide without municipal restrictions. Profit data for buildings in each zip code were used to compute a Weighted Profit per Square Meter. Household units were associated with a particular type of automobile and average Vehicle Kilometers Traveled in the relevant census tracts. The GREET program was used to compute energy use, air pollution emissions and greenhouse gas emissions. A Weighted Water Quality Index and Index of Biological Integrity were used to assess water-related impacts based on recent monitoring data supplied by the Philadelphia Water Department. It was no surprise that ECON-UNI and ECON-MUNI generated higher profit than ENV-MUNI and ENV-UNI. ENV-UNI had lower energy use and environmental impacts than all others. That ECON-MUNI had the second lowest energy use and environmental impacts, and the highest water quality, was unexpected. Some policy proposals and conclusions end the paper.