Baltimore Ecosystem Study Cary Institute of Ecosystem Studies

2012 BES Annual Meeting Presentation and Poster Abstracts

Burying Streams: Environmental Regulations and Land Development
Gnagey, Matthew

Abstract: Land development was a growing industry in the 1970s and 1980s, but many developments were located near wetlands, streams, and other environmentally sensitive locations. Thus increased development spurred concern over wetland loss leading to increased regulation of the United States waters, most significantly with the Clean Water Act (CWA) of 1972. However, the definition of the United States waters was unclear creating tension between developers and the U.S. Army Corps of Engineers resulting in a 1985 Supreme Court ruling redefining wetlands and United States waters in an effort to minimize environmental damage caused by residential developments. While the ruling’s aim was to lessen the environmental impact of development, implementation led to economic and land use consequences. I study this ruling to test whether it led to shifts in development timing and development density in Harford County, Maryland. I investigate the impact of the new regulation on subdivision timing and development intensity by treating the Supreme Court ruling as an exogenous treatment or “shock”. I use difference-in-difference estimators in a duration analysis and on a matched sample to identify the change in development timing and density of development for land parcels following the ruling. Preliminary analysis of variance between the density of development and measures of stream presence on development parcels suggest a shift toward lower density development relative to zoning for parcels with streams after 1985. This research hopes to sheds light on the potential ramifications of policies changing the definition and jurisdiction of waters of the United States.