Assessing the Effectiveness of Land Use Regulations in Developing, Rural King County, WA

Land use regulations attempt to avoid or minimize and mitigate the biophysical effects of development, yet their effectiveness is rarely assessed. We present a framework and preliminary results of a five-year study tracking change in land cover, land use, hydrology, channel complexity, water quality and benthic invertebrates in nine small (80 to 1,200 ha) fish-bearing streams comprised of six treatment and three controls following implementation of  a new set of land use regulations. The new regulations were controversial in part because effectiveness of previous regulations was unknown.  We hypothesize that if regulations are ineffective, then the direction and magnitude of change over time in select environmental response variables should differ among watersheds subject to development (treatment) and no development (control). Furthermore, if change is observed it should be commensurate with the type, direction and magnitude of change over time in land covers and land uses. The study design is strengthened by tracking changes over time rather than substituting space for time, assessing for lingering effects of historic changes,  assessing channel morphology changes using tracer technology and quantifying land cover changes using a spatially-explicit model and distance-weighted measures of land covers.