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Comprehensive Management of Watershed Quality. Steven I. Gordon City and Regional Planning Knowlton School of Architecture. Addressing Watershed Planning Questions. Will give an overview of the research agenda in planning at a watershed scale Will review the results of past research
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Comprehensive Management of Watershed Quality Steven I. Gordon City and Regional Planning Knowlton School of Architecture
Addressing Watershed Planning Questions • Will give an overview of the research agenda in planning at a watershed scale • Will review the results of past research • Focus on more recent questions that are parts of my research and that of my PhD students
Watershed Planning • Any planning process on a watershed scale is tricky for political reasons • Watersheds cross many municipal boundaries • No single entity has the authority to take action • There are bound to be many different and sometimes conflicting interests
Development and Watersheds • Any planning process for watersheds it tricky for scientific reasons • Watersheds are extremely complex environments • Not all watershed processes and conditions are completely understood • Data are often scarce or incomplete • The complete consequences of every possible action are unknown
Impacts of Human Activities on Watersheds • Destruction of habitat – particularly in the riparian zone • Changes in stream flow and form • Constraining the floodplain • Introduction of more sediment, chemicals, and other pollutants • Reduction in biodiversity, increase in flooding, reduction in recreation benefits
Approaches to the Problem • Experiments and models of single phenomena • Runoff and flooding • Point and non-point pollution load • Habitat change • Basin-wide trends • Changes in biological quality • Changes in flooding or pollution levels • Policy analysis for controlling specific sources or problems • Stormwater runoff policies • Growth and development policies
Some Rules of Thumb • Watersheds with less than 5% imperviousness maintain good health • Watersheds with 10% or more imperviousness are of poor quality biologically and physically • Watersheds with an intact riparian corridor are much better in quality • Artificial drainage adds to stream impairment • BMP's only partially effective in offsetting impacts
A Comprehensive View Preserving or improving watershed quality must deal with multiple causes, impacts, and their policy implications Most planning policies focused on general land use plans followed by site by site development review Fails to account for the cumulative impact of development from multiple causes
Practical Problems Comprehensive historical data are not available Many unique local effects create “noise” in available data Limited data for individual watersheds
Research Approach Combine available from multiple sources into single database Analyze relationships across multiple watersheds in the same eco-region Gain insights into the empirical relationships to form forecasting models
Major Variables • IBI – diversity of the fish population • ICI – diversity of the macroinvertebrate population • Land use in a subcatchment • Point source pollution • Habitat quality • Soils Big Darby IBI Trends 97-00 94-97 90-93 Very Poor Poor Good Very Good Excellent
Initial Models • Results of major USEPA funded project on watershed quality modeling • Results housed on a webserver: • http://tycho.knowlton.ohio-state.edu/model.html • Interactive mapping tool • Lead-in to other research
Related Research • Impacts of GIS illustrations of impacts on public participation (with Maria Manta Conroy) • Research by PhD students • Trade-offs between development and controls on stormwater runoff (Ayman Ismail) • Impacts of land use/habitat in the riparian zone (Sanjeev Arya) • Optimal selection of non-point water pollution controls (Wi-Ben Chen)
Recent Research Directions • Examining the impacts of land use changes on biological quality • How does change in land use impact the change in the quality of streams? • How far from the stream does land use change impact the change in quality? • What factors reduce those impacts?
Preliminary Results • Using LANDAT images from multiple years we are examining the dynamics of land use and water quality changes • Preliminary results indicate that land use change explains significant amounts of change in quality • Examining the impacts of other trends
Resources OSU Studio report -http://facweb.arch.ohio-state.edu/sgordon/research/index.html Center for Watershed Protection - http://www.cwp.org/ Forecasts for Ohio Watersheds – http://tycho.knowlton.ohio-state.edu Big Darby GIS Data Sharing http://facweb.arch.ohio-state.edu/sgordon/research/darby/start.html Big Darby Accord http://www.franklincountyohio.gov/BigDarbyAccord/index.cfm