The Effects of Imperviousness on Watersheds: Scio and Superior Townships
by Mark Brush
First Steps
Find out from city and organizations what types of analysis they would like to see.
City: City of Ann Arbor
Organization: Huron Watershed Council
What path do I choose?
The Plan
            Work with the Huron Watershed Council in determining future levels of

                Good "introduction" method
                Plenty of data to work with
                Accessible resource

        Work with the City of Ann Arbor and the HWC in coming up with imperviousness
           percentages & with investigating cluster development

                Good second step
                Encompasses two sets of interests

Why is imperviousness important?
        Water Quality
            Heavy metals, salts, oil, nutrient loading, temperature pollution
            CSO vs. SWO
            High runoff coefficient, high velocity and volume, flashing creeks             Well water
            Surface water             Living next to a clean stable stream


"Stressed streams" - 1 to 10% impervious cover

"Impacted streams" - 11 to 25% impervious cover

"Degraded streams" - 26 to 100% impervious cover
                        Watershed Protection Techniques Vol. 1, No.3, Fall 1994 pp.100-111)

Land-Use / Imperviousness conversion table
Road reductions


Outlook of Imperviousness: Superior Township
                                                                                                                                                                                           calculations based on zoning map
Outlook of Imperviousness: Scio Township
                                                                                                                                                                                              calculations based on zoning map
                    may want to look at creative more solutions
                                    cluster development
                                    shared driveways
                                   retrofits / curb - cuts
                                    stream buffers -etc.
See Phase Two - Measured Study