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• ..ionfyrater management is vie ved compre-
<br />hen ` i`'el`•, that a rational procedure is being
<br />used for the selection of measures. and that
<br />measures add up to form landscape ele-
<br />ments that are an enhancement for the com-
<br />munity.
<br />The flow diagram in Figure 7 shows the
<br />components of a stormwater management
<br />system that can be linked to form a 'treat-
<br />ment train,' starting with attenuation (vol-
<br />ume reduction) at source prior to concentra-
<br />tion, conveyance, and pre - treatment. This
<br />1ea& To- °opitons such as runoff detention
<br />(holding back and slowly releasing) or re-
<br />tention (holding back total flow) for infiltra-
<br />don. Finally there are considerations for sec-
<br />ondary impact mitigation (e.g. temperature
<br />control) and maintenance.
<br />Figure 8 shows integration of these fea-
<br />tures into the landscape. In the example
<br />shown, a perennial stream and permanently
<br />flooded wetland is surrounded with a 23 m
<br />(75 ft) riparian forest buffer. A riparian area,
<br />once barien of trees, has been reforested.
<br />Stormwater conveyed through grassy swales
<br />with check darns is pre- treated in a forebay,
<br />permitting course sediment control. It is then
<br />passed into a wet extended detention basin
<br />that settles out fine suspended solids prior to
<br />release into a constructed woody wetland
<br />with infiltration trenches. Another system
<br />shown conveys piped stormwater into a
<br />forebay, permitting the separation of small
<br />storms to be infiltrated in a blossoming
<br />stormwater meadow, while bigger storms
<br />are detained and slowly released by level
<br />spreaders for discharge dispersion in the ri-
<br />parian forest buffer.
<br />All these elements combine to create a
<br />scenic setting for people, wildlife, plant
<br />communities. and water resources. This is an
<br />example of how sustainable development
<br />can achieve open space through stormwater
<br />management, while structuring growth, and
<br />. creating a function for designated open
<br />space.
<br />Conclusion
<br />Municipalities should prepare stormwater
<br />management plans and ordinances that treat
<br />stormwater as a resource. This helps to meet
<br />state and federal guidelines, protects public
<br />health and safety, and can achieve open
<br />space greenways. Stormwater management
<br />should replenish groundwater supplies,
<br />maintain the dry weather flow of urban
<br />streams through infiltration and delayed dis-
<br />charge. reduce stream warming, use vegeta-
<br />tion to utilize water pollutants as fertilizer,
<br />and reduce flooding. Management practices
<br />can be designed to be tools for conviviality,
<br />permitting cohabitation of people, plants,
<br />and wildlife. adding to the quality of life.
<br />REFERENCES CITED
<br />I. Adams. W.A.. Dove. I..F... and Leedv. L.L. 19H..
<br />Public Attitudes Toward Urban Wetlands fin-
<br />Stormwater. Control and Wildlife Enhancement.
<br />Wildlife Soc. bull. 12:299-503.
<br />2. Ferguson. B.E. 1990. Urban Stormwater I jiItm-
<br />tion, Purposes. Implementation. Results. J. Soil
<br />and Water Cons. 45(61:601 -609.
<br />3. Ferguson. B.E. 1991. Urban Stream Reclamation.
<br />J. Soil and Water Cons. 46(5).
<br />4. Galli, J. 1990. Thermal Impacts Associated with
<br />Urbanization and Stormwater Management Best
<br />Management Practices. Metropolitan Washing-
<br />ton Council of Governments, Washington, D.C.
<br />5. Maryland Department of Natural Resources.
<br />1986. Minimum Water Quality Objectives and
<br />Planning Guidelines for Infiltration Practices.
<br />Sediment and Stormwater Division, Maryland
<br />DNR. Annapolis.
<br />6. National Water Quality Inventory. 1988. 1988
<br />Report to Congress. U.S Government Printing Of-
<br />fice. Washington. D.C.
<br />7. Schueler. T. 1987. Controlling Urban Runoff.
<br />Metropolitan Washington Council Governments.
<br />Washington. D.C.
<br />8. Schueler, T.. J. Galli, L. Herson, P. Kumble and
<br />D. Shepp. 1991. Developing Effective BMP Sys-
<br />tems for Urban Watersbeds. Metropolitan Wash-
<br />ington Council of Governments, Washington,
<br />D.C.
<br />9. Tourbier, J.T.. and A. Walmsley. 1990. Mitiga-
<br />tion Measures for Adverse Environmental Im-
<br />pacts- General Plan 1990 -2010. Loudoun Coun-
<br />ty, Virginia. Draft with Lane Kendig, Inc..
<br />Philadelphia, P.S.
<br />10. Tourbier, J.T., and A. Walmsley. (In press).
<br />Stormwater Management Plan and Stormwater
<br />Ordinance for London Grove Townsbip, Pennsyl-
<br />vania. PA. Tourbier & Walmsley, Inc.
<br />11. Tourbier, J.T., and R. Westmacott. 1992 Second
<br />Edition. Urban Lakes and Ponds. The Urban
<br />Land Institute. Washington, D.C.
<br />12. U.S. Department of Agriculture. 1991. Rtpar an
<br />Forest Buffers- Function and Design for Protec-
<br />tion and Enbancement of Water Resources.
<br />USDA Forest Service. Northeastern area, Radnor,
<br />PA.
<br />13. US. Environmental Protection Agency. 1982. Re-
<br />sults of the Nationwide Urban Runoff Program.
<br />U.S. EPA. Government Printing Office, Washing-
<br />ton. D.C.
<br />14. U.S. Environmental Protection Agency. 1990.
<br />National Pollutant Discharge Elimination System
<br />Permit Application Regulations for Storm Water
<br />Discharger Final Rule. U.S. EP k, Washington.
<br />D.C.
<br />15. Wong, L.S., and R. McCuen. 1982. The design of
<br />vegetative buffer strips for runoff and sediment
<br />control. In Stormwater Management in Coastal
<br />Areas. Tidewater Administration. Maryland De-
<br />partment of Natural Resources. Annapolis.
<br />16. Year 2020 Panel of the Chesapeake Bay Execu-
<br />tive Council. 1988. Population Growth and De-
<br />velopment in the Chesapeake Bay Watershed to
<br />the Year 2020. Referred to in Conflicts of Urban
<br />Sprawl Impact Water Quality in Cbesapeake
<br />Bay - Effects of Population Growth and Develop-
<br />ment on Water Quality. US. Water News. Octo-
<br />ber. 1990. p. 7.
<br />J. Toby Tourbier of Tourbier
<br />& Walmsley, Inc.,
<br />Pbiladelpbia, Pennsylvania,
<br />19107 -2405, is a planning
<br />consultant, autbor, and co-
<br />author of a range of
<br />stormwater related
<br />documents. He is affiliated
<br />with the Department of
<br />Landscape Architecture and
<br />Regional Planning at the
<br />University of Pennsylvania,
<br />and bas been an expert
<br />witness and consultant to
<br />units of government and to
<br />developers.
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