Stormwater Management

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Stormwater Management
For Developing Municipalities
What Residents Can Do What Towns Can Do
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ACKNOWLEDGEMENTS

• CENTER FOR WATERSHED PROTECTION, www.cwp.org
• www.stormwatercenter.net
• Tom Schueler, Director of Watershed Research and
  Practice at CWP
• NEMO PROGRAM - University of
  Connecticut, http//nemo.uconn.edu/

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Development Means Less Infiltration
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Nutrients Pathogens Sediment Toxic
Contaminants Debris Thermal Stress
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Waterway Health Declines
Waterway Health Imperviousness
Imperviousness Increases
80 70 60 50 40 30 20 10 0
WATERSHED IMPERVIOUSNESS ()
DEGRADED
IMPACTED
PROTECTED
STREAM DEGRADATION
ADAPTED FROM SCHUELER, ET. AL., 1992
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MUNICIPAL ACTION

• Public Works
• Streets
• Playing Fields and parks
• Stormwater sewer system
• New Development
• Planning
• Zoning
• Maintenance

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Culvert and Outfall Opportunity for Retrofit
Scenario for erosion
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STORMWATER MANAGEMENT ORDINANCE

• For New Development

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Groundwater Recharge Requirement

• Maintain Existing (100) Average Annual
  Groundwater Recharge post development
• OR
• Infiltrate the Post Development Increase in the
  2-year Storm

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Nonstructural SWM Strategies
(should be in municipal ordinance)

• Protect areas that provide water quality
  benefits
• Minimize Separate Impervious Cover
• Maximize protection of natural drainage
  features and vegetation
• Minimize Disturbance
• Minimize Reduction in Time of
  Concentration
• Minimize soil compaction

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• Provide Low-maintenance Landscaping and use of
  native vegetation
• Provide Opportunities for Reduction of Pollutants
  at the Source
• Trash Racks and Receptacles
• Minimize Vegetation That Needs
  Fertilizers
• Use Native Plants
• Manage stormwater runoff at source

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LAND USE ORDINANCESESTABLISH DESIGN STANDARDS