Designing An Ordinance To Promote Low-Impact Development
Key Features:
1. A standard of no net runoff from new development. (An appropriate
standard would be replication of pre-development runoff characteristics
during a 2- year, 24-hour storm event.)
2.
Flexibility for developers to use a wide range of non-structural, low-impact development practices to reduce runoff.
3. Revision of outdated requirements that interfere with low-impact
development practices or promote greater levels of impervious surface,
including requirements for excessively wide streets, large setbacks or
traditional stormwater infrastructure.
Ordinance Should Promote:
• Reduced impervious surfaces
• Preservation of 60 percent of natural habitat on-site
• Innovative site and building design
• Increased on-site stormwater retention using native vegetation
• Predevelopment hydrologic functions over full range of rainfall intensities and durations
Examples:
• Lacey, Washington – Zero Effective Drainage Discharge Ordinance (Word file)
• Warsaw, Virginia – Low Impact Development Stormwater Management Policy (PDF)
More Resources:
• Prince George’s County, Maryland: Low-Impact Development Design Strategies (PDF)
• Puget Sound Action Team: Low-Impact Development: Technical Guidance Manual for Puget Sound (PDF)
• Stafford County, Virginia: Stormwater Management Design Manual (PDF)
• Puget Sound Action Team: Natural Approaches to Stormwater Management (PDF)
• Natural Resources Defense Council: Out of the Gutter: Reducing Polluted Runoff in the District of Columbia (PDF)