By Randolph R. Sleight PE, PLS, F. ASCE

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By Randolph R. Sleight PE, PLS, F. ASCE
Integrating LID Techniques February 1, 2006

of Snohomish County
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NPDES
NPDES

• Draft Phase I National Pollutant Discharge
  Elimination Permit and what this means to Phase 1
  2 Permittees.

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2005 DOE Manual
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2005 PSAT LID Manual

• May require new ordinance or processes like
• Reduced Drainage Demonstration Project
• A stand alone LID ordinance like a draft prepared
  by AHBL Consultants
• A modified version of the above to fit the unique
  soils and topography of a City or UGA
• A recognition of LID in the Comprehensive Plan
  and Fully Contained Communities (FCC)
• A streamlined process for schools that are now
  required to use LID and Sustainable Development
  in their Master Planning

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LID Definition

• The technical guidance manual defines LID as a
  stormwater and land development strategy applied
  at the parcel or subdivision scale that
  emphasizes conservation and use of the on-site
  natural features integrated with engineered,
  small scale hydrologic controls to more closely
  mimic pre-development hydrologic functions.

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Inventory and Assessment

• Soils analysis
• Hydrologic patterns and features
• Native forest or land cover
• Wetlands, streams or critical areas
• Floodplains
• Topography
• Slope stability and infiltration proximity to
  steep slopes

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Incentives