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**Construction specifications
 
**Construction specifications
 
**Information on operation and maintenance
 
**Information on operation and maintenance
 
 
*3 foot separation from the bottom of the bioretention system to seasonal high water table
 
*Use most restrictive infiltration rate within 3 feet of the bottom of the BMP
 
*Drawdown time of 24 hours for trout streams
 
*For measured infiltration rates, apply a safety factor of 2 (2.5 for permeable pavement)
 
*Pretreatment
 
#Recommend
 
*5 acre or less for contributing area
 
*Maximum ponding depth of 18 inches, reduced to 6 inches if there is no site information (4 feet for infiltration basin)
 
*Field tested infiltration rates over table values
 
#Information – provide links to the following
 
*Guidance on determining infiltration rates
 
*Information site constraints (shallow soil, karst, etc.)
 
*Information on assessing BMPs
 
*Information on design metrics (high flow bypass, ponding depths, drawn down)
 
*Guidance on pretreatment
 
*Information on soil mixes
 
*Plant information, including species list that show water tolerance, potential effects of different species on infiltration rates, planting guidance
 
*Construction specifications
 
*Information on operation and maintenance
 

Revision as of 16:24, 6 May 2013

  • Required
    • 3 foot separation from the bottom of the bioretention system to seasonal high water table
    • Use most restrictive infiltration rate within 3 feet of the bottom of the BMP
    • Drawdown time of 24 hours for trout streams
    • For measured infiltration rates, apply a safety factor of 2 (2.5 for permeable pavement)
    • Pretreatment
  • Recommend
    • 5 acre or less for contributing area
    • Maximum ponding depth of 18 inches, reduced to 6 inches if there is no site information (4 feet for infiltration basin)
    • Field tested infiltration rates over table values
  • Information – provide links to the following*Guidance on determining infiltration rates
    • Information site constraints (shallow soil, karst, etc.)
    • Information on assessing BMPs
    • Information on design metrics (high flow bypass, ponding depths, drawn down)
    • Guidance on pretreatment
    • Information on soil mixes
    • Plant information, including species list that show water tolerance, potential effects of different species on infiltration rates, planting guidance
    • Construction specifications
    • Information on operation and maintenance