SWMM - LID Controls - Permeable Pavement

Permeable pavement - are excavated areas filled with gravel and paved with porous concrete or asphalt mix. Paving block systems consist of waterproof paving blocks placed on a bed of pea gravel or sand with a storage layer of gravel below

Schematically:

• SWMM
  • Storage
    • Storage Height - Gravel layer thickness or Rain Barrel height
    • Clogging Factor - Total volume of treated runoff required to completely clog the bottom of the layer divided by the void volume of the layer
    • Voice Index - The volume of void space in relation to the volume of solids in the layer
    • Infiltration rate - The rate at which water penetrates the native soil below the layer
  • Deep Drain
    • drainage Coefficient - The drainage coefficient (C) and the exponent (n) determine the flow rate through a drain as a function of the height of the water stored above the drain displacement li>
    • Control Curve - The name of an optional control curve that adjusts the calculated drain flow as a function of the head of water above the drain
    • Exponent - The drainage coefficient (C) and exponent (n) determine the rate of flow through a drain as a function of the height of stored water above the drain displacement< b>q = C * h ^ n
    • Opening Level - The height in the Drain's Storage Tier that causes the drain to automatically open when the water level rises above it.
    • Closing Level - The height in the Drain Storage Tier that causes the drain to automatically close when the water level drops below it
    • Offset - This is the height of the drain line above the bottom of a storage layer or rain barrel
    • Wait Time - The number of hours of dry weather that must elapse before the drain line on a rain barrel opens
  • Floor
    • Floor Thickness - The volume of void space in relation to the volume of solids in the floor for continuous systems or for the fill material used in modular systems
    • Clogging Factor - Number of void volumes of the treated runoff pavement layer that is required to completely clog the pavement
    • Fraction Regenerated - The fractional degree to which pavement permeability is restored when a regeneration interval is reached
    • Voice Index - The volume of void space in relation to the volume of solids in the floor for continuous systems or for the fill material used in modular systems
    • Regeneration Interval - The number of days that the pavement layer can fill before its permeability is restored, normally by vacuuming its surface
    • Permeability - Permeability of concrete or asphalt used in continuous systems or hydraulic Conductivity of filler material (gravel or sand) used in modular systems
    • Impermeable Surface - Ratio of waterproof paving material to total area for modular systems
  • Pollutant Removal - Specifies the removal rates for each pollutant Note: Do not repeat the pollutant and do not leave the value at zero
  • Soil
    • Field Capacity - Volume of pore water in relation to total volume after soil drains completely
    • Hydraulic Conductivity - Hydraulic Conductivity for fully saturated soil
    • Conductivity Slope - Slope of the curve of log (Conductivity) versus soil moisture content (dimensionless)
    • Thickness - Thickness of the soil layer
    • Wilting Point - Volume of pore water in relation to total volume for a very dry soil, where only bound water remains
    • Porosity - The volume of pore space in relation to the total soil volume
    • Suction Potential - The average value of soil capillary suction along the wetting front
  • Surface
    • Vegetable Coverage - Vegetal Coverage
    • Slope - Surface slope
    • Side Slope - Slope of the side walls of a cross section of a ditch
    • Storage Depth - Storage Depth
    • Surface Roughness - Roughness