SWMM - LID Controls - Bio-Retention Cell

Filtration catchments - or bio-retention cells are depressions that contain vegetation grown in an engineered soil mix placed above a gravel drainage bed. They provide storage, infiltration and evaporation of both direct rainfall and runoff captured from surrounding areas.

Schematically:

• Identification
  • Name (Name, String) - identifies the LID control
    Avoid names that are too long, or that contain the following characters: '*', '>', '<', '/', '\', '"', ':', ';', '|', '=', '`', '#', ',', '?'
  • Description (Description, String) - informational text informationl
• SWMM
  • Storage (LidStorage, SwmmLidDataStorage)
    • Storage Height (StorageHeight, Double) - Gravel layer thickness or Rain Barrel height
    • Clogging Factor (CloggingFactor, Double) - Total volume of treated runoff required to completely clog the bottom of the layer divided by the void volume of the layer
    • Void Ratio (VoidRatio, Double) - The volume of void space in relation to the volume of solids in the layer
    • Infiltration rate (SeepageRate, Double) - The rate at which water penetrates the native soil below the layer
  • Deep Drain (LidDrain, SwmmLidDataDrain)
    • Drainage Coefficient (FlowCoefficient, Double) - 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
    • Control Curve (ControlCurve, ObjectId) - 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 (DrainExponent, Double) - 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 q = C * h ^ n
    • Opening Level (OpenLevel, Double) - The height in the Drain's Storage Tier that causes the drain to automatically open when the water level rises above it
    • Closing Level (ClosedLevel, Double) - The height in the Drain Storage Tier that causes the drain to automatically close when the water level drops below it
    • Offset (DrainOffset, Double) - This is the height of the drain line above the bottom of a storage layer or rain barrel
    • Wait Time (DrainDelay, Double) - The number of hours of dry weather that must elapse before the drain line on a rain barrel opens
  • Pollutant Removal (PollutantRemovals, ListSwmmRemoval) - Specifies removal rates for each pollutant
    Note: Do not repeat the pollutant and do not leave the value at zero.
    • Removal Parameters (Removal, Double) - Allows specifying the degree of pollutant removal by an LID control, considering the flow leaving the unit through its underdrain system.
      Therefore, it applies only to LID practices that have underdrains (bioretention cells, permeable pavements, infiltration trenches, and rain barrels)
  • Soil (LidSoil, SwmmLidDataSoil)
    • Field Capacity (FieldCapacity, Double) - Volume of pore water in relation to total volume after soil drains completely
    • Hydraulic Conductivity (Condutivity, Double) - Hydraulic Conductivity for fully saturated soil
    • Conductivity Slope (CondutivitySlope, Double) - Slope of the curve of log (Conductivity) versus soil moisture content (dimensionless)
    • Thickness (SoilTickness, Double) - Thickness of the soil layer
    • Wilting Point (WiltingPoint, Double) - Volume of pore water in relation to total volume for a very dry soil, where only bound water remains
    • Porosity (Porosity, Double) - The volume of pore space in relation to the total soil volume
    • Suction Potential (SuctionHead, Double) - The average value of soil capillary suction along the wetting front
  • Surface (LidSurface, SwmmLidDataSurface)
    • Vegetable Coverage (VegetalCover, Double) - Vegetal Coverage
    • Slope (SurfaceSlope, Double) - Surface slope
    • Side Slope (SwaleSlope, Double) - Slope of the side walls of a cross section of a ditch
    • Storage Depth (BermHeight, Double) - Storage Depth
    • Surface Roughness (SurfaceRoughness, Double) - Roughness