|
|
| HOME | WHAT IS BIORETENTION | COMPONENTS | DESIGN DETAILS | SIZING METHODS | ||||
| MAINTENANCE | STATE REFERENCES | DESIGN SOFTWARE | RESOURCES | ABOUT US |
|
|
Keep up with what is going on with Bioretention! Subscribe to BioNews Bioretention News - Project features - New developments - Interviews |
The Wisconsin Department of Natural Resources has established a Conservation Practice Standard for bioretention that uses the RECARGA model. A Technical Note is also published.
The RECARGA model was developed by the University of Wisconsin – Madison Civil & Environmental Engineering Department Water Resources Group to provide a design tool for evaluating the performance of bioretention facilities, raingarden facilities, and infiltration basins. Individual facilities with surface ponding, up to 3 distinct soil layers and optional underdrains can be modeled under user-specified precipitation and evaporation conditions. The model continuously simulates the movement of water throughout the facility (ponding zone, soil layers and underdrains), records the soil moisture and volume of water in each water budget term (infiltration, recharge, overflow, underdrain flow, evapotranspiration, etc.) at each time step and summarizes the results. The results of this model can be used to size facilities to meet specific performance objectives, such as reducing runoff volume or increasing recharge, and for analyzing the potential impacts of varying the design parameters.
The model uses the Green-Ampt infiltration model for initial infiltration into the soil surface and the van Genuchten relationship for drainage between soil layers. Input facility is calculated from user specified land cover data (percent impervious area, pervious area curve numbers and the area of the facility and tributary basin) using an initial abstraction equation (for impervious areas) or the TR-55 methodology for pervious areas. Underdrain flow is calculated using the orifice equation. The model also tracks continuous soil moisture and evapotranspiration between storm events. More detail the model methodology is included in the documentation chapter of this manual.
Click here to download RECARGA. |
|
Send mail to bio@bioretention.com with
questions or comments about this web site.
|
