water. Ensure that selected plants can also tolerate dry periods, as bioretention soils are typically have a high sand content and are dry between rain events. Precedents (with comments): Infiltration basins: NCDENR Stormwater BMP Manual Chapter16: Infiltration Devices, Revised: 07-23-09: The storage volume must completely draw down to the seasonally high water table under seasonally high water conditions within 5 days Wisconsin Department of Natural Resources. 2004. Infiltration Basin (Acre-Feet) (1003) Conservation Practice Standard. Maximum ponding depth 24 inches Maximum surface pool drawdown time: 24 hours Bioretention: NCDENR Stormwater BMP Manual Chapter 12: Bioretention, Revised: 07-24-09: Ponding depth shall be 12 inches or less. Nine inches is preferred. Puget Sound 2012 LID Manual: Maximum ponding depth for bioretention 12 inches Maximum surface pool drawdown time: 24-48 hours Virginia DCR. 2010. Stormwater Design Specification No. 9. Bioretention. Version 1.7. Micro-Bioretention (Rain Garden) Design Criteria1 Level 1 Design (RR 40 TP: 25) 2 Design (RR: 80 TP: 50) Maximum Ponding Depth = 6 inches Bioretention filter or basin 1 Design (RR 40 TP: 25 ) Level 2 Design (RR: 80 TP: 50) Maximum Ponding = 6 to 12 inches 2 Maximum Ponding = 6 to 12 inches 2 Micro-Bioretention or Rain Gardens. These are small, distributed practices designed to treat runoff from small areas, such as individual rooftops, driveways and other on-lot features in single-family detatched residential developments. Inflow is typically sheet flow, or can be concentrated flow with energy dissipation, when located at downspouts. Bioretention Basins. are structures treating parking lots and/or commercial rooftops, usually in
water. Ensure that selected plants can also tolerate dry periods, as bioretention soils are typically have a high sand content and are dry between rain events. Precedents (with comments): Infiltration basins: NCDENR Stormwater BMP Manual Chapter16: Infiltration Devices, Revised: 07-23-09: The storage volume must completely draw down to the seasonally high water table under seasonally high water conditions within 5 days Wisconsin Department of Natural Resources. 2004. Infiltration Basin (Acre-Feet) (1003) Conservation Practice Standard. Maximum ponding depth 24 inches Maximum surface pool drawdown time: 24 hours Bioretention: NCDENR Stormwater BMP Manual Chapter 12: Bioretention, Revised: 07-24-09: Ponding depth shall be 12 inches or less. Nine inches is preferred. Puget Sound 2012 LID Manual: Maximum ponding depth for bioretention 12 inches Maximum surface pool drawdown time: 24-48 hours Virginia DCR. 2010. Stormwater Design Specification No. 9. Bioretention. Version 1.7. Micro-Bioretention (Rain Garden) Design Criteria1 Level 1 Design (RR 40 TP: 25) 2 Design (RR: 80 TP: 50) Maximum Ponding Depth = 6 inches Bioretention filter or basin 1 Design (RR 40 TP: 25 ) Level 2 Design (RR: 80 TP: 50) Maximum Ponding = 6 to 12 inches 2 Maximum Ponding = 6 to 12 inches 2 Micro-Bioretention or Rain Gardens. These are small, distributed practices designed to treat runoff from small areas, such as individual rooftops, driveways and other on-lot features in single-family detatched residential developments. Inflow is typically sheet flow, or can be concentrated flow with energy dissipation, when located at downspouts. Bioretention Basins. are structures treating parking lots and/or commercial rooftops, usually in
Bioretention_task_8_design_specs.docx