1 / 100

Pond and Wetland BMPs, Retrofitting Detention Basins

Pond and Wetland BMPs, Retrofitting Detention Basins. WET PONDS. Wet Pond Treatment Processes. Settling Plant Uptake and Adsorption Infiltration Evaporation. Wet Ponds - Criteria. Provide Quantity and Quality Control (not volume control)

makaio
Download Presentation

Pond and Wetland BMPs, Retrofitting Detention Basins

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pond and Wetland BMPs, Retrofitting Detention Basins

  2. WET PONDS

  3. Wet Pond Treatment Processes • Settling • Plant Uptake and Adsorption • Infiltration • Evaporation

  4. Wet Ponds - Criteria • Provide Quantity and Quality Control (not volume control) • Drainage Area: Minimum of 10 Acres (>25 Acres Preferred) • Treat Water Quality Volume • Retrofit Opportunities • Maintenance sediment removal Inlet & outlet vegetation

  5. Wet Ponds – Primary Design Parameters • Storage Volume Channel Protection & Flood Control • Detention Time (24-48 Hours) Water Quality • Release Rate Channel Protection & Flood Control

  6. Wet Pond – Other Design Criteria • Treat Up to 75 Acres • Include Forebay • Depth: 4-6 Feet • Geometry Affects Performance dead storage short circuiting

  7. Extended Detention Pond

  8. Wet Pond

  9. Multiple Pond System

  10. Pocket Pond

  11. Wet Pond – Hydraulic Design • Design Pond Using Acceptable Methodology • NRCS…TR55…TR20 • Penn State Runoff Model (PSRM) • Modified Rational Method • Other • Hydrograph Routing Is Necessary

  12. Wet Pond – Area Ratio Area Ratio = Drainage Area Pond Area Should Be Less Than 100 For Maximum Efficiency

  13. Wet Ponds – Pollutant Removal Sediment………….. 50-90% Total Phosphorus… 30-90% Soluble Nutrients…. 40-80% Lead……………….. 70-80% Zinc………………… 40-50%

  14. Wet Pond Criteria • Minimum Contributory Area: 10 Acres • Pretreatment: Sediment Forebay Sized to Contain 0.1 inches per impervious area • Design to Treat Water Quality Volume • Multiple Treatment Pathways Increase Performance …Multiple Cells …Pond-Wetland Train

  15. Wet Pond Criteria • Pond Benches A. Safety Bench – 6%Maximum Slope B. Aquatic Bench – Maximum Depth 18” Below Normal Pool 6. Provide for Maintenance Access

  16. Types of Wetlands • Shallow Wetland • Extended Detention Wetland • Pond-Wetland System • Pocket Wetland

More Related