MINIMUM DESIGN STANDARDS CHAPTER 9
MINIMUM DESIGN STANDARDS
INDEX OF MINIMUM DESIGN STANDARDS
Minimum Standard Structure Page Number
9.01 Energy Dissipator ...... 9.01 – 1 9.02 Grassed Swale ...... 9.02 – 1 9.03 Extended Detention (Dry) Pond ...... 9.03 – 1 9.04 Extended Detention with Shallow Marsh...... 9.04 – 1 9.05 Retention (Wet) Basin...... 9.05 – 1 9.06 Bioretention...... 9.06 – 1 9.07 Sand Filter ...... 9.07 – 1 9.08 Infiltration Trench ...... 9.08 – 1 9.09 Trash Rack ...... 9.09 – 1 9.10 Stream Protection Area Forestation...... 9.10 – 1 9.11 Wash Rack ...... 9.11 – 1 9.12 Conceptual BMP Landscape Plan ...... 9.12 – 1 9.13 Environmental Protection Area Sign ...... 9.13 – 1 9.14 Oil Water Separator ...... 9.14 – 1 9.15 Forebay...... 9.15 – 1
HENRICO COUNTY ENVIRONMENTAL PROGRAM MANUAL 9 - 1 MINIMUM DESIGN STANDARDS CHAPTER 9
MINIMUM DESIGN STANDARD 9.01 ENERGY DISSIPATOR
Definition
An energy dissipator is a device that is used to convert concentrated stormwater runoff to sheet flow and is constructed at the end of all storm sewers or channels that outfall into a buffer.
Purpose
The purpose of an energy dissipator is to introduce storm flows into the buffer at a slower rate and spread the flow over a larger area than would normally occur with a storm sewer outfall. The energy dissipator allows for more efficient use of the buffer by spreading the storm flow over a wider area of the buffer.
Design Criteria
Energy dissipators are required at the end of all storm sewers and constructed/altered channels that outfall into Stream Protection Areas. The energy dissipators must be designed and constructed according to the following design criteria. All appropriate details must be included in the approved plans.