Requirements, recommendations and information for using green roofs as a BMP in the MIDS calculator
File:MIDS Calculator screen shot 1.png
MIDS calculator screen shot for green roof inputs and defaults.
Below is a summary of requirements, recommendations and other information for using the Minimal Impacts Design Standards (MIDS) calculator for green roofs. Links to MIDS pages and the MIDS calculator are included at the bottom of this page.
Contents
Model defaults
- Media holding capacity = 0.33 cubic feet per cubic feet
- Percent annual volume retained = 45%
- Phosphorus reduction (particulate and dissolved) = 0
- TSS reduction = 85%
- TSS Event Mean Concentration = 15 mg/L
Model input requirements and recommendations
Caution: The following are recommendations for inputs into the MIDS calculator
- Media depth must be 4 inches or less
- The top surface area of the green roof cannot exceed the total impervious area for the site
Information
Information: The following information may be useful in determining inputs for the MIDS calculator
- Information on green roof design
- Guidance on characteristics of different types of green roofs
- Information on green roof construction