Can we count the capacity of underground drainage pipes as the retention capacity? The pipe capacity will then add to the stormwater retention capacity.

Which formula do you use to calculate peak flow rate (1 and 2-year, 24hours). I am using NRCS (SCS) TR-55 Graphical Discharge Method. Is that recommanded?

page 95 of the LEED manual (description of case 1 - option 2) states that post development runoff rate and quantity must be below "critical values" for the relevant receiving waterways.

Hello, Our project is based on the case 2.

As part of NYC's blue roof requirement, roofs must provide 24 hour detention detention for the 2-yr design storm and an equivalent peak runoff rate equal to a curve # of approx 50 for projects disc

Can you tell me how to calculate for multiple draingage sites, i have Three on this particular project. The TC is based on the length and travel and the slope towards the discharge point .

Hi, I'm currently doing a project in Indonesia and having trouble to find the 2-year 24-hour design storm data.

Hello When following the ACP, the LEED manual states that attenuation must be undertaken through Low Impact Development (LID) and green infrastructure strategies.

The data I have to work with for filling this credit out are pre- and post-development calculations for a 100 year storm with a duration of 1 hour.