How does LEED SSc6.1 calculate "Imperviousness"?

Greetings Our project is a 30 year old building undergoing a Major Renovation and will be registered as LEED-NC v2009. In calculating pre- and post-development runoff, do we consider the pre-develo

Folks: We have a project (existing imperviousness > 50%) where we have calculated that through a combination of green roof, pervious pavers, landscaped open space, and a rainwater cistern we ca

Dear All We are the construction materials manufacturers.

My project features raised green roof beds (6" deep soil) located directly downstream from a tin roof.

site is on the river. I assume this doesn't change anything, but civil engineer asked I check to see if LEED has exceptions for this.

Dear all, We have found a sample calculation to determine storm water rate and quantity for 1 yr-24 hr design storm and 2 yr-24 hr design storm from www.illinoisfloods.org/.../4D_Stormwater%20Volum

In case 1, we are required to perform a site run off calculation for 1 yr-24 hr design storm and 2 yr-24 hr design storm for both pre- and post- development period.

your comment above states: Is it an acceptable strategy to capture the rainwater into tanks and discharge it into the public sewers after the rainstorm reducing the peak discharge?

Michael DeVuono, I've digged through both forum 6.1 and 6.2 but didn't found international data for Design Storm. I am doing a project in Russia.