P-1114.1 General. A green roof drainage system receiving storm water discharge solely from a green roof shall be engineered in accordance with this Section and the design, submittal, approval, inspection and testing requirements of Section 316.1.
P-1114.2 Green Roof design. Green roof designs shall comply with Section 1101.7. Support for the weight of the green roof system shall be accounted for in the building structural design and prepared by a licensed design professional for all new building construction and alterations or retrofits to existing structures.
P-1114.2.1 Green roof rainfall rates. The green roof drainage system shall be designed based on the reduced rainfall rate in accordance with Section 1106.1 only where approved through the Philadelphia Water Department and satisfy the design, installation and maintenance requirements set forth by the Philadelphia Water Department stormwater management regulations and, if applicable, the City of Philadelphia Zoning Code.
P-1114.3 Green Roof Drains. Roof drains serving green roofs shall conform to requirements of Chapter 11 and be protected with a means to prevent sediment and debris from entering the storm drainage piping system, including provisions for roof drain access for general maintenance.