Stormwater Roof Drainage Design

Native beds established on the green roof at dpr s five borough building on randall s island.

Stormwater roof drainage design.

Separate storm and sanitary drainage systems water may accumulate on the roof because of building design and a building storm drainage system is installed which will consist of a primary and a secondary system. Slowing down water flow to reduce flooding or erosion problems downstream retaining water on the property for use in gardens as a natural filtration system. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. Stormwater drainage design modern storm water design focuses on three important areas.

This form of roof drainage is preferred if a clean exterior appearance is desired. A typical commercial or multifamily residential building will utilize one of the following types of primary roof drainage. Stormwater is then carried away to either a collection point or to the graded area around the building and flows naturally away from the building. Often the floor plan of a building is designed then a roof is fitted over the plan.

Many factors affect how quickly water drains off a roof if water drains completely and if the roof is watertight. A roof drainage system usually comprises gutters eaves and downpipes. Through dep approval of sew er certifications approval that the city sew er can accept the proposed discharge and.