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.

The new york city department of environ mental protection dep is responsible for the city s drainage plan and stormwater management. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. 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. Roof drainage design by greg burn 1 october 2009 build 114 the roof on a new building needs to be more than just aesthetically appealing and able to keep the building weathertight it must also effectively collect and dispose of rainwater.

A typical commercial or multifamily residential building will utilize one of the following types of primary roof drainage. 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. 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.

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. Stormwater drainage design modern storm water design focuses on three important areas. Through dep approval of sew er certifications approval that the city sew er can accept the proposed discharge and.