Engineering Question
What Is Stormwater Drainage?
Building stormwater drainage collects rain from roofs and area drains and conveys it to the storm sewer or an approved point of discharge.
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Michael K. Frempong, PE, LEED AP
President & Principal Engineer, BEED Engineering
Michael K. Frempong is a professional engineer and LEED AP accredited professional with over 20 years of experience in consulting engineering. As President & Principal Engineer at BEED Engineering, he leads the firm’s MEP design and consulting work for laboratory, healthcare, industrial, data center, education, commercial, municipal, and other building projects throughout Florida.
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Stormwater drainage for buildings collects rainwater from roofs, canopies, and some areaways and conveys it through leaders and building storm drains to an approved discharge. It is separate from sanitary waste. The engineer sizes roof drains, overflow drainage, and piping for local rainfall intensity and coordinates outlets with civil site design.
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Building storm drainage versus site stormwater
Building storm drainage is a plumbing system: roof drains, overflow drains, leaders, and the building storm drain.
Site stormwater is typically civil: inlets, pipes, ponds, and outfalls.
The two systems must meet at a coordinated discharge point.
Main components
- Roof drains and overflow / secondary drainage
- Vertical leaders
- Horizontal storm piping
- Cleanouts
- Discharge to civil storm or an approved location
This is distinct from the sanitary waste system.
Design issues in Florida
- High rainfall intensity
- Flat roofs and limited structure depth
- Coastal wind and overflow scupper detailing
- Coordination with canopies and enclosed courtyards
See plumbing engineering in Brevard County and Treasure Coast.
When to involve an engineer
Involve an engineer for new roofs, reroof projects that change drain locations, additions, and any interior leader replacement. Undersized overflow drainage is a structural concern.
Common Questions
Does the MEP engineer design site ponds and inlets?
Site stormwater is usually civil engineering. The plumbing engineer designs the building roof drainage and the storm piping leaving the building.
Why are overflow drains required?
If primary roof drains clog, overflow drainage prevents overloading the roof structure.
Filed under Plumbing Engineering
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Related Questions
What Is Plumbing Engineering?
Plumbing engineering is the design of domestic water, sanitary waste, storm drainage, and specialty piping systems for buildings.
What Is a Sanitary Waste System?
A sanitary waste system carries wastewater from fixtures through waste and vent piping to the building sewer and public or private treatment system.
What Is Commercial Domestic Water Design?
Commercial domestic water design sizes cold and hot water supply, heaters, pumping, and backflow protection for building fixtures and equipment.
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BEED Engineering is an MBE professional consulting engineering firm based in Palm Bay, Florida, providing mechanical, electrical, plumbing (MEP) design and consulting engineering services for commercial, institutional, healthcare, laboratory, industrial, and other facilities throughout Florida. BEED Engineering is a firm you can trust to get the job done.
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BEED Engineering designs building storm drainage coordinated with architecture, structure, and site civil work.