topic 10: storm drainage system Flashcards
What are the 6 roofing elements to collect rainwater?
- gutter
- downspout
- strainer or roof drain
- shoe
- storm line
- catch basin
____ is usually located along the entire perimeter of the roof.
gutter
___ is located every 8 to 10 meters and at every corner of the roof (but to avoid clogging of pipes, it is best to locate them every 4 to 6 meters.
downspout
Downspout is located every 8 to 10 meters and at every corner of the roof (but to avoid clogging of pipes, it is best to locate them every _____.
4 to 6 meters
____ is designed to receive water collecting on the surface of a roof and to discharge it into a downspout.
strainer or roof drain
___ is designed to prevent clogging.
strainer or roof drain
____ is at the bottom of the roof leader to direct rainwater towards the nearest catch basin.
shoe
____ connects to each catch basin.
storm line
____ downspouts should terminate in a catch basin (can serve more than one downspout).
catch basin
____ delivers water to the sewers in the street via gravity.
catch basin
_____ also collects surface water.
area-drain catch basin
_____ carries only rainwater collected from the storm drain or from the streets.
storm sewers
_____ terminates at natural drainage areas (i.e. lakes, rivers, and water reservoirs).
storm sewers
Storm sewers require manholes to serve as cleanouts and to make sewers accessible for inspection and repair built at depths of about ______; diameter ranging from _____.
2 to 3 meters, 0.6 to 1.2 meters
What are 2 rainwater pipes?
- downspouts or conductor pipes, gutters
- roof drains
_____ shall not be used as soil, waste and vent pipes.
rainwater piping
_____ sizes are based upon the maximum depth of rainfall per hour falling upon a given roof area in square meters.
downspout and gutter
An ave. ___ rainfall intensity for downspouts and gutter sizes is used around Metro Manila.
102 mm/hr
Round, square (sized to enclose its equivalent round pipe) or rectangular (shall have at least the same cross-sectional area as its equivalent round pipe, except that the ratio of its side dimensions shall not exceed ____) rainwater pipes may be used for downspouts.
3 to 1
____ for high-rise buildings shall be of stronger pipe materials to resist the high hydrostatic pressure, they shall be installed within a pipe chase, and have no intermediate branch from the roof to the ground level.
downspouts
_____ shall be equipped with dome type strainers extending 102 mm above the surface of the roof surface.
roof drains
Roof drains with a minimum total net inlet area of ____ times the area of the outlet pipe to which it is connected.
1 – ½
_____ shall be approved flat surface type, with a total net inlet area not less than 2 times the area of the outlet pipe to which the drain is connected.
roof deck strainers
_____ passing through building interiors shall be made watertight by the use of C.I. drain with integrally-cast waterstop ring around the outside of the body and placed at mid-depth of the concrete roof slab and the installation of a clamped suitable flashing material around the drain.
roof drains
What are the 3 major systems of collecting storm water?
- the independent system
- the combined system
- the natural system
____ a.k.a. “The Separate System”.
the independent system
_____ brings the collected water directly to the water reservoirs.
independent system
____ combines storm water with sanitary wastes.
combines system
____ is without using any roof gutters or downspouts.
natural system
In ____, rainwater is collected in cisterns.
natural system
