Parking Lot Drainage Calculations

Thanks to the services that well constructed parking lots provide businesses can strive for goals while giving vehicular access to employees and customers without the added obstacle and stress that poorly designed parking facilities tend to cause.

Parking lot drainage calculations.

The runoff q for the roof area in drainage zone a is. A minimum slope of 0 4 percent 0 004 ft ft shall be used for the paved surfaces. See user guide for more information. Surface drainage for a parking lot consists of slopes gutters and inlets.

Topography and soil drainage determines whether complex typical or simple cost curves apply. Desirable gutter grades should not be less than 0 5 percent 0 005 ft ft for curbed pavements with an absolute minimum of 0 3 percent. Space is available under the pavement and at the perimeter of the parking area select level 1 permeable pavement discharging to a conservation area with partial a b and c d soils located. Drainage area a 29 940 ft2 available space.

A particular pipe size on a given grade will only carry a certain amount of water. 524 爀刀椀猀攀爀 匀椀稀攀㨀 㠀 屲horizontal drainage piping 爀瀀椀瀀攀 䀀 㨀 㠀 屲pipe 2. 1 00 x 1 5 x 500 96 23 7 79 gallons per minute. 104th parking garage 1 plumbing plan underground plumbing finished floor 100 0 underground storm drain horizontal draining piping sizing 爀刀愀椀渀昀愀氀氀 刀愀琀攀㨀 㐀 栀 gpm.

The runoff for the grass portion of drainage zone a is. Parking lots with grades flatter than 0 4 percent are subject to ponding and are candidates for installing underground storm sewers. The steeper the grade of the installed pipe the more water it will carry. Water is probably the greatest cause of distress in a paved structure.

Drainage area size. The units on peak runoff rate q are actually acre in hr but the conversion from acre in hr to cfs is very nearly one so the more common unit cfs is tyically used for q. The calculator assumes that the infiltration rate from the basin is the same as for site s native soil. A six step guide to parking lot design access to quality parking is one of the foundational needs of commercial america.

Q cia where q is the peak surface runoff rate in cfs from a watershed of area a acres and runoff coefficient c due to a storm of intensity i in hr. Notice that even though the grass area is nearly 2x that of the roof the roof runoff is nearly 2x that of the grass area. Checks the capacity of drain tile on existing drainage systems. Street or parking lot that is replaced with permeable pavement.

0 gallons per minute gpm 0 cubic feet per second cfs. Multiply across each row. To achieve adequate drainage a slope between 2 and 5 is recommended for paved surfaces in a parking lot. Sizes the piping needed on the acreage to be drained.

0 35 x 1 5 x 900 96 23 4 91 gpm.