Parking Lot Drainage Calculations

To achieve adequate drainage a slope between 2 and 5 is recommended for paved surfaces in a parking lot.

Parking lot drainage calculations. The calculator assumes that the infiltration rate from the basin is the same as for site s native soil. A particular pipe size on a given grade will only carry a certain amount of water. The equation that is the centerpiece of the rational method is. A minimum slope of 0 4 percent 0 004 ft ft shall be used for the paved surfaces.

0 35 x 1 5 x 900 96 23 4 91 gpm. The runoff for the grass portion of drainage zone a is. Drainage area size. Topography and soil drainage determines whether complex typical or simple cost curves apply.

A six step guide to parking lot design access to quality parking is one of the foundational needs of commercial america. Surface drainage for a parking lot consists of slopes gutters and inlets. 0 gallons per minute gpm 0 cubic feet per second cfs. 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.

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. 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. Street or parking lot that is replaced with permeable pavement. The runoff q for the roof area in drainage zone a is.

Water is probably the greatest cause of distress in a paved structure. Sizes the piping needed on the acreage to be drained. Multiply across each row. 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.

The prinsco drainage calculator estimates the capacity of tile drainage systems. 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. Parking lots with grades flatter than 0 4 percent are subject to ponding and are candidates for installing underground storm sewers.

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. Drainage area a 29 940 ft2 available space. 1 00 x 1 5 x 500 96 23 7 79 gallons per minute. The rational method equation.

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.