Parking Lot Drainage Swale

A swale is a depression created in the ground that carries water runoff by gravity away from damaging your home or property.

Parking lot drainage swale.

Swales are used to capture sheet flow from a parking lot or trail surface and in most places where a ditch is traditionally used. Green parking lot facilities shall be designed per the green street standard drawings appendix k 2 4. Swales are the broad shallow channels along roads driveways and parking lots that are designed to keep water off your road. Parking lot islands curbless in a paved area with no curb pre cast car stops or a ribbon curb can be installed along the pavement perimeter to protect the swale area.

In several case studies done in portland oregon savings ranged from 4 000 to 5 500 per acre of developed area. Deicing salts can damage soil structure by reducing soils organic matter. The minimum slope for grassy swales and drainage ways is 1 percent to prevent standing water and muddy conditions. Properly maintained swales can collect stormwater runoff trap pollutants increase groundwater recharge and slow the flow of runoff thus reducing erosion.

Slopes greater than 5 percent may make the construction of special ramps for the disabled necessary. Section 1 4 2 green parking lot facilities cross section materials used in the various green parking lot facilities shall be in accordance with the green streets specifications appendix k 2 6. Stormwater drainage design for parking lots ace group llc course outline parking lots can be seen almost everywhere from shopping centers to office buildings to schools. The maximum cross slope is 2 percent.

Additions of mulch added organic matter may be required if drainage to swale is from roadway or parking lot. They are a key part of the city s stormwater drainage system. Maintenance responsibility is normally that of the owner. Stormwater drainage design is an integral component in the design of parking lots.

This application of swale should only be attempted where shallow grades allow for sheet flow conditions over level entrance areas. One of the three swale types described below are recommended as trailside drainage in place of a simple ditch for linear stormwater controls as needed adjacent to the trail. Slopes for walkways will not exceed 5 percent unless unavoidable.