We recently completed this patio, planting, and lighting project in Elkins Park. Due to the size of the patio we were required to install stormwater management (SWM). This is becoming more commonplace when applying for a permit that involves the increase of impervious surface.
Typical options to address stormwater management are installing a rain garden or a seepage bed. For this project we installed a seepage bed since the back yard is not that large and our client didn’t want to give up play space to install a rain garden. In general a seepage bed is a hole excavated to a specific length, width, and depth. The pit is then lined with a geotextile fabric to separate the stone from the soil keeping the void space in the stone. Pipes are then run from existing downspouts or drains to the pit. Large stone (ANSI #1 ) is then used to fill the pit to within 6″ to 1′ of the surface. The stone gets covered with additional fabric then soil is backfilled. The simple concept is the water from a downspout or drain is stored in the voids between the stones and eventually seeps back into the ground preventing runoff that adds to localized flooding. Whether or not SWM is required for a project will depend on the local municipality and the size or area of impervious surface being added to the site.
After the SWM was taken care of we were able to get on with the patio. The patio was constructed with full color flagstone with a brick border and walkway that matched the brick used on the landing by the door. Conduits and wiring for the lighting were run prior to installing the patio so we could get our lights where they needed to be. After the patio was complete we wrapped up the project with a 3 trees and a number of shrubs. We will be back in the spring to finish installing all the perennials that will add the color.