Consultation and Installation Service
Groundwork New Orleans is available to businesses, residents, and neighborhoods for consultation and installation services, providing site specific advice; advice plus project management; advice and an installation kit; or total installation.
For more information please contact Alicia Neal. Raingarden Installation Instructions
Raingarden Installation Instructions
The size, soil and plant composition, and accompanying features of a raingarden depend on many criteria including the property ownership and location of a potential site. However, there are some installation basics.
A raingarden should be no smaller than one-fifth (1/5) the area of impervious surfaces – roofs, sidewalks, street – from which it is collecting. A typical New Orleans Shotgun house of 1850 sq ft with four downspouts should have four 92.5 sq ft raingardens.
Ideally, a raingarden should be twice as long as it is wide to capture as much water as possible as the water moves downhill.
Locate the source of water like a gutter downspout or street and its terminus like a drain or muddy area of your yard. A raingarden can be located anywhere along the natural path water would move across the site. Where water already ponds is great, except if that spot is at a building foundation! Then it is important to convey the water to a new site with a hose, pipe, or gravel path.
Soil Composition and Depth
-The raingarden should be 6” – 9” lower than existing grade, dropping off slowly to allow for a temporary ponding zone during rain events.
-A top layer of mulch is optional, but recommended.
-The infiltration zone should be 16” – 36” deep. It is comprised of a roughly 40% compost, 40% existing soil, and 20% sand, depending on the properties of existing soil. This is the soil in which your plants will grow.
-Below the growing medium should be 12” - 16” of pea gravel and crushed rock. This section allows for the raingarden to hold a large amount of water over time, but below the surface where mosquitoes breed and below the zone where plant roots would be affected.