Old House Journal
A GOOD GRAVEL PATH
Landscape contractor Marilee Kuhlmann and landscape architect Tom Rao, of Urban Water Group, designed and built the gravel paths for water-wise drainage. Here is their procedure.
When we walk, drive, or move equipment over soil—or even just roll a trash can over the ground—we compact the soil. Compaction limits the infiltration of rainwater into the soil. A gravel path can be permeable if the soil under the path is minimally compacted. Eco-Rain cells or another recycled paver product is used to disperse weight over a larger area, which lessens soil compaction. A two-inch Eco-Rain device, made of recycled plastic, creates a more stable walking surface than would loosely laid gravel on soil. It can be installed for ADA compliance. Water is held in the gravel-filled chamber and slowly infiltrates the soil. The cost is approximately $8 to $15 a square foot depending on the materials used. Gravel needs edging to hold it in place; recycled material is more economical than steel or stone edging.
We excavate for a path a depth of 2 ¾ to 3 inches, then level the area, install the edging, and place an Eco-Rain drainage cell system on the soil. No weed barrier is used. The cell device is approximately 9 square feet and is cut to fit; the cost is about $30. We backfill the cell device with cheap, crushed stone to a ¾" inch depth. Crushed stone with sharp edges has more water-holding void space compared to rounded stone. We top with a
¾" layer of decorative gravel, which covers the last ¼" inch within the cells, then more gravel to cover the top of the device. The ¼" to ½" remaining in the excavated space limits stone from traveling or popping out of the path. urbanwatergroup.com