Question
I have a steep driveway. On one side of the driveway (the down side) is a steep
hillside that worries me. The vegetation is brush, weeds and pampas grass. In
other words nothing I want to keep. Fearing the downside will erode and I will
lose my driveway I am thinking of rocking the hillside using 6 inch to 10 inch
diameter rocks. How do I go about this task?  Thank you for addressing this
problem

Answer
Hello,

Placing stone or what is called "rip rap" will not be effective on a slope greater than 45 degrees.

Clear the slope of all vegetation and compact the soil to a density similar to the surrounding undisturbed soil.

Layer the stone a mimimum of 9 inches thick.

Dig a keyway trench at the foot of the slope to hold the stone in place.

Lay filter fabric on the compacted slope and lay 6 inches of sand or gravel over the fabric and then lay the stone on top. The sand/gravel and fabric will aid in holding the underlying soil in place. Bury the fabric at the top of the slope and key it in at the bottom of the slope.

Install a drain at the bottom of the slope if needed to channel away water from the slope.

Planting shrubs at the top of the slope,immediately above the stone,will aid in further reducing erosion.

Good luck. Let me know if you need further help.

Mark Harshman


For more comprehensive help check out my website at:

http://www.prestoexperts.com/expert/markland