I need to grade a road to the bottom of a property, but the road access intersects a water runoff zone channeling from the neighbors driveway. How do I properly redirect the water using swales underneath the road?
Excavate about 18" deep across the road, outsloping about 4%. Compact the soil in the hole. Place large drain rock and smaller aggregate in the hole, compacting every 6". Finish with a nice coat of gravel. Depending on how much water you need to pass and the shape of the drainage you are crossing is how wide (or long?) your "low water crossing" should be.
Invasive plants are Earth's way of insisting we notice her medicines. Stephen Herrod Buhner
Everyone learns what works by learning what doesn't work. Stephen Herrod Buhner
The first principle of permaculture is Observation.
Have you seen what happens to that area during a heavy rain?
Invasive plants are Earth's way of insisting we notice her medicines. Stephen Herrod Buhner
Everyone learns what works by learning what doesn't work. Stephen Herrod Buhner
I understand that swales are not always a good option on steep slopes due to the risk of slips. Further down the slope looks less, but it is difficult to tell from the photo.