Built a rain garden after the city raised my stormwater fee by $40 a year

All the blogs said to dig it 6 inches deep but my clay soil just turned into a pond that killed every plant I put in. Ended up digging it 2 feet deeper with a gravel base and now it drains in 4 hours has anyone else had to ignore the standard depth for heavy clay?

2 comments

2 Comments

simon_wood7210d ago

Read a study from some university extension that said clay soil needs a MINIMUM of 12 inches of gravel base to actually drain right. The standard 6 inch depth they push for sandy loam is just wrong for us clay folks. I dug mine 18 inches deep with a perforated pipe running out to a dry well and it finally stopped flooding my lawn.

ross.angela10d ago

I've had the opposite experience actually. I live in an area with heavy clay and tried the deep gravel approach years ago. It just turned into a muddy mess and the gravel ended up sinking down and clogging anyway after a few seasons. What finally worked for me was a shallower trench, maybe 8 inches of clean 3/4 inch stone, with the pipe wrapped in filter fabric and the whole thing sloped properly. Sometimes it's more about the slope and the outlet than the depth of gravel.