My attempt at a backyard rain garden flooded my patio last spring, here's what I figured out
I built a small rain garden in my side yard in Portland last April to catch runoff from the roof. Thought I followed all the YouTube guides, dug it about 6 inches deep, filled it with gravel and native plants. First big storm came and water just sat there for three days, then overflowed right onto my neighbor's walkway. Turns out I didn't check how compacted my clay soil was under the gravel, so nothing drained. I had to rip it all out, dig down 2 feet, and mix in sand and compost before replanting. Cost me an extra $90 in materials and a whole Saturday. Anyone else hit a snag like this with their first drainage project?