Update: I figured out why my garden kept flooding after 3 dry summers in a row
I used to just let water run off wherever it wanted, but after that big storm last May in Edmonton, my whole vegetable patch turned into a swamp for two days. Turns out I needed to dig a simple 2-foot trench along the low side and route it to a dry well I made from an old barrel. Has anyone else tried those rain garden kits from the local hardware store or is it better to just wing it with your own design?
Have you thought about using a perforated pipe inside that rock trench to move water faster? I did something similar in my yard, but I lined the trench with landscape fabric first to keep the silt from clogging everything up. That barrel dry well trick works way better than a standard french drain in my experience, especially in heavy clay soil.