PermieWriter's Rain garden

Creating this garden solved a huge hydrological problem for us. Basically, all of our neighbors’ properties drain through our yard. When we moved here in February of 2006, the rains flooded our side yard, backed up and threatened the house’s footings.
On a dryish day, we investigated and discovered that all of the water that falls in our micro-watershed flows through a tiny gutter in our back patio and through a hole in the patio wall, by the north side of the house and from there to the gutter. The erosion was immense. The hard, clay soil allowed no water to permeate and there was no plant life in the area at all. We cleaned out the hole in the wall, dug a huge pit in the side yard around the roots of the big, non-bearing avocado tree and backfilled with a huge pile of wood chips. Nearer the patio we filled the trench with rocks so the water could flow freely and planted baby’s tears to keep the soil in place.
The garden is flourishing beyond our wildest expectations. If any water escapes (little enough, even in hard rains) it is clear and moving slowly. The avocado is setting fruit finally and the baby’s tears and marshmallow we planted are doing wonderfully.