Rain Gardens Are Great, Except When Blocked By Excessive Mulch
Rain gardens are an environmentally-friendly way to handle water runoff, rain water runs into an area where it gets absorbed into the soil. Well, assuming the water doesn’t get blocked.
The newly rebuilt North Tucker Boulevard has numerous rain gardens, but unfortunately many are like the one shown above — not able to function as designed because too much mulch blocks the water.
— Steve Patterson
I dunno, I experiment with water & run-off solutions quite a bit here at the house. Mulch can be awesome due to its ability to absorb massive amounts of water & release over a period of time. It should prevent standing water, not create it. I would think that there should be some sort of swale at the beginning there to trap some water. The stones laid out seems to reduce the force of the water & control volume. Native plant would help a ton, and prevent erosion. Maybe they used so much mulch as a stop gap until plants can be established?
These have been in place for 18 months, the height of the mulch is keeping water out of many of them.