Drainage issues behind retaing walls

[andersman02]

Alright so we have a long time customer of ours who has been having us do some small landscape jobs lately (company just started hardscapes and softscapes, been complete fertilize/pestide/herbicide company before i graduated) and she has been having this problem with her retaining wall.....

- wall was built around 7 years ago, builder used sufficient drainage on all walls
- all of the walls and down spouts drain to this spot
- all the walls eventually drain to the same spot
-Spot gets extremely flooded during any rain and for a few days after

If you look at the picture, the spot where the mulch and wall gets flooded, all the way to the right of the edging and about 10ft into the yard.

a few years back someone put in a french drain and the right side (cant see, with 2 drains where the water enters with it daylighted way in the back yard in a wooded area.
It should be noted that just beyond the wooded area is a pond

My question is she really wants to figure out a way to stop this area from flooding, I feel one of the only ways to do this is put in a larger french drain and increase the grade but she wants something not as drastic......

My first thought was to take out 2 of the spruce trees she has along the right (cant see, theres a line of them going back to the wooded area) that are dying very fast due to the amount of water, and replacing with something that can withstand and help take up some of that water, along the lines of a willow or river birch

Then i thought this may be a good place to put in a rain garden/ small retention pond

My question i guess is would it be ok to have the rain garden start at the retaining wall? My concerns is grading a good amount from the wall may take awayfrom the integrity of the base under the retaining wall, but i would hate to have a strip of grass then start the rain garden

Any ideas how to solve this?

[TurnerLandscape]

why not just cut about 3 feet off of the existing pipes and connected them to 4" corregated pipe which you can then bury beneath the turf, so that the water drains past this area?

[Duekster]

Dry creek bed design.... with some drainage in it too.