I thought I saw that the posts were going to be buried and set in concrete to a depth greater than their exposed height above grade. The terminology of parts used is foreign to me and since I don't do wood walls, I'm not offering a professional opinion of how sound I think the wall will be. My gut says the posts will be sturdy enough, but that the horizontal wood members are too thin and will bulge after not too much time. Double that thickness, at least, seems more appropriate. Insofar as having "no posts supporting each end of it" [per my suggestion] I don't think that's the case as there is a post supporting the end of each primary wall. That support carries through from the primary wall to the diagonal piece, which is "keyed in" as well as being attached by a spike and held in place by earth pressure. However, if the posts eased out of position over time (which, of course, would never happen!) then the corner intersection of the wall could split apart. As I said, however, I think the horizontal pieces (which we would basically call 2 x 4's -- I think -- are too thin and weak for building a retaining wall. I've seen such used before and they bulge. Using them requires a much tighter post spacing. Being thin, they are also likely to succumb to rot much earlier than a stout member.) Regarding the latest proposal, I think appearance would be the problem. The rectangular milled lumber profile introduced where all other vertical members are round posts ... well, it would look like a band-aid from the start. I think doing the same thing with just another post like you are already using would look much better. I don't even think people would say you messed up. If you are concerned about symmetry, you could even add a third post (on the other side of the corner post, placed around corner at 90*) in order to have is seem like a planned design detail. It wouldn't seem strange, I don't think, to have it look like you are beefing up the corner.

Boulder retaining walls are pretty common here, especially in older neighborhoods where properties are raised from the street. Generally these rockeries are comprised of pretty large boulders (2 and 3 man boulders) and are fitted rather tightly together and have a great deal of structural integrity. Some of them have been in place for 60+ years. Without seeing a photo of your situation to see how the wall was constructed and the gaps in between, it's difficult to be precise on suggestions but these rockeries are generally planted with early blooming, low spreading plants ("rockery" plants) like aubrieta, creeping phlox, rock cress, saxifrage, helianthemums, lithodora and the like. Often sedums or hens and chicks are planted in the pockets between the rocks, as they require minimal soil for rooting and like the drainage and reflected heat the rocks provide. Pretty much any alpine-type plant is suited to these conditions.

Well I am seeing a structural engineer tomorrow. I will update with the recommendations, which will most likely be demo and re-do. To clarify the primary concrete contractors were away and the workers demonstrated pure incompetence by failing to follow the plans and pouring before inspection occurred. Concrete was poured in untamped sand as a weird attempt at a footing I guess but it is loose, unformed, without rebar crossties, and extends only about three inches horizontally. The 65' wall is 2' tall at one end and 4' tall at the other end of the yard. This is the "no footer issue." The 8' wall is only 4' long and is designed to house the reservoir and backsplash for the spill on a water feature. There is a 4' x 4' platform that should have had rebar connected to the wall. Hope this clears up any confusion as I originally posted this in two threads. Thanks!

Yardvaark - Sorry for the confusion however, the area of concern is best shown in the first picture. Walking down the center steps you run into the dirt area on the lower section which runs width of the property. I'm looking for ideas on what others would do if they had this yard area. Landscape contractor was suppose to level and grade this area but I still had no idea what to do with it. The rest of the pictures were so people could see overall area. Lazy_Gardens - Thick layer of mulch was one thought we had as well. The side eroding will have a dry river bed from the top down to the property line to channel water to the creek.