We do lots of work for local HOAS & MUDs around Austin. We are constantly paid to repair similar areas by the HOA or MUD. Is this wall a private wall owned by you or is it HOA owned? Hopefully its HOA owned, but sound like not. So if is owned by you was it installed by an engineered construction plan, either during your initial house construction or after the fact? I hope it was engineered or you may be opening up a can of worms if not. Id befriend the HOA prez, take him out for a drink or golf. Become buddies. Then later mention your wall. HOAs have tons of money for maintenance or for screwing over their members if needed. Looks like the wall is a structural retaining wall and is failing due to the runoff and or lack of design on your wall. Water drainage areas like that are common in neighborhoods but should not cause wall failures. Maybe hire an engineer on the down low to see what he thinks. Sucks to be in your spot. HOAs are notorious for being pains in the ass, but know the right board member and they may build you a new wall on their dime.