I've attached a plan for what I would do if it were up to me to the landscaping around the pool. Sorry I can't be there for better explanation, but I think for about $5000 this area can be drastically improved and it will remain low maintenance and not require irrigation. I think it will also help fix some of the problems with areas where water pools and mulch washes onto walkway.
One note I forgot to add in was that any dirt and ground cover that is removed could be placed along back of building 1 (units 1-8) to help with erosion problem.