The key to getting water to drain is to have a place for it to go. Adding dirt won't change anything unless you add it in certain places. You can add dirt around a building, but you should leave a minimum of 6" from the siding to the ground, and then only if you don't have a problem with termites and are properly protected against them (LA termite country?). My suggestion to you would be to watch where the water goes when you get a lot of it, make those areas deeper, and take the dirt from those areas to the places where the water stands or around the building where you don't want it. If the elevation of the areas around you don't allow for runoff, that is a serious problem, and I can only suggest building a drainage basin plenty deep with a lot of rocks, but the basin would also require ditches and improvements. A lot of work with the D1 (shovel), a little less with a dingo.