one of my customers has asked me for an estimate for a small wall and i want to make sure i am going about things correctly before i finalize anything. its hard to describe, but they have an above-ground pool with a slope that is about 4 feet away from the pool and goes about a third of the way around. the slope is about four to five feet high at one end, and it gradually slopes down as it curves till it is level with the yard. it is shady and nothing will grow there, so it has become a muddy eyesore. my plan of action was to dig back into the slope so that the wall will be about three feet high at the highest end, and end up level with they yard at the other end. the wall is going to follow the curve of the slope, so it will be a partial circle shape if you can picture what im saying. he has a gutter drain pipe that he wants me to hide behind the wall. (a french drain, i think, right?) the pipe is the kind that has holes in it for drainage, so i was going to replace it with a solid pipe so it wont erode the back of the wall. my questions are: 1. can i forgo the solid pipe and put drainage gravel around the slitted one, and if i do that, i would have to put fabric on the back of the wall, so soil won't wash through, correct? or should i do that no matter which pipe i use? 2. i was going to bury the first course, is that necessary with a 3 foot wall? and should i put compacted sand or crusher run under the first course or just compact the soil? 3. finally, they want those blocks from home depot, is there anything special i need to know about those? i notice that the way the blocks fit together, each course is a little bit further back than the one below it, so do i need to start the wall out a few inches and then backfill behind it? thanks for any help or insights, your a dumbass don't try this, etc.