Using a strong string and a line level, secure one end of the string at highest point and stretch the string to the point you want the wall. Use the line level to find the the height of the proposed wall. Measure the height of the level string and the ground, walla the wall height. Note: when installing the wall, make sure to use enough tie backs to keep the wall from falling down from the weight of the soil pushing on the wall.

For reference my directions are as viewed from the street looking at your house. The first pic, that's neighbor on L? The scar on R of fence is where your shed used to be? R half of 2nd pic is neighbor straight back...L half pic your yard (aiming toward neighbor with shed)? The third pic I know what is but I cannot differentiate levels. Sorry. Looks like that lot high, too? The neighbor directly straight back (w/2 large trees) looks like he's been high forever as if subd. created that way. The neighbor on you L side looks like his fill might be much newer. His grass has a new-ish look. (would have liked to seen a pic aiming further left...I'm trying to see where the drain path goes.) Aside from the water, he's dumping on you, where's the rest of his water draining? To his front? And the guy next to him (past power pole) where's his water going (other than what he's putting on you)? If the bulk of their water is going to the front...which you might be able to tell from standing in front of their houses, I'd guess one or both of them has blocked your natural flow. Which says that going to a lawyer for a consultation to discover your rights and make a plan is the place to start. Someone pointed out, what will you do with major rain like hurricane Irene type rain...or the hundred year flood? Your original plan will put you in jeopardy if such were to happen. Actually, with your drainage blocked, you're probably already in jeopardy. just won't be able to see it until that monster rain happens. I'm not trying to be an alarmist, but I think it's important to know where you stand legally...especially, if you can get the cause of your problems to pay for the solution. I would try to find out every last fact about where that water is draining...how it's draining for these neighbors...get out their during the next heavy rain. Take pictures. Make yourself knowledgeable about exactly how all these pieces of the the puzzle fit together...before going to lawyer. You don't want to go with just a few words and a complaint...to which he says, "we'll need to study your issues. That'll be $500 for our next hours worth of work." Go as prepared as you can be.

On a good day I would go out sit down in the middle of the yard and determine exactly where the water should go. Note the high spots and the low spots. Based on this survey of your back yard you can then come up with a plan to get rid of the water. I can not tell exactly from the picture but it looks like you have two trees in your yard. Picture I and III look like one tree and Picture II looks like the second tree. The second tree appears to be on the high side of your yard, It looks like there is a high spot that creates a dam that causes water to back up on your paitio. If you remove the dam, that may correct your problem. This could be done by remove the sod through the area, taking out the dirt until you are sure that the water will drain from the patio, and replaceing the sod. You must consider the thickness of the sod when you are removing the dirt. As I start the message I would sit on the ground and understand the highs and lows in your yard before I did any thing. As a last resort, you could take your problem to the town board, ask they help. My brother in law's neighbor is currently under orders from the town to fix a drainage mess he created.

Here are a few photos. In all three, one can clearly see the shape of the edge of the lawn, but not what creates it. I like this look, and it can be created with a subtly colored/camouflaged stone or brick edge. (If the photos embedded in this thread are too small, follow the link below each to get to the photo set for each and you can click on the photo there to see a larger version.) The all look to be relatively newly created and so plants will get larger and fill in over time. You don't want to overplant and create a dense thicket. Having sight lines into the woods or a path to a shady seating area under the trees would be nice. In this first one, I am not particularly fond of the abrupt in/out edges between the grass and wood, but it does have a variety of plantings of different heights, some of which are just outside the tree line and some within the trees. There are small flowering trees, some medium flowering shrubs, and low-growing groundcovers between. http://www.houzz.com/projects/29439/grand-rapids-residence In this second one, I would add plantings outside of the tree line, a combination of trees, shrubs and evergreen groundcover as I think that the transition from grass to established woods is too abrupt, but again here there is a clean edge, a combination of flowering shrubs and smaller trees set into the understory. This one, like the first photo) is taken in very early spring before the leaves fully fill out, so it is likely to look fuller/denser when there are more mature leaves. http://www.houzz.com/projects/337408/woodland-gardens In this third photo, ignore the patio in foreground and look across at the far side of the lawn. Another clear edge and a combination of ornamental small trees and shrubs that transition to denser native woods beyond. The birches were probably already there, and they cleared around them and then added the shrubs. I prefer groundcovers to the bare mulch look - more attractive and easier maintenance. http://www.houzz.com/projects/1749687/perched-lake-and-mountain-views