flowerbug
Garden Master
if you are going to do that kind of work you can include in that a 4ft block in a U shape to have the water flow around the house. dig the trench 3.5ft and use a permanent waterproof material to construct it and fill it back in. the 6 inches above grade is your berm and then cap it with another 6 inches above the material so that it won't be disturbed. water from uphill will flow down in the ground and then seek it's way around. you may not have to do as much other digging and redirecting then. actually if you have gardens you can incorporate the flows so they are used by the gardens as during dry spells it is nice to have use of anything extra.