Lot "A" and "B" are on a slope with "A" uphill from "B". To level the yard Lot "A" builds a brick retaining wall 19" tall on the property line of "A" and "B". "A" then fills the area with dirt and plants trees, shrubs, and grass. Water freely flows from the base and under B's driveway to the point that over time it needs total replacement. "A" claims that it was B's responsibility to provide proper draining for A's runoff. B's home was built two years prior to "A". What is the ruling in King County?