I have an iron fence that runs about 77 feet down from my yard to a lake on both sides of my yard. one side has grass beneath the metal rails. the other had dirt. we have had so much rain, and the water funnels right down along the fence line. the fence along the side with no grass now is about 6 to 8 inches above the ground because the water has streamed through it, taking all the dirt away. the open space is about 8 inches wide and deep. i need to put grass down. can i put rocks on the bottom three inches, fill the rest with dirt (best kind) and plant grass on the top? also, where the water funnels down from the street to the lake is like a swamp for days after it rains, is there something i can lay down to absorb the water? plants? anything? thanks.