I bought a house where the entire yard is on a grade. I paid a landscaper to grade the yard, spread topsoil and hydroseed. Two hours after he left, we got two inches of rain in 40 minutes. I now have a yard full of large ruts where the water washed out. I am trying to fix the yard in pieces since it is 1.5 acres. I spread 2 yards of topsoil, put down seed, and starter fertilizer in one section of the yard. The next day all of the topsoil was gone as we had another downpour. How do I get rid of these ruts, when the soil keeps washing away?!?! Please help, as I am tired of spending money and busting my butt, to wake up and find it all in the street.