i always try to have 50' of spillway lenth or more with a berm on the inside to keep the water from eating on the back toe. i try to make it level side to side and dropping only a inch or two downstream. i choose the most natural side to achieve this so that i dont have to disturb the grass to get it done. i control the elevation and downstream drop with the berm.
ok this is starting to make sence to me now
were the dam runs into the hill side it is going to run the water off at a slower pace then strait down the back of the dam
