Having a grate over the drop box is not good, I had one until two years ago it clogged during a 7 inch rain event and water went over the dam. My house is down below. Luckily it was at crest and subsided before it did much damage. I should also think the dozer guy because the dam was so level the water cascaded over about 200 ft of the dam instead of one low area I think this helped too. I have sense built a trash rack that has 1/4 inch screen around a steel cage. The cage is wider than the drop box and extends below the surface so as to be a bottom withdrawal when the screen gets covered with trash. Here is a picture of it.




The road goes on forever and the party nevers end...............................................