My barn sits in the corner of a field in a low spot. When it rains hard, water comes underneath the walls on two sides. I have dug an 18 inch ditch around those two sides that will empty into a small stream that runs down the property line. The soil is about 50/50 clay/loam mix. Can I fill this ditch with larger rock back to ground level or do I need to build some sort of bridges to get in and out of the barn?