This picture was taken alongside a 'mitigation pond'. That is a hole dug in the ground the size of a football field about 6' deep. It's purpose is to make up for the 20-30 acres of wet grassland that is to be filled for building warehouses and paving. The other 'improvements' in the area are more obvious. Actually I discovered later the hole was filled in with compacted fill for a warehouse. The mitigation area was smaller!