Being from Louisiana I've handled more than my share of crawfish. Don't give the burrowing through the dam a second thought. Crawfish burrow down just to the water table normally. They spend about 75% of their life in these burrows filter feeding and exit usually to mate or if the water table moves up or down. Transporting crawfish is easy..............just keep them cool out of the sun/wind and covered with a damp cloth. Do not crowd the together in water or else they'll depete the oxygen in the water and die. Also you might consider loading them into an onion sack and tying them up tightly or else they tend to attact each other.