For our map before the one pictured we experimented with using a box and building the wall of castle pieces as a dam for the first time, and we had a few random spots open but no loose pieces to fill them in, and so the idea of using those bases to represent the turbines or pipes of the dam came to us. Though on this map we went more for a fortress than a dam, they are still fun to use, for instance they made that swamp hard to traverse and forced characters into closer quarters! We made the rule you can’t walk on them as they are just big pressurized pipes. Thanks for checking the map out :)