Normally to have a swim in the pool it requires water. The pool has to be filled with clean water for one to dunk in and start swimming.
Well it seems to be a new trend in town where not necessarily a pool has to have water in it for a dog to have fun. And that is what this cutie here is trying to tell us. Look at his face smiling and filled with joy. It is obvious he is having a blast swimming in that empty pool.