Ep 15. A Watershed Moment!

Ash and his friends come across a river that they need to cross in order to continue their journey. They attempt to do so, but find that the current is too strong and they are unable to make it to the other side. While discussing what to do next, they meet up with a group of Pokémon trainers who are experts in water-type Pokémon. The trainers suggest that they take a detour and head upstream to find a place where the river is calmer. Once they arrive at this location, they discover that it is the source of the river and that something is causing the water to become polluted.

The group decides to investigate the source of the pollution, and they eventually discover a factory that is dumping waste into the river. They try to shut down the factory, but the owner refuses to comply. Ash and his friends then come up with a plan to stop the pollution by using water-type Pokémon to clean up the polluted water. The plan works, and the river is restored to its natural state.

As they continue their journey, Ash and his friends become more aware of the impact humans can have on the environment. They vow to do their part to protect nature and the Pokémon that live within it. The episode ends with the group continuing their journey, determined to make a positive difference in the world.