Lakes and Streams

I had an idea for a new update to add variety into the world, and that's a lakes and streams update. There could be new trees such as weeping willows (new wood type, and the tassels could be interesting in new recipes), new MOBS (crawfish, different fish, and dragonfly's), and I had an idea to make a special type of rock, placed in streams, which could create rapids/ fast moving water that could be reused by the player for new transportation methods