In another post its owner relieved that waterwheels are terrible for the environment, all the way down to coral tower! But he never shared that knowledge here. Why? Because he cares more about his profits than the plants and creatures of bilewater and mythfalls! Why am I telling you about this and not bilewater? Because the affected range was 15 rooms! The crawlake is a mere ten rooms away, so it and four more rooms would be affected by this!
If I am not mistaken, the water system that sustains Craw Lake is not connected to the end of Bilewater, not directly at least. Most of Greymoors water leaks through the stone above, leeching down from areas where water stagnates. The reason the water wheel would be so bad for Karak is because their ecosystems are heavily dependent on the faster flowing streams. Bilewater as a whole is currently more of a slow flowing sludge of pollution, in the past it was more like Myth Falls, a system of saltwater pools and streams, with the natural ancestors of the Muckroaches and other creatures.