Waterfall and Water Placement

Waterfall changes the usual water-bucket expectation: you cannot place a new water source just anywhere. Water must be manually spread from a naturally generated liquid body.

Plan around the source

Build canals, farms, mills, and decorative waterfalls beside a natural lake, river, or ocean edge.
Start the waterworks at that natural body and spread the water manually to the place you need it.
If a bucket refuses to create water in a dry, isolated location, that is the mod working as intended. Move the build closer to a natural source instead of planning around free water placement.

This is a placement limitation, so choose the source and route before building the rest of the project. For current behavior and updates, see Waterfall on ModDB.