Who wrote the book Waterfall?

There is no widely known book titled "Waterfall". It is possible you are thinking of a different book title or have misremembered the name.

Could you provide more context or details about the book?

For example:

* What is the book about? (e.g., fiction, non-fiction, specific topic)

* Who are the main characters? (if it's fiction)

* What are some key themes or ideas?

* Do you remember any specific quotes or scenes?

With more information, I might be able to help you identify the book you're looking for.