Second film by Hideo Nakata to be based on a novel by Koji Suzuki. He previously directed Ring (1998) and its sequel Ring 2 (1999).
Isao Yatsu, who plays Kamiya, also appeared in Ringu 2 (1999), inspired by the works of Hideo Nakata.
The story this film is based on isn't actually called Dark Water. The actual short story this film is based on is Floating Water, the first story featured in the book Dark Water, which is simply a collection of short stories written by Koji Suzuki all relating to water. This film was simply named after the entire collection.