Hydrology is a Batwoman storyline published as part of The New 52. Following the timeline reboot in Flashpoint, it establishes her continuity in the DCnU. This is the debut arc of J.H. Williams III and W. Haden Blackman on their Batwoman series, continuing the character's story from the end of her last run in Detective Comics by Greg Rucka. This is following Rucka's Cutter storyline and followed by Williams' To Drown the World storyline.