This is my patch adding the item 'scroll of flood'. (I threw together a quick version, and Dylan O'Donnell sent me an email within a couple hours of my post with lots of details I missed/fixes. Thanks!:)
Anyway, the scroll causes a magical wave of water to come crashing through the dungeon around where you're standing. It's one of those things you don't always want to happen, but it could be useful in the right time and place.
Download the updated patch (version 4) here.
Find spoily details on the scroll here.