Bride of the Water God, Volume 1 by Mi-Kyung Yun

When Soah's impoverished, desperate village decides to sacrifice her to the Water God Habaek to end a long drought, they believe that drowning one beautiful girl will save their entire community and bring much-needed rain. Not only is Soah surprised to be rescued by the Water God-instead of killed-she never imagined she'd be a welcomed guest in Habaek's magical kingdom, where an exciting new life awaits her! Most surprising, however, is the Water God himself... and how very different he is from the monster Soah imagined.