Water Tales, book 2: Indigo
Alice Hoffman2002

Oak Grove is a dry, dusty town haunted by the memories of a past flood. Everyone dreads water--everyone except two brothers, Trevor and Eli McGill. Nicknamed Trout and Eel for their darting quickness and the thin webbing between their fingers and toes, the boys dream of the farthest seas and of a mysterious past they only half remember. In helping them reach their hearts' desire, Martha Glimmer, the boys' fierce and loyal friend, is intent on running away from memories of her old life--before her mother died, before her father lost himself in grief, before her heart was broken. Little do Martha, Trout, and Eel know that running away will leave them on a journey back to their own true natures.