Under the Lake by Stuart Woods

Under the Lake - John Howell's life is in the pits.  His latest novel has not been accepted by any publishing house and his marriage is over, just waiting for the declaration.  Denham White, his brother-in-law has found him a project ghost writing an autobiography and is lending his cabin in Sutherland, Georgia to write the book.

Sutherland is run by the man who has created the lake and town by flooding the previous valley where Irish immigrants had settled.  Howell is almost immediately faced with the ghost of a little girl, an outcast family that knows before he does his needs, and a reporter who has taken a job in the local sheriff's office because she believes the sheriff is corrupt.