Bay County officials say the recent discoloration of the Gulf was caused by storm water runoff and not a sewage leak. Overflowing storm water from springs has been flowing into the Gulf through 10 outfalls along the beach and the changes in the color of Gulf waters was caused by tannins. Christian Wagley, the coastal organizer for Healthy Gulf, a nonprofit organization that works to restore and protect the Gulf, said tannins are naturally occurring minerals created by decayed vegetation. Wagley said the minerals are the reason so many creeks and rivers in the Panhandle have dark, tea-colored water and not harmful to swimmers.