Maps.
(Removed for requote)
Could you post the raw numbers for Guajira? Its residents are being affected by Hurricane Matthew, with some areas seeing the heavy rainfall after years of drought. The Washington Post anticipated this -
https://www.washingtonpost.com/national/hurricane-matthew-drenches-coastal-colombia/2016/10/01/e34fa784-8803-11e6-ac72-a29979381495_story.html With such heavy rainfall along the coast, that could have been the deciding factor. Guajira voted yes at 65%, but only had 15% turnout, unfoundedly due to the hurricane.