Sand Diggers and the Strongman

A powerful torrent during the high rains, Rio Las Canas is a trickle of muddy water from October to May. It begins ten kilometers from the city center, carving its way north past volcanic slopes, eventually feeding into the large, man-made reservoir that separates government-held terrain from contested zones. But there is no fighting between government and guerrilla forces where the river begins—only the taking of sand from its shores.

Homes made of dried mud and bamboo shafts dot ...