For centuries cities have been built near a fresh water supply. Without it we'd be lucky to live three days. But this most basic human need can be deadly too - get the supply wrong and it can poison us, get too close and it can drown us. And with every passing year the challenge of providing water to billions of people becomes harder and harder.

Streaming video file encoded with permission for digital streaming by Infobase on October 29, 2015.

Introduction: Water Works: How Cities Work --(1:10) -- Colorado River Aqueduct -- (4:41) -- Lake Mathews -- (3:02) -- Barcelona Desalination -- (4:44) -- London Gateway -- (6:05) -- Danger on the River Thames -- (5:33) -- New York Fire Department -- (6:33) -- San Francisco Sewers -- (4:53) -- San Francisco Sewer Repair -- (4:17) -- Henriksdal Wastewater Treatment Plant -- (8:31) -- Credits: Water Works: How Cities Work -- (0:37).