Homar Velazquez, resource efficiency manager with the U.S. Army Reserve at Fort Buchanan, Puerto Rico, explains the workings of potable water system in a clinic at Fort Buchanan. The water is collected on the roof of the clinic, drained into large tanks and then chlorinated. Puerto Rico has a high average yearly rainfall, and the clinic's potable water system can provide potable water to the clinic for 14 days independently if needed.