The Los Angeles River in 2013. Engineers turned it into a narrow concrete channel in the 1940s, after a flood destroyed homes and left 100 people dead in 1938. Steve Lyon/Flickr hide caption

itoggle caption Steve Lyon/Flickr

Homeowners can receive up to $4,000 for replacing their lawns with less thirsty plantings, in a rebate program run by the Los Angeles Department of Water and Power. iStock hide caption

itoggle caption iStock

Access to fresh water is not a given for many, including this Indian girl carrying bottles of drinking water filled from a municipal tap two kilometers from her village. Indranil Mukherjee/AFP/Getty Images hide caption

itoggle caption Indranil Mukherjee/AFP/Getty Images