Cameron Hamilton, who briefly led the agency on an acting basis last year but was fired for contradicting the president, also said he would get money out to states faster.

Cameron Hamilton, who briefly led the agency on an acting basis last year but was fired for contradicting the president, also said he would get money out to states faster.

© Mariam Zuhaib/Associated Press

A prolonged drought means the nation’s largest reservoirs are dwindling, and litigation over access to water could lie ahead.

A prolonged drought means the nation’s largest reservoirs are dwindling, and litigation over access to water could lie ahead.

© Nina Riggio for The New York Times

A decade-old treatment plant in San Diego County, Calif., could leave more water in the Colorado River for states facing severe shortages.

© Sandy Huffaker for The New York Times

A decade-old treatment plant in San Diego County, Calif., could leave more water in the Colorado River for states facing severe shortages.