H.R.3847: To amend the Endangered Species Act of 1973 to provide for the suspension of each provision of the Act during periods of drought with respect to Federal and State agencies that manage Federal river basins that are located in each region affected by the drought.

Amends the Endangered Species Act of 1973 to provide for the suspension of each provision of the Act with respect to a federal or state agency that manages a federal river basin if the Secretary of the Army (acting through the Chief of Engineers) or the governor of the relevant state determines that: (1) a drought is in effect in the region in which the basin is located; and (2) such drought presents a threat to the health, safety, or welfare of the region's population. Terminates such a suspension on the date the Secretary or governor determines the drought is no longer in effect.