On August 28, 2005, Waterford shut down due to Hurricane Katrina approaching and declared an unusual event,[5] the least-serious of a four-level emergency classification scale.

On August 29, 2021 the plant declared an “unusual event″ — its lowest level of emergency — after the facility lost offsite electrical power.

[10] Waterford is operated by Entergy Nuclear and is owned by Entergy Louisiana, Inc.[2] The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.

[12] The 2010 U.S. population within 10 miles (16 km) of Waterford was 75,538, an increase of 7.4 percent in a decade, according to an analysis of U.S. Census data for msnbc.com.

[13] The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Waterford was 1 in 50,000, according to an NRC study published in August 2010.