The Mid-Atlantic United States flood of 2006 was a significant flood that affected much of the Mid-Atlantic region of the eastern United States. The flooding was very widespread, affecting numerous rivers, lakes and communities from Upstate New York to North Carolina. It was widely considered to be the worst flooding in the region since Hurricane David in 1979. It was also one of the worst floodings in the United States since Hurricane Katrina in August 2005. At least 16 deaths were related to the flooding.

Lake Needwood is a 75-acre (300,000 m2) reservoir in Derwood, Maryland, United States. Located east of Rockville, in the eastern part of Montgomery County, it is situated on Rock Creek. The lake was created by damming Rock Creek in 1965 with the goal of providing flood control and reducing soil erosion. Lake Needwood also protects the water quality of the creek by functioning as a retention basin to trap sediment from storm-water runoff.