Hurricane Jeanne September 2004: Flood Magnitude
	James River Basin
	Scientists map the areal extents of floods and assign recurrence intervals using streamflow data collected by the USGS and the Virginia Department of Environmental Quality since the late 1800s. Recurrence intervals express the likelihood that an event, such as a flood, will occur in any given year. For example, a 100-year-flood has a 1% chance of occurring in any year, and a 25-year flood has a 4% chance of occurring in any year.

USGS--Water Resources of Virginia                                                 Contact: GS-W-VArmd_webmaster@usgs.gov U.S. Department of Interior, U.S. Geological Survey Privacy Statement Disclaimer Accessibility URL://va.water.usgs.gov/floodwatch/h_jeanne/v_james_jeanne.htm      Last modified: 09/30/04 01:03:05 PM