Floods

Flooding is the most common and costliest natural hazard facing the United States. Over the last 30 years, floods have caused an average of $8 billion in damages and 82 deaths per year nationwide.

Basics

A flooded farm field. Image Copyright © Michael Collier. http://www.earthscienceworld.org/images

Flooding has many causes, including heavy rain, snow melting too fast, and dams or levees breaking. Coastal flooding occurs during hurricanes from heavy rainfall and storm surge, which causes sea level to rise temporarily at the shore.   Read more

Frequently Asked Questions

National Oceanic and Atmospheric Administration
U.S. Geological Survey
American Geosciences Institute

Latest News

NASA hurricane satellite image
(2017-09-14)
August 29, 2017 In anticipation of Hurricane Harvey making landfall on the Gulf Coast, the U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), and National Aeronautics and Space Administration (NASA) were preparing for the massive storm by monitoring its...
NASA hurricane satellite image
(2017-05-18)
April 18, 2017 The Weather Research and Forecasting Innovation Act (H.R.353) was signed into law by President Trump on April 18. This law prioritizes U.S. leadership in weather forecasting and research by authorizing new forecasting programs and support existing programs. The bill primarily focuses...
Flooding webinar postcard. Image Credit: AGI
(2017-02-07)
Join hundreds of attendees from around the world for an in-depth discussion on assessing, mitigating, and communicating flood risk tomorrow, Wednesday, February 8, 2017 at 1:00pm EST. Register here. More info below.   This webinar features experts from federal and state government, who will...
Screenshot of the Marine Cadastre National Viewer. Image Credit: NOAA, BOEM
(2016-09-30)
The American Meteorological Society (AMS) Policy Program’s workshop, “Opportunities and Needs in Integrated Water Prediction, Risk Assessment, and Management for Coastal Resilience,” concluded on September 28th, providing insights to coastal scientists and managers on how to better serve their...
Screenshot of the USGS Coastal Change Hazards Portal map
(2016-09-29)
On September 27th and 28th, our Critical Issues intern attended a workshop hosted by the American Meteorological Society (AMS) Policy Program: “Opportunities and Needs in Integrated Water Prediction, Risk Assessment, and Management for Coastal Resilience.” The first day focused on resilience issues...
Interactive map of Texas Gulf shoreline change rates. Image Credit: Bureau of Economic Geology, University of Texas
(2016-09-23)
#MapOfTheDay! Today the Critical Issues Program (@AGI_GeoIssues) shared an interactive map of shoreline change rates along the Texas Gulf Coast from the Bureau of Economic Geology at the University of Texas Jackson School of Geosciences (@txgeosciences), which you can find at http://bit.ly/1GoF214...
August 2016 Statewide Precipitation Ranks. Image Credit: NOAA
(2016-09-21)
The National Oceanic and Atmospheric Administration (NOAA) held their latest Monthly Climate Briefing on September 15, 2016, and we have summarized the highlights for you below: •  August 2016 is the 17th warmest (73.6°F, 1.5°F above average), 2nd wettest August (3.47", 0.85" above average) since...
NASA hurricane satellite image
(2016-08-25)
August 16, 2016 The National Oceanic and Atmospheric Administration (NOAA) recently launched its National Water Model (NWM), a new hydrologic model that the agency claims will yield the “biggest improvement in flood forecasting the country has ever seen.” The new model will allow NOAA’s National...
(2016-06-09)
AGI's Geoscience Policy Program published the May 2016 Summary of federal-level legislation impacting the geoscience community. This includes continuing appropriations discussions in both the House and Senate for funding in FY 2017 for agencies that employ geoscientists, studying geoscience...
IES Water Glyph
(2016-04-26)
April 21, 2016 The American Water Resources Association (AWRA) Policy Committee released the second volume of their report, “Proactive Flood and Drought Management”. As in Volume I, Volume II presents detailed case studies of efforts on local and regional scales to prepare for and mitigate the...

Case Studies & Factsheets

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Introduction Dry wells improve stormwater drainage and aquifer recharge by providing a fast, direct route for rainwater to drain deep into underlying sediment and rock. Dry wells are most common in the western U.S. where clay or caliche layers slow down the natural drainage of water into...

CI_Factsheet_2017_4_drywellbasics_170906_thumb.JPG

What is a Dry Well? A dry well is a well that is used to transmit surface water underground and is deeper than its width at the surface (see image, below). Most dry wells are 30 to 70 feet deep and 3 feet wide at the surface. They are lined with perforated casings and can be filled with gravel...

Pre-Ike (left) and post-Ike (right) ASTER imagery of Galveston Island, the Bolívar Peninsula, and the mainland in August 2006. Healthy (red) and dead (brown) vegetation shows storm surge inundation effects. Image Credit: Jesse Allen, NASA Earth Observ.

Defining the Problem Hurricanes bring not only intense rainfall, but also high winds and flooding. This flooding is powered by the hurricane storm surge: a rise in coastal sea level caused by lowered barometric pressure and by wind blowing the ocean onto the land. The result is that waves and...

Research Database Publications

Cover of fs2016-3025 ; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
Managing the urban-water cycle has increasingly become a challenge for water-resources planners and regulators faced with the problem of providing clean drinking water to urban residents. Sanitary and combined sanitary and storm sewer networks convey wastewater to centralized treatment plants....
Cover of Flooding factsheet; Image credit: The Geological Society
2016, The Geological Society of London (GSL)
How many types of flood are there? Why does flooding happen, and how can we protect ourselves? This fact sheet, produced for a broad general audience, gives an overview of flooding categories, and how we can mitigate their effects.
Cover of PP1617; Source: USGS
2000, U.S. Geological Survey (USGS)
Rapid spilling of 22 acre-feet of water down the steep, 3-mile channel of Ophir Creek killed one, injured four, and destroyed or damaged five houses. Flow evolved into debris flow enroute, and compounded in volume over 30 times.
Cover of PP1821: Source: USGS
2015, U.S. Geological Survey (USGS)
Flooding in the Northeastern United States during 2011 was widespread and record setting. This report summarizes peak streamflows that were recorded by the U.S. Geological Survey (USGS) during separate flooding events in February, March, April, May, July, August, and September. The flooding of late...
Cover of O-2015-05; Source: Oregon Department of Geology and Mineral Industries (DOGAMI)
2015, Oregon Department of Geology and Mineral Industries (DOGAMI)
The objective of the Clatsop County coastal flood hazard project is to develop updated Digital Flood Insurance Rate Maps (DFIRM) and Flood Insurance Study (FIS) report for Clatsop County, Oregon (Figure 1-1). For this effort, the Oregon Department of Geology and Mineral Industries (DOGAMI) will be...
Cover of fs2016-3027 ; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
As a Federal science agency within the Department of the Interior, the U.S. Geological Survey (USGS) collects and disseminates streamflow stage and discharge information along with other types of water information as a major part of its Water mission area. Data collected at USGS streamflow-gaging...
Cover of fs2016-3073; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
The Souris River Basin is a 61,000 square kilometer basin in the provinces of Saskatchewan and Manitoba and the state of North Dakota. Record setting rains in May and June of 2011 led to record flooding with peak annual streamflow values (762 cubic meters per second [m3/s]) more than twice that of...
Cover for USGS FS 2013-3108 ; Source: USGS
2014, U.S. Geological Survey (USGS)
Flood-frequency analysis provides information about the magnitude and frequency of flood discharges based on records of annual maximum instantaneous peak discharges collected at streamgages. The information is essential for defining flood-hazard areas, for managing floodplains, and for designing...
Cover of SP-047; Source: Oregon Department of Geology and Mineral Industries (DOGAMI)
2015, Oregon Department of Geology and Mineral Industries (DOGAMI)
The objective of the Tillamook County coastal flood hazard project is to develop a digital flood insurance rate map (DFIRM) and flood insurance study (FIS) report for Tillamook County, Oregon (Figure 1-1). A parallel effort is underway to convert the existing Tillamook County Federal Emergency...
Cover of fs2016-3023 ; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
Urbanization affects streamflow characteristics, coastal flooding, and groundwater recharge. Increasing impervious areas, streamflow diversions, and groundwater pumpage are some of the ways that the natural water cycle is affected by urbanization. Assessment of the relations among these factors and...