A flood is an overflow of water that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health.
A floodplain or flood plain or flood-plain is an area of land adjacent to a stream or river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge. The soils usually consist of clays, silts, and sands deposited during floods.
A 100-year flood is a flood event that has a 1 in 100 chance of being equaled or exceeded in any given year.
The Federal Emergency Management Agency (FEMA) is an agency of the United States Department of Homeland Security, initially created under President Jimmy Carter by Presidential Reorganization Plan No. 3 of 1978 and implemented by two Executive Orders on April 1, 1979. The agency's primary purpose is to coordinate the response to a disaster that has occurred in the United States and that overwhelms the resources of local and state authorities. The governor of the state in which the disaster occurs must declare a state of emergency and formally request from the President that FEMA and the federal government respond to the disaster. The only exception to the state's gubernatorial declaration requirement occurs when an emergency or disaster takes place on federal property or to a federal asset—for example, the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, or the Space Shuttle Columbia in the 2003 return-flight disaster.
Lake Delton is a man-made freshwater lake in Sauk County in central Wisconsin. For much of 2008, it was a mostly empty lake basin after a portion of a county highway that forms part of the dike wall eroded on June 9, 2008, under the pressure of floods in the area. The resulting washout caused the lake to empty, leaving behind only rainwater pools and the flow from Dell Creek. By March 2009, major repairs to correct the problem were completed, and the lake was allowed to refill. Minor repairs were expected to continue after that time, but the lake is now completely refilled and has been usable since Memorial Day weekend of 2009.
Emergency management is the organization and management of the resources and responsibilities for dealing with all humanitarian aspects of emergencies. The aim is to reduce the harmful effects of all hazards, including disasters.
Flood insurance denotes the specific insurance coverage against property loss from flooding. To determine risk factors for specific properties, insurers will often refer to topographical maps that denote lowlands, floodplains and floodways that are susceptible to flooding.
The National Flood Insurance Program (NFIP) is a program created by the Congress of the United States in 1968 through the National Flood Insurance Act of 1968. U.S. Congress has the twofold purposes of the NFIP to share the risk of flood losses through flood insurance and to reduce flood damages by restricting floodplain development. The program enables property owners in participating communities to purchase insurance protection, administered by the government, against losses from flooding, and requires flood insurance for all loans or lines of credit that are secured by existing buildings, manufactured homes, or buildings under construction, that are located in the Special Flood Hazard Area in a community that participates in the NFIP. U.S. Congress limits the availability of National Flood Insurance to communities that adopt adequate land use and control measures with effective enforcement provisions to reduce flood damages by restricting development in areas exposed to flooding.
Mitigation is the reduction of something harmful or the reduction of its harmful effects. It may refer to measures taken to reduce the harmful effects of hazards that remain in potentia, or to manage harmful incidents that have already occurred. It is a stage or component of emergency management and of risk management.
Hazus is a geographic information system-based natural hazard analysis tool developed and freely distributed by the Federal Emergency Management Agency (FEMA).
The National Flood Insurance Act of 1968 is a piece of legislation passed in the United States that led to the creation of the National Flood Insurance Program (NFIP).
In environmental engineering, the flood mitigation involves the management and control of flood water movement, such as redirecting flood run-off through the use of floodwalls and flood gates, rather than trying to prevent floods altogether. It also involves the management of people, through measures such as evacuation and dry/wet proofing properties. The prevention and mitigation of flooding can be studied on three levels: on individual properties, small communities, and whole towns or cities. The costs of protection rise as more people and property are protected. The US FEMA, for example, estimates that for every $1.00 spent on mitigation, $4.00 is saved.
Urban runoff is surface runoff of precipitation created by urbanization. This runoff is a major source of flooding and water pollution in urban communities worldwide.
Flood control methods are used to reduce or prevent the detrimental effects of flood waters. Flood relief methods are used to reduce the effects of flood waters or high water levels.
A flood opening or flood vent is an orifice in an enclosed structure intended to allow the free passage of water between the interior and exterior.
Coastal hazards are physical phenomena that expose a coastal area to risk of property damage, loss of life and environmental degradation. Rapid-onset hazards last over periods of minutes to several days and examples include major cyclones accompanied by high winds, waves and surges or tsunamis created by submarine earthquakes and landslides. Slow-onset hazards develop incrementally over longer time periods and examples include erosion and gradual inundation.
A Special Flood Hazard Area (SFHA) is an area identified by the United States Federal Emergency Management Agency (FEMA) as an area with a special flood or mudflow, and/or flood related erosion hazard, as shown on a flood hazard boundary map or flood insurance rate map. Areas within the SFHA are designated on the flood insurance rate map as Zone A, AO, A1-A30, AE, A99, AH, AR, AR/A, AR/AE, AR/AH, AR/AO, AR/A1-A30, V1-V30 or V.
The Homeowner Flood Insurance Affordability Act of 2014 was a United States Congress bill that would have delayed the increases in flood insurance premiums that were part of the Biggert–Waters Flood Insurance Reform Act of 2012. The reforms from that law were meant to require flood insurance premiums to actually reflect the real risk of flooding, which led to an increase in premiums. At the time of the bill, the National Flood Insurance Program was $24 billion in debt.
The Homeowner Flood Insurance Affordability Act of 2013 is a bill that would reduce some of the reforms made to the federal flood insurance program that were passed two years prior. The bill would reduce federal flood insurance premium rates for some properties that are sold, were uninsured as of July 2012, or where coverage lapsed as a result of the policyholder no longer being required to maintain coverage.
The combination of topographic and climatic factors in the Tulsa, Oklahoma area have frequently caused major flash flooding, especially near streams that normally drain the area. The city was founded atop a bluff on the Arkansas River. Thus, elevation protected most of the inhabitants and their possessions from damage when the river flooded. However, by the turn of the 20th Century the population growth had moved closer to the river, and the flatlands west of the Arkansas had begun to develop as well. The floods typically caused widespread property damage and sometimes death. By the 1920s, seasonal floods of the Arkansas began to cause serious damage and loss of life. Since its founding, city leaders had responded to such events by simply rebuilding and replacing the property that had been destroyed in situ. Not until 1970 did the city government begin developing strategies to mitigate floods or at least minimize property damage and prevent loss of life. This article describes some of the more notable floods in Tulsa, then the mitigation and control strategies that evolved from them.
