Flood damage can be significantly reduced when development is not placed in harm’s way or is appropriately protected from flood hazards. Properly managed floodplains can increase property values and expand recreational opportunities, while reducing direct and indirect costs associated with flood hazards, erosion, and stormwater; improving groundwater recharge and water quality; and providing valuable wildlife habitat. Current flood data is important for community officials and the private sector to make wise land use decisions. The primary tools used to identify flood risk and manage development in flood hazard areas are Flood Insurance Studies and Flood Insurance Rate Maps. The Floodplain Management Program works with the Federal Emergency Management Agency (FEMA) and other partners to obtain and use the best data to create and update these essential tools. Each year, program staff work with nearly 200 communities to provide federal flood hazard mapping and risk data and assist with adopting compliant flood damage regulations. The Floodplain Management Program also serves as the state repository for flood data; coordinates efforts of federal, state, and local agencies involved in flood loss reduction programs; and, as Ohio’s coordinator of the National Flood Insurance Program, assists communities in gaining and maintaining eligibility for participation in the NFIP for the benefit of residents and business owners. Eighty-six of Ohio’s 88 counties and more than 660 cities and villages have chosen to manage their floodplains by voluntary participation in the NFIP.
Environmental, Economic and Public Importance
Floods cost more in lives and property damage than all other natural hazards combined. Even if we don’t live in a flood hazard area, we all bear the cost of flood damages. In Ohio, floods happen nearly every year and can happen in every county. While only 15 percent of the land area in Ohio is designated as federally identified Special Flood Hazard Area (SFHA), Ohio’s SFHAs contain more than 130,000 structures, valued at more than $11 billion. Additionally, nearly 26% of flood damage claims come from structures outside the designated SFHA. FEMA estimates that residents and business owners save $4 for every $1 invested in flood risk reduction efforts.
The Mission of the Floodplain Management Program is to provide leadership to local governments, state agencies, and interested parties toward cooperative management of Ohio's floodplains to ensure the reduction of flood damage and the recognition of the floodplain's natural benefit. This mission is accomplished through technical assistance, public awareness, education, and development / protection standards.
Floods are a fact of life along streams & rivers. Floods occur when streams overflow their banks & spill onto the adjoining land area, called a floodplain. Loss of life & property damage can result when people build in floodplains. No county in Ohio is free from the threat of flooding. The location & severity varies according to weather & ground conditions. Large floods in Ohio, such as those experienced in 1913, 1937, 1959, 1963, 1964, & 1969 have caused billions of dollars worth of property damage & the loss of many lives. Even smaller floods wreak havoc such as the June-1990 flooding along Wegee & Pipe creeks in which 26 people perished or the March-1997 flooding along the Ohio River that resulted in 20 deaths (5 in Ohio) and thousands of dollars of damage.
What is Being Done About Flood Damage?
In an effort to reverse the trend of rising flood damage, local, state, & federal agencies have undertaken a variety of programs that can be grouped into three general categories:
A. Keeping flood waters away from people & buildings by:
1. Constructing dams, levees, & floodwalls
2. Enlarging or altering stream channels
3. Decreasing runoff through land treatment measures
B. Keeping people & buildings away from flood waters by:
1. Floodplain regulations
2. Purchasing floodplains to maintain flood capacity
3. Flood Warning systems & preparedness planning
C. Reducing the cost of flooding to individuals through:
1. Flood Insurance (Fact Sheet 92-13 Facts about Flood Insurance may be viewed as an online web page or as a 43k PDF file.)
2. Flood Disaster Relief
3. Tax Adjustments
The Regulatory Floodplain
The first step in planning a floodplain management program is to determine the size of the flood against which we want to be protected. From this we can determine the area that would be covered by such a flood or, in other words, the size of the floodplain that we wish to regulate. This becomes the regulatory floodplain.
The 100-year flood has become the accepted national standard for regulatory purposes. It is defined as the flood event that has a one percent chance of occurring in any given year or, on the average, occurs once in a 100-year period. However, 100-year floods can and do occur more frequently.
Floodplain regulations are designed to guide floodplain development to lesson the damaging effects of floods. Floodplain regulations may be included in zoning, building codes, & subdivision regulations, or they can be adopted as special purpose regulations. Many Ohio communities adopt special purpose floodplain regulations that combine both building code & subdivision requirements.
For regulatory purposes, the floodplain is divided into two areas based on water velocity: the floodway & the flood fringe. The floodway includes the channel & the portion of the adjacent floodplain required to pass the 100-year flood without increasing flood heights. Typically, this is the most hazardous portion of the floodplain where the fastest flow of water occurs. Due to the high degree of hazard, most floodplain regulations require that proposed floodway developments do not block the free flow of flood water as this could dangerously increase that water's depth & velocity.
The flood fringe is the remaining portion of the floodplain, outside of the floodway, that usually contains slow-moving or standing water. Development in the fringe will not normally interfere as much with the flow of water. Therefore, floodplain regulations for the flood fringe typically allow development to occur but require protection from the flood waters through the elevation of the buildings above the 100-year flood level or floodproofing buildings so that water cannot enter the structure.
ODNR Assistance in Floodplain Management.
The Ohio Department of Natural Resources, Division of Soil and Water Resources, provides technical & planning assistance to local governments & private citizens in order to reduce flood losses in Ohio. The Division's Floodplain Management Program is responsible for:
1. Promoting floodplain management in Ohio
2. Providing technical information to support floodplain regulations
3. Assisting local units of government in establishing floodplain management programs
4. Coordinating the efforts of federal, state, & local agencies involved in flood damage reduction in Ohio
5. Assisting communities to become eligible for participation in the National Flood Insurance Program (NFIP)
6. Assisting state & local flood-preparedness efforts
If you have any questions concerning floodplain management, please contact ODNR's Floodplain Management Program staff at (614) 265 - 6750 or by e-mail.