FLOOD RISK ASSESSMENT

Floods

As a naturally occurring phenomenon that can happen almost anywhere at any time, floods represent the highest regional threat in Northern Kentucky. At the most basic level, floods are defined as the accumulation of water over normally dry areas of land. Floods can be mild, leaving minor debris, or washing landscaping away, or severe wherein buildings and structures are damaged or destroyed. As an area with main watersheds, risk assessment is essential to prepare and mitigate the negative effects of flooding on the health of our populations.

Rivers
All Three Rivers District counties border or contain main watersheds including the Ohio, Kentucky, and Licking rivers, heightening flood risk.

Flood Risk Definitions: understanding flood zone terminology.

  • Regulatory Floodway – is a channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height. (FEMA)
  • Special Floodway – an area of special consideration as designated by FEMA in regard to flooding.
  • 1% annual chance of flood hazard – an area designated as having a 1 in 100 chance of a flood happening in any given year, meaning a flood could happen this year and again next year
  • .2% annual chance of flood hazard – an area designated as having a 1 in 500 chance or (500-year flood), in any given year.
  • River or Riverine Flooding – a high flow or overflow of water from a river or similar body of water, occurring over a period of time too long to be considered a flash flood.
  • Flash Floods – are quick-rising floods that usually occur as the result of heavy rains over a short period of time, often only several hours or even less, and can occur anytime throughout the year, but mostly during summer months.
  • Dam and levee Failure Flooding – is potentially the worst flood events, occur as a result of neglect, poor design or structural damage caused by a major event such as an earthquake.
  • Watershed area – is a land area that channels rainfall and snowmelt to creeks, streams, and rivers. 

Individual County Flood Risk and Vulnerabilities

Expand county detail content by clicking on the arrows to the left of the county name.

Resources

Conclusion

It’s no surprise floods put many assets at risk. First and foremost are those impacting human life through injuries, and loss of loved ones. Second, are our many personal property and physical assets which we use in our daily lives. Third are the infrastructure assets which are the foundation upon which our communities thrive and are essential for sustaining life as we know it. Loss of these assets without the ability to recover puts families and communities at severe risk of collapse.