What Are Floodplains?
Floodplains are the areas along streams or rivers that are likely to experience repeated flooding. Over thousands of years, nature shaped the floodplain to hold excess water that spills over the banks. Simply put, floodplains are meant to flood. Because nature designed floodplains to flood, the floodplain is considered to be part of a healthy creek system.
Decades ago, homes and buildings were often built in floodplains in Charlotte and across the nation. That's because water was easily available for drinking or commercial uses and the floodplain land was often flat and easier to develop than hilly land. Since the late 1970s, building in local floodplains has been restricted. Protecting floodplains from additional development can reduce flood losses and improve the environment.
It should be noted that nature formed floodplains to flood and to carry a large volume of stormwater. Therefore, floodplains can be dangerous during heavy storms and should be avoided when water is present.
Protecting floodplains from the impacts of development is essential for protecting water quality, reducing the risks of flooding and flood insurance rates, supporting wildlife habitat, and providing areas that can potentially be used for recreation.
Improve Water Quality. Floodplains prevent and remove pollutants in stormwater by providing open space for floodwaters to slow down and absorb into the ground. This dissipates the energy and volume of floodwaters, decreasing erosion and sedimentation within the stream. It also allows pollutants such as sediment and nutrients to settle out of floodwater.
Reduce Flood Risks. Floodplains are supposed to flood. Floodplains help spread the extra energy and volume of floodwaters along an entire stream or river system rather than concentrating it in one area where it can be more destructive. For example, a one-acre floodplain can store 1.5 million gallons of floodwater. Protecting floodplains not only reduces flood risks, it lowers flood insurance rates.
Provide Wildlife Habitat and Recreation Areas. Floodplains provide spawning ground for fish and unique habitat for a wide variety of plants, insects, reptiles, amphibians, birds and mammals. Their long corridors of connected habitat make them a rich resource for wildlife and ideal area for greenway trails.
For all these reasons, Charlotte-Mecklenburg Storm Water Services proactively protects floodplains from the impacts of development through local regulations. In 2000, Charlotte-Mecklenburg became the first community in the nation to show both current FEMA Floodplains and future floodplains on its official maps. Future floodplains are also called Community Floodplains and show where flooding is likely to occur in the future based on expected development upstream. As development occurs, regulations that help protect FEMA Floodplains and Community Floodplains will avoid hundreds of millions of dollars in future flood damage.
Landowners and professionals planning any “development” activity in a floodplain within the City of Charlotte and/or Mecklenburg County should have the knowledge and skills to plan, design, and construct their project in compliance with local, state and federal Floodplain Regulations. For purposes of floodplain management, “development” means any man-made change to improved and unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavating or drilling operations. Floodplain development restrictions apply to both FEMA Floodplains and Community Floodplains.
For more information about the regulations that limit or ban new construction and other development in mapped floodplains, see the “Floodplain Regulations Technical Guidance Document” at Regulations.
Facts and Stats for the Regulated Floodplain
- There are almost 20,000 acres of land designated as regulatory floodplain across Mecklenburg County.
- More than 20,000 parcels of land touch or come in contact with the regulated floodplain, representing 5.8% of the land in the county.
- Approximately 2,700 residential and commercial structures are located in the regulated floodplain. Although many of these homes and businesses are built above the 100-year flood level, many are impacted during large rain events.
Am I in a Floodzone?
Find out by typing your address into the 3D Interactive Floodzone Map or call 704-432-RAIN.
Floodplains and Maps
Public safety is our top priority at Charlotte Mecklenburg Storm Water Services. To prevent tragedies caused by flooding, we partner with the Federal Emergency Management Agency (FEMA) to assess and map flood risks in response to any changes in land development, changes in rainfall statistics and improvements in topographic data.
Floodplain Maps also referred to as Flood Insurance Rate Maps (FIRMs), display areas near major streams that have a specific risk of flooding determined through the analysis of many factors. The maps show how likely a building, or a section of land could be affected by rising water from a stream during a storm event. Flood risks vary. Flooding can occur both inside and outside of the designated floodplains. Floodplain maps are used for flood insurance purposes and managing land development activities through permitting guided by floodplain regulations.
Floodplain Mapping Program and Revisions
Flood risks change over time. Floodplain maps must be updated regularly to accurately show flooding risk. Our Floodplain Mapping Program updates local floodplain maps. Risk mapping technology has improved, allowing our staff to more accurately predict where floodwater is likely to flow. The new maps also calculate how deep floodwater is likely to get and show how frequently a section of land is expected to flood.
Remapping regulated floodplains follows the standards, methods, and sequence of steps required by the Federal Emergency Management Agency (FEMA). The steps are: 1) Planning, 2) Development, 3) Draft, 4) Preliminary, and 5) Effective. This is relayed as the status for each phase of mapping.
The remapping process includes a series of public meetings to inform the public about the pending changes, gather feedback and allow the public to provide input and comments throughout the process.
Current Mapping Updates Schedule
To schedule updates, Mecklenburg County has been divided into four geographical areas called “phases.” New floodplain maps have been developed and adopted starting with Phase 1 and ending with Phase 4. Phases 1, 2 and 3 are now Effective; Phase 1 maps took effect in 2014, Phase 2 maps in 2015 and Phase 3 maps in 2018. Flood maps for Phase 4 are in development.
Enter an address or use the zoom controls to view the floodplain remapping phase for a property.
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Floodplain Maps FAQ
What are floodplain maps used to do?
Floodplain maps are used to:
- guide new construction and remodeling.
- determine when flood insurance is required.
- set the cost of flood insurance premiums.
What’s the difference between the FEMA Floodplain and Community Floodplain?
The FEMA Floodplain shows where flooding is likely to occur now. Community Floodplain shows where flooding is likely to occur in the future, based on expected development upstream. In 2000, Charlotte-Mecklenburg became the first community in the nation to show both current and future floodplains on its official maps.
Can I build or renovate in the floodplain?
Whether you can build or renovate in the floodplain depends on:
- Where the property is in the floodplain.
- If the building's floor is above the required elevation.
- The cost of renovation compared to the value of the existing structure.
Keep in mind: Building codes are different in the floodplain than outside of the floodplain. A special permit is required before any floodplain construction takes place to make sure it complies with the additional regulations. Floodplain development restrictions apply to grading, new construction and some renovations on floodplain property.
To get approval to renovate or repair a structure in the floodplain, you need to know:
- What is the required elevation for a building in that part of the flood zone?
- Is the floor of my building below this required elevation?
Buildings below the required elevation are at a higher risk of flood damage. For that reason, there are restrictions on renovations.
Who should buy flood insurance?
Anyone at even low to moderate risk of flooding. Everyone lives in a floodzone. Some places have higher flood risks than others. If you live on a hill, your risk may be reduced. But it is not eliminated. Flooding can happen anywhere. Each year 28% of flood insurance claims are from outside high-risk areas (regulated, mapped floodplains). Standard homeowners' insurance or business insurance does not cover flood damage.