Floodplain Management
When land is developed, the natural hydrologic system is altered. Impervious surfaces such as rooftops, driveways, streets and parking lots all prevent rainwater from soaking into the ground, which increases stormwater runoff. Drainage systems such as gutters, storm sewers and lined channels can exacerbate flooding and erosion.
Preliminary Floodplain Maps Released
Detailed, digital flood-hazard maps have been developed by the Georgia Environmental Protection Division and Federal Emergency Management Agency based on the latest digital mapping technology and updated field studies. They show the extent to which areas of the city are currently at risk for flooding. Residents and business owners in Johns Creek may find that their flood risk is higher or lower than previously shown on the old floodplain maps, some of which are now over 14 years old.
Flood Insurance Risk Zone Maps:
Read more.
Building and filling in floodplain areas intensifies flooding and erosion. In watersheds marked by rapid development, properties and structures previously unaffected by flooding could become vulnerable.
The City of Johns Creek is helping minimize potential flooding from future growth by addressing the impact of new development and redevelopment on stormwater. The City also is regulating development in floodplains based on projected land-use conditions.
Floodplain regulations and development restrictions can greatly reduce future flooding impacts, preserve greenspace and habitat, control floodwaters, and protect water quality.
Floodplain management involves identifying flood-prone areas and managing how that area is used. An effective management plan also minimizes alterations to floodplains and streambeds. That in turn reduces flooding and protects floodplain benefits, such as enhancing water quality.
New detailed, digital flood-hazard maps are being developed to show current risk levels for Johns Creek. The new maps, known as Digital Flood Insurance Rate Maps (DFIRMs), will replace outdated maps. Planners, local officials, engineers and builders will use the maps to determine where and how to build new structures and developments. Residents and business owners also can use the maps to determine their flood risk, and decide the financial and physical steps they need to take to protect against damage and loss.
To learn more about the new flood maps, visit Georgia Flood Mapping Assessment & Planning site. For more information or concerns about floodplains, please email or call the City of Johns Creek Stormwater Management Department at 678-512-3200.
Also see the Georgia Flood Map Modernization Program: