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.
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 were developed to show current risk levels for Johns Creek. The new maps, known as Digital Flood Insurance Rate Maps (DFIRMs), replaced outdated maps and were effective Sept. 18, 2013. 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.
For more information or concerns about floodplains, please email or call the City of Johns Creek Stormwater Management Department at 678-512-3200.