Flood Plain Management

The City of Johns Creek is helping minimize potential flooding by addressing the impact of new development and redevelopment on stormwater, and regulating development in floodplains based on projected land-use conditions.

A floodplain is a nearly flat plain along the course of a stream or river that is naturally subject to flooding. Approximately six percent of Johns Creek is located within a regulated floodplain, otherwise known as a Special Flood Hazard Area.

Floodplain regulations and development restrictions can greatly reduce future flooding impacts, preserve greenspace and habitat, control floodwaters, and protect water quality.

To see if your property falls into a floodplain, check the Johns Creek Flood Insurance Risk Zone Map or the Georgia DFirm site call 678-512-3200 with any floodplain-related questions.

Flood Hazard Areas

In Johns Creek's Special Flood Hazard Area, commonly referred to as the "100-year floodplain," flood elevations have a one percent chance of being equaled or exceeded each year. However, that "100-year flood" could actually occur more than once in a relatively short period of time, not necessarily just once every 100 years.

Johns Creek lies within the Upper Chattahoochee Watershed and the Chattahoochee River, Autry Mill Creek, Big Creek, Cauley Creek, and Johns Creek are all sources of possible flooding in this watershed.

For example, in late 2009, the Chattahoochee rose to its highest levels since Buford Dam was built in 1956, with some areas over the 1 percent annual chance elevation (100-year flood), and other areas even exceeding the .02 percent chance elevation (500-year flood).

Natural Benefits

Regulated floodplains provide many benefits to a community, including preserving greenspace, providing recreational opportunities, reducing the number and severity of floods, and helping handle stormwater runoff.

Flood hazard areas also help maintain and enhance water quality (natural vegetation filters out impurities from runoff and uses excess nutrients), create excellent habitats for plant, fish and wildlife, and even help protect areas for rare and endangered species.

Floodplain Development Permit Requirements 

If you live in a floodplain, be sure to check with the City's Community Development Department before you build or alter your property in any way. All development in the floodplain, not just construction of buildings, requires a local permit. Illegal development can reduce the capacity of the floodplain and create an unsafe situation. 

For more information, see Land Disturbance Permit , Development Regulations, and the Floodplain Management Ordinance. For specific plan requirements, see the Floodplain Management Plan Requirements. For more information about these permits and to report illegal development, call the City at 678-512-3200.

Flood Safety

Flood conditions, of any size, can be hazardous and potentially life threatening. To lessen flood hazards follow these steps:
  • know the local flood warning and evacuations procedures.
  • plan escape routes to high ground.
  • during time of heavy rainfall, monitor the level of water in the waterway (if possible).
  • stay tuned to radio or TV for possible flood warnings.
  • evacuate the flood hazard area in times of impending flood or when advised to do so by the police or fire department.
  • do not attempt to cross a flooded stream on foot or by car.
  • if your car stalls in high water, abandon it immediately and seek higher ground.
  • keep children away from flood waters, ditches, culverts, and storm drains.
  • shut off gas to home and stay away from downed power lines.
  • be especially cautious at night.

Property Protection Measures

Retrofitting your home (elevating it so floodwaters do not enter; constructing barriers between your home and floodwaters; and wet and dry flood proofing) can help protect against flood damage.

More information about flood proofing or retrofitting your home is available on the FEMA website and from the Homeowner's Guide to Retrofitting, Six Ways to Protect Your Home From Flooding.

Flood Insurance

Flood insurance is required if your house or building is located within a Special Flood Hazard Area/floodplain, but it is available to all property owners, regardless of flood zone. Homeowner's insurance does not cover damage or losses due to flooding. The City participates in the National Flood Insurance Program, which makes flood insurance available for purchase to all property owners.

More information about flood insurance can be obtained from your insurance agent. Flood insurance becomes effective 30 days after it has been issued by your insurance agent.

Elevation Certificates

The City maintains records and elevation certificates for floodplain properties that have obtained permits since the City's inception.

Flood Warnings

Warnings are disseminated through local radio and television stations (WXIA-11, WAGA-5, WGCL-TV, WSB-2, WSB-AM750, WGST-AM640). FLOOD WATCH means that flash flooding is possible within the watch area. FLASH FLOOD WARNING means that flash flooding is imminent or has been reported in the warning area and evacuation is advisable if you live in low lying areas.

Storm System Maintenance

The City has regulations that prohibit the dumping of trash, leaves and other pollutants into the storm system (drains, pipes, streams, ditches, etc.). This dumping can cause unexpected flooding by obstructing the free flow of stormwater, creating overflow into roads and yards, resulting in damage and potentially hazardous conditions.

If your property is near a stream, storm inlet, or drainage ditch, please keep the area clear of brush and debris. The City inspects and maintains ditches and storm structures within the rights-of-way but not on private property. If you see illegal dumping of trash, yard waste, or other pollutants or changes such as filling or rerouting streams or ditches, please call the City at 678-512-3200.

Substantial Improvements & Damage 

If your home or business is located in the floodplain, the National Flood Insurance Program requires that the building must meet the same requirements as a new building if the cost of reconstruction due to damage, rehabilitation, addition, or other improvements exceeds 50 percent of the building's market value. Please contact the City at 678-512-3200 before you make any alterations to your home or business.