Overview

Floodplains are a natural and beneficial part of any river or creek. Floodplains can serve important stormwater management, water quality, streambank protection, stream corridor protection, wetland preservation and ecological purposes when permanently protected as undisturbed or minimally disturbed areas.

The flood hazard areas of the City of Roswell are subject to periodic inundation which may result in loss of life and property, health and safety hazards. Flood hazard information is being made available to the residents of the City of Roswell because 10% of Roswell is located in or near a 100-year floodplain. It is hoped that everyone will become familiar with the possible hazards associated with these floodplain areas and use the suggested actions to protect yourself, your family, your property, and your investment.

Quick Links

• Community Rating System
• Find Your Flood Risk Using Your Address
• Elevation Certificates
• Important Floodplain Information
• Floodplain Management Documents
• Roswell Floodplain Ordinance
• External Resource Links
• Roswell Engineering Division

The National Flood Insurance Program's (NFIP) Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions meeting the three goals of the CRS reduce flood losses; facilitate accurate insurance rating; and promote the awareness of flood insurance.

The City of Roswell has earned a CRS rating of 6 which results in a reduction in flood insurance premiums of 20% for homes located in the Special Flood Hazard Area and 10% outside the Special Flood Hazard Area.



The Georgia Department of Natural Resources has developed a tool that helps homeowners quickly determine their flood risk using a web-based mapping tool. Users can quickly locate a property, either using a known address or by clicking the map, to identify the flood risk status, the effective Flood Insurance Rate Map, and even create a flood hazard report that captures all of this information in an attractive and sharable format.




An Elevation Certificate (EC) is an administrative tool used by the NFIP to provide elevation information necessary to ensure compliance with community floodplain management ordinances; to inform mitigation actions that will lower flood risk; and/or support a request for a Letter of Map Amendment (LOMA) to remove a building from a high-risk flood area. The EC lists a building’s location, lowest point of elevation, flood zone, and other characteristics.

• Elevation Certificates on File at the City of Roswell

The following flood hazard information is being made available to the residents of the City of Roswell because 10% of Roswell is located in or near a 100-year floodplain. It is hoped that everyone will become familiar with the possible hazards associated with these floodplain areas and use the suggested actions to protect yourself, your family, your property, and your investment. The largest flood that has occurred on the Chattahoochee River since the completion of Buford Dam was the flood of February 25, 1961, which reached an elevation of 768.4 feet at the Atlanta gauge on Paces Ferry Bridge. More recently, many residents were affected by the significant rainfall event in late September and early October 2009.

Flood Hazard Areas

The 100-year floodplain is the area that has a 1 in 100 chance to flood in any year. Small floods have a greater chance of occurring in any year and can create a significant flood hazard to people and property close to waterways. Flash floods can occur in the spring, summer and fall. Flood waters, as from the Chattahoochee River, could rise very fast. The flood hazard includes fast moving water, sometimes accompanied by logs and debris. The City of Roswell has restricted development within the 100-year floodplain. As a result, the City seldom experiences any damage within the floodplain areas. However, citizens should be aware that localized flooding may occur where storm drains or channels become temporarily blocked. For that reason, citizens should be prepared to evacuate flood hazard areas. For more information about the local flood threat, call the Federal Emergency Management Agency 770-220-5200.

Flood Warnings

Warnings will be 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.

Flood Safety

To lessen the flood hazard:

1. know the flood warning procedure;
2. plan escape routes to high ground;
3. turn off the gas and electricity;
4. 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;
5. evacuate the flood hazard area in times of impending flood or when advised to do so by the police or fire department;
6. do not attempt to cross a flooded stream on foot or by car;
7. if your car stalls in high water, abandon it immediately and seek higher ground;
8. keep children away from flood waters, ditches, culverts, and storm drains;
9. be especially cautious at night.

Flood Insurance

For many people, their home and its contents represent their greatest investment. Your homeowner's insurance policy will not cover losses due to flooding. The City of Roswell participates in the National Flood Insurance Program which makes flood insurance available for purchase to everyone. This is a government policy and the federal government writes the policy and sets the rates.

The City strongly urges you to buy flood insurance to protect yourself from devastating losses due to flooding. Flood insurance is available on buildings and personal property, and the contents of your home or business. The cost of the policy depends on your flood zone, elevation, and age of your home. Questions concerning flood zone locations should be directed to the City of Roswell Community Development Department at 770-641-3780. A preferred risk policy is available to people in zone X, which is not in the flood zone. Renters living in a flood zone can also insure their possessions. More information about flood insurance can be obtained from your insurance agent. Just because your house has not flooded in the past does not mean that you are safe. In order to obtain financing to buy, build, or improve property located in identified flood hazard areas, flood insurance is required by law. This law applies to any mortgage, loan, grant, or other funding directly financed by a Federal Agency (VA, FHA, EPA, etc.). Lending institutions insured or regulated by a federal agency may make conventional loans at their own discretion in identified flood hazard areas.

Property Protection Measures

Retrofitting is an affordable way to protect your building from flood damage. This involves modifications to the building such as elevating it so that floodwaters do not enter or reach damageable portions, constructing barriers between the building and floodwaters, and wet and dry flood proofing. Relocate the contents so that when floodwaters enter the building, there is little or no damage from sewer backup or sump pump failure. Emergency measures include moving belongings upstairs and sandbagging. More information about floodproofing or retrofitting your home is available at the Fulton County Library, Roswell Branch on Norcross Street or call the City of Roswell Community Development Department at 770-641-3780.

Drainage System Maintenance

Do not dump anything into the City's local waterways or drainage ditches. Doing so could cause unexpected flooding during normal thundershowers and is in violation of the City of Roswell Code Section 7.5.3.1. Debris in ditches and streams obstructs the flow of water which can cause overflow into roads and into yards. Partial or complete filling in these ditches can reduce the flood flow capacity, which will also result in overflow into roads or onto private property. If your property is near a waterway or drainage ditch, please do your part and keep the banks clear of brush and debris. The City of Roswell Environmental/Public Works Department inspects major road-cross drains and cleans and maintains the system twice a year. If you see major blockage such as downed trees or debris, unapproved changes such as filling or rerouting, or violations to the ordinance, call the City of Roswell Environmental/Public Works Department at 770-641-3715.

Floodplain Development Permit Requirements

Always check with the City of Roswell Engineering or Building Division 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 obstruct the floodplain and create an unsafe situation. For more information about these permits and to report illegal development, call the City of Roswell Engineering or Building Division at 770-641-3780.

• Currently Enforced Building Codes in Roswell
• Flood Damage Prevention Ordinance

Substantial Improvements

If your home or business is located in the floodplain, the National Flood Insurance Program requires that if the cost of reconstruction due to damage, rehabilitation, addition, or other improvements exceeds 50% of the building's market value, the building must meet the same requirements as a new building. The City of Roswell Building Inspections maintains improvement information for the life of the building; therefore, it is important to contact the Chief Building Official at 770-641-3780 before you make any alterations to your home or business.

Natural And Beneficial Functions

The City of Roswell is a beautiful place to live, and the small areas located within or near a floodplain are important assets. The undisturbed wetlands provide a wide range of benefits to the human and natural systems. Water quality is improved through the wetlands ability to filter nutrients and impurities from runoff and process organic wastes. These areas provide breeding and feeding grounds for fish and wildlife, create and enhance waterfowl habitat, support a high rate of plant growth and maintain biodiversity and the integrity of the ecosystem. Floodplains provide green space for protection of streams from development and the forces of erosion.

• Natural Resource Protection Regulations in Roswell
• Floodzones In and Around Roswell Map
• Roswell Water Resources Map

Flood Evacuation Procedure

Unusually heavy rains may cause "flash" floods. Small creeks, gullies, culverts, and low-lying ground flood quickly. In such situations, people are endangered without any warnings. Response actions involve the movement to higher ground BEFORE rising waters block evacuation routes.

Below are links to the USGS gaging stations located in and near Roswell which provide real-time stream information. The heights of water at the gage for the storm with a 10% chance of occurring each year (10-year storm) and the storm with a 1% chance of occurring each year (100-year storm) are listed for comparison:

• Big Creek near Alpharetta
  • Gage height for a 10-year storm = 11.5 feet
  • Gage height for a 100-year storm = 13.0 feet
• Big Creek at Hog Waller
  • Gage height for a 10-year storm = 10.3 feet
  • Gage height for a 100-year storm = 15.3 feet
• Willeo Creek at GA 120
  • Gage height for a 10-year storm = 12.6 feet
  • Gage height for a 100-year storm = 114.7 feet

Homeowner's Guide to Retrofitting

The Federal Emergency Management Agency (FEMA) has prepared this guide specifically for homeowners who want to know how to help protect their homes from flooding. As a homeowner, you need clear information about the options available to you and straightforward guidance that will help you make decisions. This guide gives you both, in a form designed for readers who have little or no experience with flood protection methods or building construction techniques.

• Homeowner's Guide to Retrofitting

To learn more about flood map updates, who to contact, or where to get more information, the following resources may be of assistance:

• Property owners and renters can learn more about flood insurance at FloodSmart.gov
• Insurance agents can learn about flood insurance and obtain tools to help inform their clients at agents.FloodSmart.gov.
• For current and historic flood maps, visit msc.DEMA.gov/Portal.
• Learn more about flood maps at www.FEMA.gov/Flood-Maps.
• Find general information about FEMA at www.FEMA.gov.
• For information on Georgia Department of Natural Resource's flood map update efforts, visit www.GeorgiadFirm.com.

For more details about the effects of map changes on insurance, lender requirements and other technical questions related to map modernization in general (not local), contact:

FEMA Map Assistance Center (FMAC)
1-877-FEMA-MAP
Monday - Friday
8:00 AM - 6:30 PM (Eastern Time)