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Flood Protection Information

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1. What else can I do to prevent my house from flooding?

Besides flood insurance, you should protect your structure by ordinary means. For example, do not sweep or blow yard leaves, pine needles, grass clippings or soil into the storm system. This clogs up the pipes and prevents water from draining. If you see someone dumping trash or debris in the canals, please report it to City’s Customer Service desk at 651-6565.

2. What is the difference between a Flood watch and Flood warning?

Flood watch is when conditions are in place for a flood event but location and magnitude are still uncertain. Prepare for flooding.
Flood warning is when a flood is imminent or occurring. Take immediate action to protect lives/property.

3. How do ponds prevent flooding?

As development occurs impervious surfaces and rain gutters are being installed. Rain water that would absorb into the ground is now being pushed off site in an increased amount and faster. Storm water systems are design to transport a set amount of water over a period of time. Increasing the amount of water going to the system will over tax the system thereby causing water back up and flooding. The ponds are designed to hold back certain amount of water and releasing the storm water at a later time when the system is not so full.

4. What is the difference between a Retention Pond and a Detention Pond?

A Retention Pond permanently holds the water all the time and does not have a natural discharge. A Detention Pond temporally holds the water allowing the water to drain slowly into the drainage system. Both ponds allow the water to escape by evaporation or absorption back into the ground. The ponds are mechanisms to hold the rain water as not to over burden the storm water conveyance system.

5. What is compensatory Storage?

The City’s Flood Damage Protection Ordinance (FDPO) restricts new development from obstructing the flow of water and increasing flood heights. However, this provision does not address the need to maintain flood storage. Especially in flat areas, the floodplain provides a valuable function by storing floodwaters. When fill or buildings are placed in the flood fringe, the flood storage areas are lost and flood heights will go up because there is less room for the floodwaters. This is particularly important in smaller watersheds which respond sooner to changes in the topography. One approach that may be used to address this issue is to require compensatory storage to offset any loss of flood storage capacity. The most common solution to meet the compensatory storage requirement is to remove exist earth equaling to the amount of cubic feet of water the construction is displacing. The quantity is measured from the existing grade up to the BFE.

6. Why can’t hydrostatic vents be used in the VE zone?

The VE zone requires designed breakaway walls which depend on 20 pounds per square foot to 10 pounds of water pressure to cause the walls to collapse; there by, protecting the structure by allowing the waves and flowing water to freely pass between the piles. If the breakaway walls have vents in them the water pressure will equalize on both sides of the wall causing the design walls to fail and remain attached to the pile. The walls and piles are now acting as one unit, jointly absorbing the wave action and water flow, increasing the risk of permanent damage to the foundation system and possibly causing the structure to collapse.

7. What are some of the main construction tips for the different zones?

1. Zone X: (Low Risk) The Flood Damage Protection Ordinance (FDPO) does not have any mandatory requirements in the X zone, but owners should build up the structure at least one foot above finish grade and purchase flood insurance at a preferred rate.

2. Zone X Shaded or X-500: (Moderate Risk) This area is projected to have a foot of water standing if experience a storm intensity of a small hurricane. Flood insurance is strongly encouraged to be purchased at a preferred rate and the finish floor elevation to be constructed at least two feet above the highest adjacent finished grade.

Below Areas within the Special Flood Hazard Area (SFHA) - High Risk or 100 year Floodplain
Design Flood Elevation (DFE): is the elevation based on the Base Flood Elevation (BFE) plus required freeboard. Savannah has a one foot free board requirement.

3. Zone A, AE, AH & A0
• Finish floor or bottom of the lowest wooden floor joist to be at or above the Base Flood Elevation (BFE) plus one foot freeboard. .
• Hydrostatic Vents are required if have a crawl space or garage below the DFE.
• Flood resistant materials shall be used below the DFE.
• Bottom of exterior A/C unit and bottom of all duct work, plus generators and natural gas must be above DFE.
• Elevation Certificates (EC): two submissions of an EC are required.
 + “Under Construction” EC is required to be submitted once the lowest finish floor has been set to verify the lowest floor elevation. No additional inspections can be completed until the EC has been submitted and reviewed by the Floodplain manager.
 + “Finish Construction” EC is required to record the lowest habitable finish floor, garages floor, a/c units, hydrostatic vents, and fuel tanks servicing the dwelling. Note the Finish Construction EC is required prior to releasing of power and Certificate of Occupancy.
• New construction and additions must provide a “No Adverse Impact” letter from a Georgia licensed engineer certifying the match of compensatory storage.

4. Zone VE (Velocity Zone)
• Materials requirement and Elevation Certificates: Same as above AE & AH.
• Cannot bring Fill onto the site.
• Cannot have reinforced parking slabs.
• Must have the bottom of the lowest horizontal structural member at or above the DFE.
• Must have Georgia licensed engineer design and certify “as-built” of the foundation, freedom of obstruction, and breakaway walls.
• Submit and record with the deed a “Non Conversion” letter stating that the area below the main structure will not be converted into a habitable space.
• Hydrostatic vents are not permitted – enclosures require BREAKAWAY WALLS only.
• New construction and additions must provide a “No Adverse Impact” letter from a Georgia licensed engineer certifying the match of compensatory.
• Storage Flood insurance rates increase dramatically for enclosures larger than 300 square feet.

8. How can I remove my property from the Floodplain?

If someone disagrees with the FIRM determination for a property or structure, he or she may contact a registered land surveyor to complete a detailed study of the property. If the surveyor determines that the existing ground elevation is actually outside the designated flood plain, the owner can request from FEMA a Letter of Map Amendment (LOMA). The LOMA is a legal description in which FEMA recognizes the new determination.

9. What are benchmark, datum, and datum types?

A benchmark is a fixed point with a reference measurement associated to it and an elevation is the measurement of a distance above the set point. So a concrete monument can be at 18 and the finish floor of a dwelling is 3 feet above the marker making the finish floor elevation to be 21. Datum is an assigned standard measurement associated to the reference marker; similar to how a foot is associated with Standard English and a meter is metric. There are three different datum references: Mean Sea Level (MSL), National Geodetic Vertical Datum of 1929 (NGVD29) and North American Vertical Datum of 1988 (NAVD88). The original Flood Insurance Rate Mate (FIRM) were developed using NGVD 1929 datum, but all Chatham County FIRM dated September 26, 2008 and later are based on NAVD 1988. The change of datum is a primary reason for the decrease of Base Flood Elevations on the 2008 FIRM maps. Bench mark elevations relative to NAVD 88 are available from NGS through the World Wide Web at National Geodetic Survey. A rough conversion of NGVD to NAVD in Savannah is by subtracting .93’ from NAVD 29 elevation.

10. I live in a low-risk flood zone. Do I really need flood insurance?

Most likely, yes. It's a good idea to buy flood insurance even if you live in a low or moderate-risk area. Almost 25 percent of all flood insurance claims come from areas with low-to-moderate flood risk. You may qualify for the Preferred Risk Policy.

11. What is the Substantial Damage | Substantial Improved (SD/SI) aka “50% Rule” and Pre FIRM?

The “50% rule” states that if a pre-FIRM house, a structure built prior to May 21, 1971, is below the Base Flood Elevation plus required freeboard and costs of repairs or renovations, cumulative over a five year period, exceeds 50% of the current Fair Market Value of the structure only, then the structure must be brought into the compliance with the City’s current Flood Damage Protection Ordinance.
• Post-FIRM Building. A building for which construction or substantial improvement occurred after December 31, 1974 or on or after the effective date of an initial Flood Insurance Rate Map (FIRM), whichever is later. See Pre FIRM for additional information.
• Pre-FIRM Building. A building for which new construction or substantial improvement occurred on or before December 31, 1974 or before the effective date of an initial Flood Insurance Rate Map (FIRM). The City of Savannah’s initial effective date is May 21, 1971 for the areas that were within the City limits. Pre-FIRM dates change for different areas of Savannah based on annexation dates. For example, Windsor Forest was annexed by the City 1979 and not displayed on a FIRM until November 21, 1980.

12. What is the Coastal Barrier Resources System (CBRS)?

The CBRS is a system of protected coastal areas that includes ocean-front land, the Great Lakes and Other Protected Areas (OPAs). Coastal barriers serve as important buffers between coastal storms and inland areas, often protecting properties on land from serious flood damage. Also, coastal barriers provide a protective habitat for aquatic plants and animals. The Coastal Barrier Resources Act (CBRA) of 1982 restricted development on the CBRS, in an effort to protect the barrier system and prevent future flood damage. If you live in a CBRS area, you are eligible for federally regulated flood insurance only if your property was built before 1982 and your community participates in the NFIP. However, there are no CBRS zones in Savannah’s City limits.

13. What are the different Flood Zones and Risks?

In Savannah there are six zones: A, AE, AH, VE, X, and X_500.
Most of the City is in the X and X_500. The X zone, “Low Risk”, is considered above the 100 and 500 year floodplains. The lightly shaded X or X_500, “Moderate Risk”, is above or protected from the 100 year floodplain, but may have up to a foot of water in a 500 year storm event.

The A, AH and AE Zones are the flood zones which are common in Savannah. These areas are in the “High Risk” area and are prone to flood with rising water in both the 100 year and the 500 year storms. Structures have a 1% annual chance of flooding and a 26% chance of flooding over the life of a 30-year mortgage. An unnumbered “A” zone means that no Base Flood Elevation (BFE) above Sea Level has yet been determined. “AE” means a base flood elevation has been determined. For example, “AE-15" means that the lowest finished floor elevation of the structure must be at or above 15 NAVD 1988 because that is where the predicted flood water will rise. Zone AH indicated shallow flooding, usually in the form of a pond, with an average depth ranging from 1 to 3 feet. All new construction must be constructed above the designed base flood elevation (DBFE). Also, in this zone the “50% rule” applies.

The VE Zones are the most dangerous flood zones. VE zones are in the “High Risk” area and will experience rising waters, severe winds and wave action greater than three feet. Homes in this area are on the south side of Savannah along the Forest and Vernon Rivers. To protect against wave scouring and frontal velocity, structures must be elevated so that the lowest horizontal structural member (floor joist) is above the designed base flood elevation (DBFE). Such construction usually means placing the structure on piles (pilings), and these pilings must also be anchored to resist flotation, collapse and lateral movement due to the combination effects of wind and water loading forces of the 100 year storm. A registered professional engineer or architect must develop, review and certify the structural design, specifications and plans. The 50% Rule also applies here too.

The Coastal A Zone: is a term that is used to draw a distinction between coastal V zones and inland A Zones, and to highlight similarities between V Zones and A Zones in coastal areas. A building in this area is subject to breaking wave heights between 2.9 feet and 1.5 feet. Building damage in Coastal A Zones is consistent with those observed in V Zones, not riverine A Zones. The City has not mapped the Coastal A zone at this time.

14. What is a Freeboard?

Freeboard is a factor of safety expressed in feet above the BFE. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated. Freeboard is not required by NFIP standards, but is part of the CRS program under Higher Regulations. Savannah adopted a one-foot freeboard to reduce the risk of flooding. Freeboard results in significantly lower flood insurance rates due to lower flood risk.

15. What is the difference between Base Flood Elevation (BFE) and Design Base Flood Elevation (DBFE)?

Base Flood Elevation is an elevation that a structure must be built at or above to be in compliant with the NFIP requirements. The height has been determined by hydrological methods. For example, “AE-15" means that the lowest finished floor elevation of the structure must be at or above 15 NAVD 1988 because that is where the predicted flood water will rise. When a “Freeboard” is added to the BFE, the new minimum floor elevation is known as the Design Base Flood Elevation (DBFE). The new standard will satisfy the City of Savannah Flood Damage Protection Ordinance.

16. What is a 100 year or 500 year storm event?

The flood zones shown on the FIRM maps are based on the 100 and 500 year storms. These storms are rated according to how much rain falls within a certain time period. For example, on average once in one hundred years, a one percent chance, ten inches of rain will fall within a twenty-four hour time period in Savannah, so this type of storm would be considered a 100 year storm. A much higher rate of rainfall within a twenty-four time period would classify the storm as a 500 year storm. For example, a Category IV hurricane would be expected to drop twenty inches of rain in less than twenty-four hours. That would definitely qualify as a 500 year storm.

17. What is the Community Rating System (CRS)?

The City has subscribed to a program to reduce citizen’s flood insurance policy cost and further protect structures and personnel. The CRS program is a series of activities the City carries out each year to promote flood protection and preventative measures to avoid flooding. By doing so citizens who have flood insurance receive a discount on their policy cost.

18. What is Increase Cost of Compliance (ICC)?

ICC is now available that pays up to $30,000 to assist in bringing a non-compliant structure up to the City of Savannah Flood Damage Protection Ordinance. The structure must be within the designated “High Risk” flood zone and be substantially damaged or repetitively flooded.

19. What is the National Flood Insurance Program (NFIP)?

The NFIP, created by the National Flood Insurance Act of 1968, is a Federal program based on an agreement between local communities and the Federal Government that states if a community will adopt and enforce a floodplain management ordinance to reduce flood risks in Special Flood Hazard Areas, the Federal Government will make flood insurance available within the community as a financial protection against flood losses. This insurance is designed to provide an insurance alternative to disaster assistance to meet the escalating costs of repairing damage to buildings and their contents caused by floods.

20. What is the difference between the “Floodplain” and the “Special Flood Hazard Area (SFHA)”?

The Floodplain is any land area susceptible to inundation by floodwaters from any source.
The Special Flood Hazard Area (SFHA) is the land area covered by the floodwaters of the base flood on the National Flood Insurance Program’s (NFIP) Flood Insurance Rate Maps (FIRM). The SFHA is the area where the NFIP's floodplain management regulations must be enforced and the area where the mandatory purchase of flood insurance applies. The SFHA includes Zones A, AO, AH, A1-30, AE, A99, AR, AR/A1-30, AR/AE, AR/AO, AR/AH, AR/A, VO, V1-30, VE, and V.

21. What is the City of Savannah’s Community Number?

For means of accurate identification, FEMA has devised a map identification system for county and communities jurisdiction in the Nation Flood Insurance Program (NFIP). The overall Chatham County identifying number is 13051C, but the City of Savannah’s community number is 135163 where as the Unincorporated area is 130030.

22. Do marshes and other vegetation prevent flooding?

Yes. The lack of marshes and other natural vegetation may cause increased flooding to structures that depend on the natural functions of the floodplain. The marsh and vegetation acts as a shield from storms coming across the area by reducing the energy of the storm and holding the rainwater.

23. What is the Preferred Risk Policy (PRP)?

The Preferred Risk Policy offers multiple coverage combinations for both buildings and contents (or contents-only, for renters) that are located in moderate-to-low risk areas (B, C, and X Zones). Preferred Risk Policies are available for residential or non-residential buildings located in these zones, and that meet eligibility requirements based on the building’s entire flood loss history.

24. Is flood damage from wind-driven rain covered?

No. When rain enters through a wind-damaged window or door, or comes through a hole in a wall or roof, the NFIP considers the resulting puddles and damage to be windstorm-related, not flood-related. Flood insurance covers overflow of inland or tidal waters and unusual and rapid accumulation or run-off of surface waters from any source. However, the flood must be a general and temporary condition of partial or complete inundation of two or more acres of normally dry land area or of two or more properties (at least one of which is yours). Although flood insurance specifically excludes wind and hail damage, the good news is that most homeowners insurance provides such coverage.

25. Can “north-eastern” winds affect flooding?

Yes. Winds blowing in from the north-east can affect the tidal flow by preventing the tide from going out and increase the tide level by pushing in large amount of sea water. The increased tide heights cause local flooding of streets as seen along Highway 80 going out to Tybee Island and East President Street. Another affect is the tidal influence canals and streams cannot drain, and in return local storm water conveyance systems cannot spill into the canals causing structural flooding.

26. If I live in a flood zone but my finish floor is above the BFE, do I still need flood insurance?

Yes, the property and dwelling’s foundation are still in a “High Risk” flood area and still can be flooded by a larger storm event like a hurricane. The insurer will receive lower insurance premiums because the finish floor is higher than what is projected to flood. If the contour of the property is higher than the BFE a LOMA can be submitted to remove the property.

27. Can I get flood insurance if I do not live in a High Risk Area?

Yes. Flood Insurance is also available for structures outside the 100 year floodplain: Zone X. Also see #19 Preferred Risk Policies and visit the NFIP website at FloodSmart.gov for additional information.

28. Can I get flood insurance if I'm renting a property?

Yes. If you live in a community that participates in the NFIP, you can get flood insurance to cover the contents of your home or business, even if the landlord does not carry building coverage.

29. What types of property may be insured against flood loss?

Almost every type of walled and roofed building that is principally above ground and not entirely over water may be insured if it is in a participating community. In most cases, this includes manufactured (i.e., mobile) homes that are anchored to permanent foundations and travel trailers without wheels that are anchored to permanent foundations and are regulated under the community's floodplain management and building ordinances or laws. (However, this does not include converted buses or vans.) Contents of insurable walled and roofed buildings also may be insured under separate coverage.

30. Does my policy go into effect once a payment is made?

Typically there is a 30 days waiting period for the policy to be activated, unless it is for a newly purchased dwelling or refinance. The reason for this is to encourage people to purchase Flood Insurance ahead of time instead when a storm event is just about to hit. Flood insurance is based on putting all of the nation’s paid premiums in a pot and draw from that reserve as the disasters occur throughout the nation. So, your premium may pay for a storm event in Illinois this year, but when Savannah had its events in 1994, Illinois and other states paid for our events.

31. What is Flood Insurance?

As a coastal community, Savannah is subject to hurricanes and heavy rains. Savannah participates in the NFIP. In doing so, local insurance agents can sell a Flood Insurance policy, which is separate from regular property insurance, at subsidized rates set by the Federal Government. The Federal Government passed a law making it mandatory for owners to obtain a Flood Insurance policy if the structure is in a Special Flood Hazard Area (SFHA) and the loan is federally backed. A claim can be filed if a structure is damaged due to rising waters. Flood insurance can cover the structure alone or cover a combination of the structure and contents.

32. What causes flooding in Savannah?

Stormwater run-off in Savannah is hampered by the flat terrain, low elevations and tidal influence from the Atlantic Ocean. These are major natural factors, common to coastal regions, which cause the City to be at risk for flooding during long periods of moderate rainfall followed or during high volume, short duration rainfall events. As a result of these factors structural flooding has occurred in the City. Flooding has occurred during major storms and hurricanes dating as far back as 1871 and as recent as July 2007.

33. What Is a FLOODPLAIN MANAGEMENT PLANNING?

Too often flood protection decisions are made quickly, with inadequate or outdated
information or without considering all possible mitigation alternatives or the consequences
of those alternatives. As a result, the community’s resources are not allocated most
appropriately, flood problems may not be fully addressed, and natural floodplain functions
may suffer.
To remedy this situation, a careful, systematic process of planning is recommended, and
may be credited by this activity. The Community Rating System (CRS) does not specify
what activities a plan must recommend; rather, it recognizes plans that have been prepared
according to the standard planning process explained in this activity.
Benefits: A well-prepared plan will
• Identify existing and future flood-related hazards and their causes;
• Ensure that a comprehensive review of all possible activities and mitigation measures
is conducted so that the most appropriate solutions will be implemented to address
the hazard;
• Ensure that the recommended activities meet the goals and objectives of the
community, are in coordination with land use and comprehensive planning, do not
create conflicts with other activities, and are coordinated so that the costs of
implementing individual activities are reduced;
• Ensure that the criteria used in community land use and development programs
account for the hazards faced by existing and new development;
• Educate residents and property owners about the hazards, loss reduction measures,
and the natural and beneficial functions of floodplains;
• Build public and political support for activities and projects that prevent new
problems, reduce losses, and protect the natural and beneficial functions of
floodplains; and
• Build a constituency that wants to see the plan’s recommendations implemented. Floodplain Management Plan (CRS 510 Plan)

34. What is the Flood Insurance Rate Map (FIRM) used for?

The FIRM maps were devised as a means to warn potential property owners and mortgage companies of areas for probable flooding. Also, Insurance Companies base their policy rates on the map’s flood zones. City officials use FIRM maps to enforce building code regulations. Depending upon the zone the structure is in determines the stringency of the needed requirements.

35. Where can I get More Information?

The library at 2002 Bull Street has the FIRM maps and additional documents pertaining to flood plain management topics. FIRM maps can be view and FIRMettes can be created on the web at www.msc.fema.gov. The local website www.sagis.org is another great source of on-line information on contour elevation, flood zones and dwelling history. If you would like further information on flooding, flood insurance, flood zones, retrofitting, how to pick a contractor, ect., you may call City of Savannah Development Services Department, (912)651-6530 or visit the Flood Protection Information page on the City’s main web page at www.savannahga.gov. For property in the unincorporated area, contact the Chatham County Engineering Department at (912) 652-7800 or on the web at www.chathamcounty.org.

36. How do I know if I am at risk of flooding?

The fastest and easiest way is by referring to the National Flood Insurance Program’s (NFIP) Flood Insurance Rating Map (FIRM) published by Federal Emergency Management Agency (FEMA). The FIRM maps were published in September 1970 and have been revised several times since then; the latest version is dated September 26, 2008.

37. What kinds of property are not insurable under the NFIP?

Buildings entirely over water or principally below ground, gas and liquid storage tanks, animals, birds, fish, aircraft, wharves, piers, bulkheads, growing crops, shrubbery, land, livestock, roads, machinery or equipment in the open, and most motor vehicles are not insurable. Most contents and finishing materials located in a basement or in enclosures below the lowest elevated floor of an elevated building constructed after the FIRM became effective are not covered.

38. What are FIRM Panels and how many are there?

FIRM stands for "Flood Insurance Rate Map". Savannah’s community maps are divided into over 50 different FIRM panels; however, there are over 90 panels for the entire Chatham County area. Each panel is assigned a number, such as 0235 F or 0036 F. Most of downtown Savannah is split between 0153F and 0154F. When you call for a zone determination you will get a response like, “1 Bull Street is in an X zone, from FIRM map 135163, Panel 0154F, revised date September 26, 2008.” Or, “1 Sally Mood Drive is in an AE 12 zone from FIRM map 135163, Panel 0164 F revised date September 26, 2008.”
Visit the Document Center to view FIRM maps

39. What is the purpose of an Elevation Certificate?

The Elevation Certificate is an important administrative tool of the National Flood Insurance Program (NFIP). It is to be used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a Letter of Map Amendment. (LOMA) or Letter of Map Revision based on fill (LOMR-F). These certificates are primarily completed by a Georgia Licensed Surveyor.