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To View Hurricane
Evacuation Maps, click here
Authority and Responsibility for Evacuation
Levels and Types of Storms
Under a PARTIAL Evacuation
Under a FULL Evacuation
Under a VOLUNTARY Evacuation
Under a MANDATORY Evacuation
Time Frames Necessary to Evacuate (Clearance Times)
Deadlines for Evacuation Decisions (Decision Points)
Probabilities of Hurricane Conditions
Phased Evacuations
Evacuation Decision Making Tools
Evacuation Routes
Traffic Control
County Evacuation Coordination
Authority and Responsibility for Evacuation
GEMA may recommend that evacuation be conducted locally to protect lives and property. The Governor may recommend or order evacuations on a
County-wide or regional basis. However, a mandatory evacuation decision will almost always be relegated to local jurisdictions if they are capable of
making such a decision and carrying it out.
The Georgia Emergency Management Act, The Georgia Emergency Operations Plan and the Georgia Hurricane Plan also place the responsibility
for making evacuation decisions on local officials. They further authorize that ..."local officials may
recommend or order evacuation in accordance
with the authority contained in their resolutions/ordinances." The Chatham County Resolution Pertaining to Emergency Management clearly states
that the Chairman and Mayors can "... take such emergency actions as may be necessary to promote and secure the safety, protection and
well-being of the inhabitants of the County." This includes the issuance of voluntary and mandatory evacuation orders when deemed necessary.
When a hurricane threat increases to the point that the National Weather Service (NWS) may soon issue a Hurricane Watch, the CEMA Director
will request that the Chairman and Mayors convene in the Emergency Operations Center (EOC) to assess the threat and consider future options for
a possible evacuation scenario. After a Watch but prior to and in anticipation of a Hurricane Warning for Chatham County the Chairman and Mayors
will deliberate on the need for evacuating all or any portion of the County. This may occur at periodic intervals (and actually extend into the Warning
period).
Before reaching any decision the Chairman and Mayors will be thoroughly briefed by the CEMA Director and others. They will be afforded the
opportunity to discuss the situation, forecast and available options by telephone with Georgia Emergency Management Agency (GEMA), the
National Weather Service (NWS) Charleston, Federal Emergency Management Agency (FEMA) and the National Hurricane Center (NHC).
Furthermore they may select other government officials to assist and advise them. Such officials will ordinarily include any or all of the following:
 | County/City Managers or Administrators |
 | Key Department Heads and Bureau Chiefs |
 | CEMA Director |
 | City/County Attorneys |
 | State/Federal Liaison Officers |
 | Public Information Officer |
Any decision to evacuate will be immediately communicated to and coordinated with GEMA and other State agencies in the State Operations Center
(SOC). The Chairman and Mayors will then ensure that evacuation and sheltering operations are successfully carried out as described in this plan,
by authorizing and committing all the available resources, personnel and facilities under their control.
Levels and Types of Storms
The threat of deadly storm surge, fresh water flooding and damaging winds caused by a hurricane requires that all persons in a Hurricane Warning
area be prepared to seek suitable shelter and take other protective actions in sufficient time to escape the ravaging effects of the storm. Because
Chatham County is coastal, low-lying and particularly susceptible to the full fury of a hurricane the evacuation of its citizens from high risk areas will
often be a necessity. The actual number of people who need to evacuate and the distances they should travel will be determined by the severity of the
storm itself.
In Chatham County there are basically two levels of evacuation appropriate for hurricane conditions; "Partial" and "Full", depending on the severity
of the storm:
Under a PARTIAL Evacuation,
the following areas would be affected:
 | All islands (not just "barrier islands") |
 | All waterfront properties (including rivers, creeks, canals) |
 | All low lying areas adjacent to marshes, wetlands, etc. |
 | All flood prone areas (including rainfall flooding) |
 | All mobile/manufactured type parks and homes of unsturdy construction |
Under a FULL Evacuation, the following
areas would be affected:
 | Entire County (No exceptions for the general public). |
From these two levels of evacuation, two types of evacuation may be come necessary depending on the severity of the Storm; namely "Voluntary"
and "Mandatory":
Under a VOLUNTARY Evacuation:
 | Government officials strongly urge and recommend persons in designated evacuation areas to relocate to safer
locations for their own safety. Personal discretion allowed, but not advised. |
Under a MANDATORY Evacuation:
 | Government officials order all persons in designated evacuation areas to relocate to safer locations for their
own safety. Personal discretion not to be a deciding factor. A mandatory evacuation order will apply to the public in general. Exceptions would include
public safety officials, disaster response personnel and organizational, agency,
business employees designated as "critical workforce" or "essential".
However, all of these individuals will be expected to eventually seek adequate shelter prior to the onset of hurricane conditions. Persons who refuse
to comply with a mandatory evacuation order will not be arrested nor forcibly removed from their homes. However they should not expect rescue or
other lifesaving assistance after the onset of gale force winds. ( The same will hold true for persons ignoring a voluntary evacuation order.) |
Each storm threat will dictate its own combination of levels and types of evacuations to be authorized by government officials:
For Categories 1-2 storms, either a Voluntary Full or a Mandatory Partial evacuation will be issued.
For Category 3-5 storms, only a Mandatory Full Evacuation will be issued.
Time Frames Necessary to Evacuate (Clearance
Times)
There are two critical factors in the decision making process in recommending or ordering evacuation: The first being the time necessary to clear
evacuees from the evacuation area (i.e., the clearance time which is defined as the time required to clear the roadways of all vehicles evacuating).
The second is weighing the clearance time in respect to the arrival time of hurricane pre-landfall hazards.
Clearance time begins when the first vehicle enters the evacuation route network and ends when the last vehicle reaches a local shelter or the
County line on the way to inland shelter. The clearance time is developed to include the time required for evacuees to secure their homes and
prepare to leave, the time spent by all vehicles traveling along the evacuation route network and the additional time spent on the road caused by
traffic and road congestion. Clearance time does not relate to the time any one vehicle spends traveling along the evacuation route network. It also
does not guarantee vehicles will safely reach their destination once outside the County.
Evacuation should be completed prior to the arrival of sustained 34 knot (gale force) winds or the onset of storm surge inundation whichever occurs
first. Based on a storm with a radius of 100 miles, moving at 10 miles per hour, this could reduce the evacuation time for a projected landfall at 24
hours to only 14 hours. In Georgia the primary limiting factor for hurricane evacuation is the arrival time of sustained 34 knot winds, ( which convert
to 39 miles per hour).
It is critical for decision makers to understand that H1 projections for landfall refer to the eye of the storm passing over the shoreline. Gale force
winds may extend 100-200 miles ahead of the eye. These winds will only increase as the storm approaches and could last for 6-12 hours (or more),
accompanied by rapidly deteriorating conditions (e.g., traffic hazards, torrential rain, storm surge and fresh water flooding).
Once gale force winds arrive it will become increasingly unsafe to be outdoors, particularly on the roads. Therefore any evacuation orders in effect
will be canceled (or terminated) at that point. Persons who have not yet begun evacuating will be told that it is too late to try and that they should
either stay where they are or else go immediately to a nearby refuge (discussed later in this plan). Clearance time is primarily calculated on the basis
of:
 | Number of people evacuating (including tourists) |
 | Number of vehicles on roadways |
 | Number and capacity of evacuation roadways |
 | Potential roadway choke points or bottlenecks |
 | Time of day |
 | Response time for evacuees after orders are issued |
Deadlines for Evacuation Decisions (Decision
Points)
The practical deadline for making an evacuation decision is approximately one hour before the time that gale force winds should arrive, minus the
clearance time required to safely evacuate all the people in a high risk area. (Example: Gale force winds are possible at 10:00 P.M. Clearance time
is 14 hours. Deadline is 7:00 A.M.) This is also called a "decision point". If an evacuation decision has not already been tentatively agreed upon, it
will need to be made at this time without further delay. Therefore officials should actually be assembled 15-30 minutes prior to the decision point
itself.
The additional hour will allow officials to reach an appropriate decision, notify emergence operations personnel of that decision, and if appropriate,
prepare a news release and press conference before an evacuation order would have to be publicly announced.
More than one decision point will often be required during any ongoing storm threat particularly if it suddenly fluctuates in intensity, changes course
back and forth, significantly slows down its forward motion or shrinks in diameter. In such cases officials may be faced with two - five (or more)
deadlines when they would have to consider and/or reconsider the need to evacuate or modify earlier evacuation orders.
Probabilities of Hurricane Conditions
In addition to clearance time issues, another relevant consideration must factored into the decision making process. This is the probability that a
storm will actually make landfall or at least pass close enough to Chatham County to endanger lives and property (i.e., the eye will come within 65
miles).
Probabilities are expressed as percentages around the official forecast track of a storm up to 72 hours or more into the future. They are provided by
the I'D every six hours and are useful in assessing the potential threat to a particular location along the coast as the storm approaches. However
they can be mistakenly over relied on as the primary criteria in deciding if an evacuation is warranted. While common sense dictates that there must
be some reasonable probability of a direct hit to justify any evacuation decision, there is no objective standard for determining what specific level of
probability might constitute an acceptable or unacceptable risk to the community.
The Chairman and Mayors will have to collectively (and somewhat subjectively) agree on a minimum threshold probability level for approving any
evacuation order (especially Mandatory). Ideally consensus will be reached in advance of a "decision point" so that a subsequent evacuation
decisions can be made in time to satisfy the County's clearance time requirements. The maximum theoretical probabilities, for a direct hit at any
given location over time are:
 | Eye of Storm 72 Hours Out----------------10% Probability |
 | Eye of Storm 48 Hours Out--------------13-18% Probability |
 | Eye of Storm 36 Hours Out--------------20-25% Probability |
 | Eye of Storm 24 Hours Out--------------35-45% Probability |
 | Eye of Storm 12 Hours Out--------------60-70% Probability |
It is extremely unlikely that the probability of a hurricane strike will ever exceed 25-35% at the "decision point" required to make a timely
evacuation decision. It will be virtually impossible to have as much as a 50% probability at that time, if the gale force winds arrive seven hours or
more before the eye. Therefore any evacuation order will almost always have to be issued while uncertainty is still relatively high. Delaying a
decision to evacuate past the appropriate decision point when the probability is better than 50-50 will be too late, even for a Category 1 or 2 storm.
Phased Evacuations
The decision to evacuate (and if so , to what degree) is complex, difficult, politically sensitive and personally stressful. This is especially true when
time is of the essence, a high level of uncertainty exists, and the negative consequences of an incorrect decision are great. It is equally traumatic and
potentially confusing for citizens to be informed of an evacuation order (particularly a Mandatory one) with little or no advance notice, insufficient
lead time to make last minute preparations and virtually no luxury of being able to respond at a leisurely pace. Therefore if circumstances and time
permit every effort will be made to "phase in" the levels and types of evacuation to permit emergency operations personnel and citizens alike to
prepare and respond, and to minimize roadway congestion and traffic control problems.
Prior to any evacuation decision making meetings CEMA will prepare a proposed evacuation schedule for implementing any resulting evacuation in
phases. The exact nature of the schedule (or timetable) will vary based on the immediacy of the threat, the times of day involved, and the levels and
types of evacuation considered.
If the threat of the storm diminishes over time the entire schedule may not have to be carried out. However if the storm increases speed or strength
rapidly or unpredictably some portions may have to be time compressed or even eliminated altogether in favor of an immediate Mandatory
County-wide evacuation. In any event every effort will be made to coincide the schedule with the periodic issuance of Advisories (at 11:00 and 5:00)
and consideration for clearance time requirements.
Evacuation Decision Making Tools
In addition to National Weather Service and the National Hurricane Center as well as the technical expertise and advice of the various officials and
agencies already discussed, evacuation decisions will be aided by several computer models designed specifically for that purpose.
The Hurricane Evacuation Model (HURREVAC) for the State of Georgia will be used to estimate the arrival times of hurricane conditions;
recommended actions for storms of various anticipated size, speed and intensity; the strength of wind fields throughout the County and inland once
the storm reaches a certain location along the coast.
The Sea, Lakes and Overland Surge for Hurricanes Model (SLOSH) for the State of Georgia (1997 version) will be used to estimate storm surge
potentials throughout the County for various categories of storms.
The Geographic Information System Model (GIS) with Flood Insurance Rate Map (FIRM) data will be used to estimate fresh water (i.e.,
rainfall)
flooding potentials throughout the County and will be supported by historical data for high risk areas at various levels of precipitation.
The Tides Model will be used estimate additional storm surge potential throughout the County if the storm makes landfall around high tide.
In addition two commercial versions of hurricane computer models (e.g., HURRTRAK and DTN) will be used as back ups for the HURREVAC and
Inland Winds Models. A manual method for estimating the arrival of gale force winds, the Decision Arc Method, will also be used as a last resort.
Evacuation Routes
Once an evacuation order is issued all major roadway networks within the County will be considered evacuation routes for local travel. Evacuation
routes from the County to inland areas have also been designated. They include GA 204, GA 21, U.S. 80, and I-16.
Evacuees are encouraged to use the evacuation routes instead of other side roads. I-95, US 17A and U.S. 17 (Southbound) are not designated
evacuation routes outside the County. Evacuees intending to use them should only do so before a mandatory evacuation order is issued and well in
advance of any approaching storm.
Evacuees leaving the County will be encouraged to make arrangements to go safely inland and stay with friends or relatives, or at hotels or motels.
Those who wait until a mandatory evacuation order is issued will probably have difficulty finding hotel/motel vacancies east of I-75 and south of
Macon.
Traffic Control
The time necessary to evacuate large numbers of persons depends upon a variety of variables such as:
 | Number of persons per vehicle. |
 | Number of travel lanes available. |
 | Maintained vehicle speed. |
 | Time of day or night traveled. |
 | Number of points of entry and exit from evacuation arteries. |
 | Control of traffic and clarity of directional signs. |
 | Frequency of transportation breakdowns. |
 | Location of roadway accidents. |
 | Percentage of trucks and buses. |
 | Weather Conditions. |
Evacuees caught out on the roads in traffic jams when a hurricane overtakes them are in extreme peril. Therefore, effective traffic control measures
are essential to expedite the unimpeded flow of traffic.
Outside of Chatham County evacuation route traffic control will be the responsibility of the State and local jurisdictions through which the routes
travel. However, within County boundaries, approximately 100 traffic control points at critical intersections, bridges and potential choke points will be
staffed by local law enforcement officials. Towing service vehicles at strategic locations will be on a standby status at the direction of the law
enforcement agencies with whom they have contracts.
The specific traffic control assignments and locations, as well as the agencies responsible for each, which will be staffed during a full-scale hurricane
evacuation. These traffic control points will all be activated after a Mandatory-Full evacuation order is issued (i.e., County-wide). A lesser number
may be activated after a Voluntary or Mandatory-Partial evacuation order is issued, depending on the volume of traffic experienced and the
discretion of the respective law enforcement officials within each jurisdiction. They will remain activated until traffic flow no longer requires.
However, once the gale force winds arrive the officers will be released from duty to seek shelter themselves.
In the event that the entire County is evacuated on a Mandatory basis I-16 will be converted to one way
(west-bound) travel from Martin Luther
King Boulevard to US-1 (approximately 77.5 miles). Eastbound travel will be diverted to GA 280 or US 46. This will take effect approximately two -
four hours after the evacuation order is issued. Traffic control points will set up and staffed by Georgia DOT, GSP and other personnel.
County Evacuation Coordination
Before any anticipated or actual evacuation orders are issued, CEMA will communicate and coordinate with its counterparts in all adjacent coastal
and inland risk counties, including those in South Carolina. They will be informed of the level and type of evacuation, the time it will begin, anticipated
volume of traffic and the status of I-16. Particular attention will be given to coordinate the timing of evacuation orders with Beaufort County, South
Carolina. Periodic status reports on evacuation progress will also be issued to these jurisdictions. In all cases GEMA will be kept informed and
included in any and all coordinating activities. |