COLQUITT COUNTY, GEORGIA Federal Emergency Management

COLQUITT COUNTY,
GEORGIA
AND INCORPORATED
AREAS
COMMUNITY
NAME
COMMUNITY
NUMBER
BERLIN, TOWN OF1
COLQUITT COUNTY
(Unincorporated Areas)
DOERUN, CITY OF1
ELLENTON, TOWN OF
FUNSTON, CITY OF1
MOULTRIE, CITY OF
NORMAN PARK, CITY OF
RIVERSIDE, TOWNSHIP OF
1
Non-floodprone Community
130321
130058
130675
130285
130318
130199
130346
130267
Colquitt County
EFFECTIVE: September 25, 2009
Federal Emergency Management Agency
FLOOD INSURANCE STUDY NUMBER
13071CV000A
NOTICE TO
FLOOD INSURANCE STUDY USERS
Communities participating in the National Flood Insurance Program (NFIP) have established repositories of
flood hazard data for floodplain management and flood insurance purposes. This Flood Insurance Study
(FIS) may not contain all data available within the repository. It is advisable to contact the community
repository for any additional data.
Part or all of this FIS may be revised and republished at any time. In addition, part of this FIS may be
revised by the Letter of Map Revision process, which does not involve republication or redistribution of the
FIS. It is, therefore, the responsibility of the user to consult with community officials and to check the
community repository to obtain the most current FIS components.
Initial FIS Effective Date: September 25, 2009
Revised FIS Dates:
i
TABLE OF CONTENTS
Page
1.0
INTRODUCTION
1
1.1
Purpose of Study
1
1.2
Authority and Acknowledgements
1
1.3
Coordination
2
AREA STUDIED
2
2.1
Scope of Study
2
2.2
Community Description
3
2.3
Principal Flood Problems
3
2.4
Flood Protection Measures
4
ENGINEERING METHODS
4
2.0
3.0
3.1
Hydrologic Analyses
4
3.2
Hydraulic Analyses
6
3.3
Vertical Datum
6
4.0
FLOODPLAIN MANAGEMENT APPLICATIONS
7
4.1
Floodplain Boundaries
7
4.2
Floodways
8
5.0
INSURANCE APPLICATION
9
6.0
FLOOD INSURANCE RATE MAP
9
7.0
OTHER STUDIES
12
8.0
LOCATION OF DATA
12
9.0
BIBLIOGRAPHY AND REFERENCES
12
ii
TABLE OF CONTENTS – continued
Page
FIGURES
Figure 1 - Floodway Schematic
9
TABLES
Table 1 – Summary of Discharges
Table 2 – Floodway Data Table
Table 3 - Community Map History
5
10
14
EXHIBITS
Exhibit 1 – Flood Profiles
Channel A
Channel B
Channel C
Channel C-1
Channel D
Channel E
Channel F
Channel G
Channel H
Ochlockonee River
Okapilco Creek
Panel
Panel
Panels
Panel
Panels
Panel
Panel
Panels
Panel
Panels
Panels
Exhibit 2 - Flood Insurance Rate Map Index
Flood Insurance Rate Map
iii
01P
02P
03P – 07P
08P
09P, 10P
11P
12P
13P – 15P
16P
17P, 18P
19P – 22P
FLOOD INSURANCE STUDY
COLQUITT COUNTY, GEORGIA AND INCORPORATED AREAS
1.0
INTRODUCTION
1.1
Purpose of Study
This Flood Insurance Study revises and updates information on the existence and severity of
flood hazards in the geographic area of Colquitt County, including the Cities of Doerun,
Funston, Moultrie, and Norman Park; the Towns of Berlin and Ellenton; the Township of
Riverside; and the unincorporated areas of Colquitt County (referred to collectively herein as
Colquitt County), and aids in the administration of the National Flood Insurance Act of 1968
and the Flood Disaster Protection Act of 1973. This study has developed flood-risk data for
various areas of the community that will be used to establish actuarial flood insurance rates
and to assist the community in its efforts to promote sound floodplain management.
Minimum floodplain management requirements for participation in the National Flood
Insurance Program (NFIP) are set forth in the Code of Federal Regulations at 44 CFR, 60.3.
Please note that the City of Omega is geographically located in Colquitt, and Tift Counties.
The flood-hazard information for the City of Omega is for information purposes only. See
separately published Flood Insurance Study report and Flood Insurance Rate Map.
Please note that the Cities of Doerun and Funston; and Town of Berlin are non-floodprone.
In some states or communities, floodplain management criteria or regulations may exist that
are more restrictive or comprehensive than the minimum Federal requirements. In such
cases, the more restrictive criteria take precedence and the State (or other jurisdictional
agency) will be able to explain them.
1.2
Authority and Acknowledgments
The sources of authority for this Flood Insurance Study are the National Flood Insurance Act
of 1968 and the Flood Disaster Protection Act of 1973.
For the Colquitt County FIS, dated July 16, 1997, the hydrologic and hydraulic analyses for
Okapilco Creek were prepared by Braswell Engineering, Inc., for FEMA, under InterAgency Agreement No. EMW-93-C-4147. This work was completed on May 17, 1994.
For the City of Moultrie FIS, dated July 16, 1997, the hydrologic and hydraulic analyses
were were prepared by Braswell Engineering, Inc., for the Federal Emergency Management
Agency (FEMA), under Contract No. EMW-93-C-4147. That work was completed in June
1994.
For this countywide FIS, new hydrologic and hydraulic analyses were prepared by
Watershed Concepts for the Georgia Department of Natural Resources (DNR), under
Contract No. 761-80189. This study was completed in August 2008
The coordinate system used for the production of this FIRM is NAD 1983 State Plane
Georgia West FIPS 1002. Corner coordinates shown on the FIRM are in latitude and
longitude referenced to the UTM projection, NAD 83. Differences in the datum and spheroid
used in the production of FIRMs for adjacent counties may result in slight positional
differences in map features at the county boundaries. These differences do not affect the
1
accuracy of information shown on the FIRM.
1.3
Coordination
For the Colquitt County FIS, dated July 16, 1997, FEMA notified the county on March 28,
1995, that a revision to its FIS was being prepared
For the City of Moultrie FIS, dated July 16, 1997, the community was notified by letter on
July 8, 1994, that a revision to its FIS was being prepared.
For this revision, an initial Consultation Coordination Officer’s (CCO) meeting is held with
representatives of the communities, FEMA, and the study contractors to explain the nature
and purpose of the FIS, and to identify the streams to be studied by detailed methods. A final
CCO meeting is held with representatives of the communities, FEMA, and the study
contractors to review the results of the study.
For this countywide FIS, the initial CCO meeting was held on January 28, 2007, and a final
CCO meeting was held on November 12, 2008. The meetings were attended by
representatives of the communities, the Southwest Georgia Regional Development Center,
the Georgia Department of Natural Resources (GADNR), FEMA, and the Study Contractor.
All problems raised at that meeting have been addressed in this study.
2.0
AREA STUDIED
2.1
Scope of Study
This Flood Insurance Study covers the geographic area of Colquitt County, Georgia,
including the incorporated communities listed in Section 1.1.
For the Colquitt County FIS, dated July 16, 1997, Okapilco Creek was studied by detailed
methods from Old Berlin Road, approximately 2.8 miles south of the City of Moultrie, to
State Route 35/U.S. Route 319.
The areas studied by detailed methods were selected with priority given to all known flood
hazard areas, and areas of projected development or proposed construction through August
1985.
For the City of Moultrie FIS, dated July 16, 1997, Okapilco Creek was restudied for its entire
length within the community. Flood hazard information for Channel F from Northeast 9th
Street to Northeast 7th Street was revised to include the backwater effects from the restudied
portion of Okapilco Creek. Flood hazard information for Channel D and the Ochlockonee
River, previously published in the Unincorporated Areas of Colquitt County, Georgia FIS
dated June 17, 1991, was added as the result of corporate limits changes (Reference 3).
For this revision, no new detailed studies have been performed as part of this countywide
study.
Approximate analyses were used to study those areas having a low development potential or
minimal flood hazards. The scope and methods of study were proposed to, and agreed upon,
by FEMA, the Georgia Department of Natural Resources (GADNR), Colquitt County, and
the Study Contractor.
2
2.2
Community Description
Colquitt County and its county seat, Moultrie, are located in southwest of Georgia. Colquitt
County is in southcentral Georgia. It is bordered on the north by Worth and Tift Counties, on
the east by Cook County, on the south by Brooks and Thomas Counties, and on the west by
Mitchell County. Colquitt County is served by U.S. Route 319 and Norfolk Southern
Railway.
The climate of Colquitt County is mild in nature, with the average temperature for the
summer months of June, July, and August equal to 79.8 degrees Fahrenheit (°F) (Reference
4). The average temperature during the winter months of December, January, and February is
51.9°F. During the period 1951-1980, the average annual temperature was 66.5°F.
Precipitation is evenly distributed throughout the year. March and July are the wettest
months, averaging 4.7 and 5.7 inches of rainfall, respectively. October is the driest month
with 2.3 inches of rain. Yearly precipitation averages 50.4 inches.
The floodplains of Moultrie consist of wooded areas, agricultural lands, residences, and
commercial establishments. Numerous city streets, State highways, and railroads also cross
the floodplains. The topography of Moultrie generally consists of rolling hills.
The climate of Moultrie is characterized by moderately warm summers, when temperatures
may rise above 90 degrees Fahrenheit (°F), and cool winters, when temperatures reach below
20°F. Annual precipitation in the study area averages 48 inches with a major portion
occurring in spring and winter.
The population of Colquitt County was 42,053. The land area of the county covers 557
square miles (1,441 square kilometers), of which, 552 square miles (1,430 square kilometers)
of it is land and 4 square miles (11 square kilometers) of it is water (Reference 1).
Colquitt County was created February 25, 1856 from portions of Lowndes and Thomas
counties by an act of the Georgia General Assembly named for U.S Senator Walter T.
Colquitt.
2.3
Principal Flood Problems
Floods can occur along any of the creeks or tributaries in Colquitt County during any time,
but the most frequent flooding occurs during winter and spring. Major floods occurred in
1871, 1907, 1948, 1961, 1964, 1984, and 1986 (Reference 4).
Especially, Okapilco Creek and the Ochlockonee River flow through the City of Moultrie in
poorly defined channels. Tributaries within the study area flow in narrow channels and
through numerous culverts. Floods can occur in Moultrie any time during the year. However,
the most frequent flooding occurs during winter and spring. These floods result from
prolonged heavy rainfall over a large area and are characterized by high peak flows of
moderate duration. Flooding is most severe when antecedent rainfall has resulted in saturated
ground conditions and the infiltration is minimal. Cloudbursts storms that are characterized
by high peak flows, short duration, and small volume can occur any time from late spring to
early fall, but do not constitute a serious flood hazard in the study area.
Large magnitude floods, causing extensive destruction to buildings and roads in the City of
Moultrie, have occurred on Okapilco Creek, the Ochlockonee River, and their tributaries at
least six times during the past 126 years. These floods occurred in 1871, 1907, 1945, 1948,
1961, and 1964. During the flood of April 1, 1948, the Ochlockonee River attained an
3
estimated peak discharge of 18,700 cubic feet per second, the greatest discharge ever
recorded at Moultrie.
2.4
Flood Protection Measures
There are various dams located within the study area. These dams do not protect against the
100-year flood. There are no existing or proposed flood protection projects on Okapilco
Creek, the Ochlockonee River, or their tributaries that would reduce flooding in Moultrie.
3.0
ENGINEERING METHODS
For the flooding sources studied by detailed methods in the community, standard hydrologic and
hydraulic study methods were used to determine the flood-hazard data required for this study. Flood
events of a magnitude that are expected to be equaled or exceeded once on the average during any
10-, 50-, 100-, or 500-year period (recurrence interval) have been selected as having special
significance for floodplain management and for flood insurance rates. These events, commonly
termed the 10-, 50-, 100-, and 500-year floods, have a 10-, 2-, 1-, and 0.2-percent chance,
respectively, of being equaled or exceeded during any year. Although the recurrence interval
represents the long-term, average period between floods of a specific magnitude, rare floods could
occur at short intervals or even within the same year. The risk of experiencing a rare flood increases
when periods greater than 1 year are considered. For example, the risk of having a flood that equals
or exceeds the 100-year flood (1-percent chance of annual flood) in any 50-year period is
approximately 40 percent (4 in 10); for any 90-year period, the risk increases to approximately 60
percent (6 in 10). The analyses reported herein reflect flooding potentials based on conditions
existing in the community at the time of completion of this study. Maps and flood elevations will be
amended periodically to reflect future changes.
3.1
Hydrologic Analyses
Hydrologic analyses were carried out to establish peak discharge-frequency relationships for
each flooding source studied by approximate methods affecting the community.
For the Colquitt County FIS, dated July 16, 1997, Peak discharges for Okapilco Creek were
determined using updated regional regression equations recently published by the USGS in
Techniques for Estimating Magnitude and Frequency of Floods in Rural Basins in Georgia
(Reference 6). Drainage basin areas were delineated and planimetered from USGS
topographic maps (Reference 7). A USGS stream gaging station (No. 02318600) is located
downstream on Okapilco Creek near Berlin, Georgia, with 24 years of record. However, the
drainage area at the gage is greater than two times that of the study area; therefore, the data
could not be weighted or transferred. The regression equations do correlate closely with gage
data.
Adjustments for urbanization were estimated using methods presented in the USGS Water
Supply Paper 2207, Flood Characteristics of Urban Streams in the United States (Reference
8). However, urbanization effects were not significant based on the results of the threeparameter urbanization equations.
For the City of Moultrie FIS, dated July 16, 1997, Peak discharges for Okapilco Creek were
determined using updated regional regression equations published by the USGS (Reference
6). Drainage basin areas were delineated and planimetered from USGS quadrangles
(Reference 9). A USGS stream gage (No. 02318600) is located downstream on Okapilco
Creek near Berlin, Georgia, with 24 years of record. However, the drainage area at the gage
4
Creek near Berlin, Georgia, with 24 years of record. However, the drainage area at the gage is
greater than two times that of the study area and could not be weighted or transferred. The
regression equations do correlate closely with the gage data. Adjustments for urbanization
were estimated using methods presented in USGS Water-Supply Paper 2207 (Reference 8).
However, urbanization effects were not significant based on the results of the three-parameter
urbanization equations.
A summary of the drainage area-peak discharge relationships for the streams studied by
detailed methods is shown in Table 1, "Summary of Discharges."
Table 1. Summary of Discharges
Peak Discharges (cfs)
2-Percent1-PercentAnnualAnnual-Chance
Chance
Drainage Area
(Square Miles)
10-PercentAnnualChance
94.2
2,800
4,500
5,400
7,600
76.3
73.3
2,800
2,700
4,500
4,400
5,400
5,300
7,600
7,400
43.39
3,800
7,200
9,000
14,200
At U.S. Highway 319
Bypass
34.09
3,300
6,200
7,700
12,300
At U.S. Highway 84
27.4
5,925
9,635
11,140
15,000
At Norfolk Southern
Railway
26.15
2,800
5,300
6,600
10,400
Approximately 0.9 mile
downstream of J.
Buckner Road
24.24
2,700
5,000
6,300
10,000
Flooding Source and Location
OCHLOCKONEE RIVER
Just upstream of northern
corporate limits of City
of Moultrie
At Alternate State Route
133
At State Route 133
OKAPILCO CREEK
At Old Berlin Road
0.2-PercentAnnual-Chance
For this revision, discharges for Zone A studies were developed using Region 4 regression
equations for rural areas in Georgia (Reference 2) contained in the USGS report. Drainage
areas along streams were determined using a flow accumulation grid developed from the
USGS 10 meter digital elevation models and corrected National Hydrologic Data (NHD)
stream coverage. Flow points along stream centerlines were calculated using the regression
equations in conjunction with accumulated area for every 10 percent increase in flow along a
particular stream.
5
3.2
Hydraulic Analyses
Analyses of the hydraulic characteristics of flooding from the sources studied were carried
out to provide estimates of the elevations of floods of the selected recurrence intervals.
Users should be aware that flood elevations shown on the FIRM represent rounded wholefoot elevations and may not exactly reflect the elevations shown on the Flood Profiles or in
the Floodway Data tables in the FIS report. For construction and/or floodplain management
purposes, users are encouraged to use the flood elevation data presented in this FIS in
conjunction with the data shown on the FIRM. Locations of selected cross sections used in
the hydraulic analyses are shown on the Flood Profiles (Exhibit 1). For stream segments for
which a floodway was computed (Section 4.2), selected cross section locations are also
shown on the Flood Insurance Rate Map (Exhibit 2)
For the Colquitt County FIS, dated July 16, 1997 cross sections for Okapilco Creek were
determined from field surveys. All bridges, dams, and culverts were field surveyed to obtain
elevation data and structural geometry.
Water-surface elevations of floods of the selected recurrence intervals were computed using
the USACE HEC-2 step-backwater computer program (Reference 10). Starting water-surface
elevations were calculated using the slope/area method. Roughness factors (Manning's "n")
used in the hydraulic computations for Okapilco Creek were chosen by field observation of
the stream and floodplain areas. Channel "n" values ranged from 0.035 to 0.100, and the
overbank "n" values ranged from 0.03 to 0.15.
For the City of Moultrie FIS, dated July 16, 1997, Cross sections for Okapilco Creek were
obtained from field surveys. All bridges and culverts were field surveyed to obtain elevation
data and structural geometry.
Water-surface elevations of floods of the selected recurrence intervals were computed using
the USAGE HEC-2 step-backwater computer program (Reference 9). Starting water-surface
elevations for Okapilco Creek were determined using the slope/area method.
Roughness factors (Manning's "n") used in the hydraulic computations for Okapilco Creek
were assigned on the basis of field inspection of the floodplain areas. Channel "n" values
ranged from 0.035 to 0.060, and the overbank "n" values ranged from 0.030 to 0.150.
For this revision, floodplains were delineated using automated approximate methods.
Floodplains were mapped to include backwater effects that govern each flooding source near
its downstream extent. Floodplains were reviewed for accuracy and adjusted as necessary.
The hydraulic analyses for this study were based on unobstructed flow. The flood elevations
shown on the profiles are thus considered valid only if hydraulic structures remain
unobstructed, operate properly, and do not fail.
3.3
Vertical Datum
All FIS reports and FIRMs are referenced to a specific vertical datum. The vertical datum
provides a starting point against which flood, ground, and structure elevations can be
referenced and compared. Until recently, the standard vertical datum in use for newly
created or revised FIS reports and FIRMs was the National Geodetic Vertical Datum of 1929
(NGVD 29). With the finalization of the North American Vertical Datum of 1988 (NAVD
88), many FIS reports and FIRMs are being prepared using NAVD 88 as the referenced
vertical datum. The average datum shift for Colquitt County, Georgia is -0.565 feet.
6
Flood elevations shown in this FIS report and on the FIRM are referenced to NAVD 88.
These flood elevations must be compared to structure and ground elevations referenced to
the same vertical datum. It is important to note that adjacent counties may be referenced to
NGVD 29. This may result in differences in base flood elevations across county lines.
For information regarding conversion between the NGVD and NAVD, visit the National
Geodetic Survey website at www.ngs.noaa.gov , or contact the National Geodetic Survey at
the following address:
TU
UTH
Vertical Network Branch, N/CG13
National Geodetic Survey, NOAA
Silver Spring Metro Center 3
1315 East-West Highway
Silver Spring, Maryland 20910
(301) 713-3191
Temporary vertical monuments are often established during the preparation of a flood hazard
analysis for the purpose of establishing local vertical control. Although these monuments are
not shown on the FIRM, they may be found in the Technical Support Data Notebook
associated with the FIS report and FIRM for this community. Interested individuals may
contact FEMA to access these data.
4.0
FLOODPLAIN MANAGEMENT APPLICATIONS
The NFIP encourages State and local governments to adopt sound floodplain management programs.
To assist in this endeavor, each FIS report provides 1-percent-annual-chance floodplain data, which
may include a combination of the following: 10-, 2-, 1-, and 0.2-percent-annual-chance flood
elevations; delineations of the 1- and 0.2-percent-annual-chance floodplains; and a
1-percent-annual-chance floodway. This information is presented on the FIRM and in many
components of the FIS report, including Flood Profiles, Floodway Data tables, and Summary of
Stillwater Elevation tables. Users should reference the data presented in the FIS report as well as
additional information that may be available at the local community map repository before making
flood elevation and/or floodplain boundary determinations.
4.1
Floodplain Boundaries
To provide a national standard without regional discrimination, the 1-percent annual chance
(100-year) flood has been adopted by FEMA as the base flood for floodplain management
purposes. The 0.2-percent annual chance (500-year) flood is employed to indicate additional
areas of flood risk in the community. For each stream studied in detail, the 100-year and 500
year floodplain boundaries have been delineated using the flood elevations determined at
each cross section. For each stream studied by approximate methods, the 1-percent-annualchance floodplain boundaries have been delineated using interpolation using 5-foot
topographic mapping developed from USGS DEM data.
The 100- and 500-year floodplain boundaries are shown on the Flood Insurance Rate Map
(Exhibit 2). On this map, the 100-year floodplain boundary corresponds to the boundary of
the areas of special flood hazards (Zones A and AE,), and the 500-year floodplain boundary
corresponds to the boundary of areas of moderate flood hazards. In cases where the 100- and
500-year floodplain boundaries are close together, only the 100-year floodplain boundary
has been shown. Small areas within the floodplain boundaries may lie above the flood
elevations but cannot be shown due to limitations of the map scale and/or lack of detailed
7
topographic data. For the streams studied by approximate methods, only the 100-year
floodplain boundary is shown on the Flood Insurance Rate Map (Exhibit 2).
4.2
Floodways
Encroachment on floodplains, such as structures and fill, reduces flood-carrying capacity,
increases flood heights and velocities, and increases flood hazards in areas beyond the
encroachment itself. One aspect of floodplain management involves balancing the economic
gain from floodplain development against the resulting increase in flood hazard. For
purposes of the NFIP, a floodway is used as a tool to assist local communities in this aspect
of floodplain management. Under this concept, the area of the 1-percent-annual-chance
floodplain is divided into a floodway and a floodway fringe. The floodway is the channel of
a stream, plus any adjacent floodplain areas, that must be kept free of encroachment so that
the 1-percent-annual-chance flood can be carried without substantial increases in flood
heights. Minimum Federal standards limit such increases to 1 foot, provided that hazardous
velocities are not produced. The floodways in this study are presented to local agencies as
minimum standards that can be adopted directly or that can be used as a basis for additional
floodway studies.
The floodways presented in this study were computed for certain stream segments on the
basis of equal-conveyance reduction from each side of the floodplain. Floodway widths
were computed at cross sections. Between cross sections, the floodway boundaries were
interpolated. The results of the floodway computations are tabulated for selected cross
sections (see Table 2, “Floodway Data”). In cases where the floodway and 100-year
floodplain boundaries are either close together or collinear, only the floodway boundary is
shown.
Floodways are computed on the basis of equal-conveyance reduction from each side of the
floodplain. Floodway widths are computed at cross sections. Between cross sections, the
floodway boundaries are interpolated. The results of the floodway computations are
tabulated for selected cross sections. In cases where the floodway and 1-percent-annualchance floodplain boundaries are either close together or collinear, only the floodway
boundary is shown.
Encroachment into areas subject to inundation by floodwaters having hazardous velocities
aggravates the risk of flood damage and heightens potential flood hazards by further
increasing velocities. To reduce the risk of property damage in areas where the stream
velocities are high, the community may wish to restrict development in areas outside the
floodway.
Near the mouths of streams studied in detail, floodway computations are made without
regard to flood elevations on the receiving water body.
Along streams where floodways have not been computed, the community must ensure that
the cumulative effect of development in the floodplain will not cause more than a 1.0-foot
increase in the BFEs at any point within the community.
The area between the floodway and 1-percent-annual-chance floodplain boundaries is termed
the floodway fringe. The floodway fringe encompasses the portion of the floodplain that
could be completely obstructed without increasing the water-surface elevation of the 1percent-annual-chance flood more than 1 foot at any point. Typical relationships between
the floodway and the floodway fringe and their significance to floodplain development are
8
shown in Figure 1.
Figure 1. Floodway Schematic
5.0
INSURANCE APPLICATION
For flood insurance rating purposes, flood insurance zone designations are assigned to a community
based on the results of the engineering analyses. These zones are as follows:
Zone A
Zone A is the flood insurance rate zone that corresponds to the 100-year floodplains that are
determined in the Flood Insurance Study by approximate methods. Because detailed hydraulic
analyses are not performed for such areas, no base (100-year) flood elevations (BFEs) or depths are
shown within this zone.
Zone X
Zone X is the flood insurance rate zone that corresponds to areas outside the 500-year floodplain,
areas within the 500-year floodplain, areas of 100-year flooding where average depths are less than 1
foot, areas of 100-year flooding where the contributing drainage area is less than 1 square mile, and
areas protected from the 100-year flood by levees. No BFEs or depths are shown within this zone.
6.0
FLOOD INSURANCE RATE MAP
The Flood Insurance Rate Map is designed for flood insurance and floodplain management
applications.
For flood insurance applications, the map designates flood insurance rate zones as described in
Section 5.0. Insurance agents use the zones and BFEs in conjunction with information on structures
and their contents to assign premium rates for flood insurance policies.
9
TABLE 2
1
2
1
1631521
1639441
1652641
1666371
1704381
1709661
1720751
1738701
DISTANCE
680
1,130
600
1,110
430
630
390
1,170
WIDTH
(FEET)
4,930
9,370
3,840
9,080
4,420
3,920
3,140
9,960
SECTION
AREA
(SQUARE
FEET)
FLOODWAY
AND INCORPORATED AREAS
COLQUITT COUNTY, GA
FEDERAL EMERGENCY MANAGEMENT AGENCY
Feet above State Route 38
No floodway data computed
A
B
C
D
E
F
G
H
I - N2
OCHLOCKONEE
RIVER
CROSS
SECTION
FLOODING SOURCE
1.9
0.9
2.7
0.9
2.1
2.2
2.6
0.8
MEAN
VELOCITY
(FEET PER
SECOND)
253.6
254.1
254.8
255.5
257.4
259.1
261.0
262.5
WITHOUT
FLOODWAY
(NAVD)
254.6
255.1
255.8
256.5
258.4
260.1
262.0
264.3
WITH
FLOODWAY
(NAVD)
OCHLOCKONEE RIVER
FLOODWAY DATA
253.6
254.1
254.8
255.5
257.4
259.1
261.0
262.5
REGULATORY
(NAVD)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.9
INCREASE
BASE FLOOD WATER SURFACE
ELEVATION
TABLE 2
1
2
1
1716001
1736591
1799421
1900801
1981581
2015381
2030001
2051971
2061101
2072561
2089561
2094001
2103181
2115381
2164801
DISTANCE
520
964
1,081
1,437
1,250
1,078
900
470
886
400
710
700
1,796
1,340
1,199
WIDTH
(FEET)
165
528
661
910
580
483
577
459
388
355
239
176
170
159
4,620
SECTION
AREA
(SQUARE
FEET)
FLOODWAY
AND INCORPORATED AREAS
COLQUITT COUNTY, GA
FEDERAL EMERGENCY MANAGEMENT AGENCY
Feet above mouth
No floodway data computed
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P - V2
OKAPILCO
CREEK
CROSS
SECTION
FLOODING SOURCE
4.7
1.5
1.2
0.8
1.3
0.7
0.6
0.7
0.9
0.9
1.4
1.9
1.9
2.1
1.5
MEAN
VELOCITY
(FEET PER
SECOND)
230.1
232.5
238.4
248.1
258.4
263.9
265.5
268.1
268.2
272.2
272.9
274.1
274.2
274.2
277.6
WITHOUT
FLOODWAY
(NAVD)
230.6
233.3
239.3
249.0
258.6
264.8
266.1
268.6
269.2
272.7
273.6
275.0
275.2
275.2
278.0
WITH
FLOODWAY
(NAVD)
OKAPILCO CREEK
FLOODWAY DATA
230.1
232.5
238.4
248.1
258.4
263.9
265.5
268.1
268.2
272.2
272.9
274.1
274.2
274.2
277.6
REGULATORY
(NAVD)
0.5
0.8
0.9
0.9
0.2
0.9
0.6
0.5
1.0
0.5
0.7
0.9
1.0
1.0
0.4
INCREASE
BASE FLOOD WATER SURFACE
ELEVATION
For floodplain management applications, the map shows by tints, screens, and symbols, the 100-year
floodplains used in the hydraulic analyses.
The countywide Flood Insurance Rate Map presents flooding information for the entire geographic
area of Colquitt County. Previously, Flood Insurance Rate Maps were prepared for each incorporated
community and the unincorporated areas of the County identified as flood-prone. This countywide
Flood Insurance Rate Map also includes flood-hazard information that was presented separately on
Flood Boundary and Floodway Maps, where applicable. Historical data relating to the maps prepared
for each community are presented in Table 3, “Community Map History.”
7.0
OTHER STUDIES
This report either supersedes or is compatible with all previous studies published on streams studied in
this report and should be considered authoritative for the purposes of the NFIP.
8.0
LOCATION OF DATA
Information concerning the pertinent data used in the preparation of this FIS can be obtained by
contacting FEMA, Federal Insurance and Mitigation Administration, Koger Center - Rutgers
Building, 3003 Chamblee Tucker Road, Atlanta, Georgia 30341.
Future revisions may be made that do not result in the republishing of the Flood Insurance Study
report. To ensure that any user is aware of all revisions, it is advisable to contact the map repository of
flood hazard data located in the community.
9.0
BIBLIOGRAPHY AND REFERENCES
1.
U.S. Department of Commerce, Bureau of the Census, 2000 Census, Fact Sheet, Colquitt
County, Georgia.
2.
U.S. Department of the Interior, U.S. Geological Survey, The National Flood-Frequency
Program – Methods for Estimating Flood Magnitude and Frequency in Rural and Urban
Areas in Georgia, August 1999.
3.
Federal Emergency Management Agency, Flood Insurance Study, Colquitt County and
Unincorporated Areas, Georgia, Washington, D.C., June 17, 1991
4.
U.S. Department of Commerce, National Oceanic Atmospheric Administration, Climatology
of the United States No. 81, Monthly Normals of Temperature, Precipitation, and Heating
and Cooling Degree Days, 1951-81, Alabama, September 1982.
5.
U.S. Department of the Interior, Geological Survey, Georgia District, Atlanta, Georgia.
6.
U.S. Department of the Interior, Geological Survey, Water Resources Investigation 93-4016,
Techniques for Estimating Magnitude and Frequency of Floods in Rural Basins in Georgia,
T. C. Stamey and G. W. Hess, Atlanta, Georgia, 1993.
12
7.
Abrams Aerial Survey Corporation, Topographic Maps Compiled by Photogrammetric
Methods, Scale 1"=200', Contour Interval 2 Feet, April 1974, photography flown in April
1973.
8.
U.S. Department of the Interior, Geological Survey, Water Supply Paper 2207, Flood
Characteristics of Urban Streams in the United States, V. B. Sauer, W. 0. Thomas, and V.
A. Stricker.
9.
U.S. Department of the Interior, Geological Survey, 7.5-Minute Series Topographic Maps,
Scale 1:24,000, Contour Interval 10 Feet: Coolidge, Georgia, 1978, Photorevised 1987;
Moultrie, Georgia, 1978, Photorevised 1988; Pineboro, Georgia, 1974, Photorevised 1988.
10.
Federal Emergency Management Agency, Flood Insurance Study, Colquitt County and
Unincorporated Areas, Georgia, Washington, D.C., July 16, 1997.
11.
Federal Emergency Management Agency, Flood Insurance Study, City of Moultrie, Georgia,
Washington, D.C., July 16, 1997.
13
TABLE 3
1
1
1
AND INCORPORATED AREAS
COLQUITT COUNTY, GA
FEDERAL EMERGENCY MANAGEMENT AGENCY
Non-floodprone community.
July 18, 1975
Riverside, Township of
November 22, 1974
N/A
N/A
1
N/A
N/A
May 19, 1978
N/A
INITIAL
IDENTIFICATION
Norman Park, City of
Moultrie, City of
Funston, City of
Ellenton, Town of
Doerun, City of
Colquitt County
(
(Unincorporated
Areas)
Berlin, Town of
COMMUNTIY
NAME
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
August 16, 1988
September 25, 2009
May 15, 1979
N/A
September 25, 2009
N/A
June 17, 1991
N/A
FIRM
EFFECTIVE DATE
July 16, 1997
July 16, 1997
FIRM
REVISIONS DATE
COMMUNITY MAP HISTORY
FLOOD HAZARD
BOUNDARY MAP
REVISIONS DATE