Old Town LOMR-CS080221February 21, 2008
Frank Pagano
Director, FEMA Mitigation Division
800 N. Loop 288
Denton, TX 76209
RE: FEMA Map Modification for the City of Coppell
Tributary G -1
Dear Frank Pagano:
The City of Coppell (City) has retained the services of Freese and Nichols, hie. (FNI) to evaluate the
DFIRM floodplain for Tributary G -1 currently a Zone A. FNI compared the new FEMA mapping to the
existing FIRM and compared that delineation to recent hydrologic and hydraulic studies provided by the
City. Recent design of Coppell Road and Bethel Road has required developers to determine a 100 -year
water surface elevation to reflect proposed changes. These studies were provided to FNI by the City and
were reviewed. It was determined by FNI that these studies represent the most current hydrologic and
hydraulic information.
Based on the hydraulic models provided, the existing 100 -year base flood elevation upstream Bethel Road
was 507.19 ft and approximately 504.93 upstream of Coppell Road and 504.23 downstream. FNI
obtained the City current 2 -ft contours and delineated the existing 100 -year water surface. The
comparison between the three (3) sources, the FIRM, DI'MM and City provided data, is provided in the
attached Figure 1. FNI has also included the effective FIRM for your reference.
FNI has concluded that the recent studies in conjunction with current topography best represent the
existing 100 -year floodplain. The City protests the approval of this DFIRM and respectively requests a
meeting with a FEMA representative at the earliest convenience to discuss updates and concerns with the
new DFIRM. Please contact Mike Wayts to schedule a meeting at 214- 217 -2222.
Sincerely,
Mike Wayts, P.E., C.F.M
Attachments
cc: Keith Marvin, P.E. - City of Coppell
TAH &HIL.etter to FEMAdoc
'I
All
y
r
a ll
y � v
92
F 4 # y' �,.��f+.. UCO� .. � Y-o i�� J� ♦ .. yo i ` ati �t . i � � �4.
L T
,J
,-
14A Ilk
City of Coppell CPLD8130
■,
c
Tributary G -1 DPDruarV 2008
CO Februa 008
Z
scn e
Freese and Nichols ,' = 300
1701 ,T—MarketStSte.500,LE5'I Zone A Floodplain °E =� °�E°
Dail DCS FIG D.11-, Tezac 75202 -2001
t214) 217-2200 °R-- ---
c
G
,
Z Z
T ip
'I
All
y
r
a ll
y � v
92
F 4 # y' �,.��f+.. UCO� .. � Y-o i�� J� ♦ .. yo i ` ati �t . i � � �4.
L T
,J
,-
14A Ilk
City of Coppell CPLD8130
■,
c
Tributary G -1 DPDruarV 2008
CO Februa 008
Z
scn e
Freese and Nichols ,' = 300
1701 ,T—MarketStSte.500,LE5'I Zone A Floodplain °E =� °�E°
Dail DCS FIG D.11-, Tezac 75202 -2001
t214) 217-2200 °R-- ---
- C p
d Y�
V I L•-.I C _ __ Z c-7 -� � _ _
its
w C = o n? m
G = q r _ a$
p=
Lu
p o
tC �
1 ( �
uj I O
Z �� - l
} O - � 13d,
LLI
ct
:j> r_
cr
fZ
,;tr�n -yd7d
Y � luc�_�tia
0
a�
J C
U N
C
1
J v�iF
aZ
U Op (j
O U /
-oz v
X
mac, i
W
7 Z
x < u
- v: I