Copperstone FS-CS 950125Federal Emergency Management gency
Washington, D.C. 20472
CERTIFIED NAiL
RETURN RECEIPT REQUESTED
IN REPLY REFER TO:
Case No.: 94-06-307P
The Honorable Tom Morton
Mayor, City of Coppell
255 Parkway Boulevard
Coppell, Texas 75019
Community~ City of Coppell,
Texas
Community No.i 480170
Panel Affected: 0010 E
Effective Date of
This Revi,ion= JAN 25 1995
102-I-A
Dear Mayor Mortonl
This is in response to a request for-a revision to the effective Flood
Insurance Study (FIg) and National Flood Insurance Program (NFIP) map for
your community. Specifically, this responds to a letter dated June 2?, 1994,
from Mr. Kenneth M. Griffin, P.E., City Engineer, City of Coppell, regarding
the effective FIg report and Flood Insurance Rate Map (FIR//) for the City of
Coppell, Texas. Mr. Criffin requested that we revise the effective FIRM to
show the effects of channelization and construction of Parkway Boulevard
along Cottonwood Branch and channelization along Denton Creek.
All data required to complete our review of this request were submitted with
Mr. Criffin*s June 27 letter, and a letter dated September 8, 1994, and
transmittal dated November 10, 1994, from Ms. Terl D. Jones, Dowdey, Anderson
and Associates, Inc. All fees necessary to process this Letter of Map
Revision (LOMR), a total of ~1,475, have been received.
We have completed our review of the submitted data and the flood data sho~n
on the effective' FIRM, and have revised the FIRM to modify the elevations and
floodplain and floodway boundary delineations of a flood having a 1-percent
probability of being equaled or exceeded in any given year (base flood) along
Cottonwood Branch, from Denton Tap Road to approximately 3,200 feet upstream
of the Parkway Boulevard Bridge, and along Denton Creek, from Denton Tap Road
to approximately 6,100 feet upstream. As a result of this revision, the
Special Flood Hazard Area decreases along Denton Creek and Cottonwood Branch.
The base (100-year) flood elevations (BFEs) decrease along Denton Creek and
increase slightly along Cottonwood Branch in the vicinity of Parkway
Boulevard. All increases in BFEs are located on the requester's property.
The floodways for both creeks change as a result o£ this revision. Public
notice of the revised floodplaln and floodway was given in the Citizen's
Advocate on September 23, 1994.
The modifications are shorn on the enclosed annotated copies of FIRM
Panel 480170 0010 E and the Floodway Data Table for Cottonwood Branch. This
LOHR hereby revises this panel of the effective FIRM dated April 15, 1994,
and the Flood Profile and Floodway Data Table in the FIS report dated
April 15, 1994.
The following table is a partial listing of existing and modified BFEs:
Location
Cottonwood Branch Denton Tap Road
Approximately 800 feet upstream
of Denton Tap Road
Approximately 2,900 feet upstream
of Denton Tap Road
Existing BFE Modified BFE
(feet)* (feet)*
458 458
462 463
468 468
Denton Creek
Just downstream of Denton Tap Road
Approximately 1,400 feet upstream
of Denton Tap Road
Approximately 5,100 feet upstream
of Denton Tap Road
Approximately 6,100 feet upstream
of Denton Tap Road
458 458
462 460
466 ~65
467 467
*Referenced to the National Geodetic Vertical Datum, rounded to the nearest
whole foot
Public notification of the revised BFEs will be given in the Citizen's
Advocate on or about February 17 and February 24, 1995. A copy of this
notification is enclosed. Any request for reconsideration must be based on
scientific or technical data. In addition, a notice of changes will be
published in the Federal ReKister.
Because this LOMR will not be printed and distributed to primary users, such
as local insurance agents and mortgage lenders, your community will serve as
a repository for these new data. We encourage you to disseminate the
information reflected by this LOMR throughout the community, so that
interested persons, such as property owners, local insurance agents, and
mortgage lenders, may benefit from the information. We also encourage you to
prepare a related article for publication in your community's local
newspaper. This article should describe the assistance that officials of
your community will give to interested persons by providing these data and
interpreting the NFIP maps.
The revisions are effective as of the date of this letter; however, within
90 days of the second publication in the Citizen's Advocate, a citizen may
request that the Federal Emergency Management Agency (FEMA) reconsider the
determination made by this LOMR. Any request for reconsideration must be
based on scientific or technical data. All interested parties are on notice
that, until the 90-day period elapses, the determination to modify the BFEs
presented in this LOMR may itself be modified.
Due to present funding constraints, FEMA must limit the number of physical
map revisions processed. Consequently, we will not republish the FIRM and
FIS report for your community to reflect the determination of this LOMR at
this time. However, when changes to FIRM Panel 480170 0010 E and the
report for your community warrant a physlcal revision and republication in
the future, the determination in this LOHR will be incorporated at that time.
The floodway is provided to your community as a tool to regulate floodplain
development. Therefore, the floodway modifications described in this letter,
while acceptable to FEI/A, must also be acceptable to your community and
adopted by appropriate community action, as specified in Paragraph 60.3(d) of
the NFIP regulations.
This response to Mr. Criffin's request is based on minimum floodplain
management criteria established under the NFIP. Your community is
responsible for approving all proposed floodplain developments, includlng
this request, and for ensuring that necessary permits required by Federal or
State law have been received. With knowledge of local conditions and in the
interest of safety, State and community officials may set higher standards
for construction, or may limit development in floodplain areas. If the State
of Texas or your community has adopted more restrictive or comprehensive
floodplaln management criteria, these criteria take precedence.
The basis of this LONR is, in whole or in part, a channel-modification
project. I/FIP regulations, as cited in Paragraph 60.3(b)(7), require that
communities assure that the flood-carrying capacity within the altered or
relocated portion of any watercourse is maintained. This provision is
incorporated into your community's existing floodplaln management
regulations. Consequently, the ultimate responsibility for maintenance of
the channel modification rests with your community.
The map panel as listed above and as revised by this letter will be used for
all flood insurance policles and renewals issued for your community.
.A Consultation Coordination Officer (CCO) has been designated to assist your
community with any difficulties you may be encountering in enacting the
floodplain management regulations. The CCO will be the primary llaison
between your community and FENA. For information on your CCO, please
contact:
Hr. James LeCrotte
Director, Nicigation Division
Federal ~mergency Hanagement Agency, Region VI
Federal Regional Center, Room 206
800 North Loop 288
Denton, Texas 76201-3698
(817) 898-5127
Any questions may be directed to your CCO.
Sincer
~ey~ P.~-.~ Chief
Hazard Identification Branch
Mitigation Directorate
Enclosures
cc=
Hr. Kenneth N. Griffin~ P.E.
City Engineer
City of Coppell
Ms. Terl D. Jones
Dovde7~ Anderson and Associates~ Inc.
ZONE X
NE¸
465
ZONE X
X
ARROWHEA]3 LANE~
COPPERSTONE TRAIL~
AUBURN
MARKED TREE
ZONE X
MINYARD
AE
WINDING
HOLLOW LANE-
INE X
ZONE X
463
464
WILLOW
ZONE X
LANE
COUNTY BOUNDARY
;EVISED AREA
I
CORPORATL ~
ZONE X
ZONE:
X
196
PARKWAY
APPROXIMATE SCALE
10oo 0
I I ' I '1 I I
MAP LEGEND
Revised Floodway
Revised lO0-Year Floodplain
Revised SOO-Year Floodplain
NATIONAL FLOOD INSURANCE PROORAR
1000 FEET
1
FIRM
FLOOD INSURANCE RATE MAI)
and
STREET INDEX
CiTY OF
COPPELL,
TEXAS
DALLAS AND DENTON COUNTIES
ONLY PANEL PRINTED
TO
'COMMUNITY-PANEL NUMBER
480170 0010 E
MAP REVISED:
APRIL 15, 1994
Federal Enm~ncy Mm~m~ent A~ncy
FLOODING SOURCE FLOODWAY BASE FLOOD
WATER SURFACE ELEVATION
SECTION MEAN 'REGULATORY FLOODWAY FLOODWAY
, WIDTH ARF_J% VELOCITY INCREASE
CROSS SECTION DISTANCE (FEET) i (SQUP.RE (FEET PER
FEET; S_~OND) (FEET NGVD) ..
Denton Creek I
A 21,1402 329 5,316i 3.9 452.4 452.4 453.4 1.0
B 23,3701 325 { * * 453.0 453.0 453.5 0.5
C 26,2201 571 3,677 5.8 454.7 454.7 455.1 0.4
D 29,280l' 1,134 8,383 2.5 456.3 ~ 456.3 457.0 0.7
E 36,8661 931 7,271 2.1 466.7 466.7 467.4 I 0.7
I F 39,200~ 499 3,526 2.9 468.8 468·8 469.6 ' 0.8
Old Denton Creek
A 1,1002 90 * * 453.0 453.0 453.6 0.6
Cottonwood Branch
A 3,8502 356 1,780 .... 4..1 463.7 463.7 464.5 0.8
B 6,710z 587 ~, ,2,340 3.1 ' '470.1 4~0'.0 ...... ~7'0'27 .... 0.7'
C 11,3352. 270 2,156 '"3 1 ~8/.4 ~-~ / .~ u.,
· :' "' ..... l
D 14,705; 223 1,411 4..0 495.1 495.1 \ 495.8 0.7
EVISED DATA
1Feet above confluence with Elm Fork of Trinity River EVI~DIU~
ZFeet above confluence with Denton Creek
· Data not available gi:R I:: T I
~ FEDERAL EMERGENCY MANAGEMENT AGENCY .v .
- FLOODWAY DATA DATED
m CITY OF COPPELL, TX JAN 2 5
I~r?'l (DALLAS & DENTON COS.) DENTON CREEK - OLD DENTON CREEK - coTTONWOOD BRANCH
FLOODING SOURCE FLOODWAY BASE FLOOD
WATER SURFACE ELEVATION
WIDTH ARF_J% VELOCITY WITHOUT WITH
CROSS SECTION DISTANCE (FEET) (SQUP.RE (FEET PER
FEET; S_~OND) (FEET NGVD)
Denton Creek
A 21,1402 329 5,316 3.9 452.4 452.4 453.4 1.0
B 23,370~ 325 * * 453.0 453.0 453.5 0.5
C 26,2201 571 3,677 5.8 454.7 454.7 455.1 0.4
D 29,280~ 1,134 8,383 2.5 456.3 456.3 457.0 0.7
E 36,866~ 931 7,271 2.1 466.7 466.7 467.4 0.7
F 39,200~ 499 3,526 2.9 468.8 468.8 469.6 0.8
Old Denton Creek
A 1,1002 90 * * 453.0 453.0 453.6 0.6
Cottonwood Branch
A 3,8502 356 1,780 4.1 463.7 463.7 464.5 0.8
B 6,7102 587 !,,2,340 3.1 ''470.1 4~0~0 ...... ~76'~7 ' 0.7
C 11,3352. 270 2,156 '"3.1 48/.4
D 14,705; 223 1,411 4..0 495.1 495.1 \ 495.8 0.7
tREviSED DATA
Iqlr
Z
Z
470
46O
4,5O
4~0
~_Z-~Z--Z--~Z- - -- ~-'-'-----' ' "~
-4--LL S-___~_~ I I I I I I J I [ I I I I I I I I i i I i I I I I I I t I 11
~-_- ........... I I I I I I I I II
-1 .'- -J,-.J-J- ...... ~1 I I I I I I I j I li.I I I I I I I j j ' I I I I i i i i il
Z ZT--FZ"ZZZ
_ z Zz ZZ_ zZ_ zZZZ - ~.2.._-- .:.
~__ _~_ .......... -.,_~_ , - ..... . -
H-.-I-I ~ -.--., --~ ;;
~- ~.~ ~-, ........ .~_~.
........ ._~___-_ .-. - --~;~-- -': Z:"
" ............ ' !
_a_ _~ ....
; _~ _. _- _-* - _- _, = _- _ _-
ZzE_~z -
...... .~____
__. ......... : .... -
~; ................ .-~.~ . ---
..~ ............. ___ _~ .... '_-2
zzzC z
~ - -'1---~ -YEAR FLOOD
"'"'"'"'"'"" '"'"" "" " ""'"' ,,,,, IIIII .... ,oo-YEAR F,O00
~IIJ'''L'''''''''', ,,,,,,,, ,,~ ,, ,,,,,,,"'" '"
~I~''''''''''', ,,,,,,,, ,,. ,, ,.,.,, ,,,,, ,,,,,
'""'"'""'""' '"'" "" " t,,,,,, ..,,, ,,,,, ~--~
'"'" ! ' ' ' '" " '"'"' il''' ,,,,,
' ' ' ' ' ' ' ' ''t " ' ' ' ' ' ' ' il''' ~ ....... '0-YEAR '=~-000
I~l~' " "' ' " ~''''~ i~''' ~,,,,
I I IllJ I I I I I 11 I I I I I ~1 I I I I I I I I I I I I I I I I t I
I.l,,1'"NI I I I I I I I 1 t I I I I I ,,! i'- i I I I I I I I I I I I I I I I I I I I I I I I I I
I I r__.lll J I I I I I I I I I I I I I I B j I I I I I I I I I I I I t I I I I I I I I I I I I I I I I A
I 1'"4.~~ I I I I I I I I I I I I ',,d/ I I 11 I I I I I I I I I I I I I I ' I I I I I I I
,,,,,,,,,,,,,,,,,,, ,,, ,, ,,,,,,I tt~, ,,,,, I..J JJ, J'J.qjli~JJ6 ~J'J'J
[llllltllllllllllll i IIIIIII Eli I1 -iF1'-- III111.1 ~[11 IIIII ....... ~ ,~c~jJ~ .,J...~l~
29 30 31 32 33 34 35 36
STREAM DISTANCE IN THOUSANDS OF FEE'IC ABOVE CONFLUENCE WITH ELM FORK OF TRINITY RIVER
lle
UJ
uJ ~ ~
~.J
U.
09P
'REFLECT LOMlt
470
460
45O
430
500
D REACH
100o
1500
2500 3OOO 3500 4000 4500
STREAM DISTANCE IN FEET ABOVE CONFLUENCE WITH DENTON CREEK
LEGEND
500. YEAR FLOOD
..... 100 - YEAR FLOOD
50 - YEAR FLOOD
10 - YEAR FLOOD
DATE9 ~,,~ ~
12P
CHANCES ARE MADE IN DETERMINATIONS OF BASE FLOOD ELEVATIONS FOR THE CITY OF
'COPPELL, DALLAS AND DENTON COUNTIES,
INSURANCE PROGRAM
On April 15, 1994, the Federal
TEXAS, UNDER THE NATIONAL FLOOD
Emergency Management Agency (FEMA)
identified Special Flood Hazard Areas (SFHAs) in the City of Coppell, Dallas
and Denton Counties, Texas, through issuance of a Flood Insurance Rate Map
(FIRM).
The Mitigation Directorate has determined that modification of the
elevations of the flood having a 1-percent chance of occurrence in any given
year (base flood) for certain locations in the City of Coppell is
appropriate. The modified base (100-year) flood elevations (BFEs) revise the
FENA FIRM for the comity.
The changes are being made pursuant to Section 206 of the Flood Disaster
Protection Act of 1973 (Public Law 93-234) and are in accordance with the
National Flood Insurance Act of 1968, as amended (Title XlII of the Housing
and Urban Development Act of 1968, Public Law 90-a8), 42 U.S.C. 4001-4128,
and 44 CFR Part 65.
A hydraulic analysls vas performed to incorporate channellzatlon and
construction of the Parkvay Boulevard Bridge and has resulted in a revised
delineatlon of the regulatory floodvay, a reduction in SF~A~ and revised BFEs
along Cottonvood Branch from the Parkvay Boulevard Bridge to 3,200 feet
upstream and along Denton Creek from approximately 4,000 feet upstream of
Denton Tap Road to 4,700 feet upstream. The table belov indicates the
modified BFEs for several locations along the affected lengths of Cottonvood
Branch and Denton Creek.
Any person having knowledge or wishing to comment on these changes
should immediately notify:
The Honorable Tom Morton
Mayor, City of Coppell
255 Parkway Boulevard
Coppell, Texas 75019