Alexander Ct-CS070727
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Rhonda Adloo - Fwd: Grapevine Creek/Alexander Court LOMR Review
From:
To:
Date:
Sub,ject:
Attachmen ts:
Ken Griffin
Rhonda Adloo
7/27/2007 11: 15 AM
Fwd: Grapevine Creek! Alexander Court LOMR Review
Grapevine Creek! Alexander Court LOMR Review; Grapevine Creek LOMR
Application; Grapevine Creek LOMR Application; Grapevine Creek LOMR
application; Grapevine Creek LOMR Application Approval Letter; Grapevine Creek
LOMR Application; Grapevine Creek LOMR Application; Grapevine Creek LOMR
Application; RE: Grapevine Creek LOMR Application Approval Letter; Grapevine
Creek - City Effective Modeling; RE: Grapevine Creek - City Effective Modeling; FW:
Alexander Court; Grapevine Creek
Odalys,
Per our telephone conversation this morning, please email the most recent digital files for the Grapevine Creek
LOMR Application to me. The files contained on the CD in the most recent submittal do not reflect the modeling
in the report. Also, please note the following items as we discussed:
1. The bridge modeling method used for the Bethel Road crossing of Grapevine Creek in the revised existing
model is not consistent with the imported effective model. The imported effective model uses the energy method
and the revised existing model uses the Yarnell method.
2. Contraction and expansion coefficients for cross sections 27620 and 27540 in the revised existing model are
not consistent with the imported effective model.
Please provide an explanation as to the differences between the imported effective and revised existing models.
Please provide updated digital files by email if the revised existing modeling is changed as a result of the above
comments. Also, please provide hardcopies of any modeling and workmaps that change as a result of updated
modeling. PDF copies provided by email will be sufficient.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: prad.Qi~~eriDg@JsLt1lley-horn .com
file:IIC: \Documents%2 Oand %2 OSettings\rbrother\Local %20Settings\ Temp \XPgrpwise\46... 7/2712007
Page 1 of 1
Rhonda Adloo - Fwd: Grapevine Creek/Alexander Court LOMR Review
From:
To:
Date:
Sub,iec't:
Attachments:
Ken Griffin
Rhonda Ad100
7/271200711:15 AM
Fwd: Grapevine Creek/Alexander Court LOMR Review
Grapevine Creek! Alexander Court LOMR Review; Grapevine Creek LOMR
Application; Grapevine Creek LOMR Application; Grapevine Creek LOMR
application; Grapevine Creek LOMR Application Approval Letter; Grapevine Creek
LOMR Application; Grapevine Creek LOMR Application; Grapevine Creek LOMR
Application; RE: Grapevine Creek LOMR Application Approval Letter; Grapevine
Creek - City Effective Modeling; RE: Grapevine Creek - City Effective Modeling; FW:
Alexander Court; Grapevine Creek
Ken:
As discussed this afternoon with Nadia Dahab, attached are KHA's comments for the Grapevine Creek LOMR
application for Alexander Court, dated April 26, 2007, prepared by Nathan D. Maier Consulting Engineers, Inc. If
you have any questions regarding the attached comments, please do not hesitate to give us a call.
Thank you,
Brad W. Pickering, EIT (IN), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, TX 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
file://C :\Documents%20and%20Settings\rbrother\Loca1%20Settings\ T emp\XPgrpwise\46.,. 7/27/2007
",,_n
....... -, .,
Kimley-Horn
and Associates, Inc.
May 23, 2007
Mr. Kenneth M. Griffin, P.E.
Director of Engineering/Public Works
255 Parkway Boulevard
Coppell, TX 75019
RE: Letter of Map RevisiOll (LOMR) Review
Grapevine Creek/Alexander Court
KHA No.: 063124008
Dear Mr. Griffin:
Kimley-Horn and Associates, Inc. (KHA) has performed the first review of the
Grapevine Creek LOMR application for Alexander Court, dated April 26, 2007,
prepared by Nathan D. Maier Consulting Engineers, Inc. (NDMCE).
KHA reviewed the document for adherence to currently published City of
Coppell and Federal Emergency Management Agency (FEMA) drainage design
guidelines. KHA recommends that NDMCE address the following items:
1. The MT-2 Form 2, page 1 of 2, states that the upstream tie-in of the
study is at cross section 27620. Cross section 27900 has been added to
the revised existing conditions model and is not included in the effective
model. Revise the forms to reflect an effective tie-in upstream of the
model modifications.
2. Revise the Floodplain Work Map to include the benchmarks and vertical
datum used for the on-ground survey.
3. The water surface elevations table in the report text is not consistent with
the modeling output for the effective flood way HEC-RAS model.
Revise the report to be consistent with the modeling output.
4. Revise the Location Map to rcnect the boundaries of the LOMR
submittal.
5. Cross section 22600. the location of the downstream effective tie-in, is
not shown on the Floodplain Work Map. Revise the workmap to show
this cross section.
.
TEL 972 770 1300
FAX 972 239 3820
.
Suite 1800
12700 Park Cenlral Drive
Dallas, Texas
75251
':;"
~=~
Kimley-Horn
and Associates, Inc.
Mr. Kenneth M. Griffin
May 23, 2007
Page 2 of2
6. The sum of reach lengths for the HEC-RAS revised condition model
does not match the sum of the reach lengths in the FEMA effective
model. Revise the reach lengths in the revised condition model or
explain this discrepancy.
7. The report text states that Manning's 'n' values were taken from the
effective model, but they vary from the effective model at multiple
locations. Revise the model to be consistent with the effective modeling
or justify the proposed Manning's 'n' values.
8. Property owner notification is required by NFIP regulations 65.7(b)(1)
due to the floodway revision. The notices must include the extent of
revision, the changes to the floodway, and contact information for any
interested parties.
9. Revise the legend on the Floodplain Work Map to reflect revised existing
conditions and not proposed conditions.
10. Future development adjacent to the subject reach shall respect both the
100-year fully developed and FEMA effective floodplain boundaries.
Please note that any future development adjacent to the subject reach will need to
comply with all of the provisions set forth in the ordinances of the City of
Coppell including, but not limited to, the Subdivision Ordinance, Zoning
Ordinance, and Floodplain Management Ordinance.
If you have any questions regarding the comments included in this letter, please
feel free to contact us at 972.770.1300.
Sincerely,
KIMI.EY-HORN AND ASSOCIATES, INC.
~~9b~
Steven D. Galloway, P.E., CFM
G:\HYDRO\PROJECTS\631 24008\Alexander Court\20070523.doc
Page 1 of 1
Rhonda Adloo - Fwd: RE: Denton Creek Bridge Plans
From:
To:
Date:
Subject:
Attachments:
Ken Griffin
Rhonda Adloo
7/2712007 11:16 AM
Fwd: RE: Denton Creek Bridge Plans
RE: Denton Creek Bridge Plans; RE: Grapevine Creek! Alexander Court LOMR
Review; RE: Grapevine Creek LOMR Application Approval Letter; RE: Floodplain
Study for Alexander Tract
Thanks Ken, thats works great...mboyd
-----Original Message-----
From: Ken Griffin [mailto:kgriffin@cLcoppell.tx.us]
Sent: Wednesday, January 17, 2007 15:57
To: Mike Boyd
Subject: Denton Creek Bridge Plans
Mike
I was correct the first time. The plans are available through our web site as follows:
go to \\iw\\i.ci,c;QppeJl,tx.us
click on "Public Documents" on the left hand side;
click on "Engineering";
click on "Number Projects" on the right side;
click on "Street Projects";
click on "ST 82-01 Denton Tap";
click on "Plans";
click on "ST82-01 Denton Tap Plans";
this will open the construction plans.
The bridge plans start on sheet 58.
Good luck.
Ken Griffin
file:IIC: \Documents%20and %20Settings\rbrother\Local %20Settings\ Temp \XPgrpwise\46... 7/27/2007
(7/27/2007) Rhonda
Page 1
From:
To:
Date:
Subject:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/24/20079:34 AM
Grapevine Creek
Ken,
The modeling submitted by NDMCE on July 19 via email is consistent with
the approved LOMR model. The model contains a new profile for ultimate
condition flows. What will you be expecting from NDMCE in terms of a
formal submittal to the City? I will request any additional information
from NDMCE that you need.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto :brad .pickering@kimley-horn.com>
(7/27/2007) Rhonda Adloo - RE: Grapevine C?r_~~~~~ity ~~~~tiv~~~~~ElI~~.~~_____
Page 1
From:
To:
Date:
Subject:
.Attachments:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/11/20078:15 AM
RE: Grapevine Creek - City Effective Modeling
cityEX.dat; CITYEX.OUT
, .
Ken,
Mike Boyd forwarded the attached model for Grapevine Creek to me. It is
titled Coppell City-Wide Storm Water Management Study and is dated Dee,
2003 by Halff Associates. It appears that this particular model was
updated to reflect an expanded Belt Line Road crossing of Grapevine
Creek. That crossing is just outside the Coppelllimits, so it's
possible it was submitted to another City.
I believe NDMCE's intent is to rerun the model with new Q's to get
ultimate water surface elevations. The model that was submitted by Mike
Boyd via email on Monday included ultimate flows. However, the modeling
was not the most recent, but was from the first submittal. I have
contacted Mike Boyd and he is working on getting the correct model to
me. I'll let you know when I receive it.
Thanks,
Brad W. Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
From: Ken Griffin [mailto:kgriffin@cLcoppell.tx.us]
Sent: Tuesday, July 10, 2007 4:43 PM
To: Pickering, Brad
Subject: Re: Grapevine Creek - City Effective Modeling
Brad
I left Mike a voice mail. We do not have any modeling here at the City.
I assumed he would just increase the Q and rerun his model to give us an
ultimate elevation so we could set finish floors.
Ken Griffin, P. E.
Director of Engineering/Public Works
972 -304-3686
kgriffin@ci.coppell.tx.us
>>> <brad.pickering@kimley-horn.com> 7/10/2007 1 :48 PM >>>
Ken,
Mike Boyd has a question about the City effective modeling. Can you
please email to me the most recent City effective modeling for Grapevine
Creek that should be used for ultimate conditions hydraulic modeling.
Thanks,
--
(7/27/2007) Rhonda Adloo ~_ R~~qrape\li~~e~c:;~eek~_~~t~ Ef!.~~~\l.e Mo~~ling_~_~
Page 2
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailta :brad .pickering@kimley-harn.cam>
~.__...._._--
!(7/i7/2007) Rhonda Adloo - Grapevine Creek - City Effective Modeling
Page 1
From:
To:
Date:
Subject:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/10/20074:13 PM
Grapevine Creek - City Effective Modeling
Ken,
Mike Boyd has a question about the City effective modeling. Can you
please email to me the most recent City effective modeling for Grapevine
Creek that should be used for ultimate conditions hydraulic modeling.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto :brad .pickering@kimley-horn.com>
I (7 /27 /2007L~hond~A{j)~()c-_~!=~~~r~E~"i~~gr~~~"~~~"R Appl ication App"~C?,,,~I, Letter
-----,',-.,.--.-...-..--.---
._._..............m.__nm....m___
Page 1 '
From:
To:
CC:
Date:
Subject:
Attachments:
"Mike Boyd" <mboyd@ndmce.com>
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/9/20078:35 AM
RE: Grapevine Creek LOMR Application Approval Letter
07026.zip
Brad,
Attached are the files for the approved LOMR submittal that has the ultimate
1 OO-year flow included on the flow file. These flows were taken from the
Halff January 1991 Coppell City Wide Management Study. I am checking on the
datum for the bench mark used in the mapping. Thanks Mike Boyd
-----Original Message-----
From: brad .pickering@kimley-horn.com
[mailto: brad .pickering@kimley-horn.com]
Sent: Wednesday, June 27,200709:02
To: kgriffin@cLcoppell.tx.us
Cc: mboyd@ndmce.com; ojohnson@ndmce.com
Subject: Grapevine Creek LOMR Application Approval Letter
Ken,
Attached is the approval letter for the Grapevine Creek LOMR Application
submitted by Nathan D. Maier Consulting Engineers, Inc. (NDMCE) on June 11,
2007. KHA received updated revised existing modeling via email on June 26,
2007. NDMCE should submit a revised final LOMR application to the City and
KHA prior to the City's signing of the document and submittal to FEMA. The
final LOMR application should reflect the most recent modeling submitted to
KHA.
If you have any questions, please do not hesitate to contact me.
Thank you,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
. (7/27/2007) Rhonda Adloo - RE: Grapevine Creek LOMR Application Approval Lett~r_
L__ _ __c__.._~~..__,_cc__. ______~~~-.-.--~~~~c.-....~-.------------------.-.-.,~~~_ c
Page 1
From:
To:
CC:
Date:
Subject:
<brad .pickering@kimley-horn.com>
<mboyd@ndmce.com>
<kgriffin@ci.coppell.tx.us>
7/9/20073:19 PM
RE: Grapevine Creek LOMR Application Approval Letter
,
~
Mike,
Thank you for emailing the modeling. Can you also provide hardcopies of
the ultimate condition workmap and the HEC-2 output from the City
effective model. PDF will be sufficient.
Thanks,
Brad W. Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
From: Mike Boyd [mailto:mboyd@ndmce.com]
Sent: Monday, July 09, 2007 8:34 AM
To: Pickering, Brad
Cc: kgriffin@ci.coppell.tx.us
Subject: RE: Grapevine Creek LOMR Application Approval Letter
Brad,
Attached are the files for the approved LOMR submittal that has the
ultimate 1 OO-year flow included on the flow file. These flows were taken
from the Halff January 1991 Coppell City Wide Management Study. I am
checking on the datum for the bench mark used in the mapping. Thanks
Mike Boyd
-----Original Message-----
From: brad.pickering@kimley-horn.com
[mailto:brad .pickering@kimley-horn.com]
Sent: Wednesday, June 27,200709:02
To: kgriffin@ci.coppell.tx.us
Cc: mboyd@ndmce.com; ojohnson@ndmce.com
Subject: Grapevine Creek LOMR Application Approval Letter
Ken,
Attached is the approval letter for the Grapevine Creek LOMR
Application submitted by Nathan D. Maier Consulting Engineers, Inc.
(NDMCE) on June 11, 2007. KHA received updated revised existing
modeling via email on June 26,2007. NDMCE should submit a revised
final LOMR application to the City and KHA prior to the City's signing
of the document and submittal to FEMA. The final LOMR application
should reflect the most recent modeling submitted to KHA.
[(1727 /2()()7YRh-ond~A~I~~-. RE:. Grape~i~~ .Creek COM R Applici3fionAppr6vaILetter----------------~=__ - _c=~-..c=~=-----~age~]
If you have any questions, please do not hesitate to contact me.
Thank you,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto: brad .pickering@kimley-horn.com>
(7/27/2007) ~~~n-~c3A~I~2~-~iapevi~~_<?~~~k LO~~R Application,~_~~~~ .......__--- ,'..'~..'. ~-=- c~----~--_-~a2~1]
From:
To:
Date:
Subject:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/6/2007 12:54 PM
Grapevine Creek LOMR Application
Ken,
I spoke wfth Mike Boyd today, and NDMCE will be providing additional
information regarding the ultimate conditions water surface elevations
through Grapevine Creek, as well as additional information regarding the
benchmark used for the study. I will forward any information I receive
to you.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto: brad .pickering@kimley-horn.com>
- - ~----~~-~_.~-~- --"--~~--.-'-".--~-''-'--'~---=-------~~---~~~-~'----'-''-'''-'--.~_.._-~. - ---~~~-,--
(7/27/2007) Rhonda Ad 100 -GrClEevi~E3_CrE3_E3~_~~t\i1 R Appl!~~ti~~~__~~____m _c__.___...._.__._~__.mCC_...~.
- -.----...---..--....---....--...-.1
_ _~age 1 I
From:
To:
Date:
Subject:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
7/2/20078:33 AM
Grapevine Creek LOMR Application
Ken,
The Grapevine Creek LOMR Application submitted by NDMCE on Friday, June
29th is consistent with the modeling approved by KHA on June 27,2007.
Thanks,
Brad W. Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
From: Pickering, Brad
Sent: Friday, June 29,200712:12 PM
To: Ken Griffin (kgriffin@cLcoppell.tx.us)
Subject: Grapevine Creek LOMR Application
Ken,
We received a final copy of the Grapevine Creek LOMR application from
NDMCE today. I will give it a quick look to make sure it is consistent
with the modeling submitted on the 26th and send you another emaH on
Monday.
Have a good weekend.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto:brad .pickering@kimley-horn.com>
! (7/27/2007) Rhonda Adloo - Grapevine Creek LOMR. Application
___ . ____mo.._ ___...__"~__._.__.~_____~.__._..~._~__~._._______."_._.__,..,.,_.___..._...___,___~___~~___~__~_________._
Page 1
From:
To:
. Date:
Subject:
<brad. pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
6/29/200712:12 PM
Grapevine Creek LOMR Application
Ken,
. We received a final copy of the Grapevine Creek LOMR application from
NDMCE today. I will give it a quick look to make sure it is consistent
with the modeling submitted on the 26th and send you another email on
Monday.
Have a good weekend.
Thanks,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto: brad .pickering@kimley-horn.com>
(7/27/2007) Rhonda Adloo - Grapevi~e~<:-,"~ek~9_~~~pe'i~ation ~ppro~~1 Lett~l~~_.~_~..._.c.
Page 1
From:
. To:
CC:
Date:
Subject:
Attachments:
<brad .pickering@kimley-horn.com>
<kgriffin@ci.coppell.tx.us>
<mboyd@ndmce.com>, <ojohnson@ndmce.com>
6/27/20079:03 AM
Grapevine Creek LOMR Application Approval Letter
20070627.pdf
Ken,
Attached is the approval letter for the Grapevine Creek LOMR Application
submitted by Nathan D. Maier Consulting Engineers, Inc. (NDMCE) on June
11, 2007. KHA received updated revised existing modeling via email on
June 26,2007. NDMCE should submit a revised final LOMR application to
the City and KHA prior to the City's signing of the document and
submittal to FEMA. The final LOMR application should reflect the most
recent modeling submitted to KHA.
If you have any questions, please do not hesitate to contact me.
Thank you,
Brad Pickering, EIT (TX), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
<mailto: brad. pickering@kimley-horn.com>
~=,~
Kimley-Horn
and Associates. Inc.
June 27, 2007
Mr. Kenneth M. Griffin, P.E.
Director of Engineering/Public Works
255 Parkway Boulevard
Coppell, TX 75019
Re: Letter of Map Revision (lOMR) Review
Grapevine Creek/Alexander Court
Second Submittal
KHA No.: 063124008
Dear Mr. Griflin:
Kimley-Horn and Associates, Inc. (KHA) has performed the second review of
the Grapevine Creek LOMR application for Alexander Court, dated June 11,
2007, prepared by Nathan D. Maier Consulting Engineers, Inc. (NDMCE). KHA
spoke by phone with NDMCE on June 25, 2007 regarding the submittal. As a
result of issues raised during this call, NDMCE submitted updated revised
existing modeling to KHA via email on June 26, 2007.
KHA reviewed the document and updated modeling for adherence to currently
published City of Coppell and Federal Emergency Management Agency (FEMA)
drainage design guidelines. KHA recommends approval of the LOMR
application.
NDMCE should submit a revised final LOMR application to the City and KHA
prior to the City's signing of the document and submittal to FEMA.
If you have any questions, please do not hesitate to contact us at 972-770-1300.
Very truly yours,
KIMLEY-HORN AND ASSOCIATES, INC.
~ %/..,
~k~
Steven D. Galloway, P.E. (IX), CFM
Brad W. Pickering, EIT (TX), CFM
Cc: Mike Boyd. P.E.; Nathan D. Maier Consulting Engineers, Inc.
Odalys C. Johnson, EIT; Nathan D. Maier Consulting Engineers. Inc.
.
TEL 972 770 1300
FAX 972 239 3820
.
Suite 1800
12700 Park Central Drive
Dallas, Texas .
75251
i (7/2iFi6-07) Rhonda Adloo --RE:Grapevine-Creek/Alexander CO-urt LOIvlR Review -----~- -------------
__m______.'~_____m.__.__...______....._~_m_ ... - --' ._ _m..__...._.~_...__._.,_________._,___.__.___.....__________.._....~___..".~__~._____,_~~_.~___~~_.".....___.___.---------_..______~_____..._.__m..._________..__.______~____________._.
Page 1
From:
To:
CC:
Date:
Subject:
Attachments:
"Mike Boyd" <mboyd@ndmce.com>
"'Ken Griffin'" <kgriffin@ci.coppell:tx.us>
"Brad. Pickering (E-mail)..<brad.pickering@kimley-horn.com>
6/22/2007 12:02 PM
RE: Grapevine Creek/Alexander Court LOMR Review
Temp00596.PDF
Ken,
I sent a revised study back to K-H that addresses their comments earlier
this month (I thought you had been copied on the transmittal). Brad
Pickering has said that they would have the second review completed by the
26th. Attached is a copy of the transmitalletter for your files. Thanks,
Mike Boyd
-----Original Message-----
From: Ken Griffin [mailto:kgriffin@ci.coppell.tx.us]
Sent: Friday, June 22, 2007 10:55
To: Mike Boyd
Cc: Paula Crocker
Subject: Fwd: Grapevine Creek/Alexander Court LOMR Review
Mike
Could you provide a status update on revisions to the flood study? Plans
are in on the project and I would to make sure that all outstanding items
are moving forward.
Thanks
Ken Griffin
>>> Ken Griffin 5/30/2007 12:55 PM >>>
Mike
The review letter from Kimley-Horn for the Alexander flood study is
attached.
Please make necessary changes. It probably would be quicker to work
directly with K-H.
(~~7/2~~!1!3hon9~_~~loo-c~~: Grapevine Cr~k/~~~~~der Court LOMR ~~,~~~_~
Page 2
Ken Griffin, P. E.
Director of Engineering/Public Works
972-304-3686
kgriffin@ci.coppell.tx.us
>>> <brad.pickering@kimley-horn.com> 5/23/2007 5:01 PM >>>
Ken:
As discussed this afternoon with Nadia Dahab, attached are KHA's comments
for the Grapevine Creek LOMR application for Alexander Court, dated April
26,2007, prepared by Nathan D. Maier Consulting Engineers, Inc. If you
have any questions regarding the attached comments, please do not hesitate
to give us a call.
Thank you, .
Brad W. Pickering, EIT (IN), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, TX 75251
p: (972) 776-1781
f: (972) 239-3820
e: brad.pickering@kimley-horn.com
~DM
NATHAN D. MAIER
CONSULTING ENGINEERS, INC.
June 10, 2007
Mr. Brad'W. Pickering, EIT (IN), CFM
Kimley-Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, TX 75251
Re: Letter of Map Revision (LOMR)
Grapevine Creelc/AJexander Court
NDMCE Project No. 07-03-026
KHA No.: 0613124008
Dear Mr. Pickering:
This is in response to your letter dated May 23, 2007 regarding the above referenced LOMR request. We
have addressed each of the items requested in that letter and have made revisions to the submittal
accordingly. Here are provided your comments in bold with our responses following.
Item 1: The MT -2 Form 2, page 1 of 2, states that the upstream tie-in of the study is at cross
section 27620. Cross section 27900 has been added to the revised existing conditions model and
is not included in the effective model. Revise the forms to reflect an effective tie-in upstream of
the model modifications.
The MT -2 Form 2 has been modified to reflect the effective cross-section 30130 as the tie-in cross
section.
Item 2: Revise the Floodplain Work Map to include the benchmarks and vertical datum used for
the on-ground survey.
An updated copy of the Floodplain Work Map with benchmarks and vertical datum used for the on-ground
survey is included as part of this package.
Item 3: The water surface elevations table in the report text is not consistent with the modeling
output for the effective floodway HEC-RAS model. Revise the report to be consistent with the
modeling output.
The water surface elevation table in the report has been modified to be consistent with the Effective
Floodway HEC-RAS modeling output.
Item 4: Revise the Location Map to reflect the boundaries of the LOMR submittal.
The Location Map has been reviewed to include the boundaries of the LOMR submittal. An updated copy
is included in this package.
Item 5: Cross section 22600, the location of the downstream effective tie-in, is not shown on the
Floodplain Work Map. Revise the Work Map to show this cross-section.
The Work Map has been revised to include cross-section 22600.
Two Park Lane Place I 8080 Park Lane I Suite 600 I Dallas. Texas 15231 I (214) 139-4141
Item 6: The sum' of reach lengths for the HEC-RAS revised conditions model does not match the
sum of reach lengths in the FEMA effective model. Revise the reach lengths in the revised
conditions model or explain the discrepancy.
Channel lengths' vary slightly due to the more detailed topographic information in the area. The sum of
channel reach lengths in the revised conditions model is a total of 11.0-ft larger than the sum of the
channel reach lengths in the effective model. Such a small difference should not significantly impact the
results obtained.
Item 7: The report text states that Manning's "n' values were taken from the effective model, but
they vary from the effective model at multiple locations. Revise the model to be consistent with
the effective modeling or justify the proposed Manning's 'n' values.
The revised conditions model Manning's 'n' values have been modified to be consistent with the effective
model. This change affected the resulting water surface elevations. An updated water surface elevation
summary table and a copy of the modified computer run are also included in this revision.
Item 8: Property owner notification is required by NFIP regulation 65.7(b)(1) due to the f100dway
revision. The notices must include the extent of revision, the changes to the f1oodway, and
contact information for any interested parties.
Property owner notifications will be sent once the City approves the results obtained by this study, and a
final submittal to FEMA is done.
Item 9: Revise the legend on the Floodplain Work Map to reflect revised existing conditions and
not proposed conditions.
The Floodplain Work Map legend has been modified and an updated copy has been included in this
package.
Item 10: Future development adjacent to the subject reach shall respect both the 100-year fully
developed and FEMA effective floodplain boundaries.
The plat being approved has set the minimum finished floor elevations to be the higher of 2-ft above
FEMA, or 1-ft above the fully developed.
Don't hesitate to contact me at (214) if you have any questions regarding the information listed above.
Thank you for your assistance.
P: (214) 739-4741
F: (214) 739-5961
E: oiohnson@ndmce.com
Cc: Ken Griffin, P.E.