Carter Addn 3-SY110427 A r r a DOWDEY, ANDERSON
WC% & ASSOCIATES, INC.
CIVIL ENGINEERS
5225 Village Creek Drive
Suite 200
Plano, Texas 75093
972-931-0694
972-931-9538 fax
April 27, 2011
Mr. Brad W. Pickering, P.E., CFM
Project Manager
Kimley -Horn and Associates, Inc.
12700 Park Central Drive, Suite 1800
Dallas, Texas 75251 -1516
RE: Carter Addition Phase 111
Grapevine Creek
Conditional Letter of Map Revision
DAA Job No. 07111C
Dear Mr. Pickering:
We have received your comments regarding the Carter Addition Phase 111 CLOMR and offer
the following responses in red.
1. The fully developed flows used in the Fully Developed Flood Study do not match the
City -Wide Storm Water Management Study. Fully developed flows used in the hydraulic
models should be revised to be consistent with the City's study. The applicant should
refer to Table E -1 located in the City -Wide Storm Water Management Study or the
effective hydraulic model for flows at each cross section.
Done as requested.
2. The CLOMR application should include output from the HEC -2 effective model.
Done as requested.
3. The existing and proposed condition floodway models show a negative surcharge at
cross section 60. The floodway model should be revised to remove the negative
surcharge.
Done as requested.
4. The CLOMR application should include output from the HEC -2 effective floodway model.
Done as requested.
5. No floodway encroachments are shown at effective cross sections in the existing and
proposed floodway models. The applicant should verify the FEMA effective floodway
model does not include encroachments at any cross section, or revise the existing and
proposed floodway models to be consistent with the FEMA effective model.
Done as requested.
R: \Data \2007\07111 \00\ Correspondence \Letters \07111C- Ltr- Kimley Horn -2011 -04-27 -CLOMR Response Ltr.docx
F r DOWDEY, ANDERSON
A &AS,
S lik
N
CIVIL SOCIATES ENGINEER INC.
5225 Village Creek Drive
Suite 200
Plano, Texas 75093
972.931.0694
972.931.9538 fax
6. The 500 -year floodplain delineation is shown to be the same as the 100 -year floodplain
delineation on the provided floodplain workmaps. The 500 -year floodplain should be
added to the workmaps as separate delineations where the lines do not overlap.
Done as requested.
7. The applicant has stated they are in the process of obtaining a letter from the U.S. Fish
and Wildlife Service related to the Endangered Species Act. KHA recommends
information related to compliance with the Endangered Species Act and correspondence
with the U.S. Fish and Wildlife Serve be included in the CLOMR application. Recent
correspondence with FEMA indicates they are still in the process of determining the
appropriate documentation to comply with these requirements. This information may
help facilitate the CLOMR review at FEMA.
Jones and Ridenour, Inc. has been hired to perform this analysis. Their proposal was
received on April 25, 2011, and the study will take approximately 3 to 4 weeks to
complete.
8. The vertical datum of the on- ground topographic information should be listed on the
workmaps.
Done as requested.
9. The FuIIy Developed Flood Study indicates the floodplain will not be modified and a
Letter of Map Revision will be submitted to FEMA to revise incorrect floodplain mapping.
This statement is inconsistent with the submittal provided by the applicant. The report
text in the FuIIy Developed Flood Study should be revised to reflect the submittal.
Done as requested.
Sincerely,
J. Casey R l6"f
,, CFM
Cc: Kenneth Griffin, P.E.
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