Northlake 635(5)-CS 990616lll
· ,, Halff Associates
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PLANNERS · SURVEYORS
8616 NORTHWEST PLAZA DRIVE
DALLAS, TEXAS 75225
(214) 346-6200
FAX (214) 739-0095
06-17-99Al1:02 RCVD
June 16, 1999
AVO 17695
Mr. Kent M. Collins, E.I.T.
City of Coppell, Engineering Dept.
P.O. Box 478
Coppell, Texas 75019
RE: Northlake 635 Business Park, Lotl, Block D
Dear Mr. Collins:
Please find attached revised drawings for the above referenced project. For your convenience, I
am providing a list of your comments and our responses.
1. Include a paving plan that should include paving dimensions and paving design (thickness,
subgrade, etc)
Please reference Sheet SC-1 as provided. The detailed dimensions are provided in
the architectural site plan as referenced in Note 6.
2. Consider providing storm drain stub-outs to the south such that future phases can tie into the
proposed system without tearing up existing concrete paving.
Due to the uncertainty of the site plan for Phase II of this project, drainage tie in
points have not been set. We have designed the storm system to remain flexible for
future development to the south by maintaining an oversize portion of the pipe
along the possible future connection points. The storm drain line has also been
placed along the south side of the paving so that the impact to the existing facilities
may be minimized.
3. Include profiles and all appropriate information for all sections of storm drain pipe.
Please reference sheet STM-4.
4. For erosion control purposes at storm drain outfalls, consider using rock rip-rap instead of the
proposed curlex blanket.
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ARCHITECTURE · LANDSCAPE ARCHITECTURE · PLANNING
,,, Halff Associates
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS · SURVEYORS
Mr. Kent M. Collins, E.I.T.
City of Coppell, Engineering Dept.
June 16, 1999
Page 2
The storm drain outfalls are to be constructed using both rock rip-rap for energy
dissipation and high velocity curlex blankets for the erosion protection of the
disturbed areas.
5. Indicate protected areas on the plan as per the 404 wetland permit.
Jurisdictional waters of the United States are referenced on Sheets
6. As per the Dallas Drainage Design Manual, concrete drainage pipe will be installed on a
minimum of 0.30% grade.
As discussed with Mike Martin on May 26, the 0.20% slope is a requirement
resulting from the existing flow lines of the north drainage channel. The slope has
been maximized for the current conditions.
7. All pipe size changes require a concrete collar.
Please reference note added to Sheets STM-2, STM-3, and STM-4.
8. All fire hydrant locations need to be approved by the Fire Marshal, Travis Crump. He can be
reached at (972) 304-3053.
A copy of the Sheet WS-1 has been forwarded to Mr. Crump with this second
submittal.
9. Show the location of the stabilized construction entrance on the erosion control plan.
Please reference Sheet EC-1.
10. For the proposed left-turn lane, brick pavers need to be provided in the median noses per City
Standards.
Please reference Sheet LT-1.
11. The paving depth for the left-turn lanes should match the adjacent concrete paving.
,,, Halff Associates
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS ° SURVEYORS
Mr. Kent M. Collins, E.I.T.
City of Coppell, Engineering Dept.
June 16, 1999
Page 3
The note on Sheet LT-1 instructs the contractor to match the adjacent paving
thickness, with a minimum thickness of 8 inches.
12. Any work in or adjacent to Beltline Rd. will be conducted between the hours of 9am and
3pm.
Please reference Sheet LT-1, Note 3.
If you have any questions or require and additional information, please contact me at (214) 346-
6248.
Sincerely,
HALFF ASSOCIATES, INC.
Todd Abbott, E.I.T.
cc: Jim Gaspard, Transwestern Property Company
Richard Nordyke, O'Brien & Associates