W Sandy Lk Addn-CS040916September 16, 2004
Mr. B. David Littleton, P.E.
Halff Associates
8616 Northwest Plaza Drive
Dallas TX 75225
CoPi ELL
RE: West Sandy Lake Road Addition, Lot 1 Block 1
Second Submittal Construction Plan Review Comments
Dear Mr. Littleton:
The City of Coppell has reviewed the referenced plans and has the following comments to offer:
Grading Plan -
1. We need the letter of permission for the grading work that will be done on the property to the
east of this site.
Drainage Area Map -
1. You show 40 cfs at the culvert adjacent to State Hwy 121 driveway, yet there is no Drainage
Area Map or calculations to support that. Please include that information in the DA Map.
2. Also in the DA map is a statement that there is a "reduction in flow due to truck court
detention." Please send details and calculations to show how that will work with the pipes
and inlets being designed for the full flow.
Storm Drain Channel -
1. The section of concrete riprap that is poured adjacent to Sandy Lake Rd needs to in some
way be coordinated with the Sandy Lake Road Project being designed by Teague, Nall&
Perkins. If your construction takes place first, perhaps we need to stop short of the proposed
headwall and escrow that portion for the City's contractor to complete. Let's plan for a
contingency so there is no duplication of effort.
Storm Drain Channel Sheet 2 -
1. Is an carthen bottom still being planned for the area with concrete riprap? Please confirm
and/or clarify.
2. The terminus of your channel is right at the sanitary sewer manhole on the adjacent property.
The property owner to your east will need to relocate that sanitary sewer, so we will need to
coordinate where your service line comes into the main. That will make it easier for
relocation.
2
Storm Drain Plan -
1. Please provide a profile view of the 5'x 2' box culvert under the drive adjacent to SH 121.
XVater and Wastewater Plan -
1. We will consider allowing your 12" crossing of Sandy Lake Rd. to be open cut under the
following conditions:
a) Maintain a minimum one lane of traffic open at all times.
b) Provide appropriate signage and flagmen for the lane closure.
c) Lane closure is allowed only between the hours of 9:00 a.m. and 3:30 p.m. on weekdays.
Please make the necessary changes and submit the appropriate number of sets of the revised
plans to the City for stamping. The City of Coppell requires three sets for its use. Your
contractors and subcontractors must have a stamped set of the approved plans onsite at all times.
Please refer to the Fee Assessment Letter of August 4, 2004 for any amounts due. The Roadway
Impact Fee has been waived, therefore Construction Inspection fees of 2% and 4% shall be paid
with the Construction Development Permit application when submitted (a permit form is
provided with this letter for your convenience). The pre-construction conference can be
scheduled at that time. If you have any questions, please feel free to contact me.
Sincerely,
~ L '"[~'~"-'-'-~-~
Keith R. Marvin, P.E.
Civil Engineer
Office Phone: (972) 304-7044
Fax: (972) 304-3570