Amberpoint BP 2-CS020912T H E C 1 T Y O F
COPPELL
T =-~. ~ ~/~~ o
e x n S t a a
September 12, 2002
Mark McGraw
Halff Associates
8616 Northwest Plaza Drive
Dallas, TX 75225
RE: Amberpoint at CoppeII, Lot lA Block A (Staples)
Construction Plan Review Comments
Dear Mr. MaGraw:
The City of Coppell has reviewed the referenced plans and has the following comments to offer:
Plat -
A 20' x 20' easement should be provided on the plat to encompass the two vaults off Northpoint
Drive.
Sheet CPPOl -
l. While we concur with the elimination of lime subgrade for the private parking lot, a letter
should be submitted requesting a variance.
2. Please explain why the ten parking spaces adjacent to Northpoint Drive are crosshatched.
3. It was my understanding that a security gate would isolate the truck courts; however, there is
no security gate provided at the northwest comer.
Sheet CDA01 -
The location of your northern drive approach to Northpoint Drive conflicts with an existing low
point inlet in Northpoint Drive. The driveway will need to be relocated such that you have a 10'
transition section of curb line leading into the low point inlet before you start your curb return for
the driveway. This means that the centerline for the proposed driveway will need to be a
minimum of 55' north of the north edge of the existing low point inlet. Currently the centerline
of your proposed north driveway is approximately 32' north of the north edge of the existing low
point inlet.
Sheet CSDO1 -
In reviewing the original drainage layout for Amberpoint and the proposed storm drain layout for
this addition, it appeazs some of the water intended for the 30" RCP at the southeast corner of
this development is being placed in the 33" RCP along the east side of the development. The
rerouting of a portion of drainage area into the 33" RCP is creating a situation where it appeazs
that the hydraulic grade line is at or above the proposed inlet. To determine whether or not this
is a correct observation, you should rerun the hydraulic grade line starting at the junction box
233 PARKWAY # P,O.BOX 478 # CO PPELL TX 73019 # TEL 972/482 0022 # F4X 972/304 3873
between the 54" and 66" RCP in Northpoint Dr. It appears that roughly half of drainage area C1
should be taken into drainage area B2 as shown on Sheet CDA01. This will necessitate
regrading of the property to accommodate that change.
Sheet CSD02 -
1. Based on the depth of lateral B 1, you may want to consider using Class N pipe.
2. The starting hydraulic grade line elevation on line C 1 should be closer to 515.
Sheet CWWOl -
1. Six-inch cleanouts should be provided at the north end of both 8" sanitary sewer stub-outs.
2. Based on information provided in the DRC process, it appears that your monument sign will
be located just north of your southern driveway. However, at that location, you have a
private waterline and vault, an irrigation and domestic service and two storm drain systems.
Please show the location of your proposed sign on this drawing to insure it does not conflict
with any proposed utilities.
3. In lieu of tapping the existing 12" waterline three times, you should only tap it once with an
8" line to your private system. You should then install the domestic and irrigation service off
that lead line prior to installing the valve prior to the vault. If you tap the existing IZ" line
with an 8" tapping, sleeve and valve, then an additional valve will still be required prior to
the placement of the vault for the private waterline.
Sheet CWW02 -
1. The proposed manholes on lines D and E at stations 0+00 should be 5' diameter, not 4' as
shown.
2. It appears that the 8" sanitary sewer line is being stubbed out to provide service to the north;
however, a substantial amount of the depth is being removed based on the steeper grades of
the 8" sanitary sewer. To insure this line can adequately serve the property to the north, you
should lower both lines approximately two feet at their termination point. This will change
the grades on the 8" sanitary sewer line.
Once the necessary corrections have been made, please return this marked-up set and two sets
of revised plans to the City for review. If you have any questions or need any additional
information, please contact this office at your convenience.
Sincerely,
~~o~...
Kenneth M. ri m, P.E.
Director of Engineering & Public Works
Office Phone: (972) 304-3686
Fax: (972) 304-7041
cc: Jim Gaspard, Transwestern Commercial Properties