HomeMy WebLinkAboutLetter Acknowledging City StandardsSeptember 24, 2009
Erika Bridges, E.I.T.
Graduate Civil Engineer
City of College Station
1101 Texas Avenue South
College Station, TX 77842
RE: Creek Meadows — Section 2, Phase 1B
Acknowledgement of City Standards — Rev. No. 2
RME No. 202 -0316
Erika Bridges:
ME
Gomel *rny Eny/neers
P.O. Box 9253, College Station, TX 77842
Off /Fax: (979) 690 -0329
email: civil @rmengineer.com
The purpose of this letter is to acknowledge that the construction plans for the public
infrastructure improvements, for the above referenced project, to the best of my knowledge, do
not deviate from the latest B /CS Design Guideline Manual. With the exception of the following
items:
❖ All segments of sanitary sewer line installed for this phase of construction, do not meet
the minimum flow velocity of 2.0 ft/s at peak flow conditions. The design of these lines
comply with minimum size, type and slope, however, the low number of dwelling units
discharging to these lines prevent peak flows from reaching a flow velocity of 2.0 ft/s;
❖ Some segments of the water lines installed for this phase of construction exceeds the
maximum bury depth of five (5) feet. This occurs only at utility crossings with grade
critical elements, where the water line cannot cross above the grade critical element and
still meet minimum bury depth of four (4) feet;
❖ The four (4) foot wide concrete pilot channel installed in the bottom of the detention
pond built in this phase of construction does not meet the minimum longitudinal slope of
0.50 %. The proposed concrete pilot channel is specified at a longitudinal slope of 0.20 %,
based on the design constraints of the detention pond that cannot be changed;
❖ The typical bottom slope of the detention pond built in this phase of construction does not
meet the minimum cross slope of 5.00 %. The proposed detention pond is specified with a
bottom cross -slope of 2.00 %, based on design constraints of the detention pond that
cannot be changed.
❖ Approximately 95 feet of the proposed Clear Meadow Creek Ave., to be built in this
phase of construction, sheet flows storm water into the Right -of -Way of Greens Prairie
Trail. This portion of the proposed Clear Meadow Creek Ave. must be constructed this
way to allow proper clearance for effective installation and operation of the proposed 18"
RCP driveway culvert. The design of the proposed driveway apron on Clear Meadow
Creek Ave. is such that the storm water draining towards Greens Prairie Trail will drain
into the bar ditch along Greens Prairie Trail and not onto the driving surface of the
intersection of Greens Prairie Trail and the proposed Clear Meadow Creek Ave.;
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Ar
Gonsul�tn9 Eryineer^s September 24, 2009
❖ Proposed storm sewer located in areas that will be subjected to vehicular loadings
(including fire truck loading) are designed with Reinforced Concrete Pipe (Class 3) and
bedded with cement stabilized sand. This design standard will withstand the stated
loadings even when the cover over the pipe is less than two -feet (2');
I also acknowledge, to the best of my knowledge that the details provided in the construction
plans are in accordance with the B /CS Standard Details.
Please do not hesitate to call if you have any questions.
Sincerely,
0 F i r X X 1
•
*:
1
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Rabon A. Metcalf, P.E.
Texas Firm Registration No. F- 004695
rabon @rmengineer.com
Creek Meadows - Section 2, Phase 1B
Acknowledgement of City Standards
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