HomeMy WebLinkAboutResponse to CommentsKB
111
\ \ ·ru ·u-l
\'.03
McCLURE & BROWNE ENGINEERING/SURVEYING, INC. oOlJ
1008 Woodcreek Drive, Suite 103 •College Station, Texas 77845
(979) 693-3838 •Fax: (979) 693-2554 •Email: McClureBrowne@Verizon.net
November 5, 2007
Ms. Carol Cotter, EIT
Planning & Development Services
City of College Station
P.O. Box 9960
College Station, Texas 77842
Re.: PEBBLE CREEK PH 9G (FP)-Final Plat
Staff Review Response -Engineering Comments
MBESI#: 1065-0011
Dear Ms. Cotter:
Below is the summary of the revisions made per staff's comments.
ENGINEERING: (Reviewed by Carol Cotter; Date: October 16, 2007)
-vioMMENT #1 : Show conflict with existing 6" sanitary sewer. (Sheet 3)
ACTION : See revised sheet 3.
bl· lOOJ6"(p
VcoMMENT #2: Both K values for sag and crest do not meet minimum requirements for St.
Andrews Drive. (Sheet 3)
ACTION :
COMMENT#3:
ACTION :
vCCMMENT #4:
ACTION:
COMMENT#5:
ACTION:
COMMENT #16:
ACTION :
See revised sheet 3.
Revise Construction plans to match easements as designated on Final Plat.
See revised eet 2
The center line of utilities including storm sewer shall be placed 5.5' from edge of
easement. (Sheet 4)
See revised sheet 4.
Provide Executive Summary as outlined in Appendix D of the Unified Stormwater
Design Guidelines.
See revised drainage report.
Provide hydraulic grade lines for design storm and 100 year.
See revised drainage report.
Bridgette George
November 5, 2007
Page of 2
COMMENT#?:
ACTION :
COMMENT#8:
ACTION:
COMMENT#9:
ACTION : ~MMENT#10:
ACTION:
It appears that the BFE was established with the St Andrews culverts in place.
How does the BFE change with out the culverts , since they won't be installed until
later with Phase 9H?
The culvert was not sized as to retain water upstream. Therefore, the culvert has
no effect on the downstream BFE's. I have attached output from HEC-RAS to this
Jetter showing that the BFE's do not change in the channel when the culvert is
removed.
Provide a map showing locations of all inlets listed in Exhibit C-3.
See Exhibit B-2 in revised drainage report.
Inlet 11 is shown on the plans, but I don't see it listed in Exhibit C-2.
See Exhibit C-2 in revised drainage report.
Is 12' lane in St. Andrews clear during 100 year storm?
See Exhibit F. The drainage guidelines only require a 12' lane to be open during
the 10-yeareventfor a collector roadway. (Section Vl.A.d.(2))
v/cMMENT #11: Is 100-year storm accepted at Inlets 4 and 5? If not, provide conveyance
ACTION :
pathway.
The inlets and pipes for inlets 4 and 6 have been sized for the 100 year event.
See Exhibit C-2 and C-3.
/coMMENT #12: For creek crossings where sanitary sewer pipe is less than 3.5 feet in depth ,
ACTION:
vf oMMENT #13:
ACTION :
concrete encasement shall be considered.
See revised plans.
Please refer to Design guidelines for below grade sanitary sewer crossings of
creeks. It appears that the encasement needs to be lengthened.
Drawing a 1 :1 sloped line from the high bank of the creek, the encasement is
more than long enough (see revised plans) .
OMMENT #14: Insure that there is at least 9' separation between the end of water line WA-3 and
sanitary sewer line SE-1 .
ACTION: Water line WA-3 has been adjusted. See revised plans.
Please find attached the followings as per your request:
Five (5) set of revised construction documents; and
• Two (2) copies of revised drainage report
If you have any questions or need any additional information, please do not hesitate to contact me.
cc: Davis Young, Pebble Creek Development via fax# 979-690-6081
F:\1065 -Davis Young\0011 -Pebble Creek -Phase 9G\Correspondence\COCS -Response Letter -101707.doc