Pecan Hollow-CS 900402 CIVIL ENGINEERS /Z:~/~..~ $~ ~,,~
DALLAS. TEXAS 75248
April 2, 1990
MS. Shohre Daneshmand
City of CoppellTexas
255 Parkway Blvd.
Re: Pecan Hollow Addition /~/ ~/~
Coppell, Texas
Doar Shohre:
~ftor tho March 29, 1990 D.R.C. moetin~, I rev~owod tho co~onts
suggested by the City Staf~ and tho~r consultant. I havo concorns about tho
followin~ ~ssues.
1. I havo approximatoly ten locagSon8 where ~ho
425 feot. ~ho roason for th~s docroasod radius ~s to accomodato tho dosi~n
of the final plat based on tho approvod prol~minar7 plat. I usod an
accoptablo radius to most citios, such as Piano and tho City of Dallas.
· ho subdivisions in the C~t7 of Coppoll l~sted below have radii similar
to those ~n quostion.
~ORTHL~KE WOOD~DS, 8~CTIOR8 1~2,3,4~5,6,7 ~ 8.
NORTHB~KE ~OOD~DS E~ST~ PHASE 3~4 &
ME~DO~S SECTIO~ 1 ~
P~RK ~E~DO~S SECTION 1.
P~RK~OOD SEC~IO~ 1 ~
8hMH~L BLVD. ~
SH~DO~RIDGE
SHERWOOD P~RK SECTION 1
SUb, ER PLACE
WATERSIDE ESTATES, PHASE 1
WHISPERING HILLS
WILLO~OOD NO. 2
WOODRIDGE, SECTION 1,2 & 5.
Cont'd
We could ask for a variance from the Subdivision Ordinance, however, I did
not notice any variances listed on the final plat for these Subdivisions.
Please consider this issue at the staff level to avoid a variance request.
2. The centerline radius selected for the sanitary sewer lines was selected
based on the engineering criteria that P.V.C. pipe manufacturers recommend.
I am requesting that we be allowed to develop our system for the following
reasons.
A. By locating the sewer lines (and water) parallel to the curb lines, the
following construction related items are enhanced.
a) Repair of the system is easier because you limit the irregular trench/
pavement locations. This allows for a regular sawcut (if necessary)
pattern.
b) Other utilities can be prepared to locate their facilities a given
distance from the City facilities.
c) As long as minimum radius criteria is met, you avoid excessive use
of manholes, an area that is susceptable to clogging.
d) All service repair occurs at a uniform distance from the curb line.
e) Initial construction reduces the number of situations where manholes
would be located in pavement and/or sewer mains falling in front yard
easements.
B. The additional cost of manholes is significant in subdivisions with
curvilinear streets.
C. Additional manholes require additional grade differential (enter/outer)
where slope is extremely critical.
D. The only advantage of straight alignment is for "cross-country" installation
where a curb line is not present to locate the system.
3. Due to a "very" tight grade design, I am requesting that we be allowed
to encase the sanitary sewer main in concrete where the depth is less than
normally designed. Please note that the finished pads are above the
necessary minimum to provide proper service. If acceptable, we can show
minimum Finish Floor Elevations on the plat.
I feel that we have addressed your concerns, and we are submitting two sets
of plans for your review.
Very truly yours,
/ ...'5~'
·-' ... ~.
William A. Anderson, P.E.
WAA:jma
we couZd ask Eot a variance grot. ~he Subdivision Ordinance, however, ! did
not notice any variances iLsted on the ~5. n~L aLat Eo~ ~hese SabdivisLons.
P].easo consider 1:his issue at the staffze,.-e.,' "' to avoid a variance request.
'2. Uhe centerline radius selected for the sanitary sewer lines was selecte~
Eased on the engineering criteria that P.V.C. pipe manufacturers recommend.
I am requesting that we be a].iowe~ to develop our system for the following
reasons .
A. ~" ].ocahinq the sower iineut'an~.,~ waher~ :)~ra].].e]. to the curb ~ 5. nes the
[o].lowin(2 consuruction related itc:~.s are en,,,z..=~d.
Repair of the syste::t i.n easier- becauEo you limit the irregular -trench/
pavement ioc:at:J, on:~. ']'i~.i.n ~i].owr~ [or n roUu]ar nnwcut {.i.f
b) Other utilities can be prepared to locate their faciiiuies a given
distance from the City facJ. lities.
c As long as minimum rad[.us criteria is mot, you avoid excessive uso
of manholes, an area that is suscep=able to clogging.
d Ail service repair occurs at a uniform distance from the curb line.
e initial construction reduces the number of situations where manholes
would be located in p~vement and/or sewer malns fa].~ng in front },are
easements.
B. The addi~J, onal cost of manholes is significant in subdivisions with
curvilinear streets.
c, Additional mankoles require additional trade differential (enter/outer~
whore s- ode is extrcmclv crit.[cal.
~ wD. Ti~e only ~dvantage of s~rai~ht aii~nment :i.s for "cross-coun-ury" installation
here a curb line :[.~ no~ pros, cnt 'ao lo.va ~t2 ~ };p f~.~
~}uc to a 'very" ti~hk grade desion, I a~:: reques~5, n~ eha~ we be a].~owed
to encaoe ~he sanitary sewer maLn 5n concrete whore the aopgh ~s loss
normail/ dos:i.~ned, i>~oas~ note ~n~ ~ho [.[nishod pads are above the
--~ necessary minJ. mum to .... ' ............. -: ~- -'' ' ~:'~
nlsh Floor Elevations on
I feel that we have ar](lrossc(] '/our co/looms, and we J, re nub:::i Itt:i. ng [:we
Very truly yours, .