HomeMy WebLinkAboutFORT COLLINS WHOLESALE FLORIST - PDP/FDP - 18-97 - REPORTS - DRAINAGE REPORTCOMMUTATION;. STEWART- NSSOCIATES
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214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331
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ConsulfiMEn.3ineersarxi Surveyors
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By: Date Client: -01le'l Sheet No. of 14--
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STEWART&ALSSOC[ATES
Consulting Engineers and Surveyors
Runoff Computations .
(Ratioual 1.4ethod) PAGE_2 OF 14-
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STEWART&ASSOCIATES
Consultin3 En3ineers and Surveyors
Runoff Computations
(Rational Method) PAGE
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STEWART&ASSOCIATES
Consulting Engineers and Surveyors
Runoff Computations
(Rational Method) PAGE_ OF 1¢
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COMPUTATIONS
STEWARI ASSOCIATES
Consulthy
.3 Er.3ineersandSurveyors
214 N. Howes St. Ft. Collins, CO 80521 (303) 482.9331
By: PI TZ Date 3 I 9 Client: Sheet No. S of ) 4
Chkd By: Date Project: CO �I n eta l P 13vs i n &.f.I
Subject -s-han Orainagc On Si�� �P�en�-ioh %�t,I on 770'rcnISZ13�S
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COMPUTATIONS
James H. Stewart & Assoc. Fort Collins, Colorado
By P1 Date Client: K. !3 i 11 % 1 l e x Sheet No.4-- of _ 14—
Chkd By: Date Project: 6011i1rciQIP 6vs �Pts f a�ff Job No.
Subject �iorw' Drca i nacre CCL CI �/o/7s
7'o�a1 TJe�enlioi. J-�ervi r-ccl rev,:. LTa�rd)-6,4r-eA, eP Por-cels zj 3 s)
M.9sS D► �rrr��N+ METN40D = 44-5- /0.1 = 3¢.4-acres
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COMPUTATION,
James H..Stewart & Assoc. Fort Collins, Colorado
By: Date Client: lam. �3i1/ Tiiey Sheet No. 3 of 14-
Chkd By: Date Project: Collino'ale 305ineJU FOrk Job No.
Subject sforr"i rcajrlc+ce CQIc=L) cz4-lonl
7-0 -'OL G1'Oss /4re0. = g-q-.S Acres C inc1, /z- R��/ra���L%i Serlf�e�¢ch.dwicl,
J}iSir�ric G=.0.20 5 - 0.(58 - (. _ /800
1.e7 .ZO) is o - 74:5r-��^
Qz = Gl1-9t _ �O.Z01�0.6¢¢•5/ 7� its HLLo9LE 0UTr-vZL
f}!)owo 6le ova - F1o.✓ per- acre = 7.IZ + 4-4•s = 0.
Developed Cori d i pi ohs_
G = 0.85 Fr;orrq `0`11 5
S/oP0-_ lafs Use LO
Slope 0-�r Sireek.S — us e o.4-e7
✓o%vMe- of- de�er4ion
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p Z 67500
4.3 3 y 000
14 10 zo00
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rewired
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✓elaei� 5 u4e-i = . Z. Z FPs
Z. 313a00 CG" P- = 7J9 c,,-- . 4.
Vo lv Me Tori�L t/olvMP
1,300
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1 37 50(2
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Z 3050
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11
Storm Drainage Report
Collindale Business Park
March 14, 1989
Page.2
The Collindale Business Park will be developed in phases. The first phase
will be the streets, Parcel 1, the drain swale along Timberline Road, and
the detention pond. The detention pond area will be used as a settling
basin for erosion control during the first phase construction period.
No outlet shall be connected to the Sunstone swale before the streets and
grading on Parcel 1 are completed. At the time of connection, erosion
control may be needed to protect the outfall from sedimentation. A concrete
pan is to be placed in the drain swales to prevent erosion. Flow capacities
of these pans are calculated on sheet 13 of this report.
The attached calculation sheets show the run—off calculations from each
of the parcels, the allowable gutter flows, the allowable outflow from
the detention ponds, the required detention, and the volume of the pond.
Also, there are run—off computation sheets showing flows at design points.
These design points are shown on the attached map.
Out —flow from the detention pond will cross under Timberline Road in a
24 inch pipe which empties into the Sunstone swale. This 24 inch pipe
will also carry out —flow from the W.W. Reynolds property located directly
north of the Collindale Business Park. The W.W. Reynolds out —flow is
approximately 5 c.f.s.
There will not be a property owners association for this development,
therefore we propose that the City of Fort Collins maintain the detention,
area -and channels. A 2 year or 2 growing season time period is required,
plus, acceptance by Stormwater Utility, prior to assuming maintenance._
Should the adjacent property owners desire to place more intense landscaping
in the detention area and channel than that required by the City, they
shall become responsible for placing and maintaining this additional
landscaping. All landscaping in the detention area and channels shall
be subject to approval by the Stormwater Utility, City of Fort Collins.
Office of STEWART. & ASSOCIATES, INC. a(�-•.�..,,.� 3lISlFr°f
Phillip I. Robinson, P.E. & L.S.
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STORM DRAINAGE REPORT
COLLINDALE BUSINESS PARK
Collindale Business Park is within the Fox Meadow Drainage Basin. The
property is located on the west side of Timberline Road and extends west
to the Union Pacific Railroad. The property begins 1330 feet south of
Horsetooth Road and runs south approximately 1700 feet to the top of a
ridge. The Tiley property covers only the north 1330 feet, and the property
to the south belongs to Tom Chandler and Don Chadwick. The gross area
of the property, including the Chandler and Chadwick properties, the west
of Timberline Road, and the East I of the Union Pacific Railroad R.O.W.
is 44.5 acres. There is no offsite run—off onto the site. The south
boundary is a ridge from which the drainage goes southerly to the Chandler
sump. Flows from the west are blocked by the Railroad embankment. The
north boundary is the low point and drainage flows east along this north
line. There is an irrigation ditch running east parallel to and about
six feet north of the north line. This ditch belongs to Bob Shields.
The ditch can carry irrigation water from Warren Lake across the golf
course, under the railroad and along the north property line. Historically,
this ditch has carried storm drainage under the railroad from the golf
course and from the railroad right—of—way. This flow from the golf course,
according to the Fox Meadows report is Q2=1.0 c.f.s. — Q10=3.'0 c.f.s. —
Q100=9.0 c.f.s. per page 12 of the report. We propose to not distrub this
ditch or alter the flows which it now receives.
The attached map shows the entire 44.5 acres divided into 10 sub —basins
and a detention pond area, which are shown as parcels 1 through 10 on the
map. We propose to provide detention for parcels 1,4,6,7,8,9,10 and the
pond area. The total area being detained in the pond will be 44.5 acres
minus 5.7 acres in Parcel 2, minus 1.3 acres in Parcel 3. and minus 3.1
acres in Parcel 5, which equals 34.4 acres. Detention shall be provided
on site on parcels 2 and 3 for the difference between 2 year undeveloped
run—off and 100 year developed run—off. - Parcel 5, the'Chadwick property,
has a 10 year undeveloped run—off of 1.4 c.f.s. which will be carried
through the proposed drainage system to the detention pond, area. Future
detention must be provided on Parcel 5 when and if its present use is
changed. The undeveloped 10.year out —flow from Parcels 2 and 3 was used
to determine gutter flows because it is greater than the future allowable
out —flow when the Parcels are developed and on —site detention is provided.
These out —flows are shown on sheet 14 of this report. The proposed
detention pond is located at the northeast corner of the site. The outfall
from the pond will drain under Timberline Road to the east and then into
the Sunstone swale. The new pipe under Timberline Road is per the design
plans of the Fox Meadows Business Park Drainage Channel. We plan to carry
the storm runoff by overland flows to. the detention pond. The majority
of the flow will be carried to the pond by a drainage. swale which runs
to the north along the west side of Timberline Road.
STORM DRAINAGE REPORT
COLLINDALE BUSINESS PARK
MARCH 14, 1989
PREPARED FOR K. BILL TILEY
STEWART & ASSOCIATES, INC.
214 NORTH HOWES
FORT
COLLINS. CO 80521
TABLE 5-3. CONSTRUCTION SEQUENCE FOR CONSTRUCTION
PROJECT: FORT COLLINS WHOLESALE FLORIST SITE STANDARD FORM C
SEQUENCE FOR: 1997-98 COMPLETED BY: KGS DATE: Sept. 4, 1997
Indicate by use of bar line or symbols when erosion control measures will be installed. Major
modifications to an approved schedule may require submitting a new schedule for approval by the
City Engineer.
YEAR
1997
1998
MONTH
10
11
12
1
2
3
OVERLOT GRADING
WIND EROSION CONTROL
Soil Roughing
Perimeter Barrier
Additional Barriers
Vegetative Methods
Soil Sealant
Other
RAINFALL EROSION CONTROL
STRUCTURAL:
Sediment Trap/Basin
Inlet Filters
Straw Barriers
Silt Fence Barriers
Sand Bags
Bare Soil Preparation
Contour Furrows
Terracing
Asphalt/Concrete Paving
Other
VEGETATIVE:
Permanent Seed Planting
Mulching/Sealant
Temp. Seed Planting
Sod Installation
Netti ngs/Mats/Blankets
Other
STRUCTURES: INSTALLED BY CONTRACTOR MAINTAINED BY: CONTRACTOR
VEGETATION/MULCHING CONTRACTOR: TO BE DECIDED BY BID
DATE SUBMITTED: 9/4/97 APPROVED BY CITY OF FORT COLLINS ON
OPINION OF COST
Client: Thorp and Associates
Project: Fort Collins Wholesale Florist Site
Date: 9/4/97
Job No. 10-881-000
No. Item Quantity Units Unit Cost
Total
1. EROSION CONTROL ( Developer)
SILT FENCE 1 2401 L.F. 1 $2.001
$480.00
Erosion Control Subtotal
15006 Subtotal
$480.00
$720.00
2. EROSION CONTROL (City)
RESEEDVMULCH 1 1.721 Ac. I $565.00
$971.80
Erosion Control Subtotal
150% Subtotal
$971.80
$1,457.70
EROSION CONTROL ESCROW AMOUNT
$1,457.70
This is an Opinion of Cost and supplied only as a guide. TST is not responsible for fluctuation in costs
of material, labor or unforeseen contigencies.
TST, INC.
Consulting Engineers Page 1 of 1
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TABLE 8-A
RAINFALL PERFORMANCE STANDARDS FOR FORT COLLINS. COLORADO
FLOW
LENGTH
SLOPE ($)
(FT)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
'6.0
7.0
8.0
9.0
10.0
20.0
30.0 40.0 50.0
100
70.9
74.6
76.8
78.4
79.5
80.3
81.1
81.6
82.1
82.5
83.0
83.4
83.6
83.8
84.0
84.7
84.8 84.9 84.9
200
72.0
76.3
78.2
79.5
80.5
81.2
82.1
82.5
82.8
83.2
83.6
83.9
84.0
84.2
84.3
84.8
84.9 84.9 84.9
300
72.4
77.0
78.8
80.0
80.9
81.6
82.5
82.8
83.1
83.5
83.8
84.1
84.2
84.3
84.4
84.8
84.9 84.9 85.0
400
72.6
77.4,79.1.80.3
81.2
81.8
82.7
83.0
83.3
83.7
84.0
84.2
84.3
84.4
84.5
84.8
84.9 84.9 85.0
500
72.7.77.7
79.4
80.5
81.3
81.9
82.8
83.1
83.4.83.8
84.1
84.3
84.4
84.5
84.6
84.9
84.9 85.0 85.0
600
72.8
77.9
79.5
80.6
81.4
82.0
83.0
83.2
83.5
83.9
84.1
84.3
84.4
84.5
84.6
84.9
84.9 85.0
700
72.8
78.0
79.7
80.8
81.5
82.1
83.0
83.3
83.5
84.0
84.2
84.4
84.5
84.5
84.6
84.9
84.9 85.0
800
72.7
78.1
79.7
80.8
81.6
82.2
83.1
83.4
83.6
84.0
84.2
84.4
84.5
84.6
84.6
84.9
84.9 85.0
900
72.7
78.2
79.6
80.9
81.7
82.2
83.2
83.4
83.6.84.1
84.3
84.4
84.5
84.6
84.7
84.9
84.9 85.0
1000
72.7
78.3
79.9
81.0
81.7
82.3
83.2
83.5
83.7
84.1
84.3
84.4
84.5
84.6
84.7
84.9
84.9 85.0
1100
72.6
78.3
79.9
81.0
81.7
82.3
83.3
83.5
83.7
84.1
84.3
84.5
84.6
$4.6
84.7
84.9
84.9
1200
72.6
78.4
80.0
81.0
81.8
82.3
83.3
83.5
83.1
84.2
84.3
84.5
84.6
84.6
84.7
84.9
84.9
1300
72.6
78.4
80.0
81.1
81.8
82.4
83.3
83.6
83.8
84.2
84.4
84.5
84.6
84.6
84.7
84.9
85.0
1400
72.5
78.5
80.1
81.1
81.8
82.4
83.4
83.6
83.8
84.2
84.4
84.5
84.6
84.7
84.7
84.9
85.0
1500
72.4
78.5
80.1
81.1
81.9
82.4
83.4
83.6
83.8
84.2
84.4
84.5
84.6
84.7
84.7
84.9
85.0
1600
72.4
78.5
80.1
81.1
81.9
82.4
83.4
83.6
83.8
84.2
84.4
84.5
84.6
84.7
84.7
84.9
1700
72.3
78.5
80.1
81.2
81.9
82.4
83.4
83.6
83.8
84.3
84.4.84.5
84.6
84.7
84.7
84.9
1800
72.3
78.6
80.1
81.2
81.9
82.4
83.4
83.7
83.8
84.3
84.4
84.5
84.6
84.7
84.7
84.9
1900
72.2
78.6
80.2
81.2
81.9
82.5
83.5
83.7
83.9
84.3
84.4
84.5
84.6
84.7
84.7
84.9
2000
72.2
78.6
80.2
81.2
81.9
82.5
83.5
83.7
83.9
84.3
84.4
84.6
84.6
84.7
84.7
84.9
2500
71.9
78.6
80.2
81.3
82.0
82.5
83.5
83.7
83.9
84.3
84.5
84.6
84.7
84.7
84.8
3000
71.6
78.7
80.3
81.3
82.0
82.5
83..6
83.8
84.0
84.4
84.5
84.6
84.7
84.7
84.8
3500
71.4
78.7
80.3
81.3
82.0
82.6
83.6
83.8
84.0
84.4
84.5
84.6
84.7
84.7
84.8
4000
71.1
78.6
80.3
81.3
82.0
82.6
83.6
83.8
84.0
84.4
84.5
84.6
84.7
84.8
84.8
4500
70.9
78.6
80.3
8.1.3
82.0
82.6
83.7
83.9
84.0
84.4
84.6
84.6
84.7
84.8
84.8
5000
70.6
78.6
80.3
81.3
82.0
82.6
83.7
83.9
84.0
84.4
84.6
84.7
84.7
84.8
84.8
RAINFALL PERFORMANCE STANDARD EVALUATION
PROJECT: FnorLou�✓s/✓NocFSfcE CLn2rT .S'i+E STANDARD FORM A
COMPLETED BY: 'TSr-,L. c� t�s,.��� �-k �EceS DATE:
DEVELOPED
ERODIBILITY
Asb
Lsb
Ssb
Lb
Sb
PS
SUBBA§IN
ZONE
(ac)
(ft)
M
(feet).
M
M
A
MDGEIL TE
�. 72
�00
% 20
TD D
4 2.0
MARCH 1991 8-14 DESIGN CRITERIA
7
EFFECTIVENESS CALCULATIONS
PROJECT: Fkr 6u.,1is 6Ja-, r- aA L�- Fcoiz,sr -:5,TE STANDARD FORM B
COMPLETED BY: T5 i , J �lG . C�,✓5�� e, EA-�s n3E.t=c2S DATE :
Erosion Control C-Factor P-Factor
Method Value Comment
/ `Value
�JE IO �/Ho(Gi L.Or.��t-TON Ohil-`-1 }�o5i �or�S¢.�c.r.o.J .W1rS CUA`✓w-'�-Y?
' r- TABUsoeo (feASS-
/. o0
MAJOR
PS
SUB
AREA
BASIN
($)
BASIN
(Ac)
CALCULATIONS
/. 72
Pveo /. 32.4c. = 77% 6, 32Ae-)
EST-. 6eAS$ D,"/o Ac = 2D.glo Ac:�)
Wt C- FAcroe = �0•t,i)6,32) + {0.67.5-40���.�2
Cwt.= O.oN3
p- FA
b00%
®.oj(r�1 x f 00% -
PEP FcRri D.497 G�A/1DAW /S.I
/.
fjs
MARCH 1991 8-15 DESIGN CRITERIA
G-O L
__ - `3' � �.r—_ — —•f174f7�Tr--P,•d�'ff1C'-7tFTC�G �— — -- � �- — — — `— _ � _ —• �--- — - — - — — — fir- -- —
1.0 t
2.4CiiO: 3.0 G�f .
`—/N00•0443'E ��� 1330.85 \\�— —/ tiros: 9.0 Gfc
NOTE t Shields' irri✓a}io diic
carries storm fJo�
f ror Ra l )road -/il r.✓
and corn Gvlt Course
PAKC6L W6 pro pos a to no—
dF
%s vrb SrTieldi d
O RCL
( \
�.3 ;4C. /DETELITION REQUIRED c 48060c.%. J
/ �DETEI-MO 99GScf / /-lLLpw GLE OVTRLus✓ Z1'•Z$ Gfr QP eta / ��-�
OVTELUW: 0. 3T7c3c / r� ,• `G / 6. 4- Ac.
R E STR E I � / A,UTOMC�T 10 DR 1 i/E b I
/ , /_ / / /O�—.pG--- — / G6� 57,0 FL: iI. / Ri@ O -� - .•
KUL
/
S Cr � / ��
`L Nv: as. is T
l5 Cot.1CT ¢ CATC>+'rsQsrAl
PAICCEL. /-FPRCfL Qrb: ./c ry GONST. L09�- Z7'„Qtr=Z1y Qur'SL3•
i CL RP
m CWt7H HE >OW.�a;S
J tI V
1•Z A 2.9 /�—cowsT q GATCF7 3ASM1,
t I/ r_� /
FPRCEL I / / CO O / /
iL
/sG.
Y _
3.I AOe
c
5a1cCEL / ? C� ��1fl e :, / y1'-' ram•
E�(IST/NG p 4� F1rJ15r1
9 C�NTOVR \
u� ���' •4t � /� � � h d cPliRCEL 1
Q .z0.�L y'
/ 1
X / TTj.
v a �` F `'Q c-
a�RE e([�pED LP
///
I i : J111/a 41.5 S.A
J / �•OcCrfr Q,toc - u /INv: a
4-'tot.IC RETF Pall
yq 9
•Z9• re itV.C4.2 INrS-rS"RCp ¢' GOHCRE7 P.oN 30-/S RCP PROaJS,•2D Z4' rOVTF,•a LL /7IPE
L+ F a?i r +r•ac.s �pER
500�0444 G ` 290.00' —�-----•--' SO01 / 49' f 30 _— TIMOERCIN[ OVE FLW -47.0 GAT=— q-
CAST y4 CORHHR SECTION 4x' R 3
cgZ 1 -SI 691571N6: Z4 PIPELU
1 1 � t 1 � �Sr-+1ct.DS' DITct•1%
Z S I
--J, Jjivy i o Q h
h7 uv n11
°voi Np o•h �f �I
O J Zo `]
Id or 14-
`- -
AMENDED OVERAL L DEVELOPMENT PLAN OF
COL L /NDAL E BUSINESS PARK
RLP Zone
LEGAL DESCRIPTION
A tract of'IV attwta /n the fast { s/ Seetton 71, lchn+hlp 7 brtb. Ranga
/9 Yaa of tM Sl.tb P.N., City of fart Co111n6 CWnty of GriZ Sbb of
Colorado. Mileh, cW+id.rl�p lM Gat Iln of the YertMnt } of uld Ssettw
31 !+ Well" S 00' 05 00 E or, .10 ell G.rings crtaind ho,eln 1-1-tine
afar td Letloo:ie 71.ved1
rue lnenhe elengrytM Ee+t 111nae/l th.ea
tSt1h
wtM .t ! ofn"r
seId Settee )1, S 00 01 )7` Y 811,12 feet: thane. M 89' S9' 2T• Y 70.00
N.
Let: Manca M 7!' 01' !8• Y 19 17 fur: thrW hats
MNw Y 71' N' l/• Y 187.11 fast: tlen e. Y 81. /9' i1• Y Slf.el hat to tM
els-.gllue�fN OC 700' /7• E 1911 lS hat1Ctph.nwo5 B9'h56Ca27• IOSe.781fee
.eon pEo.+ttl N� a 00't05 00"f Et 1770.19n/ a to tie 0 Inteef bnglnninp, W along
�derlpnti</+emj2nW h pLe.. or efancerd. Ming wbd.et to all rarelG
RLP Zone
' SE
SCALE-1, 100'
0 a0 00 zoo I00
'GOLF LOUR
r-�
IPLANNING AND 7OIIYG CERTIFICATION • • _. —
�I A,Vwd by the Fl.n"oll and Too" 9oard of to City of fort Callihan Colorado.
QQm r thO _ day of , 19_.
-chary of Fl9 -m,d Zoning bail
Q. OMFSS SIGUTIDE
V TM ud.rlign". being the 1Wful When of Ile preporty d..erlbd on thl. glu
,luh o hereby certify t/lat they scot too conditions ad n,tr/etion, set
forth a sad Hto Ales
Signed W to
Signed Do to
Signed Oat,
Signed 0M
Stgted . D.te
Sighed D.to
— 1551
WAY------ --------- ---
SITE DATA
Edellnq IWInq
/p e7A NE
hwdneel Bu/Ml p No/pdf —
10 Ndl .
7bro/ AAirneYe, FAtar Area—
656,504 square /oaf
ANTICIPATED LAIRD USES:
Off/ge
50 %
NolwleaNr/a0
2S %
wo,.nowno
21 z
Afl A0110010d Lon1 """ of" Do arolladN for 80 phase!
ONE o. ONE
Path: C:\UTILS
File: WEST .TXT 1,243 .a.. 9-05-97 11:59:10 am Page 1
Fort Collins Wholesale Florist Site
INPUT DATA:
DISCHARGE = 5.870000 CFS loo-,J •
BOTTOM WIDTH = 0.000000E+00 FT
BED SLOPE = 1.000000E-02 FT/FT
SIDE SLOPE = 4.000000
MANNINGS N = 1.600000E-02
RESULTS:
NORMAL DEPTH =
5.998787E-01
FT
FLOW VELOCITY =
4.078794
FPS
HYDR. DEPTH =
2.998838E-01
FT
TOP WIDTH =
4.799029
FT
FROUDE NUMBER =
1.312585
SPECIFIC ENERGY=
8.582103E-01
FT
INPUT DATA:
DISCHARGE =
2.680000
CFS �---
BOTTOM WIDTH =
0.000000E+00
FT
BED SLOPE =
1.000000E-02
FT/FT
SIDE SLOPE =
4.000000
MANNINGS N =
1.600000E-02
NORMAL DEPTH =
4.470502E-01
FT
FLOW VELOCITY =
3.351937
FPS
HYDR. DEPTH =
2.235592E-01
FT
TOP WIDTH =
3.576402
FT
FROUDE NUMBER =
1.249314
SPECIFIC ENERGY=
6.215143E-01
FT
Icr - yr l Lo.•J 1^7� = rK = C. (" o
to-t)- 7-.+
Path: C:\UTILS
File: EAST .TXT 1,243 .a.. 9-05-97 11:56:48 an Page 1
Fort Collins Wholesale Florist Site
INPUT DATA:
DISCHARGE _
BOTTOM WIDTH =
BED SLOPE _
SIDE SLOPE _
MANNINGS N =
RESULTS:
NORMAL DEPTH =
FLOW VELOCITY =
HYDR. DEPTH =
TOP WIDTH =
FROUDE NUMBER =
SPECIFIC ENERGY=
INPUT DATA:
DISCHARGE _
BOTTOM WIDTH =
BED SLOPE _
SIDE SLOPE _
MANNINGS N =
RESULTS:
NORMAL DEPTH =
FLOW VELOCITY =
HYDR. DEPTH =
TOP WIDTH =
FROUDE NUMBER =
SPECIFIC ENERGY=
3.520000 CFS�-
O.000000E+00 FT
1.700000E-02 FT/FT
4.000000
1.600000E-02
4.482644E-01 FT
4.377446 FPS
2.242320E-01 FT
3.586115 FT
1.629086
7.458115E-01 FT
1.850000 CFS — 10-r
0.000000E+00 FT
1.700000E-02 FT/FT
4.000000
1.600000E-02
3.521951E-01 FT
3.727839 FPS
1.761332E-01 FT
2.817561 FT
1.565340
5.679837E-01 FT
fai.
TST, INC.
Consulting Engineers rsp
CLIENT C c e-e_ II+o2A n JOB NO. /V
PROJECT [+-[w/S Io[-F.i�L� f[.a0_[ST gC CALCULATIONS FOR
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CLIENT ,e011", r- rf4 JOB NO. /O - 88,51 -OGU
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01 71
G0507/3-84
TABLE 2. SUMMARY OF ATTENUATED RUNOFF
iE
l
RAINFALL1:
ED
PFAKID CHARGV.::'
DESIGN,
CONtIlIBUT ING;;AREACO
F-1.
BASIN
POINT
SYiDRAS1N5'
Acy
..... .....
A3
3
A3
0.49
0.82
7.98
4.6
7.0
1.85
3.52
A2
2
A2
0.86
0.78
13.11
4.0
7.0
2.68
5.87
Al
I
Al, DP2, DP3
1.66
0.77
13.11
4.0
7.0
5 11
1118
TST, INC.
CONSULTING 9/4/97
ENGINEERS 000hydro.xls
TABLE 1. HYDROLOGIC CALCULATIONS WORKSHEET
GU..TTER
GUTTER
TIME OP RAINFAL
PEAWDISC HARGE:
14L-OWi!'!i!�I:;
:!
1!�:TRAVEL .T1Mk
og :11(:!
........
... .
SUB
... ........
0.
1,1
"BAWBASN
f o
n j
kiin
r):
(efs)
A Al
1
0.00
0.00
9.76
4.1
7.0
0.94
2.01
A2
2
0.00
0.00
13.11
4.0
7.0
2.68
5.87
A3
1
0.00
0.00
7.98
4.6
7.0
1.85
3.52
os OS
3
0.00
0.00
3.38
5.6
7.0
0.69
1.08
TST, INC.
CONSULTING 914/97
ENGINEERS 000hydro.xls
TABLE 1. HYDROLOGIC CALCULATIONS WORKSHEET
. .... .... .
OVERLAND
;l:
�'TAVERAGE;10,!ill
;�:�ii;�:OVi—E:.IR(LANIDJ�!:ii
Til
WERAGVi,'
OVERLAND
11RAV TE%l
OT
TER -flil;
SUB:
DESIGN:!:!'
1!
ji: j!:!,
';:LENGTHi"i!;!
...... 2 T., T
.1 -
L
S LOPE
,
.... .. ....
rnp)
...... . .... . ..
(0)
x
A
Al
1
0.31
0.74
210
1.00
9.76
0
0.00
A2
2
0.86
0.78
480
1.00
13.11
0
0.00
A3
3
0.49
0.82
330
1.70
7.98
0
0.00
os
osl
4
0.13
0.95
230
2.00
3.38
0
0.00
TST, INC. . I
CONSULTING 9/4/97
ENGINEERS 000hydro.xls
TST, INC.
Mr. Schleuter
July 18, 1997
Page 2
assumed in the 1989 Drainage Report for the Business Park. We have included the 1989 Master
Drainage Report which documents the sizing and quantities of the conveyance and detention
facilities.
Based on our calculations, the proposed runoff is within tolerance of the runoff quantities
calculated for the Business Park and no modifications of the Master Planned Facilities and no
new improvements are required as a result of this project.
We believe that the proposed Fort Collins Wholesale Florist Site addresses and complies to all
criteria set forth by the City of Fort Collins Stormwater Utilities Division and the Drainage
Report for the Collindale Business Park. We look forward to your review and if you have any
questions or comments, please feel free to contact us.
Respectfully,
TST, INC. CONSULTING ENGINEERS
Keith G. eaffer
KGS/jts
Steve F. Humann, P.E.
SFH
September 5, 1997
Mr. Glen Schleuter
City of Fort Collins — Stormwater Utilities
235 Mathews St.
Fort Collins, CO 80522
Re: Fort Collins Wholesale Florist Site
Project No.: 10-881-000
We are pleased to submit this Drainage Report letter and supplemental calculations for the Fort
Collins Wholesale Florist Site. We have analyzed the 1.72 acre site in conjunction with the 1989
Storm Drainage Report for the Collindale Business Park prepared by Stewart & Associates, Inc.
which has been included with this report for your reference, and the City of Fort Collins
Stormwater Drainage and Design Criteria Manual. The 1989 Drainage report prepared for the
Business Park accounted for the storm runoff generated by the proposed site and sized the
detention facility to account for the runoff, the detention sizing calculations have been included
with this report. In the report, Parcel 4 (the approximate proposed site) was assumed to consist
of 1.5 acres and have a runoff coefficient of 0.85. The Parcel was assumed to sheet flow to the
Northeast corner then continue flowing East along the existing Caribou Road to existing inlets
located at the intersection of Caribou and Timberline Road. The runoff then was conveyed
North to the detention pond, which was sized to take the runoff generated from our site, and is
located in Parcel 10 of the Business Park. In our evaluation of the 1989 Drainage Report, the 10-
year runoff and the 100-year runoff from Parcel 4 was calculated to be 5.3 cfs and 10.5 cfs
respectively. However, during our evaluation, we recalculated the runoff for the assumed site in
the 1989 Drainage Report using the City of Fort Collins SDDCM equation:
Q = CCf IA
Where Q is runoff, C is the runoff coefficient, Cf is the frequency factor, I is rainfall intensity,
and A is area in acres. We found a mathematical error and the runoff from the site for the 10-
year and 100-year storm should have been calculated to be 5.23 cfs and 11.16 cfs respectively.
While analyzing the proposed site a composite runoff coefficient was calculated based on the
amount of impervious and landscaped area. The composite coefficient for our site was
calculated to be 0.77 this is less that the assumed 0.85 established in the 1989 Drainage Report.
The runoff was then calculated for our site. The 10-year storm runoff was calculated to be 5.47
cfs and the 100-year storm runoff was calculated to be 11.40 cfs. In comparison, the 1989
Drainage Report assumed a 1.5 acre site, where as the proposed site is 1.72 acres. Even though
our site is 0.22 acres larger, the net total acreage for the Collindale Business Park has not
changed. The composite runoff coefficient we calculated of 0.77 is less than the 0.85 coefficient
TST, INC.
Consulting Engineers
748 Whalers Way— Building E
Fort Collins, CO 80525
(970) 226-0557
Metro Denver(303) 595-9103
Fax (970) 226.0204
102 Inverness Terrace East
Suite 105
Englewood, CO 80112
(303) 792-0557
Fax (303) 792-9489