HomeMy WebLinkAboutDrainage Reports - 03/16/2012City of Ft. Collins Ap rov Plans
Approved By
Date -�>--& —l.Z
Final Drainage, Erosion Control and Water Quality Report
For
Colorado Iron & Metal
Fort Collins, Colorado
Prepared for:
GTC INVESTMENTS, LLC
1400 EAST MULBERRY STREET
C/O KENT GARVIN
FORT COLLINS, CO 80524
Prepared by:
ENGINEERING
908 LAPORTE AVENUE
FORT COLLINS, CO 80521
970-219-2.834
JULY 15, 2011
Final Drainage Report
Colorado Iron & Metal
ENGINEER'S CERTIFICATION
I hereby state that this Final Drainage and Erosion Control report for the Colorado Iron &
Metal project was prepared by me or under my direct supervision for the owners thereof and
meets or exceeds the criteria in the City of Fort Collins Storm Drainage Design Criteria and
Construction Standards.
Stacy J. Gowing
Registered Professional Engineer
State of Colorado No: 34290
Final Drainage Report
• Colorado Iron & Metal
TABLE OF CONTENTS
I. INTRODUCTION................................................................................................ 3
II. GENERAL LOCATION AND DESCRIPTION......................................................3
A. Property Location....................................................................................................................................3
B. Property Description..............................................................................................................................3
M. DRAINAGE BASINS AND SUB-BASINS...........................................................4
A.
Major Basin Description.......................................................................................................................4
B.
Existing Conditions.................................................................................................................................4
C.
Developed Conditions...........................................................................................................................4
IV.
DRAINAGE DESIGN CRITERIA..........................................................................5
A.
Development Regulations...................................................................................................................5
B.
Development Criteria Reference and Constraints.......................................................................5
C.
Hydrological Criteria..............................................................................................................................5
..
D.
Hydraulic Criteria....................................................................................................................................5
V.
DRAINAGE FACILITY DESIGN..........................................................................6
A.
General Concept......................................................................................................................................6
B.
Specific Details — Detention.................................................................................................................6
C.
Specific Details — Stormwater Quality.............................................................................................7
D.
Specific Details — Swales.......................................................................................................................7
E.
Specific Details — Inlets and Storm Sewer.....................................................................................7
F.
Specific Details — Curb Cuts................................................................................................................7
VI.
SEDIMENT/EROSION CONTROL......................................................................8
A. General Concept......................................................................................................................................8
VII. CONCLUSIONS...................................................................................................9
A. Compliance with standards.................................................................................................................9
B. Drainage Concept..................................................................................................................................9
Vm. REFERENCES.......................................................................................................9
IX. APENDICES........................................................................................................10
Final Drainage Report
Colorado Iron & Metal
I. INTRODUCTION
This report presents the pertinent data, methods, assumptions, and references used in
analyzing and preparing the final drainage, erosion control and water quality design
for the Colorado Iron & Metal project (the "project").
II. GENERAL LOCATION AND DESCRIPTION
A. Property Location
1. The project is located on Lots 2 and 3 of Vanworks Subdivision Second Filing,
consisting of 5.73 acres. The street address of the project is 903 Buckingham
Street, Fort Collins, Colorado, as shown below:
Mmn S
u,vn 51
'.
LopxiG
wnC—•v'1
Nur era 51
x .,
`SITE
Vicinity Map, NTS
B. Property Description
1. The project site is currently partially developed. Existing improvements consist
of a large metal building, with two driveways and associated parking and
hardscape. The project was originally developed in the late 1990's as part of
the "Vanworks Subdivision Second Filing".
2. The site is relatively flat, with a gentle slope from north to south. There are no
subsurface drainage facilities near the site, and the surrounding topography is
generally flat.
Final Drainage Report
Colorado Iron & Metal
M. DRAINAGE BASINS AND SUB -BASINS
A. Major Basin Description
1. The project site lies within the City of Fort Collins Dry Creek Basin.
2. The project site is located outside the Dry Creek and Cache La Poudre River
100-year floodplains, but is inside the Cache La Poudre River 500-year
floodplain. Copies of the FEMA FIRM panel 08069C0983G, dated June 17, 2008,
and the City Floodplain Mapping are included in the appendix.
B. Existing Conditions
1. As mentioned, the project site is currently partially developed. The existing
development was part of the "Vanworks Subdivision Second Filing". The
construction plans for that subdivision included Lots 1, 2 and 3. A detention
pond was constructed within Lot 1 to mitigate storm water flows from all three
lots. The original engineering plans were prepared by Shear Engineering and
are dated March 1998.
2. The existing detention pond is located in the rear portion of Lot 1, which is
located immediately east of the project site. The pond discharges through a
control structure to a swale which connects to the borrow ditch along the west
side of Lemay Avenue. Lots 2 and 3 are included in drainage basin A, which
was shown to have a drainage area of 14.76 acres and a composite runoff
coefficient of 0.48.
C. Developed Conditions
1. The proposed use is an metal recycling and fabrication facility. The proposed
project consists of the renovation of the existing building, construction of two
new buildings, one new driveway, concrete and asphalt drive aisles and parking
areas. The new buildings consist of a metal shop building and a building to
house the bailer used in the paper recycling process.
2. Portions of the project site will continue to drain to the existing detention pond
which was originally constructed for the entire site. In general, this includes the
existing building, the existing pavement on the east side of the building, and a
portion of the southern half of Buckingham Street. It should be noted that the
existing pond was originally designed to mitigate all these existing
improvements plus some existing areas that will be redirected to the new
detention pond described below.
Final Drainage Report
• Colorado Iron & Metal
3. A large portion of the development site and a portion of the south portion of
• Buckingham Street drains to a new detention pond located in the southwest
corner of the site. This new detention pond drains through a proposed storm
drain in a southerly direction to the borrow ditch along the north side if Lincoln
Avenue. This has the effect of reducing the drainage area to the existing pond
by 3.18 acres. Therefore, the only impact to the existing, previously approved
pond is a reduction of drainage area in the proposed condition.
IV. DRAINAGE DESIGN CRITERIA
A. Development Regulations
1. Design criteria from the City of Fort Collins Storm Drainage and Design Criteria
and Construction Standards were followed for this drainage report.
B. Development Criteria Reference and Constraints
1. The proposed storm water release rate is 0.20 cfs/acre, in accordance with the
Dry Creek Master Plan. The drainage area of the pond is 3.18 acres, which
equates to a release rate of 0.64 CFS.
C. Hydrological Criteria
1. Peak flow rates for the 100-year storm have been calculated in accordance with
the City of Fort Collins Storm Drainage and Design Criteria and Construction
Standards. Please see these calculations in the Hydrology section of Appendix
I.
D. Hydraulic Criteria
1. The City of Fort Collins Storm Drainage and Design Criteria and Construction
Standards are used to determine the adequacy of the hydraulic structures
associated with the project.
2. Analyses are performed using methodologies presented in Urban Storm
Drainage Criteria Manual Volumes 1 and 2; Urban Drainage and Flood Control
District, Denver, Colorado, September, 1999. Please see the various
computation spreadsheets in the Hydraulics section of Appendix 1.
• Final Drainage Report
Colorado Iron & Metal
V. DRAINAGE FACILITY DESIGN
A. General Concept
1. The general direction of storm water flow is from north to south.
2. Storm water from Buckingham Street is carried through curb cuts and
sidewalk culverts to the parking areas within the site. These flows are then
conveyed through the site, along with flows from the site itself.
3. Portions of the site will continue to drain to the existing detention pond.
As previously discussed, the total drainage area to this existing pond will
be substantially decreased as a result of the development. No revised
analysis is included for this existing pond, since the only proposed change
is to reduce the drainage area.
4. Newly developed areas, with a portion of the existing developed area
(Drainage Basin A) will flow to a new detention pond located near the
southwest corner of the property.
B. Specific Details -Detention
1. The drainage area to the new detention pond is 3.18 acres. The additional
developed area within the site will be treated for detention and water quality by
a new detention pond. The required water quality volume is 0.117 acre-feet
and the required detention volume is 0.861 acre-feet, for a total pond volume
of 0.978 acre-feet. This volume is provided in the proposed detention pond at
elevation 4944.09'.
2. The detention pond drains to a new storm drain pipe which flows southerly and
into the borrow ditch along the north side of Lincoln Avenue. This proposed
pipe (storm drain A) is 15" in diameter. An off -site easement will be obtained
from the owner of the property to the south to contain this new storm drain
line.
3. As stated previously, the existing drainage area to the existing detention pond
is being reduced by 3.18 acres. This reduction will allow the existing pond to
function at a higher level of performance when compared to existing.
4. An emergency spillway is proposed to convey emergency flow from the site
towards the southeast. The proposed design of the spillway is a trapezoidal
channel with a bottom width of 60' and side slopes of 33:1, with a weir
elevation of 4944.20'. Since the spillway discharges to natural ground, the
Final Drainage Report
Colorado Iron & Metal
Manning's Equation was used to determine the spillway capacity. The results
indicate that the spillway can convey the 100-year discharge from this drainage
basin (27.1 CFS) at a normal depth of 0.28'. The flow velocity is quite low at
1.46 FPS, so the erosion potential in this area is insignificant. This area is
proposed to be covered with gravel.
5. Once the emergency overflow discharge passes through the pond spillway, it
generally flows towards the south and east. This emergency flow is directed by
existing topography towards the existing detention pond on Lot 1, and
ultimately to the borrow ditch along the west side of Lemay.
C. Specific Details - Stormwater Quality
1. Water quality will be provided in accordance with Best Management Practices
as presented in the Urban Storm Drainage Criteria Manual Volume 3, Best
Management Practices; Urban Drainage and Flood Control District, Denver,
Colorado, September, 1999.
2. Permanent structural BMP's consists of extended detention within the proposed
detention pond.
D. Specific Details - Swales
1. There are no swales requiring analysis within the project site.
E. Specific Details - Inlets and Storm Sewer
1. The detention pond discharges through a 15" pipe which runs through the Van
Works property directly to the south. Ultimately, this pipe discharges to the
existing borrow ditch along the north side of Lincoln Avenue. An off -site
easement will be provided for this pipe by separate instrument.
2. The discharge through the storm drain is 0.64 CFS, which is the release
discharge from the detention pond. The pipe sizing calculations are included
in the appendix, and indicate that capacity in the proposed pipe is more than
adequate.
F. Specific Details - Curb Cuts
1. Three curb cuts are proposed along the southern flowline of Buckingham
Street. These are located within sumps with very small drainage basins. Each
curb cut will be 2' wide, connected to a sidewalk culvert with a 2' wide, 6" deep
concrete U channel at 0.5% slope.
Final Drainage Report
Colorado Iron & Metal
VI. SEDIMENT/EROSION CONTROL
A. General Concept
1. Temporary erosion control measures will be installed with this project. These
measures will include:
a. Silt fence along the property lines.
b. Gravel filters along the U channels between the back of walk and the site.
c. Water trucks and soil terracing to address construction dust abatement.
d. Vehicle tracking pad at the construction entrance.
e. The detention pond will act as a sediment basin during construction.
2. Permanent sediment erosion control measures will consist of paving,
concrete hardscape, and landscaping to stabilize the disturbed areas.
3. Maintenance of all sediment erosion control devices will remain the
responsibility of the contractor until the project is completed.
4. An Engineer's opinion of probable cost for the erosion/sediment control
measures are located in the appendix.
Final Drainage Report
Colorado Iron & Metal
VII. CONCLUSIONS
A. Compliance with standards
1. All drainage design conform to the criteria and requirements of City of Fort
Collins Storm Drainage and Design Criteria and Construction Standards.
2. Proposed drainage improvements conform to the concepts and
recommendations of the Dry Creek Basin master plan.
3. Proposed sediment/erosion control measures conform to the
recommendations of City of Fort Collins Storm Drainage and Design Criteria
and Construction Standards and generally accepted erosion control
procedures.
B. Drainage Concept
1. The proposed drainage plan concept for the project will be effective for the
control of stormwater runoff and water quality for the proposed site and
conforms to City of Fort Collins standards.
VIIIAEFERENCES
• City of Fort Collins Storm Drainage and Design Criteria and Construction Standards
• The Dry Creek Basin Master Plan
• Urban Storm Drainage Criteria Manual Volume 1; Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
• Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
• Urban Storm Drainage Criteria Manual Volume 3, Best Management Practices; Urban
Drainage and Flood Control District, Denver, Colorado, September, 1999.
0
Final Drainage Report
Colorado Iron & Metal
IX. APENDICES
Appendix I - Hydrologic Calculations
• Runoff Curve Number
■ Time of Concentration and Peak Discharge
Appendix II - Hydraulic and Detention Calculations
■ Water Quality Calculations
■ Detention Pond Sizing Worksheet
■ Pond Stage -Storage Worksheet
■ Storm Sewer Calculations
■ Sediment and Erosion Control Opinion of Probable Cost
Appendix III - Mapping and Plans
■ FEMA Firmette
■ City Floodplain Map
■ Drainage and Erosion Control Plan (24"06")
0
Final Drainage Report
Colorado Iron & Metal
Appendix 1 - Hydrology
Area -Weighting for Runoff Coefficient Calculation
Project Title: CIM
Catchment ID: Basin A. 100-year
Illustration
Su%awa 3
s�
$
Flow Dvechoa
•
cotcLm ®t
Boundarg
I nstru ct ons: For each catchment subarea, enter values br A and C.
�iJill�1®
1 •
surrul 4.10 j bum.1 Z.= i
Area -Weighted Runoff Coefficient (sum C A -sum A) = 0.89
See sheet "Design Into" for inperviousness-based runoff coefficient values.
UD Raiional -Basin A 100yr xis. Weighted C 4/20/2011 10 07 AM
Final Drainage Report
Colorado Iron & Metal
CALCULATION OF A PEAK RUNOFF USING RATIONAL IETHOO
Project THIG CM
Catchment ID: Basin A, 100-year Discharge
1. Catchment Hydrologic Data
Catchment ID = A
Area = 3.18 Acres
Percent Imperviousness= B6.00 %
NRCS SoilType= BA, B, C. or
j O. Rainfall Information I(IncNFr)= C1 I P11(C2• Tdr C3
�\ Design Storm Return Period, Tr=
100 years (input return period fordesign storm>
C1=
2850 ( nput the valu a of C 11
C2=
10.00 (Input the Yalu a of C 2)
C3=
0.793 (input the value of C 3)
P1=
2.91 inches (input one-hr preapaahon—see Sheet "Design Ink"
8L Analysis of Flow Time(rimeof Concentration) fora Catchment
Runoff Coefhciern, C =
0.76
Ovende Runoff Coefficient, C =
(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient. C c =
0.67
_- Overide 5-yr. Runoff Coefficient. C =
arter an ovende C-5 value ifdesired, or leave blank to accept calculated C-5. )
ttlustratkm
rV.
Rexh 1 Dsv
Huh ` .1 L7 SeZiw�
_ Flan- Dirrrtia.
Caartuwewl
anaaLes
40---S Land
Hevy
Tillage
Shut
Newt
Grassed
Pwmd Pressa
Type
frkadvv
11
�ieki
Pastor.
Dwe
Swales
Shalkw P�Swdes
LLrrs
Ground
Ni sterwa
(Shed�
.roe
2
5
7
10
15-1
�Flan
t—
Calculations:
Reach
Sim"
Length
5-yr
NRCS
Flow
Flea'
ID
5
L
Runoff
cmvey-
Veksdy
Tare
Codl
arsrs
V
Tf
Poa
It
cz
fm
minutes
input
input
output
input
output
cutpui
Overland
0.0200
25
0.67
0.13
3.09
1
0.0050
540
20.00
1,41
6.3E
2
3
4
5
Sum
565
C omputed
Tc =
9 4c
Regional Tc= 13.14
Peak Runoff Prediction using Computed Tc Kliction using Regional Tc
Rainfall Intensity at Tc. 1= 7.88 in dtlltr Rainfall lntensityatTc, l= 6.87 inchhtr
Peak Flovrate, Op= 19.10 cfs Peek Flovaate, Op= 16.64 cfs
UD Rational- Basin A 100yr.)ds, Tc and PeakO
4202011. 10:D7 AM
0
Final Drainage Report
Colorado Iron & Metal
Area -Weighting for Runoff Coefficient Calculation
Project Title: CIM
Catchment ID: Basin SW (for emergency spillway). 100-year
Illustration
A
ecEvD:
Iow Duecuon
:`atchm ent
3oui
Instructions For each catchm ent subarea, enter values for A and C.
Subarea
Area
Runoff
Product
ID
acres
Coeff.
A
C'
CA
inrut
input
input
output
Pavinq
3 02
0 96
2 90
Open
1 4?
0 50
0 74
sumd 4.49 sumd 3.63
Area -Weighted Runoff Coefficient (sum Cksum A) = 0.81
'See sheet "Design Info" for inperviousness-based runoff coefficient values.
UD Rational - Basin SW 100yrx1s. Weighted C 611/2011, 10:18 AM
Final Drainage Report
Colorado Iron & Metal
CALCULATION OF A PEAK RUNOFF U SING RATIONAL METHOD
Project Title clu
CatchmentIO: Basin SW,100-year Discharge
1. Catchment Hydrologic Data
Catchment ID = SW
Area = 4.49 Acres
Percent lmper,nousrless= 72.00%
NRCS Soil Type = B A. B. C. orD
R. Rainfalllnformation IlincNhrl=C1'P17IC2+Tdy'C3
Design Storm Return Period, Tr=
1 DO years
C 1 =
28.50
C2=
10.DD
C3=
0.793
P1=
2.91 inches
(input return period fordesign storm)
(input the value of C 1)
(input the value of C 2)
(input the value of C3)
(input cne-hr preciptation—see Sheet "Design Into-,,
A. Analysis of Flow -rime (Time of Concentration) fora Catchment
Runoff Coefficient. C = 0.^3
OterideRunoffCoef4dent. C = 0.81 ester air o:eride C :alie if desired cr leave blank tc accect calculated C
5-yr.Runoff Coefficient C-5= M1
Overide 5-yr. Runoff Coefficient. C = enterar e.eride Cti value if desired cr leave blank It accept calculated C-5.;
Illustration
IV.
werlat Lram
/ Reach t1wP
Reath 2 >�xctfoi
Flaw Di
C�121ment
itrarA } Bowaaa;r
lip. :S laic
Heavy
I n1la6s
Shot
Nearly
Gassed
Paved i7,1n
Type
bleadp
=iNC
Fa•ura�
Bare
S.wla
5t allaYPw
l..a ,m
Cm red
IN aftery 5
;She -et
CdnYeyarxe
25 IF_5
-ICIF
15 I
2n
C a Iculation &
React,
Slope
Lerglh
5-yr
rdRCS
Flag
Fla:'
ID
5
L
Rung(
Convey-
`.`Jc:,i:,
Tr
Coco
mm
Vf
tolt
It
C-5
fps
inpult
inpiit
output
i . ut
at ut
a.ip�,
Overland
0.0800
62
0.51
024
4.22
1
0.0D50
%5
20.00
1.41
6.66
2
3
4
5
Sum
o27
Computed-c=
10.88
Regional—c= 13.48
Peak Runoff Predie6en using Computed Tc ton using Regional Tc
Rainfall lrtendyffiTe, 1= 7.45 ind►Ru Rainfall Intensity at—c I = 6.79 inchlhr
Peak Fbvrate. Op= 27.10 c# 7 Peak Flcveate. Op = 24.69 cfs
UDRational-Basin SW 100yrxls,TcandPeakQ C.t tC t5
-hl
Final Drainage Report
Colorado Iron & Metal
Designer:
Cornpany.
Date
Project
Location:
Appendix II - Hydraulics
Design Procedure Form: Extended Detention Basin (EDB) • Sedimentation Facility
Sheet 1 of 3
B. Gowng
APEX Engineering
April 20 2011
Colorado Iron and If tml - Pond 1
Fort Collins, CO
t Bas inSda0e Volrre
1,=
aeoB
x
A) Trilm my Areas Imparviarsmesz R atio I i = Is/ 100)
i =
VIRF--
el Coreouag wasssheo Area Area)
Ares=
118
aaa-
C) Waa0ua"ty QNp eVdume(WOCV)
ACCV=
037
watw.hw inure=
(WOCV=10' (0B1 -C - 1.19' V -0.78' D)
D) Desgn Vdurre:Vd=(WOCV112J'Aaes'l2
Vol=
0.117
aadteet
2 Outlet Worts
AI Qrtlet Type 1Ched[ 010
X
Qlfee Phme
Perforated
R 6 a - Pk
other
B) Depth a Outlet Above Lwvst Palwac+(H)
H=
1.4e
fer3
C) Required h`xirum Outlet Area W Row.(Ad
A,=
010
Sc6are alhes
D) Pslore6m D arersom tenth one onlyl
0 Circular perforation Darter OR
D =
0 eba
inches. OR
T 7 HeBN Redargular PerMaon W iah
W =
mches
E)linsbw of Cdu Im See Table e-al Fa t.oxnum)
nc=
1
number
F) Adpel Design Owlet Aran Per Row IA,)
A. =
0.37
square aches
G) Nursher of Roes (M
nr =
4
r, nbw
H) Hxaf Uuet ArealAJ
Ay.=
1.03
square mhes
Trash Rad
A) Nseoeo Upen Area: Ar=U. h'(FU, ( Vetre)-A,
M=
57
square acres
B) Type of Chalet Open^O Iched One)
X
52'Diarhaw Round
2 High RMarwular
7[ncn
C) For 2, or Smaller, Rotmd Opaanim (Ref.: Figure as)
y worm a [rash Hact and Cmgete Upensg Im J
wan rceotfi
v =
ir.�s
®1 HeON of Trash Rad Screw (Hral
Hv =
4a
i.chft
USOCIJ Shl P EDB - Pond 1, EDB
7113.2011, 4.52 PM
Final Drainage Report
Colorado Iron & Metal
Detention Pond Sizing Worksheet
Colorado Iron & Metal
This is to convert % impto a C value Required detention
(must inset % imp. and C pervious). ftl acre-ft
'c value 0.89
r • 1.25 1
Area 3.1 acres
Release Rate 1 0.64
DETENTION POND SIZING
45734.4 08614
M od(led Modified
M. FA TER D. JUDISH C. LI
995 Nov-97 Nov-98
TIME
(mnst
TIME
cumm.
(secs,)
INTENSITY
100 y®r
(Nhr)
Q 100
(ds)
Runoff
Volume
(ft"3)
Release
Cumm. total
(ft"3)
Required
Detention
(ft^3)
Required
Detention
(ac-ft)
0
0
0
ODO
0
0.0
0.0
OD000
5
300
9950
31.64
9492.3
192.0
9300.3
02135
10
600
7720
24.55
14729.76
384.0
14345.8
03293
15
900
6S20
20.73
18660.24
576.0
180841
0.4152
20
1200
5,600
17.81
21369.6
768.0
20601.6
0.4729
25
1500
4.980
15.84
23754.6
960.0
22794.6
0.5233
30
1800
4520
14.37
25872.48
1152.0
24720.5
05675
35
2100
4D80
12-97
27246.24
1344.0
259022
05946
40
2400
3740
11.89
28543.68
153&0
27007.7
0b200
45
2700
3.460
11.00
29707.56
1728.0
27979.6
06423
50
3000
3230
10.27
308142
1920.0
288942
Ob633
55
3300
31130
9b4
31796.82
2112.0
29684.8
0.6815
60
3600
21160
909
32741.28
2304.0
30437.3
06987
65
3900
2720
8.65
3373344
2496.0
31737.4
07171
70
4200
2590
824
3459104
2688.0
31904.0
07324
75
4500
2480
7.89
35488.8
2880.0
32608.8
0.7486
80
4800
2330
757
36328.32
3072.0
33256.3
07635
85
5100
2290
728
3713922
3264.0
338752
07777
90
5400
2210
7D3
37950.12
3456.0
34494.1
07919
95
5700
2.130
677
38608.38
3648.0
34960.4
OB026
100
6000
2D60
655
39304.8
3840.0
35464Z
OB 142
105
6300
2.000
636
40068
4032.0
36036.0
OB273
110
6600
1.940
6.17
40716.72
4224.0
36492.7
08378
115
6900
1B90
6111
41470.38
4416.0
37054.4
OB507
120
T200
IS40
5.85
42128.64
4608-0
37520.6
OB614
Apex Engineering Confidential dl2012011 Page
Final Drainage Report
Colorado Iron & Metal
Pond Stage -Storage Worksheet
Colorado Iron and Metal
Pond ID: Detention Pbnd I
Input:
Detention Volume Required = 0.861 acre-ft
WQCV Required = 0.117 acre4t
Total Pond Volume Required = 0.978 acre-ft
Where:
Volume = I/3(d)(A+B+A Y10.5)
d = elevation - elevation, ,
A = area of elevation,, contour
B = area of elevation„ contour
Results.
100-year WSEL = 42.46
WQ WSB. = 44.09
Calculations:
Cumulative
Bev. Area Area Storage Storage
(feet) (S17 (acre) (acre-ft) (acre-feet)
41.00
0
0.000
0.000
0.000
42.00
3,445
0.079
0.026
0.026
43.00
14,959
0.343
0.196
0.222
44.00
45,199
1.038
0.659
0.881
44.20
51,078
1.173
0.221
1.102
Final Drainage Report
Colorado Iron & Metal
Circular Pipe Flow
C Project: CIM
Pipe ID: Storm A - 1003rear
Aim / ti
i
t)
Invert Slope
So =
0.0030 ftft
Manning's navalue
n =
0 0130
Diameter
D =
15 00 inches
gn discharge
0 =
0.6 cfs
1-flow area
Af =
1.23 sq ft
1-flow wetted perimeter
Pf =
3.93 ft
If Central Angle
Theta =
3.14 rad
11-flow capacity
Qf =
3.6 cfs
Central angle (0<Theta<3 14)
Theta =
1.13 rad
m area
An =
029 sq It
fled perimeter
Pn =
1A2 ft
N depth
Yn =
0 36 ft
n; velocity
Vn =
2 19 fps
charge
On =
0.6 cfs
ilf Central Angle (0<Theta-c<3 14)
Theta-c =
1 05 rad
rtical flow area
Ac =
0.24 sq ft
ttical top width
Tc =
1,08 ft
itical flow depth
Yc=
0 31 ft
itical flow v elocity
Vc =
2.67 fps
oudenumber
Fr—
1.00
UD-Culvert v1 01 STORM AXIS Pipe X20i2011 10 17 ANI
Final Drainage Report
Colorado Iron & Metal
H
w
w
G
3
z
0
H
w
Q U
3
J
J_
d
h
z
w
W
E
w
w
Final Drainage Report
Colorado Iron & Metal
EROSION CONTROL COST ESTIMATE
Prgect:
Colorado Iron and Metal
P repsred By:
BG
Daft W t2011
CITY RE SEE DING CO ST
Unit
Total
tAtnod
Quantity
Unit
Goat
Cast Noses
R esee2
51.050
S4.263.0C
r•^. a
S4.263
50%
$2.132
—t1a
t �yc
EROSION CONTROL MEASURE S
Unit
Total
Nonder IAMod
Quantity
Unit
Cost
Cast Notes
6 Gravel Inlet F.re-
7
ea
$300
$2.100
8 Sit Faroe Bamer
211
LF
$3
$633
38 Gravel Mulch
0.74
ac
$1.350
S999
39 HayorStrawOryMuidt(1S%slope',
0.89
ac
SSW
S445
SuCtota
S4.1 T7
Ccrt:ro_e^c%
50%
$2.039
'rta 1
$6.266
Final Drainage Report
Colorado Iron & Metal
Appendix III - Mapping.