HomeMy WebLinkAboutRAW URTH DESIGNS - PDP - PDP150007 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT• •-
eeeeeeeeeee®
• ...
.,mwwwWrom-
._.
__=eeeeeeeee
eeeeeeeeeeee
BEST MANAGEMENT PRACTICES -
STRUCTURAL
SILT FENCE BARRIEF�S--
...
VEHICLE TRACKING PADS
—ETC)
FLOW BARRIEWS (WATTLES,
CONCRETE WASHOUT
ROCK SOCKS
BARE SOIL PREPARATION—:-::��mmwmmmmm
m
TERRACING 7mmmmmmmm
-
mmemmmeeeeee
VEGETATIVE
—ANT
7 SEAL
- D -S
eeeee--eeeeee
OD
®®®®®®®®®®®®
Erosion and Sediment Control Escrow/Security Calculation
- for-fh-e City of-Fort-Colli-ns -- -----
Project: Raw Urth Designs
Disturbed Acres: 0.90
')4 f 'F 4 t�jG Y1't'rA '^ • Y ,. y 7 x'
9 < a n n7,
V:u
Estimated
Unit
Total
EROSION CONTROL BMPs
Units
Quantity
Price
Price
Silt Fence
L.F.
730
$3.00
$2,190.00
Rock Sock
each
15
$85.00
$1,275.00
Vehicle Tracking Control Pad
each
1
$1,500.00
$1,500.00
Concrete Washout
each
1
$1,200.00
$1,200.00
(add all other BMPs for the site in this list)
Sub -Total:
$6,165.00
1.5 x Sub -Total:
$9,247.50
Amount
of security:
$9,247.50
5 g+ i , .P`v�1 9 'f Y 'i' Y.. 7•1 l
', �a
Total Acres x Price/acre: $1,080.00
Unit Price of Seeding per acre: $1,200.00 Sub -Total: $1,080.00
1.5 x Sub -Total: $1,620.00
Amount to Re -seed: $1,620.00
" w {� "a>ti ...Minulmum Escrow'Amount <* Yx
..-�»s ... _..-.. �.....,., ..., ..,e.�.�-, ,........�.d.we...�.:..........s.fi...w�...�ix.i>. ��.. ,Z.t.-._,,`lus:� 5 ,
Minimum escrow amount: $3,000.00
.GM01111M,
�'��i+r ,:d' t= a �. u _ �t3, A.Sir$ g;•,. ,4 r- $+,�.;�4��.�,v
Erosion Control Escrow: $9,247.50
"Tire amount of the security mist be based on one and one-lm6(dmes the estiurate oldie cost to install the approved measures, or one and one-half times
the cost to re -vegetate the disturbed land to dry land grasses based upon unit coat determined by the City's Annual Revegetation and Stabilization Rid,
whichever is greater. Its no instance, will the amount of security be less than one thousand five hundred dollars ($1,500) for residential development or three
thousand dollars ($3,000) for commercial development"
5/12/2015 3:13 PM NW7-00maw UnhWminag6ExampWEacmw.xla
APPENDIX D
BMP SCHEDULE & COST ESTIMATE
Emergency Overflow Spillway Sizing
LOCATION: Raw Urth Designs
PROJECT NO: 177-09
COMPUTATIONS BY: PPK
SUBMITTED BY: North Star Design, Inc.
DATE: 5/24/2005
Equation for flow over a broad crested weir�bem
Q = CLH312 � � SpIII elevationwhere C = weir coefficient = 2.8
H = overflow height 1 900yrWSEL
L = length of the weir 17
The pond has a spill elevation 0 ft above the maximum water surface elevation in the pond
Spillways will be designed with 0.25 ft flow depth, thus H = 0.25 ft
Size the spillway assuming that the pond outlet is completely clogged
Q (100) = 6.4 cfs
Spill elev = 4971.65 ft 100 yr WSEL = 4971.65 ft
Top of berm elev.= 4972.05
Weir length required:
L= 18 ft
Use L = 20 ft
v = 0.91 ft/s
0 • 1
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
SUBMITTED BY:
DATE:
Detention Pond Outlet Sizing
Raw Urth Designs
177-09
PPK
North Star Design, Inc.
5/12/2015
Submerged Orifice Outlet:
release rate is described by the orifice equation,
Qo = CA sqrt( 2g(h-Eo))
where Qo = orifice outflow (cfs)
Co = orifice discharge coefficient
g = gravitational acceleration = 32.2 ft/s
Aa = effective area of the orifice (ft)
Eo = greater of geometric center elevation of the orifice or d/s HGL (ft)
h = water surface elevation (ft)
Qa = 0.18 cfs
outlet pipe dia = D = 12.0 in
Invert elev. = 4768.80 ft
Eo = 4768.88 ft
h = 4771.65 ft - 100 yr WSEL
Co = 0.62
solve for effective area of orifice using the orifice equation
Ao = 0.022 ftZ
3.1 inZ
orifice dia. = d = 2.00 in
Check orifice discharge coefficient using Figure 5-21 (Hydraulic Engineering)
d/D= 0.17
kinematic viscosity, u = 1.22E-05 ftZ/s
Reynolds no. = Red = 4Q/(pdu) = 1.13E+05
Ca = (K in figure) = 0.62 check
Use d = 2.00 in
Aa = 0.022 ft' = 3.14 in
Q max 0.2 cfs
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
SUBMITTED BY:
DATE:
WQCV
100 WSEL
STAGE - STORAGE TABLE
Raw Urth Designs
177-09
PPK
North Star Design, Inc.
8/1/2008
100 yr Detention Volume Required = 0.154
Water Quality Volume Required = 0.000
Total Volume Required= 0.154
Stage
(ft)
Surface
Area
(ft)
Incremental
Storage
(ac-ft)
Total
Storage
(ac-ft)
4768.80
0
4770.0
1,590
0.015
0.01
4770.34
2,437
0.016
0.030
4771.0
4,082
0.063
0.077
4771.65
6,513
0.078
0.156 El
4772.1
8,009
0.143
0.221
DETENTION VOLUME BY THE MODIFIED FAA METHOD
---Project:-Raw-Urth.Designs—
BasIn ID: 1
Inflow and Outflow Volumes vs. Rainfall Duration
0.25
0.2
-7-
0.15
L
E
0.1
P
0 rD D 00 C,
3 0 0 o ODD
900 .: c10330
0-�c OoD
0.05
0
0
50 100 150 200 250 300 350
Duration (Minutes)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK
2013
Version 224, ReWsed NovemSer
UD
aoWuon 4.34.9a Mod&md FAA 5112=15. 2:49 are
Version 224, ReWsed NovemSer
UD
aoWuon 4.34.9a Mod&md FAA 5112=15. 2:49 are
a% a
DETENTION VOLUME BY THE MODIFIED FAA METHOD
__ P_rolect:_Raw-Urth.Designs______._____-__
Basin ID: 1
(For catchfronls less than 160 acres only, For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are reconvrlended)
Deterrrlinatlon of MINOR Detention Volum Using Modified FAA Method I Determination of MAJOR Detention Volufre Using Modified FAA Method
Cat[MpM DreNpe Int drao vwee
Ce.ot Drauu00 Ana
Preletebgn onl MiCO SON Grow
Rah4n Ponod for Daenoon CmhW
Thne of Comenha0en of WmN,ed
Aavnme UNf Rebaao RAW
Cna4,our P,ociptitlon
Daa4n RabHSIDFFoemuM I-C,P,nC,FTJ•C,
Coeflklont Cm
Co.downl Two
CoefficeA nne
I••
e5,00
Parton,
A•
Dam
Tye.-
C
AB•C, Or
T.
10'
yws (2. 5.10.25, 50. or 1 DO)
TO
2
mluHa
0•
0.20 -
"aloe
P,•
'1A1
I,cMs
c,•
' 2a.50
c,•
10
c,•
o.Tea
Caamp,n Oran ag. f eadra. M
GkhmMOrm,pa Ara
PnOawagmanlNRCS Se0 Gm,q
Rehm Faroe 1b 0.,n,bon Control
n. of Cocoon moon Ol Wabeared
AlbweM Um RWaaa RYe
one. P,a6'ma a n
Dselgn R.IMaSIDFF--U I-C,- P,4L,nTJ-C,
Coracle. CFa
CoefficWt Two
CoeekkNTMe
la-
05.00
pamml
A•
0.me
TyyaC
A.B. C, or
T•
100
yeas (2.5.10,25. W. or 100)
Tc-
T
re...
A-
0.20
or F77�nciro.
C, •
29.50
Cr-
10
C,•
o.2ae
RumRCoaff[Ian C.
0.5e
RonoffC ffclenl C.
0.05
IMnw Paak Ruwfl on- •
2.40
[fa
Infmu Pea. Runoff 0F4n-
4 00
of
AWwIIe ft Wdbw RaN Opwl•
0.13
[la
NbwaaM Pask Wbw Rap cs,.,-
a.10
cfa
Mod. FM Mbar SWpa Volume-
2.744
cuhk feel
Mod. FM Major Store" VeWma-
a,720
cook hat
Mod, Mbar Storage Velw,e•
0Ae4
a[ma4,
Mad. FM Maier$wage Vo krme-
0.154
<re11
5 •- Grwr Re nlYl
DuraOenlrcrengMN lrcreasa Vlue
Wre la .SIerSAlmubal
RaINY
Ranfea
m
Inflow AdjuaoM
A.M.
Outflow
S.M.
fLnlao needed odor. Adu.aranl
Average
Wdbw
stnga
Wmm�
IMenaly
V.1um
Facto
Qrdbw
Volume
Vekana
Duragon
IMenMry
Volume
Fe[br
Outlaw—
V—
mvaNa
M[hea/h
a[nlaal
'm'
[H
v ..t
c,a{ae1
mMa
ecMa/H
crNM
ln'
[f.
a[Meel
cMeel
And. FM Miner S.I., Velbne lcuMa a.j- 2.754 Mod. FAA Maw damage Volume bchlc fLl• a)M
Mod.FM Minor Sbraga Volume jacrafi.l• 0.009 Mad. FM Major S.a'. VONma la<re-ILI- 0.1542
UOFCO DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2,34, Released November 2013
UDoelemmn 4.34.ae, Meddled FM V1=015, 2:49 PM
APPENDIX C
DETENTION POND SIZING CALCULATIONS
C
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor. CO 80550
i
LOCATION: Raw Urth Designs
PROJECT NO: 177-06
COMPUTATIONS BY: ppk
DATE: 5/12/2015
i
100-yr storm, Cf = 1.25
RATIONAL METHOD PEAK RUNOFF
(100-YEAR)
DIRECT RUNOFF
CARRY OVER
TOTAL
REMARKS
Des.
Point
Area
Design.
A
(ac)
C'Cf
tc
(min)
i
(new)
(in/hr)
Q (100)
(cfs).
from
Design
Point
Q (100)
(cfs)
Q(100)tot
(cfs)
1
1
0.19
0.99
5.5
9.66
1.9
1.9
To area inlet
1
2
0.15
1.00
5.0
9.95
1.5
1.5
to sidewalk culvert
1
3
0.51
0.86
9.1
7.35
3.2
3.2
To Det Pond
1
ALL
0.89
0.92
8.3
7.84
1 6.4
1 6.4
ITo Det Pond
Q=CIA
Q = peak discharge (cfs)
C = runoff coefficient
= rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
Flow.xls Q100
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80650
I
i
LOCATION:
PROJECT NO:
i COMPUTATIONS BY:
DATE:
Raw Urth Designs
177-06
ppk
5/12/2015
2-yr storm, Cf = 1.00
RATIONAL METHOD PEAK RUNOFF
(2-YEAR)
DIRECT RUNOFF
CARRY OVER
TOTAL
REMARKS
Design
Point
Tributary
Sub -basin
A!
(ac)
C`Cf
tc
(min)
i
(new)
(in/hr)
Q (2)
(cfs)
from
Design
Point
Q (2)
(cfs)
Q(2)tot
(cfs)
1
1
0.19
0.79
7.1
2.49
0.4
0.4
To area inlet
1
2
0.15
0.88
5.0
2.70
0.3
0.3
to sidewalk culvert
1
3
0.51
0.69
11.5
2.05
0.7
0.7
To Det Pond
0.89
0.73
10.9
2.11
1.4
1.4
To Det Pond
Q=CrCiA
Q = peak discharge (cfs)
C = runoff coefficient
Cr = frequency adjustment factor
i = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
FlowAs Q2
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
DATE:
100-yr storm
Raw Urth Designs
177-06
ppk
5/12/2015
Cf = 1.25
STANDARD FORM SF-2
TIME OF CONCENTRATION -100 YR
SUB -BASIN DATA
INITIAL /OVERLAND
TIME (ti)
TRAVEL TIME / GUTTER OR CHANNEL FLOW
(tt)
tc CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
DESIGN
POINT
ISUBBASIN(s)
(1)
Area
(ac)
(2)
C
(3)
C'Cf
Length
(ft)
(4)
Slope
(%)
(5)
It
(min)
(6)
Length
(ft)
(7)
Slope
(%)
(8)
n
Manning
rough.
Val.
(Ws)
(9)
tt
(min)
(10)
tc =
ti+tt
01)
Total L
(ft)
(12)
tc=(U180)+10
(min)
(13)
(min)
(14)
'
I
1
1
0.19
0.79
0.99
35
2.0
1.0
204
0.5
0.030
0.8
4.49
5.5
239
11.3
5.5
1
2
0.15
0.88
1.00
24
1.5
0.8
146
0.6
0.016
1.6
1.56
2.3
170
10.9
5.0
1
3
0.51
0.69
0.86
62
1.0
3.4
283
0.6
0.030
0.8
5.68
9.1
345
11.9
9.1
1
ALL
1 0.89.
0.73
0.92
62
1.0
2.6
283
0.6
0.030
0.8
5.68
8.3
345
11.9
1 8.3
EQUATIONS:
tc=ti+It
II-[1.57(1.1-CC,)Lo.5)IS1/3
It _ L/Vel. Velocity from Manning's Equation with R=0.1 (corresponds to Figure 3-3 of City of Fart Collins Design Manual)
l
final tc = minimum of ti + It and urbanized basin check
min. tc = 5 minutes
I
ii
I
Flow.xls TOC-100
i
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
I
LOCATION:
Raw Urth Designs
PROJECT NO:
177-06
COMPUTATIONS BY:
ppk
DATE:
5/12/2015
2 yr storm
Cf = 1.00
STANDARD FORM SF-2
TIME OF CONCENTRATION - 2 YEAR
SUB -BASIN DATA
INITIAL /OVERLAND
TIME It!)
TRAVEL TIME I GUTTER OR CHANNEL FLOW
(tt)
to CHECK
(URBANIZED BASIN)
FINAL
to
REMARKS
DESIGN
POINT
SUBBASIN(s)
(1)
Area
(ac)
(2)
C
(3)
Length,
(ft)
(4)
Slope
(%)
(5)
ti
(min)
(6)
Length
(fl)
(7)
Slope
(%)
(8)
n
Manning
rough.
(ft/s)
Vel.b4.4
(9)
to =
ti+it
01)
Total L
(ft)
(12)
tc=(1/180)+10
(min)
(13)
(min)
(14)
I
1
1
0.19
0.79
35
2.0
2.6
204
0.5
0.030
0.8
7.1239
11.3
7.11
2
0.15
0.88
24
1.5
1.7
146
0.6
0.016
1.6
3.3
170
10.9
5.0
1
3
0.51
0.69
62
1.0
5.8
283
0.6
0.030
0.8
11.5
345
11.9
11.5
1
1
1
ALL
0.89
0.73
62
1.0
5.2
283
0.6
0.030
0.8
5.68
10.9
345
11.9
10.9
i
EQUATIONS:
to ti + It
ti=[1.87(1.1-CCt)L05]/Stn
tt= L/Vel. Velocity from Manning's Equation with R=0.1 (corresponds to Figure 3-3 of City of Fort Collins Design Manual)
final tc = minimum of ti + tt and urbanized basin check
min. tc = 5 minutes
Flow.xls TOC-2
i
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
1
LOCATION: Raw Urth Designs
PROJECT NO: 177-06
COMPUTATIONS BY: ppk
DATE: 5/122015
Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria
Recommended % Impervious from Urban Storm Drainage Criteria Manual
Streets, parking lots (asphalt)
Sidewalks
Gravel
Roofs
Lawns (flat <2%, heavy soil)
%
Runoff
Impervious
coefficient
C
100%
0.95
96%
0.95
40%
0.50
90%
0.95
0%
0.20
SUBBASIN
DESIGNATION
TOTAL
AREA
(ac.)
TOTAL
AREA
(sq.ft)
ROOF
AREA
(sq.ft)
PAVED
AREA
(sq.ft)
SIDEWALK
AREA
(sq.ft)
GRAVEL
AREA
(sq.ft)
LANDSCAPE
AREA
(sq.ft)
%
Impervious
RUNOFF
COEFF.
(C)
1
0.19
8474
0
6368
0
0
2,106
76%
0.79
2
0.15
6427
0
5,354
360
0
713
89%
0.88
3
0.51
22236
12415
0
904
0
8,917
56%
0.69
ALL
0.89
38,584
12,415
12,010
1.264
0
12,895
65%
0.73
Equations
- Calculated C coefficients & % Impervious are area weighted
C=E(Ci Ai) /At
Ci = runoff coefficient for specific area, Ai
Ai = areas of surface with runoff coefficient of Ci
n = number of different surfaces to consider
Al = total area over which C is applicable; the sum of all Ai's
FlowAs Cval
APPENDIX B
HYDROLOGIC COMPUTATIONS
PROJECT
LOCATION
VICINITY MAP
APPENDIX A
VICINITY MAP
A
7. REFERENCES
1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March,
1986.
2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria
Manual", Volumes 1 and 2, dated March, 1969, and Volume 3 dated September,
1992.
13
6. CONCLUSIONS
6.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
"City of Fort Collins Erosion Control Reference Manual for Construction Sites", the
"City of Fort Collins Storm Drainage Design Criteria Manual", and the "Urban Storm
Drainage Criteria Manual' except where variances are requested as noted in Section 4.2
of this report.
6.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
adequately provide for the collection and conveyance of on -site runoff to the detention
area. Conveyance elements exist to adequately convey detained runoff downstream.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit would be required.
12
5) Waste Management and Disposal:
Portable toilets will be anchored & periodically maintained by waste management company.
Dumpsters on site will be covered & periodically emptied by waste management company.
Concrete waste will be allowed to harden and then will be removed from site.
No washing activities will occur on site.
Location of the concrete washout is shown on the site map. The washout will be suitably
deep to accommodate all anticipated concrete truck wash water. Waste concrete will be
allowed to harden & be removed from site periodically as the washout reaches 50% of
capacity. Truck wash water will not be allowed to reach the curb & gutter or any other water
course.
6) Groundwater and Stormwater Dewatering:
No groundwater was encountered during soils exploration therefore ground water is not
anticipated to be an issue. If groundwater is encountered a groundwater discharge permit
shall be obtained and a detailed report shall be completed describing the location and the
route of where pumped groundwater will be conveyed and the measures taken to prevent the
transport of any pollutants to downstream waters.
7) Inspection & Maintenance:
It is required that routine site inspections are performed to effectively address maintenance
and repair of Best Management Practices (BMP's). The site inspections are to be performed
by the contractor or an inspector designated by the administrator at a minimum of once every
fourteen (14) calendar days on active construction sites and after any significant storm event
(an event causing runoff). As part of the site inspections the inspector is required to keep
documentation of all inspections and BMP maintenance, including an updated Site Map
indicating new BMP's or the removal of BMP's since the previous inspection.
Any maintenance, repair, or necessary installation of BMP's that are noted during the
inspection must be completed within seven (7) calendar days from the date of the
inspection
m
2 Matenals Handling and S ill
Prevention:
. Matenals Handling &Spill rr
krApphcable.to
location on site
this
Prevention BMP.�Yf�, i'lt
q
� a*�.iApproximate
,+ Project ,
..i'r�'k..'+'°v'aev'Sr:—.i."..i4
Portable toilets, anchored &
located away from drainages
Contractor to determine
}(
Fuel storage located in bulk tanks
with secondary containment &
spill kit
Mobile fueling performed at least
200 feet away from drainages &
Contractor to determine
X
fully attended
Fertilizers, form oil, solvents,
cleaners, detergent stored in 55 gal
or smaller containers, kept in
Contractor to determine
}�
storage units
Dumpsters containing used
chemicals containers & liquid
Contractor to determine
X
wastes kept covered
Equipment cleaning (on site) uses
no detergents & flows to onsite
retention basin
In case of a release of fuel or other
chemicals, absorbent booms or ,
earthen berms will be immediately
constructed to contain the spill
Location of spill
X
prevent runoff to adjacent surface
waters
MSDS sheets for onsite chemicals
will be kept at the construction
trailer to facilitate spill response &
Contractor [o determine
}(
cleanup
3) Dedicated Asphalt or Concrete Batch Plant:
Not proposed with this development
4) Vehicle Tracking Pad:
Vehicle tracking control pad shall be installed wherever construction vehicle access routes
intersect paved public roads. Vehicle tracking control pads shall be installed to minimize the
transport of sediment (mud) by runoff or vehicles tracking onto the paved surface. Any mud
tracked to public roads shall be removed on a daily basis and after any significant storm that
causes sediment to be transported. It is unlawful to track sediment/mud onto public streets
- --- ---- - - — and -may -be enforced -by the City of Fort Collins, by-tlie State of Colorado or by the EPA.
--- -
H
No--area.-shall-remain-exposed-by-land disturbing-activity--for-more-than-thirty (30)-days-before
required temporary or permanent erosion control (e.g. seed/mulch, landscaping, etc.) is installed.
Temporary & Permanent non-structural BMP's:
r v :n tit . y ".:, ,,
PPt
+ n, tu Non Strucral BMP 1, '�
;t Approximate location on site; a i
a w v.-
PrO�eC.t
af'1'S r � 1. l
3 t Ft F'.n
C�. S.S�i•l '�i 4 t Y Y �
�F' f t
j
4 y:, r. x, f�k+�ti
t d YF"'E�
� .
Surface roughening
Entire site
X
Soil stockpile height limit (less than
10')
Perimeter vegetative buffer
North boundary of site
X
Minimization of site disturbance
Mulch
Seed & mulch stockpiles after 30 days
Stockpile toe protection (silt fence,
wattles or ditch)
Preservation & protection of existing
North boundary of site
X
vegetation & trees
Good site housekeeping (routine
Entire Site
X
cleanup of trash & constr debris)
Sweeping & scraping of hardscape
On and off site pavements
X
areas
Heavy equip staged on site, properly
maintained & inspected daily (no
Staging area
X
onsite maintenance)
5.5 BMP Implementation
1) Phased BMP Implementation
BMP's are expected to change as the construction progresses and it is the responsibility of
the contractor to ensure appropriate BMP's are in place and/or removed at the appropriate
time in the construction sequence. A construction sequence schedule has been included on
the Drainage & Erosion Control Plan and included in the construction plans for this site.
All BMP's shall be inspected and repaired or replaced as required to satisfy the conditions of
the Stormwater Discharge Permit. All BMP's must be maintained and repaired as needed to
assure continued performance of their intended function. Refer to Appendix D for the BMP
schedule and estimated costs.
9
All BMP's shall be installed per the details shown on the construction plan set.
Temporary & Permanent Structural BMP's:
Structural BMP ,
",.., l., � . x. � . � PG »t' ?... �`..:
on site '�`r
Approximate location N c, 1, Al
a a• , P �',ti + r , + F t e ��'�,
APphcable o this f <
d �.Pio
Silt Fence
Site perimeter, refer to site map
X
Straw bale dams
Rock Socks
At sidewalk culverts, in swales, at new inlet,
in existing gutters, refer to site map
X
Earthen diversion dams
Vegetated swales
Sediment trap/pond
Pipe slope drains
Geogrid
Inlet/outlet protection
In the detention Pond
X
Culverts
Riprap
Erosion control mats
Inlet protection
Vehicle Tracking Control Pad
At site entrance, refer to site map
X
Concrete Washout
To be located by Contractor, near site entry
X
Non -Structural Practices for Erosion and Sediment Control:
Soils exposed during the earthwork phase and landscape prep phase shall be kept in a roughened
condition by ripping or disking along land contours until mulch, vegetation, or other permanent
erosion control is installed. No large amount of soils (in excess of 15 yards). will -be allowed to be
stock piled on site. Overburden from the utility pipe trenching will be piled adjacent to trenches
upstream of sediment controls and will be replaced in the trenches within 72 hours.
Excess excavated materials from the demolition and grading phases of the project that cannot be
reused on site will be exported as it is excavated. This includes any asphalt pavement from the
existing site that is to be removed.
A vehicle tracking pad will be installed at a location most beneficial to the site construction as
determined by the contractor. Vehicles will not be permitted in the excavated area if soil is
muddy. Gravel sub base will be placed and compacted .in the areas indicated for pavement
following excavation. In the current pre construction state the site enables tracking of silt onto
the adjacent streets during wet conditions. During construction activities the street will be
monitored_for _foreian debris_tracked_out_of_the_site_and-mechanical_sweeping..and_clean-up.will-
be performed as needed.
8
5.3 Identification and location of all
sources
Disturbed Areas
Sediment
){
Soil stockpiles
Sediment
X
Travel to adjacent public streets
Tracked sediment
X
Contaminated soils
Sediment, chemicals
Loading and unloading chemicals
Chemicals
Unloading of building materials
Trash, debris
X
Outdoor storage of chemicals
Chemicals
On site equipment maintenance
Oil, grease
On site equipment fueling
Diesel, gasoline
X
Dust generating activities
Particulates, sediment
X
Use of fertilizer, pesticides, herbicides
Fertilizer, pesticides
Use of detergents, solvents, oils
Detergents, solvents, oil
X
Waste dumpsters, waste piles
Chemicals, trash, debris
X
Concrete washout
Concrete, sediment, wash water
X
On site equipment washing
Detergents, oil
On site asphalt batch plant
Asphaltic cement, sediment
On site concrete batch plant
Cement, sediment
Portable toilets
Domestic sewage
X
5.4 Best Management Practices (BMP's) for Stormwater Pollution Prevention
Structural Practices for Erosion and Sediment Control
Structural practices for the site will consist mainly of silt fence and rock sock filters and are
described in detail in the following paragraphs. These BMP's are expected to change as the
construction progresses and it is the responsibility of the contractor to ensure appropriate BMP's
are in place and/or removed at the appropriate time in the construction sequence. All temporary
and permanent erosion and sediment control practices must be maintained and repaired as
needed to assure continued performance of their intended function.
Silt fence and rock sock filters shall be in place prior to commencement of construction
activities. During clearing and grubbing necessary for silt fence installation, all cleared material
shall be placed on the uphill side so that if erosion occurs from the cleared material, the sediment
will be trapped and not transported downstream. Rock socks shall be implemented in the existing
_curb. line as shown on the.Drainage_& Erosion Control Plan.--- - - -- -- - -- -- .- - --. - - --.
7
Permit holder:
Name:
Address:
Phone Number:
Email Address:
Appointed agent:
Name:
Address:
Phone Number:
Email Address:
M
6
5. STORMWATER MANAGEMENT CONTROLS
5.1 Written Analysis
The soils on this site are classified by the USGS Soil Survey as Nunn Clay Loam and are
classified in the hydrologic group C. The soils are described as having a slow runoff rate
and the hazard of water erosion is moderate and the hazard of wind erosion is moderate.
The site is surrounded by developed sites including streets and paved areas. The
construction shall utilize silt fence around the perimeter to control sediment transport
from rainfall and from wind. The silt fence that is located in the proposed pavement areas
will be removed prior to placing new pavement. Rock socks will be utilized in the
existing curb and the newly constructed swales to capture sediments that are not fully
contained by the silt fence placement. The locations of the rock socks will be in the areas
of concentrated flow such as in the existing curb, at the new swales and as needed.
The site will also utilize a vehicle tracking control pad to minimize sediment from being
tracked onto adjacent pavements. Sediment that is tracked will be removed and placed
within the site or permanently disposed of offsite. A concretewashout will be used on
site during the concrete placement. All hardened concrete will be disposed of offsite.
These BMP's have not been located on the site map due to the fact that the site is very
small and these BMP's will need to be placed by the contractor in locations that are most
beneficial and will minimize disruption of adjacent traffic.
Permanent erosion control consists of covering the soils with a building, concrete walks,
concrete drives and sod. No soil will be left exposed to erosion after the construction is
complete. Refer to the landscape plan for areas of and instructions for placement of sod
and soil amendments required prior to placement of sod.
Refer to Appendix D for the timing of the construction phases and the sequential
installation of all BMP phasing for this site.
Refer to the Appendix D for the Erosion Control Surety calculations.
5:2- WMP contact information
5
Basin 3 is located in the southwest portion of the site and contains the building and the
detention pond (landscape area). The roof of the storage building is sloped to drain to the
south and the bottom of the detention area is sloped to drain east. This basin accepts
runoff from Basins 1 and 2. The detained runoff will enter the existing storm System via
a new storm pipe with an orifice to restrict flows to the 2 year historic rate (0.2cfs per
acre).
Drainage design for this site has been designed to convey on -site runoff to the proposed
detention pond and incorporate the required LID enhancement features. On -site runoff
will be conveyed to the detention pond via surface flow in the drive aisles, in the LID
Swale and subsurface in the perforated pipes. The detention pond will release the
detained runoff from the site at the existing (historic) 2-year runoff rate of 0.2 cfs per
acre. The developed 2-year runoff rate for this site is 1.4 cfs and the developed 100-year
runoff rate is 6.4 cfs.
4.3 Drainage Summary
This site has been designed to meet or exceed the "City of Fort Collins Storm Drainage
Design Criteria Manual specifications. The proposed drainage design for this site has
been designed to convey on -site runoff to the detention pond while minimizing future
maintenance. The site incorporates a LID (Low Impact Development) treatment areas
including an LID swale without underdrain along the north property line, and permeable
interlocking pavers in the parking lot. Refer to. the end of Appendix B for a table
indicating the size of the LID treatment area and the area of the site that drains to that
LID treatment area.
All drainage facilities proposed with this project, including the detention pond, LID
features, porous pavers and outlet structure are private and will be owned and maintained
by the property owner.
4
4.
3.4 Hydraulic Criteria
Hydraulic elements have been designed per City of Fort Collins standards to adequately
convey the 100-year storm runoff from this site to the proposed detention pond. A
proposed 12" storm pipe will convey the detained runoff from the site to the existing
manhole at the southeast corner of the site.
DRAINAGE FACILITY DESIGN
4.1 General Concept
The runoff from this site will flow into the drive aisle and parking lot which will be
constructed using conventional materials (asphalt or concrete) and permeable
interlocking pavers. The runoff from the site will either flow on the surface or enter a
storm pipe via the permeable interlocking pavers or inlet. In a situation where the
permeable interlocking pavements are clogged, the runoff will flow on the surface and
enter the detention pond through a metal sidewalk culvert. On -site runoff will also be
conveyed to the detention pond via flows in LID swales along the north property
boundary to an area inlet and storm pipe.
The detained runoff will discharge into the
existing storm pipe located at the southeast corner of the site.
4.2 Specific Flow Routing
With this design, the site has been broken into 3 basins which correspond with the LID
feature that the basin flows to. The basin are described in the following paragraphs.
Basin 1 is located in the northmost portion of the site and contains a majority of the
private drive and LID feature #1 which is an LID Swale without an underdrain. The
runoff from the paved area will flow to the swale and will be collected in an area inlet.
The storm pipe then conveys the flows to the south into the detention pond.
Basin 2 is located in the eastmost portion of the site and contains a portion of the paved
private drive and the parking lot which is surfaced with porous pavers. The runoff from
this basin flows to a low point in the private drive then south into the parking lot porous
pavers. The flow, if it exceeds the capacity of the pavers, will flow into the detention
pond via a metal sidewalk culvert.
2.2 Sub -basin
Runoff from this site currently flows to the existing streets and alley. From there, the
runoff enters an existing inlet near the intersection of Red Cedar and Conifer. With the
proposed drainage concept for this site, the runoff from the site will flow to a proposed
detention pond and be released at the 2 year historic runoff rate into the storm system
near the intersection of Red Cedar and Conifer.
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations
This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage
Design Criteria Manual' specifications except where variances are requested as noted in
Section 4.2 of this report. Where applicable, the criteria established in the "Urban Storm
Drainage Criteria Manual" (UDFCD), 2001, developed by the Denver Regional Council..,
of Governments, has been used.
3.2 Development Criteria Reference and Constraints
The runoff from this site has been routed to conform to the requirements of the Dry
Creek Drainage Basin and the City of Fort Collins Stormwater Department. Both
stormwater runoff detention and water quality extended detention are required for this
site with on -site detention and offsite water quality. The release rate from the site will be
equal to the existing 2-year runoff (0.2 cfs per acre).
3.3 Hydrologic Criteria
Runoff computations were prepared for the 10-year minor and 100-year major storm
frequencies utilizing the rational method. All hydrologic calculations associated with the
basins are included in Appendix B of this report. Standard Form 8 (SF-8) provides time
of concentration calculations for all sub -basins.
Detention volume was calculated using the predetermined release rate of 0.2 cfs per acre.
The FAA method for detention pond sizing was utilized to determine the required
volume. Refer to the detention calculations included in Appendix C of this report.
2
1. GENERAL LOCATION AND DESCRIPTION
1.1 Location
This site is located on the north side of Conifer Street, west of Red Cedar Circle and east
of the existing alley in the Northwest Quarter of Section 1, Township 7 North, Range 69
West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County,
Colorado. See the Vicinity Map in Appendix A of this report.
This project is bounded on the north by an existing building, on the east by existing Red
Cedar Circle, on the west by a paved alley, and on the south by existing Conifer Street.
1.2 Description of Property
The entire project consists of approximately 0.9 acres. The site is currently undeveloped,
with areas of existing volunteer weeds and grasses. The existing site is flat with existing
slope to the southeast at approximately 0.5% to 1%. The site currently drains into the
adjacent streets and alley.
Proposed development on -site will include one building, a private drive along the north
side of the building, a parking lot and sidewalks. Existing drainage patterns will be
altered to direct flow to a proposed detention pond in the southeast corner of the site
which will release into the existing storm system in this location.
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description
The proposed development lies within the Dry Creek Drainage Basin. Stormwater
detention is required for this basin but water quality extended detention is not required
because it is provided in the North East College Corridor Outfall (NECCO) detention
pond. The City requirement for stormwater detention in the Dry Creek basin is a single -
stage detention with a 100-year release rate equal to the existing 2-year runoff (0.2 cfs
per acre).
1
n
TABLE OF CONTENTS
..
TABLE OF CONTENTS............................................................................................................... iii
GENERAL LOCATION AND DESCRIPTION
1.1 Location...................................................................................................................1
1.2 Description of Property ............................................................................................ I
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description..........................................................................................1
2.2 Sub -Basin Description.............................................................................................I
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations..............................................................................................................2
3.2 Development Criteria Reference and Constraints...................................................2
3.3 Hydrologic Criteria..................................................................................................2
3.4 Hydraulic Criteria....................................................................................................3
4. DRAINAGE FACILITY DESIGN
4.1 General Concept......................................................................................................3
4.2 Specific Flow Routing.............................................................................................3
4.3 Drainage Summary ..................................................................................................5,
5. STORMWATER MANAGEMENT CONTROLS
5.1 Written Analysis.....................................................................................................6
5.2 SWMP Contact Information...................................................................................7 .
5.3 Identification and location of all potential pollution sources..................................8
5.4 Best Management Practices (BMP's) for Stormwater Pollution Prevention ........... 8
5.5 BMP Implementation.............................................................................................10
6. CONCLUSIONS
6.1 Compliance with Standards..................................................................................13
6.2 Drainage Concept..................................................................................................13
7. REFERENCES..................................................................................................................14
APPENDICES
A Vicinity Map
B Hydrologic Computations
C Detention Pond Sizing Calculations
D BMP Schedule and Cost Estimate
E Figures and Tables
iii
North Star
design
700 Automation Drive, Unit I
Windsor, CO 80550
Phone: 970-686-6939
Fax:970-686-1188
May 6, 2015
Shane Boyle
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Final Drainage and Erosion Control Report for Raw Urth Designs
Dear Shane,
I am pleased to submit for your review and approval, this Final Drainage and Erosion Control
Report for Raw Urth Designs (Lot 20, Block 3, Evergreen Replat 1). I certify that this report for
the drainage design was prepared in accordance with the criteria in the City of Fort Collins
Storm Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Sincer
Patricia Kroetch, P.E.
ii
FINAL DRAINAGE AND EROSION
CONTROL REPORT
FOR
RAW URTH DESIGNS
(LOT 20, BLOCK 3,
EVERGREEN REPLAT 1)
Prepared for:
Raw Urth Designs
P.O. Box 369
Bellvue, CO 80537
Prepared by:
North Star Design
700 Automation Drive, Unit I
Windsor, Colorado 80550
(970) 686-6939
May 6, 2015
--- --- -- ------- --- ---- ----- --- Job Number 264-10
m
FINAL DRAINAGE AND EROSION
CONTROL REPORT
FOR
RAW URTH DESIGNS
(LOT 20, BLOCK 3,
EVERGREEN REPLAT 1)