HomeMy WebLinkAboutMORNINGSTAR ASSISTED LIVING & MEMORY CARE - FDP - FDP130055 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPermeable Pavement Systems T-10
PERMEABLE
PAVEMENT
BASE COURSE
FILTER LAYER
SUBGRADE
CAST IRON VALVE BOX
WITH LOCKING LID
-REMOVABLE PVC THREADED
PLUG k COUPLER
3" MIN. THICK
CONCRETE COLLAR
0
Figure PPS-8. Observation Well
4"0 SLOTTED
PVC PIPE MEETING
TABLE PPS-2
(TERMINATE PIPE AT
THE BOTTOM OF THE
FILTER LAYER WITH A
NO INFILTRATION
SECTION)
BARRIER
ABLE)
WELL
R
August 2013 Urban Drainage and Flood Control District PPS-19
Urban Storm Drainage Criteria Manual Volume 3
I 1.
T-10 Permeable Pavement Systems
Oi,fiY'PINIiT
♦' SOLID PIPE SMRM MANHOLE Y
A OR VAULT (IYP.)
IrjjT To OUTLET
I
�SLO1TED PVC MEERNG
TABLE PPS-2
,,,CONCRETE EDGE
(WHERE APPLICABLE)
P:. :.- _. � •
`OOMPACIED JVVMWL
ECIK&Lt
W A NTs B
Figure PPS-7. Underdrain System Layout and Outlet Details
PPS-18
Urban Drainage and Flood Control District August 2013
Urban Storm Drainage Criteria Manual Volume 3
T-10 Permeable Pavement Systems
GEOMEMBRANE LINER ----
--
CONNECTION TO
So FIL7 IR M%!�
CONCRETE
MEETING ABLE 1-/
(SEE DETAIL PPS-4)1
k12:A
SEPARATOR FABRIC
UNDERORAIN MEETING
TABLE PPS-2
30 MIL (MIN.)
SEPARATOR FABRIC (ONLY
ENSURE INSTALLATION is CONSISTENT
GEOMEMBRANE8ESWHEN
SUBGRADE CONTAINS
WITH MANUFACTURER RECOMMENDATIONS
LINER PER TABLE PPS-4
ANGULAR ROCK OR an*R
TMT PUNCTU
MATMAL MAY RE
NO -INFILTRATION
SECTION
Tm GF-OmaniANE uNER'
PERIMETER BARRIER PERMEABLE PAVEM'311 41A'-
V WN. (IF APPLICABLE) DELEVELING COURSE OF APPL;i
PTH DEPENDANT ON TYPE
Ir MIN. RESERVOIR
(AASHTID #57 OR j"7)
x--FiLTER MATERIAL MEETING TABLE
PPS-1 OR SEPARATOR FABRIC
IF NEEDED FOR MATERIAL COMPATIBILITY.
TO BE DETERMINED BY A GEOTECHNICAL
ENGINEER
.FULL INFILTRATION SECTION
Figure PPS-1. Permeable Pavement Sections
PPS-6 Urban Drainage and Flood Control District August 2013
Urban Storm Drainage Criteria Manual Volume 3
Extended Detention Basin (EDB) T-5
FLOW LENGTH 12W
OR VERTICAL COINC. ELM
WALL J. LM
NTS
ACCESSIBLE OUTLET
WITH TRASH RACK
INITIAL SURCHARGE ---�
URFACE PROVIDE DUW 4' MIN.
NFLOW ENERGY MICROPOOL DEPTH
DISSIPATON 2.5' MIN.
INFLOW ARMORED BERM OR VERTICAL
CONC. WALL
INVERT OF
TRICKLE
_----- -- CHANNEL
8- MIN. PIPE)
WITH BERM. USE
NOTCH FOR WALL
'SOFT BOTTOM WHERE BASE FLOWS
OR GROUNDWATER IS ANTICIPATED
'INCREASE WHERE BASE
FLOWS ARE ANTICIPATED
4:1 SIDESLOPES WITH NO AREAS
GREATER THAN 3:1. FOR AESTHETIC
DESIGN. VARY SLOPES AND DESIGN
ONE SIDE MILDER THAN THE OTHER.
FOREBAY WITH CONCRETE OR
GROUTED ROCK FLOOR. PROVIDE
ENERGY DISSIPATION FOR
CONCENTRATED FLOW.
® IN THE BOTTOM OF THE BASIN
PROVIDE A 3% MIN. SLOPE TO
THE TRICKLE CHANNEL OR
MICROPOOL.
NC ETE SLOPE BETWEEN 0.4 AND 1.05
EMBANKMENT WITH
SPILLWAY
CONCRETE TRICKLE
CHARNEL RUNDOWN
CONCRETE OR SOFT
BOTTOM 'MICROPOOL
OUTLET WORK (SEE
ADDITIONAL DETAILS
PROR IN FACT SHEET T-12)
N S SEEPAGE CUTOFF
COLLAR OF
NECESSARY)
Figure EDB-3. Extended Detention Basin (EDB) Plan and Profile
t detarls rncludurg orifice p s and trash racks
December 2010 Urban Drainage and Flood Control District EDB-11
Urban Storm Drainage Criteria Manual Volume 3
T-2 Grass Swale
RESIDUAL CAPACITY FOR
LARGER FLOODS
FPS
4" (MIN) SANDY LOAM I LJ 1" MIN
12 MIN
BOTTOM WIDTH (W)
RESIDUAL CAPACITY FOR
LARGER FLOODS
72" MIN. _
2-YR WSE 4 MIN.
6" MIN /1
4' MIN. SANDY LOAM
1" MIN.
D1.0' " --- T-
V (2-YR) 1.0 FPS 12"
0 _z 21 7,73I 1Lai ►
CONCRETE COLLAR
r GRADE CONTROL
ii mew ENERGY
u / STRUCTURE
n1
4 MIN.
GRADE CONTROL STRUCTURE
BEYOND
• GRADE CONTROL STRUCTURE
BEYOND
O UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR
LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE
MEERNG TABLE GS-3 WITH CDOT CLASS C FILTER
MATERIAL. ALL AROUND OR PERFORATED HOPE
PIPE WITH AASHTO #67 ALL AROUND CONTAINED
WITHIN GEOTEXTILE FABRIC. ASTM D4751-ADS US
STD. SIEVE #50 TO #70. ASTM D4533 MIN.
TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS.
MINIMUM COE SPECIFIED OPEN AREA OF 4R.
EXTEND GRADE CONTROL
STRUCTURES INTO THE
BANK A MIN. 0.5'
ABOVE THE 2-YR WSE
PROVIDE DOUBLE CLEAN0UT5 -
WITH WATER TIGHT CAPS 0150'
O.C. USE 90- SWEEP OR (2)
45- BENDS (OFFSET FROM SWALE
UNDERORAIN
CENTERUNE TO AVOID IMPEDING
ENSURE ACCESS TO OUTLET
FLOW WHEN USING A TRIANGULAR
BY CLFiVJ OUT OR OTHER
SECTION
ACCESSIBLE STRUCTURE
SWALE
PROF]
NTS
Figure GS-1.
Grass Swale Profile and Sections
Design Example
The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at
www.udfcd.or>?. This section provides a completed design form from this workbook as an example.
GS-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Designer:
Company:
Date:
Project:
Location:
MM
Interwest Consulting Group
December 6, 2013
MVG - Morningstar Facility
DETENTION BASIN B (NW)
3of3
6. Two -Stage Design - See Figure EDB-1
A) Top Stage (Depth Dwo = 2' Minimum)
Dwo =
feet
Top Stage Storage: no less than 99.5%of Design Volume (0.0627 acre-feet.)
Storage=
acre-feet
B) Bottom Stage Depth (DBs = 0.33' Minimum Below Trickle Channel Invert)
DBS =
feet
Bottom Stage Storage: no less than 0.50%of Design Volume (0.0003 acre-feet.)
Storage=
acre-feet
Storage = A' Depth Above WS To Bottom Of Top Stage
Surf. Area='
acres
C) Micro Pool (Minimum Depth = the Larger of
Depth=
feet
0.50 ' Top Stage Depth or 2.5 Feet)
D) Total Volume: Vora = Storage from 5A + 6A + 6B
Vol,o, =
acre-feet
(Must be > Design Volume in 1 D, or 0.063 acre-feet.)
7. Basin Side Slopes (Z, horizontal distance per unit vertical)
Z =
(horizontal/vertical)
Minimum Z = 4, Flatter Preferred
6. Dam Embankment Side Slopes (Z, horizontal distance)
Z =
(horizontal/vertical)
per unit vertical) Minimum Z = 3, Flatter Preferred
9. Vegetation (Check the method or describe "Other")
Native Grass
Irrigated Turf Grass
Other:
Notes:
UD-BMP v2.06.x1s, EDB - NW POND 12/6/2013, 10:29 AM
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Sheet 2 of 3
Designer:
MM
Company:
Interwest Consulting Group
Date:
December 6, 2013
Project:
MVG - Morningstar Facility
Location:
DETENTION BASIN B (NW)
iii) Type of Screen (Based on Depth H), Describe if "Other" I S.S. #93 VEE Wire (US Filter)
Other:
iv) Screen Opening Slot Dimension, Describe if "Other" I i 0.139" (US Filter)
Other:
v) Spacing of Support Rod (O.C.)
Type and Size of Support Rod (Ref.: Table 6a-2)
vi) Type and Size of Holding Frame (Ref.: Table 6a-2)
inches
D) For 2' High Rectangular Opening (Refer to Figure 6b):
1) Width of Rectangular Opening (W)
W =(
inches
ii) Width of Perforated Plate Opening (W.. = W + 12")
Ww. ='
inches
iii) Width of Trashrack Opening (W,,,,;,,) from Table 6b-1
Wo nft =1
-inches
iv) Height of Trash Rack Screen (HTR)
HTR =;
inches
v) Type of Screen (based on depth H) (Describe if "Other")
Klemprm
KPP Series Aluminum
Other:
vi) Cross -bar Spacing (Based on Table 6b-1, KlempTM KPP inches
Grating). Describe if "Other" Other:
vii) Minimum Bearing Bar Size (KlempTM Series, Table 61b-2)
Based on depth of WOCV surcharge)
4. Detention Basin length to width ratio (L/W)
5 Pre -sedimentation Forebay Basin - Enter design values
A) Volume (3%to 5%of Design Volume from 1D) acre-feet
(3% - 5% of Design Volume (0.0019 - 0.0032 acre-feet.)
B) Surface Area acres
C) Connector Pipe Diameter inches
(Size to drain this volume in 5-minutes under inlet control)
D) Paved/Hard Bottom and Sides yes/no
UD-BMP v2.06.x(s, EDB - NW POND 12/6/2013, 10:29 AM
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
1
Designer:
Company:
Date:
Project:
Location:
MM
Interwest Consulting Group
December 6, 2013
MVG - Morningstar Facility
DETENTION BASIN B
1. Basin Storage Volume
la =
47.00
%
A) Tributary Area's Imperviousness Ratio (i = la / 100)
i =1
0.47
B) Contributing Watershed Area (Area)
Area =
3.180
acres
C) Water Quality Capture Volume (WQCV)
WQCV =;
0.20
(watershed inches
(WQCV =1.0 ' (0.91 ' 13 - 1.19. Iz + 0.78 ' 1))
D) Design Volume: Vol = (WQCV / 12)' Area' 1.2
Vol =i
0.0630
, acre-feet
2. Outlet Works
A) Outlet Type (Check One) X Orifice Plate
Perforated Riser Pipe
Other:
B) Depth at Outlet Above Lowest Perforation (H)
H =
1.95
feet
C) Recommended Maximum Outlet Area per Row, (Aa)
Ao =i
0.2
square inches
D) Perforation Dimensions:
i) Circular Perforation Diameter or
D =.
0.500
inches
ii) Width of 2" High Rectangular Perforations
W ='
inches
E) Number of Columns (nc, See Table 6a-1 For Maximum)
nc =z
1
number
F) Actual Design Outlet Area per Row (k)
Aa ='
0.2
square inches
G) Number of Rows (nr)
nr =,`
6
number
H) Total Outlet Area (A,,)
Ap, _
1.2
'square inches
3. Trash Rack
A) Needed Open Area: A, = 0.5' (Figure 7 Value) ' Ae,
A, =1 4-2 square inches
B) Type of Outlet Opening (Check One)
i X < 2" Diameter Round
2" High Rectanaular
Other:
C) For 2", or Smaller, Round Opening (Ref.: Figure 6a):
i) Width of Trash Rack and Concrete Opening (W..)
from Table 6a-1
Wiz _' 3 inches
ii) Height of Trash Rack Screen (HTR)
HTR =� 54 inches
UD-BMP v2.06.xls, EDB - NW POND 12/6/2013, 10:29 AM
Designer:
Company:
Date:
Project:
Location:
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Sheet 3 of 3
MM
Interwest Consulting Grout
December 6, 2013
MVG - Morningstar Facility
DETENTION BASIN A (SW)
6. Two -Stage Design - See Figure EDB-1
A) Top Stage (Depth Dwo = 2' Minimum)
Dwo =
feet
Top Stage Storage: no less than 99.5% of Design Volume (0.0215 acre-feet.)
Storage=
acre-feet
B) Bottom Stage Depth (DBS = 0.33' Minimum Below Trickle Channel Invert)
DBS =
feet
Bottom Stage Storage: no less than 0.5%of Design Volume (0.0001 acre-feet.)
Storage=
acre-feet
Storage = A " Depth Above W S To Bottom Of Top Stage
Surf. Area=l
acres
C) Micro Pool (Minimum Depth = the Larger of
Depth=
feet
0.50 ' Top Stage Depth or 2.5 Feet)
D) Total Volume: Vol,, = Storage from 5A + 6A + 6B
Vol,, =i
acre-feet
(Must be> Design Volume in 1D, or 0.0216 acre-feet.)
7. Basin Side Slopes (Z, horizontal distance per unit vertical)
Z =
(horizontal/vertical)
Minimum Z = 4, Flatter Preferred
8. Dam Embankment Side Slopes (Z, horizontal distance)
Z =
(horizontal/vertical)
per unit vertical) Minimum Z = 3, Flatter Preferred
9. Vegetation (Check the method or describe "Other")
Native Grass
Irrigated Turf Grass
Other:
Notes:
UD-BMP v2.06.xis, EDB - SW POND 12/6/2013, 10:28 AM
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Sheet 2 of 3
Designer:
MM
Company:
Interwest Consulting Group
Date:
December 6, 2013
Project:
MVG - Morningstar Facility
Location:
DETENTION BASIN A (SW)
iii) Type of Screen (Based on Depth H), Describe if "Other" I S.S. #93 VEE Wire (US Filter)
Other:
iv) Screen Opening Slot Dimension, Describe if "Other"
0.139" (US Filter)
Other:
v) Spacing of Support Rod (O.C.)
inches
Type and Size of Support Rod (Ref.: Table 6a-2)
vi) Type and Size of Holding Frame (Ref.: Table 6a-2)
D) For 2" High Rectangular Opening (Refer to Figure 6b):
1) Width of Rectangular Opening (W)
W =i inches
ii) Width of Perforated Plate Opening (W.. = W + 12")
Ww. _`. inches
iii) Width of Trashrack Opening (W,,,;,,o) from Table 6b-1
W�rwv =i -inches
iv) Height of Trash Rack Screen (HTR)
HTR =1 - - inches
v) Type of Screen (based on depth H) (Describe if "Other") I KlempTm KPP Series Aluminum
Other:
vi) Cross -bar Spacing (Based on Table 6b-1, KlempTm KPP I ( inches
Grating). Describe if "Other" Other:
vii) Minimum Bearing Bar Size (Klemp'" Series, Table 6b-2)
Based on depth of WQCV surcharge)
4. Detention Basin length to width ratio (L/W)
5 Pre -sedimentation Forebay Basin - Enter design values
A) Volume (3%to 5%of Design Volume from 1D) acre-feet
(3% - 5% of Design Volume (0.0006 - 0.0011 acre-feet.)
B) Surface Area acres
C) Connector Pipe Diameter inches
(Size to drain this volume in 5-minutes under inlet control)
D) Paved/Hard Bottom and Sides yes/no
UD-BMP v2.06.xls, EDB - SW POND 12/6/2013, 10:28 AM
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Sheet 1 of 3
Designer: MM
Company:
Interwest Consulting Group
Date:
December 6, 2013
Project:
MVG - Morningstar Facility
Location:
DETENTION BASIN A (SW)
1. Basin Storage Volume
A) Tributary Area's Imperviousness Ratio (i = 1./ 100 )
B) Contributing Watershed Area (Area)
C) Water Quality Capture Volume (WQCV)
(WQCV =1.0' (0.91 ' 13 - 1.19. 12 + 0.78 " p)
D) Design Volume: Vol = (WQCV / 12) " Area " 1.2
2. Outlet Works
A) Outlet Type (Check One)
B) Depth at Outlet Above Lowest Perforation (H)
C) Recommended Maximum Outlet Area per Row, (A.)
D) Perforation Dimensions:
i) Circular Perforation Diameter or
ii) Width of 2" High Rectangular Perforations
E) Number of Columns Inc, See Table 6a-1 For Maximum)
F) Actual Design Outlet Area per Row (k)
G) Number of Rows (nr)
H) Total Outlet Area (A,)
3. Trash Rack
A) Needed Open Area: A, = 0.5' (Figure 7 Value)' Pe,
B) Type of Outlet Opening (Check One)
C) For 2", or Smaller, Round Opening (Ref.: Figure 6a):
I) Width of Trash Rack and Concrete Opening (W...)
from Table 6a-1
ii) Height of Trash Rack Screen (HTR)
1. = 38.00 %
i =' 0.38
Area = 1.240 acres
WQCV =; 0.17 watershed inches
Vol = 6.0216 'acre-feet
X Orifice Plate
Perforated Riser Pipe
Other:
H = 1.60 feet
k = 0.1 square inches
D =.
0.500
inches
W =
inches
nc
1
number
Ao ='
0.2
'square inches
nr=
5
number
k, =
1.0
square inches
A, = 35 square inches
X < 2" Diameter Round
2" High Rectangular
Other:
Wes, -3 'inches
HTR 54 inches
UD-BMP v2.06.xls, EDB - SW POND 12/6/2013, 10:28 AM
_rL
rotuNnwtevuo
fl
II_I I
50 25 0 50
SCALE: 1"= 100_ —
uua�sls cou�rr
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covaas
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WI1MW.r ,lor�do 80550
P :(9T0)61a0000
F.: (970) 674J000
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opt
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LID BASIN AREA EXHIBIT
NEW IMPERVIOUS AREA:
2.15
acre
MINIMUM AREA TO BE TREATED:
Oa
acre
BASIN AREA I - GRASS SWAIE
0.31
acre
BASIN AREA 2-GLASS SWAIE
0.50
acre
BASIN AREA 3-GRAVEL DRYWEUS:
0.54
acre
BASIN AREA 4A -PERVIOUS PAVERS
0.12
acre
BASIN AREA 4B-PERVIOUS PAVERS
0.11
acre
BASIN AREA 4C-PERVIOUSPAVERS
0.10
acre
TOTAL
AREA TREATED:
t!fi8�
acre
MVG - MORNINGSTAR
LID AREA EXHIBIT
DATE CREATED: 12/23/13
APPENDIX D
WATER QUALITY
ME
LOCATION: MVG - Morningstar
PROJECT NO: 1173-105-00
COMPUTATIONS BY: MHM
SUBMITTED BY: INTERWEST CONSULTING GROUP
DATE: 10/1/2013 t* of berth
Equation for flow over a broad crested weir _
Q = CLH H
where C = weir coefficient = 2.6 4 elevtltlotl
H = overflow height
L = length of the weir
The pond has a spill elevation equal to the maximum water surface elevation in the pond
Design spillway with 0.5 It flow depth, thus H = 0.5 ft
Size the spillway assuming that the pond outlet is completely clogged.
SW Detention Pond
0 (100) = 4.5 cfs (peak flow into pond)
Spill elev = 70.00 ft = 100-year WSEL
Min top of berm elev.= 70.50
Weir length required:
L= 5 It
Use L . 5 K
v = 1.01 ft/s
NW Detention Pond
0 (100) = 12.3 cfs (peak flow into pond)
Spill elev = 67.40 It = 100-year WSEL
Min top of berm elev.= 67.90
Weir length required:
L = 13 ft
Use L = 13 h
v = 1.42 ft/s
Pond
Design
Point
0(100)
(cfs)
Weir Length
Available(ft)
Min. Spill
Height (ft)
Approx.
Velocity (ft/s)
SW Detention Pond
A
5
5
0.49
1.01
NW Detention Pond
B
12
13
0.51
1.42
spillway, detentionAs
EXTENDED DETENTION BASIN B (NW)
Proposed Detention Pond - Stage/Storage
LOCATION:
MVG - Morningstar
PROJECT NO:
1173-105-00
COMPUTATIONS BY:
MHM
SUBMITTED BY:
INTERWEST CONSULTING GROUP
DATE:
10/1/2013
WO WSEL-
100-yr WSEL-
SPILL WA Y -
TOP OF BERM -
V = 1/3 d (A + B + sgrt(A`B))
where V = volume between contours, ft3
d = depth between contours, ft
A = surface area of contour
Stage
(Elev)
Surface
Area
(Ft^2)
Incremental
Storage
(Ac-ft)
Detention
Storage
(Ac-ft)
Total
Storage
(Ac-ft)
62.80
0
63.0
180
64.0
2168
0.02
0.02
64.5
3813
0.03
0.00
0.06
65.0
5458
0.05
0.05
0.11
66.0
7535
0.15
0.20
0.26
67.0
9287
0.19
0.39
0.45
67.25
9871
0.05
0.45
0.51
67.4
10235
0.03
0.48
0.54
67.9
0
0.04
0.52
0.58
Total Storage Req'd Storage
0.540 > 0.377
detention.xls
Interwest Consulting Group
DETENTION VOLUME CALCULATIONS
Rational Volumetric (FAA) Method
100-Year Event
LOCATION:
MVG MORNINGSTAR - EXTENDED DETENTION BASIN B (NW)
PROJECT NO:
1173-105-00
COMPUTATIONS BY: MM
DATE:
10/1/2013
Equations:
Area trib. to pond =
3.18
acre
Developed flow = Qp = CIA
C (100) =
0.59
Vol. In = Vi = T C I A = T Qo
Developed C A =
1.9
acre
Vol. Out = Vo =K QPo T
Release rate, QPo =
1.2
cfs
storage = S = Vi - Vo
K =
0.9
(from fig 2.1)
Rainfall intensity from City of Fort Collins IDF Curve with updated (3.67") rainfall
Storm
Duration, T
(min)
Rainfall
Intensity, I
(in/hr)
Qp
(cfs)
Vol. In
Vi
(ft)
Vol. Out
Vo
(ft)
Storage
S
(ft)
Storage
S
(ac-ft)
5
9.95
18.7
5600
335
5266
0.12
10
7.77
14.6
8743
670
8073
0.19
20
1 5.62
10.5
12655
1339
11315
0.26
30
4.47
8.4
15090
2009
13081
0.30
40
3.74
7.0
16840
2679
14162
0.33
50
3.23
6.1
18202
3349
14853
0.34
60
2.86
5.4
19316
4018
15297
0.35
70
2.57
4.8
20258
4688
15570
0.36
80
2.34
4.4
21077
5358
15719
0.36
90
2.15
4.0
21800
6027
t 773�
<eg-M
100
1.99
3.7
22450
6697
15753
0.36
110
1.86
3.5
23039
7367
15672
0.36
120
1.75
3.3
23579
8036
15543
0.36
130
1.65
3.1
24078
8706
15372
0.35
140
1.56
2.9
24542
9376
15166
0.35
150
1.48
2.8
24976
10046
14931
0.34
160
1.41
2.6
25384
10715
14669
0.34
170
1.35
2.5
25769
11385
14384
0.33
180
1.29
2.4
26133
12055
14078
0.32
Required Storage Volume: 15773 ft3
0.36 acre-ft
detention.xls,FAA-100yr NW POND
EXTENDED DETENTION BASIN A (SW)
Proposed Detention Pond - Stage/Storage
LOCATION:
MVG - Morningstar
PROJECT NO:
1173-105-00
COMPUTATIONS BY:
MHM
SUBMITTED BY:
INTERWEST CONSULTING GROUP
DATE:
10/1/2013
WO WSEL-
100-yr WSEL-
SPILLWAY-
TOP OF BERM -
V= 1/3d (A+B+sgrt(A'B))
where V = volume between contours, ft3
d = depth between contours, ft
A = surface area of contour
Stage
(Elev)
Surface
Area
(Ft^2)
Incremental
Storage
(Ac-ft)
Detention
Storage
(Ac-ft)
Total
Storage
(Ac-ft)
66.7
0
67.0
199
0.00
0.00
0.000
68.0
673
0.01
0.00
0.010
68.5
2151
0.02
0.03
0.025
69.0
3630
0.03
0.06
0.058
69.70
5386
0.07
0.13
0.130
70.00
6151
0.04
0.17
0.170
70.50
0
0.02
0.19
0.193
Total Storage Req'd Storage
0.193 > 0.130
detention.xls
Interwest Consulting Group
DETENTION VOLUME CALCULATIONS
Rational Volumetric (FAA) Method
100-Year Event
LOCATION:
MVG MORNINGSTAR - EXTENDED DETENTION BASIN A (SW)
PROJECT NO:
1173-105-00
COMPUTATIONS BY: MHM
DATE:
10/1/2013
Equations:
Area trib. to pond =
1.24
acre
Developed flow = Qp = CIA
C (100) =
0.49
Vol. In = Vi = T C I A = T Qo
Developed C A =
0.6
acre
Vol. Out = Vo =K Qpo T
Release rate, Oao =
0.5
cfs
storage = S = Vi - Vo
K =
0.9
(from fig 2.1)
Rainfall intensity from City of Fort Collins IDF Curve with updated (3.67") rainfall
Storm
Duration, T
(min)
Rainfall
Intensity, I
(in/hr)
OD
(cfs)
Vol. In
Vi
(ft)
Vol. Out
Vo
(ft)
Storage
S
(ft)
Storage
S
(ac-ft)
5
9.95
6.0
1814
131
1683
0.04
10
7.77
4.7
2831
261
2570
0.06
20
1 5.62
3.4
4098
522
3576
0.08
30
4.47
2.7
4887
783
4104
0.09
40
3.74
2.3
5454
1045
4409
0.10
50
3.23
2.0
5895
1306
4589
0.11
60
2.86
1.7
6255
1567
4688
0.11
70
2.57
1.6
6561
1828
4733
0.11
80
2.34
1.4
6826
2089
4736
0. 1
90
2.15
1.3
7060
2350
4710
0.11
100
1.99
1.2
7270
2611
4659
0.11
110
1.86
1.1
7461
2873
4589
0.11
120
1.75
1.1
7636
3134
4502
0.10
130
1.65
1.0
7798
3395
4403
0.10
140
1.56
0.9
7948
3656
4292
0.10
150
1.48
0.9
8088
3917
4171
0.10
160
1.41
0.9
8220
4178
4042
0.09
170
1.35
0.8
8345
4439
3906
0.09
180
1.29
0.8
8463
4701
3762
0.09
Required Storage Volume: 4736 ft3
0.11 acre-ft
detention.xls,FAA-100yr SW POND
Cross Section for WOO West Drainage Easement Cross-section
Protect l)escnphon
. ............. . .
Flow Element: Irregular Section
Friction Method:
Solve For.
Manning Formula
Normal Depth
wow
Roughness Coefficient: 0.019
Channel Slope:
0.00600
Normal Depth:
1.53 ft
Elevation Range:
0.00 to 7.85 It
Discharge:
150.20 fels
-r
1.63 It
-L
i38.63 ft
Vs L
H.1
Worksheet for WOO West Drainage Easement Cross-section
Worksheet for Q100 West Drainage Easement Cross-section
�' '� p 4 b'•,+� � ��� �3r� �� �s(,r ��,,"�rPy�R�'e'�',u'4���3i��I�p�� . . � i�r� �
i3.a udrhtRi7�A`�1e-i�.-,x;SW �fi�.,v� «'x edis:�t�titsF.r�'.�m��C1 �'k�i�'.�` L� G �• aifi (?1zi_`YiGN� x1t �IU �YS,+^:'?14.S�k44n��'.�'.;x�`5u
Flow Element: lrreguler Section
Friction Method: Manning Formula
Solve For. Normal Depth
Channel Slope: 0.00600 Wit
Discharge: 150.20 fN/s
Current Roughness Weighted Meth( Improvedt-otters
Open Channel Weighted Roughnes: Improvedl_otters
Closed Channel Weighted Roughne Hortons
Roughness Coefficient:
0.019
Water Surface Elevation:
1.53
ft
Elevation Range:
0.00 to 7.85 ft
Flow Area:
29.48
ft2
Wetted Perimeter.
38.76
ft
Top Width:
38.63
ft
Normal Depth:
1.53
ft
Critical Depth:
1.55
ft
Critical Slope:
0.00566
ft/ft
Velocity:
5.09
f /S
Velocity Head:
0.40
ft
Specific Energy:
1.94
ft
Froude Number.
1.03
Flow Type:
Supercrttical
(•0+25, 2.15) (-0+02, 0.17) 0.025
017) 10+.02 9 `17) 0 013 � Y
(0+02, 0.17) (0+21, 1.55) 0.025
(0+21, 4.55) (0+25, 5.35) 0.025
James ]EL Si Tart and Assocaates, Ine.
Consulting Engineers
March 15, 1978
STORM DRAINAGE SWALE
COLLINDALE SECOND FILING,
The swale that exists at the Easterly side of Collindale, Second Filing will
receive drainage from the following areas:
Foothills Meadow Apartments - 16 Acres:
Warren Shores - 23 Acres
North Shore P.U.D. - 10 Acres
Warren Lake Park - 26 Acres
Collindale, First Filing - 11 Acres .
TOTAL 86 Acres
Of the above areas, North Shore P.U.D. does have onsight detention and the
Warren Lake Park will.not increase the runoff, due to development, to a
great extent. The runoff for a 100 year frequency storm would be as follows:
."Foothills.Meadows Q 0.8 x 4.2 x 16 =• 54. c.f.s. '
Warren Shores Q = 0."6 x 4.2 x 23 = 58 c:f.s
North Shore P.U.D. Q '0.4.x 5 x 10 =. 20 c.f;s.
Warren Lake Park Q = 0.4.x 5. x 26 = 52 c.f.s
Collindale. Q = 0.6 x 5 x 11 = 33 c.f.s.
TOTAL = 217 c.f.s
The swale would be as shown below to carry the 100 year storm.
Sox �'� G r� � x �ooG�� � . _ .. �P -. Y:'P �.�•'r.S�
' = 23oG�=5 /ja �i✓N..rGr aarsc iu��u.�' mr F+�i2
e o,.,v�nwt
Therefore; it is determined that Buildings C. D, E, and F as shown on the
site plan would not be damaged during 4,100 year frequency storm.,.
a
Richard A. Rutherford, P.E. L.S.
OFFICE-214 NORTH 110%VES O r.0: BOX 429 O FORT COLLINS. COLORADO 805220 O 1F.I.E11110NE AREA SOX.M9.9931
APPENDIX C
HYDRAULIC COMPUTATIONS
SUMMARY
PROPOSED DRAINAGE SUMMARY TABLE
Design
Point
Tributary
Sub -basin
Area
(ac)
C (2)
C (10)
C (100)
tc (2)
(min)
to (10)
(min)
to (100)
(min)
0(2)tot
(cfs)
0(10)tot
(cfs)
G(100)tot
(cfs)
DRAINAGE
STRUCTURE
/REMARKS
A SW
A SW
1.24
0.39
0.39
0.49
12.0
12.0
11.1
1.0
1.7
4.5
B (NW)
B (NW)
3.18
0.47
0.47
0.59
14.1
14.1
14.1
2.9
4.9
12.5
Page 1
SUMMARY
EXISTING DRAINAGE SUMMARY TABLE
Design
Point
Tributary
Sub -basin
Area
(ac)
C (2)
C (10)
C (100)
tc (2)
(min)
tc (10)
(min)
to (100)
(min)
G(2)tot
(cfa)
0(10)tot
(efa)
0(100)tot
(efa)
DRAINAGE
STRUCTURE
/REMARKS
1
OVERALL SITE
4.41
0.20
0.20
0.25
13.3
17.2
17.2
1.7
2.6
6.7
Page 1
Interwest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
DATE:
100-yrstorm, Cl=
RATIONAL METHOD PEAK RUNOFF
(100-YEAR)
MVG MORNINGSTAR
1173-105-00
MM
12/ 19/2013
1.25
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)
0(100)tot
(cfs)
A (SW)
1.24
0.49
11.1
7.43
4.5
4.5
B NW
3.18
0.59
14.1
6.70
12.5
12.5
Q=CiA
Q = peak discharge (cfs)
C = runoff coefficient
I = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
NOTE: Intensity based on Figure 3-1, 1999 (Regional Analysis)
Flow-PDP.xIs Q100
Interwest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
LOCATION:
PROJECT NO:
COMPUTATIONS BY
DATE:
10-yr storm, Cf =
RATIONAL METHOD PEAK RUNOFF
(10-YEAR)
MVG MORNINGSTAR
1173-105-00
MM
12/19/2013
1.00
DIRECT RUNOFF
CARRY OVER
TOTAL
REMARKS
Design
Point
Tributary
Sub -basin
A
(ac)
C Cf
tc
(min)
i
(new)
(in/hr)
Q (10)
(Cfs)
from
Design
Point
O (10)
(cfs)
Q(10)tot
(cfs)
A SW
1.24
0.39
12.0
3.52
1.7
1.7
B NW
3.18
0.47
14.1
3.28
4.9
4.9
Q=CfCiA
Q = peak discharge (cfs)
C = runoff coefficient
Cf = frequency adjustment factor
I = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
NOTE: Intensity based on Figure 3-1, 1999 (Regional Analysis)
Flow-PDP.xls 010
Interest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
LOCATION:
PROJECT NO:
COMPUTATIONS BY
DATE:
2-yr storm, Cf =
RATIONAL METHOD PEAK RUNOFF
(2-YEAR)
MVG MORNINGSTAR
1173-105-00
MM
12/19/2013
1.00
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)
A SW
1.24
0.39
12.0
2.06
1.0
1.0
B NW
3.18
0.47
14.1
1.92
2.9
2.9
Q=CtCiA
Q = peak discharge (cfs)
C = runoff coefficient
Cf = frequency adjustment factor
I = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
NOTE: Intensity based on Figure 3-1, 1999 (Regional Analysis)
Flow-PDP.xIs Q2
Interest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
DATE:
100-yr storm
MVG MORNINGSTAR
1173-105-00
MM
12/19/2013
C1= 1.25
STANDARD FORM SF-2
TIME OF CONCENTRATION - 100 YR
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME
TRAVEL TIME / GUTTER OR CHANNEL FLOW
00
to CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
DESIGN
POINT
SUBBASIN(s)
(1)
Area
(ac)
(2)
C
(3)
C'Cf
Length
(it)
(4)
Slope
(%)
(5)
ti
(min)
(6)
Length
(ft)
(7)
Slope
I%)
(8)
n
Manning
rough.
Val.
(ft/s)
(9)
It
(min)
(10)
tc =
ti+d
(11)
Total L
(It)
(12)
tc=(I/180)+10
(min)
(13)
(min)
(14)
A SW
1.24
0.39
0.49
125
2.0
9.7
240
2.00
0.016
2.8
1.4
11.1
365
12.0
11.1
B NW
3.18
0.47
0.59
345
2.0
13.6
385
1.50
0.016
2.5
2.6
16.2
730
14.1
14.1
EQUATIONS:
tc=ti+tt
ti=[1.87(1.1-CC,)Los]/S''
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 If + tt and urbanized basin check
min. tc = 5 min. due to limits of IDF curves
Flow-PDP.zIs TOC-100
Interest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
STANDARD FORM SF-2
TIME OF CONCENTRATION - 10 YEAR
LOCATION: MVG MORNINGSTAR
PROJECT NO: 1173-105-00
COMPUTATIONS BY: MM
DATE: 12/19/2013
10-yr storm C1= 1.00
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME (it)
TRAVEL TIME / GUTTER OR CHANNEL FLOW
(II)
to CHECK
(URBANIZED BASIN)
FINAL
to
REMARKS
DESIGN
POINT
SUBBASIN(s)
(1)
Area
(ac)
(2)
C
(3)
Length
(it)
(4)
Slope
(%)
(5)
ti
(min)
(6)
Length
(it)
(7)
Slope
(%)
(8)
n
Manning
1 rough.
Vol.
(@/s)
(9)
it
(min)
(10)
to-
li + It
(11)
Total
(t)
(12)
tc-(1/180)+10
(min)
(13)
(min)
(14)
A SW
1.24
0.39
125
2.0
11.3
240
2.00
0.016
2.8
1.4
12.7
365
12.0
12.0
B (NW
3.18
0.47
345
2.0
16.8
385
1.50
0.016
2.5
2.6
19.4
730
14.1
14.1
EQUATIONS:
It; =ti+Ill
ti=[1.87(1.1-CC,)L0'I/S"3
It = 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 + It and urbanized basin check
min. tc = 5 min. due to limits of OF curves
Flow-PDPAs TOC-10
STANDARD FORM SF-2
TIME OF CONCENTRATION - 2 YEAR
LOCATION:
MVGMORNINGSTAR
PROJECT NO:
1173-105-00
COMPUTATIONS BY:
MM
DATE:
12/ 19/2013
2-yr storm Cl = 1.00
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME(tl)
TRAVEL TIME / GUTTER OR CHANNEL FLOW
(tt)
to CHECK
(URBANIZED BASIN)
FINAL
to
REMARKS
DESIGN
POINT
SUBBASIN(s
(1)
Area
(ac)
(2)
C
(3)
Length
(k)
(4)
Slope
(`Y)
(5)
ti
(min)
(6)
Length
(k)
(7)
Slope
(%)
(8)
n
Manning
rough.
Val.
(k/s)
(9)
it
(min)
(10)
tc =
ti+k
(11)
Total L
(k)
(12)
tc=(V780)+10
(min)
(13)
(min)
(14)
1
A (SW)
1.24
0.39
125
2.0
11.3
240
2.00
0.030
1.5
2.6
13.9
365
12.0
12.0
2
B (NW)
3.18
0.47
345
2.0
16.8
385
1.50
0.030
1.3
4.9
21.6
730
14.1
14.1
EQUATIONS:
tc=ti+tt
ti=[1.67(1.1-CCiI)L0.5]/S.113
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 min. due to limits of IDF curves
Interwest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
DATE:
RUNOFF COEFFICIENTS & % IMPERVIOUS
M VG MORNINGSTAR
1173-105-00
MM
12/6/2013
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):
Concrete:
Roofs:
Gravel:
Lawns (fiat Q%, heavy soil):
Runoff
coefficient
C
%
Impervious
0.95
100
0.95
96
0.95
90
0.50
40
0.20
0
SUBBASIN
DESIGNATION
TOTAL
AREA
(ac.)
TOTAL
AREA
(sq.ft)
PAVED
AREA
(sq.tt)
CONCRETE
AREA
(sq.ft)
ROOF
AREA
(sq.it)
GRAVEL
AREA
(sq.ft)
LANDSCAPE
AREA
(sq.ft)
RUNOFF
COEFF.
(C)
%
Impervious
REMARKS
A (SW)
1.24
53,825
0
4,097
18,131
0
0.39
38
Roof, SW portion of site
B (NW)
3.18
138,360
37,019
6,401
24,869
0
0.47
47
Parking, Roof, remainder of site
E uai ns
- Calculated C coefficients & % Impervious are area weighted
C=£.(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
At = total area over which C is applicable; the sum of all Ai's
Flow-PDP.xls Cval
10.00
9.00
8.00
7.00
a
m
i
c 6.00
(
Co 5.00
W
H
Z 4.00
J
J
Q
LL
2 3.00
C
2.00
1.00
0.00 4-
0.00
RAINFALL INTENSITY -DURATION -FREQUENCY CURVE
10.00 20.00 30.00 40.00 50.00
STORM DURATION (minutes)
— 2-Year Storm - - - 10-Year Storrs —100-Year Stonn
Figure RA-16 City of Fort Collins Rainfall Intensity -Duration -Frequency Curves
(13) Section 5.0 is deleted in its entirety.
(14) Section 6.0 is deleted in its entirety.
(15) Section 7.0 is deleted in its entirety.
(16) Section 7.1 is deleted in its entirety.
(17) Section 7.2 is deleted in its entirety.
(18) Section 7.3 is deleted in its entirety.
(19) Section 8.0 is deleted in its entirety.
(20) Table RA-1 is deleted in its entirety.
RLol
60.00
Table RO-11
Rational Method Runoff Coefficients for Composite Analysis
Character of Surface
Runoff Coefficient
Streets, Parking Lots,
Drives:
Asphalt
0.95
Concrete
0.95
Gravel
0.5
Roofs
0.95
Recycled Asphalt
0.8
Lawns, Sandy Soil:
Flat <2%
0.1
Average 2 to 7%
0.15
Steep >7%
0.2
Lawns, Heavy Soil:
Flat <2%
0.2
Average 2 to 7%
0.25
Steep >7%
0.35
(4) A new Section 2.9 is added, to read as follows:
2.9 Composite Runoff Coefficient
Drainage sub -basins are frequently composed of land that has multiple surfaces or zoning
classifications. In such cases a composite runoff coefficient must be calculated for any
given drainage sub -basin.
The composite runoff coefficient is obtained using the following formula:
,f
J(C;*A,)
C = "t A (RO-8)
Where: C = Composite Runoff Coefficient
C; = Runoff Coefficient for Specific Area (A)
A; = Area of Surface with Runoff Coefficient of C;, acres or fee
t2
n = Number of different surfaces to be considered
At= Total Area over which C is applicable, acres or feet2
(5) Anew Section 2.10 is added, to read as follows:
41
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40 20 0 40 80
SCALE: 1"= 40'
LEGEND
EXISTING MINOR CONTOUR
_XXXX� EXISTING MAJOR CONTOUR
PROPOSED MINOR CONTOUR
--40001_ PROPOSED MAJOR CONTOUR
PROPOSED DIRECTION OF OVERUND FLOW
PRONSED DRAINAGE
BASIN DIVIDE LINE
A DRAINAGE BASIN ID
MAJOR STORM RUNOFF COEFFICIENT
DRAINAGE BASIN AREA. ACRES
Fr JIT CONSTRUCTION ENTRANCE
O` SILT FENCE
P-1 `
IP_2 OJ STORM DRAIN INLETPROTECTON
•(S) ` WATTLE
(SWALE. ETCH. OR VEGETATED FLOWUNE)
WATTLE
(GUTTER PROTECTONI
NOTES:
1. SEE DETAIL SHEET 5 (DT-5) FOR SPILLWAY CROSS SECTIONS
CALL UTILITY NOTIFICATION
CENTER OF COLORADO
811
CAL 2-BUSINESS DAYS IN ADVANCE
BEFORE W)U OIC. GRADE. CR EXCAVATE
FOR THE MARKING OF UNDERGRWND
MEMBER UTUTES.
DRAINAGE SUMMARY TABLE
C..N.
TdbNM
Afi.
C(2)
c(101
CI100)
fs(21
t9110)
tc I1N)
Opryel
116NOt
2
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Wli..ln
lnl p.
Im FI
Iminl
It CI
Nt.l
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A ISWI
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IN
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130
120
If.
10
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.5
B(NW)
B(MN
].IB
0.6
OAB
I
J %O H
Z z g w 0
R J 0. X 0
U. JU. m
a G J W 0
Q
Ir W U
wwX .
C u. J> O)>
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a 0) Cl 0 p 0
a \
p U
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a
PRDJ.N0. 11]}105
DR
APPENDIX B
HYDROLOGIC COMPUTATIONS
oWns FCMaps
GIs
0.5 0 0.27 0.5
W GS_1984_W eb_Mercator_Auxi liary_Sphere
City of Fort Collins - GIS
This map is a user generated static output from the City of Fort Collins FCMaps
Internet mapping site and is for reference only. Data layers that appear on this
map may or may not be accurate, current, or otherwise reliable.
Legend
FEMA Floodplain
■ FEMA High Risk - Floodway
❑ FEMA High Risk - 100 Year
❑ FEMA Moderate Risk -100 /
City Floodplains
. City High Risk - Floodway
❑ City High Risk -100 Year
❑ City Moderate Risk -100 Year
❑
Parks
❑
Natural Areas
L�
City Limits
Notes
T7N
R69W
LAKESHERWOOD
HORSETOO
ITE
�i■■m■►///7l//QI
WARREN PARK
SECTION
36
31
NONE
mom p
AY]
COLLINDALE GOLF COURSE
WARIEN LAKE (mil
U
Q
a
0
MVG MORNINGSTAR m VICINITY MAP
SCALE: 1 '=1000'
APPENDIX A
VICINITY MAP, AND FLOODPLAIN MAPS
A
5. CONCLUSIONS
5.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
COFC Storm water Criteria Manual, the COFC Master Drainage Plans, and the COFC
floodplain regulations. All floodway information is in compliance with Chapter 10 of the
City of Fort Collins Municipal Code and all State and Federal regulations.
5.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
adequately provide for stormwater quantity and quality treatment of proposed impervious
areas. Conveyance elements have been designed to pass required flows and to minimize
future maintenance.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit will be required.
6. 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 June 2001, and Volume 3 dated September
1999.
3. ICON Engineering, Inc., "McClelland's Creek Master Drainage Plan Update",
dated November 20, 2000 (Revised March 2003).
4. Kumar & Associates, Inc., "Geotechnical Engineering Study Proposed MVG-
Morningstar Assisted Living and Memory Care Facility Northwest Corner of East
Horsetooth Road and Lochwood Drive, Fort Collins, Colorado" dated November
12, 2013 and a Supplemental Memorandum December 10, 2013.
8
areas carrying flow away from the building or sheet flow over -top the sidewalk.
Remaining Sub -basin A flow will be collected and routed through a Grass Swale along
the south edge of the property and two (2) Gravel Dry Wells in the bottom of the
Extended Detention Basin A, which is located just southwest of the proposed building.
Once the run-off is treated, the outlet structure discharges into the existing concrete
channel to the west of the site, eventually reaching McClelland's Channel. Sub -Basin A
is calculated to have a 2-year, 10-year, and 100-year discharges of 1.0, 1.7, and 4.5 cfs,
respectively.
Sub -Basin B includes the remaining approximately 3.18 acres located northeast of Sub -
basin A within the site, including the north half of the proposed building downspouts. A
portion of the east side building down -spout run-off as well as that immediately adjacent
to the southeast side of the proposed building will be collected in a proposed Grass Swale
before entering the site's private storm drain system. The north side building down -spout
run-off as well as that immediately adjacent to the north, northeast, and northwest sides of
the building shall sheet flow to the northwest to the proposed Extended Detention Basin
B. Parking and access road run-off will sheet flow to the northwest or enter the site's
storm drain system, which also drains into Extended Detention Basin B. Several rows of
parking spaces are proposed to be constructed with Pervious Pavers to treat small areas of
runoff. Once the flow reach Extended Detention Basin B they are again treated and
released through a water quality outlet structure into the existing drainage ditch flowing
northeast into McClelland's Channel. Sub -basin B is calculated to have a 2-year, 10-year,
and 100-year discharges of 2.8, 4.8 and 12.3 cfs, respectively.
4.3 Drainage Summary
The percent impervious weighted average of the entire site is 48.7%. All proposed site
runoff follows existing drainage flow patterns while adding a level of water quality to the
discharge.
Drainage facilities located outside of the right of way (including the rain garden, water
quality pond, proposed storm sewer system and the detention basin outlets) will be
maintained by the owners of the property. The property owner shall also be responsible
for maintaining the portion of the common drainage channel located on the subject
property.
7
the City of Fort Collins Drainage Criteria.
3.5 Floodplain Regulations Compliance
No work is proposed within an existing floodplain.
4. DRAINAGE FACILITY DESIGN
4.1 General Concept
The proposed MVG-Morningstar site was designed to treat run-off as close to the point -
source as possible, while also minimizing the length of drainage routing to the most
feasible extents of the site.
The proposed site shall be divided into two sub -basins based on design points A and B.
The proposed drainage design follows the existing drainage pattern of southeast to
northwest. The project will consist of an Assisted & Memory Care Complex building
with a footprint of approximately 43,000 SF, a parking area for patients and employees,
an access lane, sidewalks and landscaped areas. Proposed site run-off is directed to a
series of LIDs and an extended detention basin at one of the two design points before
being released off -site. Each extended detention basin shall be equipped with a Water
Quality Outlet Structure, designed specifically for that sub -basin, to treat and release the
run-off into the existing concrete ditch at or below historic run-off rates.
Both of the extended detention basins serving as water quality basins shall also act as on -
site detention areas for the proposed construction. The on -site detention shall hold the
proposed 100-year run-off and release it at the historic 2-year storm release rate.
4.2 Specific Flow Routing
A summary of the drainage patterns within each basin is provided in the following
paragraphs.
Sub -Basin A includes the southern portion of the property, excluding the existing
drainage ditch, and the south half of the downspouts from the proposed building, and is
approximately 1.24 ac. From the downspouts, flow will be routed through vegetated
6
0.02 ac-ft and 0.06 ac-ft, respectively. Water quality volumes for both basins shall be
provided in the proposed designs of Extended Detention Basins A and B. Final water
quality volumes are presented in the Appendix D and calculated using the method
recommended in the "Urban Storm Drainage Criteria Manual".
3.4 Hydraulic Criteria
Using methods described in the City of Fort Collins Drainage Criteria, it was determined
that Sub -basins A and B are required to detain 0.11 and 0.36 ac-ft respectively, in
addition to the water quality volumes referenced in section 3.3 of this report.
Sub -Basin A
The proposed Extended Detention Basin A meets the water quality requirement for
storage at elevation 4968.50 and the 100-yr storm detention at elevation 4969.70. A 5
foot long spillway shall be constructed at elevation 4970.00. A water quality outlet
structure shall be utilized in releasing flows at or below historic rates into an 18" RCP
culvert that shall discharge into a proposed Rip Rap lined channel before entering the
existing concrete channel along the west boundary of the site.
Sub -Basin B
Runoff from the existing adjacent roadways shall be collected in a proposed Type `R'
Inlet along Lochwood Drive, south of the northernmost Morningstar site access. This
runoff will be piped in 18" and 24" RCP pipes in the site's storm drain system to the
Extended Detention Basin B. Downspout runoff from the southeast portion of the
building as well as that runoff adjacent to the southeast portion of the building will be
collected in a small proposed rain garden infiltration area before entering the site's storm
drain system. Runoff from the parking areas and the runoff adjacent to the northeast,
north, and northwest sides of the building shall sheet flow overland toward Extended
Detention Basin B.
The proposed Extended Detention Basin B meets the water quality requirement for
storage at elevation 4964.50 and the 100-yr storm detention at elevation 4967.00. A 13
foot long spillway shall be constructed at elevation 4967.40. A water quality outlet
structure shall be utilized in releasing flows at or below historic rates into a 24" RCP
culvert which shall discharge into a proposed Rip Rap lined channel before entering the
existing concrete channel to the northwest of the site.
All hydraulic calculations are presented in Appendix C and prepared in accordance with
5
spout runoff before conveying the water to the second water quality treatment basin.
Pervious Pavers are located within Sub -basin B upstream of Extended Detention Basin B
to help reduce total runoff by allowing water to infiltrate. Extended Detention Basin B
also shall be equipped with a Water Quality Outlet Structure designed to allow sediments
to settle while releasing treated flows at or less than historic rates.
Step 3: Stabilize Drainageways
Natural Drainageways are subject to bed and bank erosion due to increases in frequency,
duration, rate and volume of runoff during and following development. Rip -Rap shall be
used at the outlet of both Extended Detention Basins as well as the two points where a
majority of water will enter Extended Detention Basin B. The Rip Rap shall be stabilized
in place.
Step 4: Implement Site Specific and Other Source Control BMPs
Proactively controlling pollutants at their source by preventing pollution rather than
removing contaminants once they have entered the stormwater system or receiving waters
is important when protecting storm systems and receiving waters. This can be
accomplished through site specific needs such as construction site runoff control, post -
construction runoff control and pollution prevention / good housekeeping. It will be the
responsibility of the contractor to develop a procedural best management practice for the
site.
3.3 Hydrologic Criteria
Runoff computations were prepared for the 2-year and 10-year minor and 100-year major
storm frequency utilizing the rational method. The Modified FAA method was used to
determine preliminary detention volumes for the proposed extended detention basins.
All hydrologic calculations associated with the basins are included in Appendix B of this
report. Sub -Basin A will encompass 1.24 acres, 38% of which will be impervious, and is
calculated to have 2-year, 10-year, and 100-year discharges of 1.0, 1.7, and 4.5 cfs,
respectively. Sub -basin B will encompass 3.18 acres, 47% of which will be impervious,
and is calculated to have 2-year, 10-year, and 100-year discharges of 2.9, 4.9 and 12.5 cfs,
respectively.
The water quality storage volumes in Sub -basin A and Sub -basin B were calculated to be
4
for receiving water protection that focuses on reducing runoff volumes, treating the water
quality capture volume (WQCV), stabilizing drainageways and implementing long-term
source controls. The Four Step Process applies to the management of smaller, frequently
occurring events.
Step 1: Employ Runoff Reduction Practices
To reduce runoff peaks, volumes, and pollutant loads from urbanizing areas, implement
Low Impact Development (LID) strategies, including Minimizing Directly Connected
Impervious Areas (MDCIA). See the LID Area Exhibit in Appendix D.
Runoff for the site will be split around the proposed building's southeast corner to the
west and north, respectively.
Sub -Basin A
Runoff directed to the west will be routed south of the building through a Grass Swale to
an extended detention basin, herein referred to as "Extended Detention Basin A"
equipped with a Water Quality Outlet Structure which will release flow into the existing
concrete drainage ditch along the west edge of the property. Extended Detention Basin A
will also be constructed with Gravel Dry Wells along the flow line of the basin to help
slow the basin's time of concentration and serve as supplemental Low Impact
Development (LID) measures.
Sub -Basin B
Runoff directed to the north will be routed through another Grass Swale thereby reducing
runoff from impervious surfaces over permeable areas to slow runoff and increase the
time of concentration and promote infiltration. Runoff from portions of the parking lot
shall drain across Pervious Pavers before entering a second extended detention basin,
herein referred to as "Extended Detention Basin B".
Step 2: Implement BMPs that Provide a Water Quality Capture Volume with Slow
Release
Sub -Basin A
Extended Detention Basin A utilizes a Grass Swale, Gravel Dry Wells and a Water
Quality Outlet Structure designed to allow sediments to settle while releasing treated
flows at or less than historic rates.
Sub -Basin B
A Grass Swale located southeast of the main building entrance shall collect the down-
tj
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description
The proposed development lies within the McClelland's Creek Master Drainage Basin.
The entire site currently drains to an existing concrete drainage ditch along the west and
northwest property boundary. James H. Stewart and Associates performed a drainage
study on this drainage in March of 1978 and determined the 100-year storm to produce
217.0 cfs. However, the updated 2010 SWMM model for the basin shows a 2-year storm
run-off of 20.6 cfs and a 100-year storm run-off of 150.2 cfs. See Appendix B for
existing site hydrologic computations.
2.2 Sub -basin Description
The existing site has a historic runoff of 1.7 cfs and 6.7 cfs for the 2-year & 100-year run-
off event, respectively, with a historic 2-year release rate of 0.39 cfs/acre. The site will be
divided into 2 sub -basins for proposed construction activities. Sub -basin A will consist
of approximately 1.24 ac and will be collected in a small extended detention basin located
southwest of the proposed building before releasing into the existing drainage ditch to the
west. Sub -basin B consists of approximately 3.18 ac and drains to the northwest corner
of the property where it will be collected in a second extended detention basin before
releasing into the existing concrete drainage ditch west of the property. Once the run-off
enters the existing ditch, it will flow northeast eventually reaching McClelland's Channel.
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. Where applicable, the criteria established in the
"Urban Storm Drainage Criteria Manual" (UDFCD), developed by the Denver Regional
Council of Governments, has been used.
3.2 Development Criteria Reference and Constraints
Urban Drainage and Flood Control District (UDFCD) recommends a Four Step Process
2
1. GENERAL LOCATION AND DESCRIPTION
1.1 Location
The MVG-Morningstar Assisted & Memory Care Project development is located in
southeast Fort Collins. It is located in the Southwest Quarter of Section 30, Township 6
North, Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins,
Larimer County, Colorado. See the location map in Appendix A.
The project is located west of Lochwood Drive, north of E. Horsetooth Road, and
bounded on the west and north sides by existing residential lots. An existing drainage
ditch with an existing 25 ft Drainage Easement runs along the west edge of the property,
dividing it from the residential properties.
1.2 Description of Property
The property consists of approximately 4.42 acres of land. The existing land currently
drains from southeast to northwest at approximately a 2% grade. The land is currently
vacant with mild sloping terrain and covered with natural dry -land vegetation across the
entire site. The only offsite flow entering the site is through an existing concrete drainage
ditch originating at the Southwest corner of the property and conveys runoff to the
northeast. There is an existing 25' drainage easement accompanying the existing
concrete ditch, extending from the existing flowline 25' to the west. An additional 25'
drainage easement is proposed, extending from the flowline 25' to the east, to make the
entire Drainage Easement 50' wide up to the Tract A -Utility & Drainage Easement. The
channel is not mapped by FEMA, but the project is located in Zone X of FEMA FIRM
Panel 08069C 1000F.
The Geotechnical Report and Supplemental Memorandum by Kumar and Associates
dated November 12, 2013 and December 10, 2013, respectfully, indicate the presence of
groundwater at approximate depths of 8 to 9 feet below existing grade. However, based
on the recommended drilled pier design, a building perimeter drain system is not
required.
The poorly draining onsite materials do present the need for a supplementary underdrain
system for the proposed site LID's.
I
TABLE OF CONTENTS
TABLEOF CONTENTS............................................................................................................ iii
1. GENERAL LOCATION AND DESCRIPTION................................................................ 1
1.1 Location...........................................................................................................................1
1.2 Description of Property................................................................................................. 1
2. DRAINAGE BASINS AND SUB-BASINS.......................................................................... 2
2.1 Major Basin Description................................................................................................ 2
2.2 Sub -basin Description.................................................................................................... 2
3. DRAINAGE DESIGN CRITERIA...................................................................................... 2
3.1 Regulations......................................................................................................................2
3.2 Development Criteria Reference and Constraints...................................................... 2
3.3 Hydrological Criteria..................................................................................................... 4
3.4 Hydraulic Criteria.......................................................................................................... 5
3.5 Floodplain Regulations Compliance............................................................................. 6
4. DRAINAGE FACILITY DESIGN....................................................................................... 6
4.1 General Concept............................................................................................................. 6
4.2 Specific Flow Routing.................................................................................:.................. 6
4.3 Drainage Summary........................................................................................................ 7
5. CONCLUSIONS.................................................................................................................... 8
5.1 Compliance with Standards.......................................................................................... 8
5.2 Drainage Concept........................................................................................................... 8
6. REFERENCES...................................................................................................................... 8
APPENDIX
VICINITY MAP AND FLOODPLAIN MAPS......................................................................... A
HYDROLOGIC COMPUTATIONS..........................................................................................B
HYDRAULIC COMPUTATIONS..............................................................................................0
WATERQUALITY..................................................................................................................... D
iii
December 23, 2013
Mr. Wes Lamarque
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Final Drainage Report for MVG-Morningstar Assisted & Memory Care Project
Dear Wes,
I am pleased to submit for your review and approval, this Final Drainage Report for the MVG-
Morningstar Assisted & Memory Care Project development. 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.
Sincerely,
Mark Morrison, E.I.T.
ii
Reviewed By:
Robert Almirall, P.E.
Colorado Professional
Engineer No. 33441
•4 n
FINAL DRAINAGE REPORT
MVG-MORNINGSTAR
ASSISTED & MEMORY CARE PROJECT, : )
Prepared by:
Interwest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado 80550
(970)674-8488
Prepared for:
MVG — MS (Fort Collins) LLC,
A Colorado Limited Liability Company
c/o MVG Development
1509 York Street
Denver, CO 80206
December 23, 2013
Job Number 1173-105-00