HomeMy WebLinkAboutCLOCK TOWER APARTMENTS - PDP - 37-02A - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDesign Procedure Form: Porous Landscape Detention (PLD)
Designer:
J. Miller
Company:
DMW Civil Engineers
Date:
November 27, 2002
Project
Clock Tower Apartmerds 0218.60 - CTA
Location:
Font Collins, CO
1. Basin Storage Volume
( I, = 100% lt all paved and roofed areas u/s or PLD)
1, = 100.00 %
A) Tributary Area's Imperviousness Ratio (i = I,/ 100)
i
B) Contributing Watershed Area Including the PLD (Area)
Area = 13,068 square feet
C) Water Quality Capture Volume (WQCV)
WQCV =,. - Yf"40a watershed inches
(WQCV =0.8`(0.91'13-1.19.12+0.78'1))
D) Design Volume: Voles _ (WQCV / 12) ' Area
Vol = 4356 cubic feet
2. PLD Surface Area (ApLD) and Average Depth (d,,.)
ApLD = 520 square feet
(d,,: _ (Vol / Ate), Min=0.5', Ma)=1.0')
d,,, = 084 feet
3. Base Course (See Figure PLD-1)
X 6" (Min.) Sandy Loam Turf Layer, Plus 18" (Min.)
Layer of 25% Peat and 75% Sand Mix, Plus 9'
(Min.) Layer of ASSHTO #8 Coarse Aggregate
(CDOT Section 703 Specification).
Other:
5. Draining of porous pavement (Check a, or b, or c, answer d)
X Infiltration to Subgrade with Permeable
Based on answers to 5a through 5d, check the appropriate method
Membrane: 5(c) checked and 5(d) = no
a) Check box if subgrade is heavy or expansive clay
Underdrain with Impermeable
b) Check box if subgrade is silty or clayey sands
Membrane: 5(a) checked or 5(d) = yes
c) Check box if subgrade is well -draining soils X
U nderdrain with Permeable Membrane:
d) Does tributary catchment contain land uses that may have
5(b) checked and 5(d) = no
petroleum products, greases, or other chemicals
present, such as gas station, yes no
Other:
hardware store, restaurant, etc.? I I X
Notes:
CTA-PLD.)ds, PLD
Appendix E
Effectiveness Calculations
Project: Clock Tower Apartments STANDARD FORM B
Calculations By: J. Miller
Project No.: 0218.00-CTA
Client: Barbara Seik Date: 11/27/02
EROSION CONTROL METHOD
G
P-Factor
Comment
Factor
Value
Value
Roads / Walks
0.01
1.00
Existing and proposed pavement
Established Grass
0.03
1.00
Existing grass
Sediment Basin
1.00
0.50
Water quality pond
Silt Fence
1.00
0.50
Along south & east of project
MAJOR
PS
SUB-
AREA
CALCULATIONS
BASIN
(%)
BASIN
(AC)
1-2
72.4
1.02
DURING CONSTRUCTION:
Plan intent: Erect silt fencing and construct
water quality/detention pond.
Impervious:
Impervious area = 0.70 acres
Pervious:
Established Grass = 0.13 acres
Weighted C Factor-
((0.01 x 0.70)+(0.03 x 0.13)/1.02 = 0.011
Weighted P Factor- 0.5 x 0.5 = 0.25
EFF = [1-(C x P))100=(1-(0.011 x 0.25) x 100 =
99.7 > 72.4
' F:\DMWIProjects\CTA\CTA-ECFormB.wpd Davis, Miller & Wohnrade Civil Engineers, Inc
Rainfall Performance Standard Evaluation
Project: Clock Tower Apartments STANDARD FORM A
Calculations By: J. Miller
Project No.: 0218.00-CTA
Client: Barbara Seik Date: 11/27/02
DEVELOPED
ERODIBILITY
Asb
Lb
Alb x Lsb
S,b
Alb x Ssb
4
Sb
PS
SUBBASIN
ZONE
(ac)
(ft)
(%)
(ft)
(%)
(%)
1
MODERATE
0.54
250.0
135.0
0.60
0.3
2
MODERATE
0.48
440.0
211.2
0.50
0.2
EXAMPLE CALCULATIONS
Lb = SUM(Asb'Lsb)/A
Sb = SUM(Asb'Ssb)/A
PS (during construction) = 77.7 (From Table 8-A)
PS (after construction) = 77.7/0.85 = 91.4
F: ADM W 1P"ects\CTA\CTA-E C F omiA. wpd
i
1
Davis, Miller & Wohnrade Civil Engineers, Inc. 1
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m
P
D
TABLE 8-A
FLOW RAINFALL PERFORMANCE STANDARDS FOR FORT COLLINS# COLORADO
LENGTH SLOPE (%)
(FT) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 6.0 7.0 8.0 9.0 10.0 20.0 30.0 40.0 50.
100 70.9 74.6 76.8 78.4 79.5 80.3 81.1 81.6 82.1 82.5 83.0 83.4 83.6 83.8 84.0 84.7 84.8 84.9 84.
200 72.0 76.3 78.2 79.5 80.5 81.2 82.1 82.5 82.8 83.2 83.6 83.9 84.0 84.2 84.3 84.8 84.9 84.9 84.
300 72.4 77.0 78.8 80.0 80.9 81.6 82.5 82.8 83.1 83.5 83.8 84.1 84.2 84.3 84.4 84.8 84.9 84.9 85.
400 72.6 77.4 79.1 80.3 81.2 81.8 82.7 83.0 83.3 83.7 84.0 84.2 84.3 84.4 84.5 84.8 84.9 84.9 85.
500 72.7 77.7 79.4 80.5 81.3 81.9 82.8 83.1 83.4 83.8 84.1 84.3 84.4 84.5 84.6 84.9 84.9 85.0 85.
600 72.8 77.9 79.5 80.6 81.4 82.0 83.0 83.2 83.5 83.9 84.1 84.3 84.4 84.5 84.6 84.9 84.9 85.0
700 72.8 78.0 79.7 80.8 81.5 82.1 83.0 83.3 83.5 84.0 84.2 84.4 84.5 84.5 84.6 84.9 84.9 85.0
800 72.7 78.1 79.7 80.8 81.6 82.2 83.1 83.4 83.6 84.0 84.2 84.4 84.5 84.6 84.6 84.9 84.9 85.0
900 72.7 78.2 79.8 80.9 81.7 82.2 83.2 83.4 83.6 84.1 84.3 84.4 84.5 84.6 84.7 84.9 84.9 85.0
1000 72.7 78.3 79.9 81.0 81.7 82.3 83.2 83.5 83.7 84.1 84.3 84.4 84.5 84.6 84.7 84.9 84.9 85.0
1100 72.6 78.3 79.9 81.0 81.7 82.3 83.3 83.5 83.7 84.1 84.3 84.5 84.6 84.6 84.7 84.9 84.9
1200 72.6 78.4 80.0 81.0 81.8 82.3 83.3 83.5 83.7 84.2 84.3 84.5 84.6 84.6 84.7 84.9 84.9
1300 72.6 78.4 80.0 81.1 81.8 82.4 83.3 83.6 83.8 84.2 84.4 84.5 84.6 84.6 84.7 84.9 85.0
1400 72.5 78.5 80.1 81.1 81.8 82.4 83.4 83.6 83.8 84.2 84.4 84.5 84.6 84.7 84.7 84.9 85.0
1500 72.4 78.5 80.1 81.1 81.9 82.4 83.4 83.6 83.8 84.2 84.4 84.5 84.6 84.7 84.7 84.9 85.0
1600 72.4 78.5 80.1 81.1 81.9 82.4 83.4 83.6 83.8 84.2 84.4 84.5 84.6 84.7 84.7 84.9
1700 72.3 78.5 80.1 81.2 81.9 82.4 83.4 83.6 83.8 84.3 84.4 84.5 84.6 84.7 84.7 84.9
1800 72.3 78.6 80.1 81.2 81.9 82.4 83.4 83.7 83.8 84.3 84.4 84.5 84.6 84.7 84.7 84.9
1900 72.2 78.6 80.2 81.2 81.9 82.5 63.5 83.7 83.9 84.3 84.4 84.5 84.6 84.7 84.7 84.9
2000 72.2 78.6 80.2 81.2 81.9 82.5 83.5 83.7 83.9 84.3 84.4 84.6 84.6 84.7 84.7 84.9
2500 71.9 78.6 80.2 81.3 82.0 82.5 83.5 83.7 83.9 84.3 84.5 84.6 84.7 84.7 84.8
3000 71.6 78.7 80.3 81.3 82.0 82.5 83.6 83.8 84.0 84.4 84.5 84.6 84.7 84.7 84.8
3500 71.4 78.7 B0.3 81.3 82.0 82.6 83.6 83.8 84.0 84.4 84.5 84.6 84.7 84.7 84.8
4000 71.1 78.6 80.3 81.3 82.0 82.6 83.6 83.8 84.0 84.4 84.5 84.6 84.7 84.8 84.8
4500 70.9 78.6 80.3 81.3 82.0 82.6 83.7 83.9 84.0 84.4 84.6 84.6 84.7 84.8 84.8
5000 70.6 78.6 80.3 81.3 82.0 82.6 83.7 83.9 84.0 84.4 84.6 84.7 84.7 84.8 84.8
m
6
Appendix D
er Name: Workstation
oiect: CTA - Clock Tower Apartments
Scenario: Clock Tower Apartments
Date: 11-27-02
Time: 05:40:19
Page: 1
SUMMARY REPORT
rNIT HYDROGRAPHI
<None>
(FLOOD HYDROGRAPHI
- Pond 1 Inflow - 100 Yr
Type
Peak Flow
Peak Time
' - Pond 1 Routina - 100 Yr
Tvpe
Peak Flow
Peak Time
Inflow Hvdroaraph
1 - Pond 1 Inflow - 100 Yr
OUTLET STRUCTURE]
Orifice
Type
Maximum Discharge
Weir
Type
Maximum Discharge
RESERVOIR]
- Pond 1
Tvpe
Maximum Storaae
Maximum Discharge
Discharge Structure:
1 - Orifice
Rational
3.62
9.10
cfs
min
Reservoir: Modified Puls
1.41 cfs
18.50 min
: Circular Orifice
: 2..47 cfs
: Rectanaular Weir Suppressed
: 6.66 cfs
: User -Defined Storage
: 13481.59 cu ft
: 2.47 cfs
iser Name: Workstation
Proiect: CTA - Clock Tower Apartments
Scenario: Clock Tower Apartments
Date: 11-27-02
Time: 05:36:37
Page: 1
Structure Number
rvpe
Name
(RATING CURVE LIMITI
Minimum Elevation
Maximum Elevation
Elevation Increment
OUTLET STRUCTURE REPORT
2
Rectangular Weir Suppressed
Weir
(OUTLET STRUCTURE INFORMATIONI
Crest Lenath
Crest Elevation
Weir Coefficient
Exponential
(RECTANGULAR SUPRESSED EQUATION]
Q = Cw * L * H^exp
(DEFINITIONSI
Cw = Weir Coefficient
H = Headwater depth
L = Crest lenght
(MAXIMUM DISCHARGEI
Q
(WEIR STAGE VS. DISCHARGEI
5030.50
5033.00
0.10
2.00
5032.00
3.33
1.50
above inlet control section invert .
= 6.66
Elevation (ft) Staae (ft) Discharae (cfs)
(ft)
(ft)
(ft)
(ft)
(ft)
(cfs)
I
5030.50
0.00
0.00
5030.60
0.10
0.00
5030.70
0.20
0.00 '
5030.80
0.30
0.00
5030.90
0.40
0.00
5031.00
0.50
0.00
5031.10
0.60
0.00 '
5031.20
0.70
0.00
5031.30
0.80
0.00
5031.40
0.90
0.00
5031.50
1.00
'
0.00
5031.60
1.10
0.00
5031.70
1.20
0.00
5031.80
1.30
0.00
5031.90
1.40
'
0.00
5032.00
1.50
0.00
5032.10
1.60
0.21
5032.20
1.70
0.60.
5032.30
1.80
'
1.09
5032.40
1.90
1.68
5032.50
2.00
2.35
5032.60
2.10
3.10
5032.70
2.20
3.90
5032.80
2.30
4.77
5032.90
2.40
5.69
5033.00
2.50
6.66 '
er Name: Workstation
oiect: CTA - Clock Tower Apartments
Scenario: Clock Tower Apartments
Date: 11-27-02
Time: 05:36:04
Page: l
It
ructure Number
vpe
ame
RATING CURVE LIMITI
Minimum Elevation
Maximum Elevation
Elevation Increment
OUTLET STRUCTURE REPORT
: 1
: Circular Orifice
: Orifice
'OUTLET STRUCTURE INFORMATIONI
Diameter
Orifice Coefficient
' Invert Elevation
Number of Openings
(CIRCULAR ORIFICE EOUATIONI
Q = Co*A((2gh)/W 0.5
DEFINITIONSI
Co = Orifice Coefficient
A = Wetted Area, (cfs)
k = 1
MAXIMUM DISCHARGEI
Q
(ORIFICE STAGE VS. DISCHARGEI
5030.50 (ft)
= 5033.00 (ft)
0.10 (ft)
0.67 (ft)
0.60
5030.50 (ft)
1
2.47 (cfs)
----------------------------------------------------------------
levation (ft) Staae (ft) Discharae (cfs)
5030.50
0.00
0.00
030.60
0.10
0.04
030.70
0.20
0.13
030.80
0.30
0.28
5030.90
0.40
0.47
0.50
0.68
t031.00
031.10
0.60
0.87
031.20
0.70
1.02
5031.30
0.80
1.15
31.40
0.90
1.26
31.50
C031.60
1.00
1.37
1.10
1.47
5031.70
1.20
1.56
1.30
1.65
t031.80
031.90
1.40
1.74
032.00
1.50
1.81
5032.10
1.60
1.89
1.70
1.96
1032.20
032.30
1.80
2.03
032.40
1.90
2.10
5032.50
2.00
2.17
2.10
2.23
1032.60
032.70
2.20
2.30
032.80
2.30
2.36
5032.90
2.40
2.42
033.00
2.50
2.47
User Name: Workstation
Proiect: CTA - Clock Tower Apartments
Scenario: Clock Tower Apartments
Date: 11-27-0
Time: 05:33:5
Page: 2
RESERVOIR REPORT
(RESERVOIR STAGE STORAGE/DISCHARGEI
Elevation
Staae
Area
Storaae
Discharae
(ft)
(ft)
(sa ft)
(cu ft)
(cfs)
5030.50
0.00
0..00
0.00
0.00
5030.60
0.10
14760.65
492.02
0.04
5030.70
0.20
8321.20
554.75
0.13
5030.80
0.30
6215.14
621.51
0.28
5030.90
0.40
5197.51
693.00
0.47
5031.00
0.50
4613.49
768.91
0.68
5031.10
0.60
4257.16
851.43
0.87
5031.20
0.70
4078.10
951.56
1.02
5031.30
0.80
4056.69
1081.78
1.15
5031.40
0.90
4181.75
1254.53
1.26
5031.50
1.00
4413.29
1471.10
1.37
5031.60
1.10
4773.91
1750.43
1.47
5031.70
1.20
5287.96
2115.18
1.56
5031.80
1.30
5938.20
2573.22
1.65
5031.90
1.40
6704.67
3128.85
1.74
5032.00
1.50
7565.66
3782.83
1.81
5032.10
1.60
8485.11
4525.39
1.89
5032.20
1.70
9434.46
5346.20
1.96
5032.30
1.80
10356.44
6213.86
2.03
5032.40
1.90
11230.29
7112.52
2.10
'
5032.50
2.00
12062.98
8041.99
2.17
5032.60
2.10
12863.70
9004.59
2.23
5032.70
2.20
13637.80
10001.06
2.30
5032.80
2.30
14419.51
11054.96
2.36
5032.90
2.40
15266.17
12212.93
2.42
5033.00
2.50
16177.90
13481.59
2.47
Maximum
Storaae
=
13481.59
(cu ft)
Maximum
Discharge
=
2.47
(cfs)
ser Name: Workstation Date: 11-27-02
roiect: CTA - Clock Tower Apartments Time: 05:33:52
Scenario: Clock Tower Apartments Page: 1
RESERVOIR REPORT
�eservoir Number: 1
ame: Pond 1
(RATING CURVE LIMITI
Minimum Elevation 5030.50 (ft)
Maximum Elevation 5033.00 (ft)
Elevation Increment - 0.10 (ft)
STAGE STORAGE INFORMATIONI
Storage Method: User -Defined Storage
Input Method: Volume
umber Elevation Area Ave Area Volume Cumulative Volume
(ft) (sa ft) (so ft) (cu ft) (cu ft)
5028.85
0.00
0.00
0.00
0.00
5029.00
67.66
33.83
5.07
5.07
5029.10
65.24
66.45
6.65
11.72
4
5029.20
120.35
.92.80
9.28
21.00
5029.30
118.96
119.66
11.97
32.96
5029.40
178.74
148.85
14.89
47.85
5029.50
178.64
178.69
17.87
65.72
8
5029.60
240.76
209.70
20.97
86.69
5029.70
242.99
241.87
24.19
110.87
0
5029.80
304.59
273.79
27.38
138.25
1
5029.90
314.52
309.55
30.96
169.21
5030.00
375.93
345.22
34.52
203.73
3
J2
5030.10
388.19
382.06
38.21
241.94
4
5030.20
451.93
420.06
42.01
283.94
15
5030.30
461.85
456.89
45.69
329.63
6
5030.40
536.88
499.37
49.94
379.57
7
5030.50
544.85
540.86
54.09
433.65
8
5030.60
622.51
583.68
58.37
492.02
19
5030.70
631.99
627.25
62.72
554.75
0
5030.80
703.36
667.67
66.77
621.51
1
5030.90
726.39
714.87
71.49
693.00
2
5031.00
791.88
759.13
75.91
768.91
23
5031.10
858.48
825.18
82.52
851.43
4
5031.20
1144.00
1001.24
100.12
951.56
5
f6
5031.30
1460.56
1302.28
130.23
1081.78
5031.40
1994.26
1727.41
172.74
1254.53
27
5031.50
2337.17
2165.71
216.57
1471.10
5031.60
3249.58
2793.37
279.34
1750.43
i8
9
5031.70
4045.40
3647.49
364.75
2115.18
o
5031.80
5115.38
4580.39
458.04
2573.22
31
5031.90
5997.11
5556.24
555.62
3128.85
2
5032.00
7082.53
6539.82
653.98
3782.83
3
f4
5032.10
7768.76
7425.64
742.56
4525.39
5032.20
8647.30
8208.03
820.80
5346.20
35
5032.30
8706.05
8676.67
867.67
6213.86
6
5032.40
9267.07
8986.56
898.66
7112.52
7
5032.50
9322.35
9294.71
929.47
8041.99
8
5032.60
9929.66
9626.01
962.60
9004.59
39
5032.70
9999.64
9964.65
996.47
10001.06
5032.80
11078.41
10539.02
1053.90
11054.96
90
1
5032.90
12081.10
11579.76
1157.98
12212.93
2
5033.00
13291.97
12686.54
1268.65
13481.59
DISCHARGE
INFORMATIONI
Structure Number:
1
TVDe:
Circular
Orifice
Name:
Orifice
7ser Name: Workstation Date: 11-27-02�
Proiect: CTA - Clock Tower Apartments Time: 05:34:52
Scenario: Clock Tower Apartments Page: 2
FLOOD -HYDROGRAPH- REPORT
=====____-___________________�
18
9.00
1.22
11.56
0.20
3.58
19
9.50
1.23
12.79
-0.06
3.53
20
10.00
1.23
14.02
-0.12
3.41
21
10.50
1.23
15.25
-0.12
3.29
22
11.00
1.23
16.48
-0.12
3.17
23
11.50
1.23
17.71
-0.12
3.05
24
12.00
1.23
18.94
-0.12
2.93
25
12.50
1.23
20.17
-0.12
2.81
26
13.00
1.23
21.41
-0.12
2.69
27
13.50
1.23
22.64
-0.12
2.57
28
14.00
1.23
23.87
-0.12
2.45
29
14.50
1.23
25.10
-0.12
2.34
30
15.00
1.23
26.33
-0.12
2.22
31
15.50
1.23
27.56
-0.12
2.10
32
16.00
1.23
28.79
-0.12
1.98
33
16.50
1.23
30.02
-0.12
1.86
34
17.00
1.23
31.25
-0.12
1.74
35
17.50
1.23
32.48
-0.12
1.62
36
18.00
1.23
33.71
-0.12
1.50
37
18.50
1.23
34.94
-0.12
1.38
38
19.00
1.23
36.17
-0.12
1.26
39
19.50
1.23
37.40.
-0.12
1.14
40
20.00
1.23
38.63
-0.12
1.02
41
20.50
1.23
39.87
-0.12
0.91
42
21.00
1.23
41.10
-0.12
0.79
43
21.50
1.23
42.33
-0.12
0.67
44
22.00
1.23
43.56
-0.12
0.55
45
22.50
1.23
44.79
-0.12
0.43
46
23.00
1.23
46.02
-0.12
0.31
47
23.50
1.23
47.25
-0.12
0.19
48
24.00
1.23
48.48
-0.12
0.07
ter Name: Workstation Date: 11-27-02
oiect: CTA - Clock Tower Apartments Time: 05:34:52
Scenario: Clock Tower Apartments Page: 1
FLOOD HYDROGRAPH REPORT
----------------
droaraDh Number: 1
me: Pond l Inflow - 100 Yr
pe: Modified Rational
YDROGRAPH INFORMATIONI
Peak Flow (OD) -
3.62
(cfs)
Time to Peak (Tp) =
9.10
(min)
Time of Base (Tb) =
24.30
(min)
Volume
0.06
(ac-ft)
Time Step
0.50
(min)
Flow Multiplier -
1.00
TIONAL HYDROGRAPH INFORMATIONI
Flow Multiplier -
1.00
Receding Limb Factor =
1.67
[APPROXIMATE STORAGEI
Maximum Outflow -
0.00
(cfs)
Maximum Storage =
0.06
(cu ft)
[BASIN INFORMATION)
[WEIGHTED WATERSHED
-------------------------------------
' Description
-------------------
<None>
------------------------------
Overall Approximation
TIME CONCENTRATION -- User Definedl
Time of Concentration (Tc)
(RAINFALL DESCRIPTIONI
Distribution Type
Total Precipitation
' Return Period
Storm Duration
[Hvdroaraph
[TIME
Time
Time
Interval
(min)
1
-- -----
0.50
1.0
1.50
2.00
5
2.50
3.0
3.50
4.00
9
4.50
0
5.00
1
5.50
2
6.00
13
6.50
4
7.00
5
7.50
6
8.00
17
8.50
Area
AREA1
--------------------------------
CN Runoff Coef
--------------------------------
--------------------------------------
0.54 NA 0.82
9.10 (min)
= Svnthetic
1.23 (in)
100 (vr)
0.15 (hr)
Flow Values:
Time vs.
Flow)
CONCENTRATION
------------------------------------------------
-- 0.501
Incremental
Cumulative Incremental
Design
Rainfall
Rainfall
Outflow
Outflow
(in)----------(in)--------(cfs)
(cfs)
0.07
0.07
---------
0.00
0.20 -
0.14
0.20
0.20
0.40
0.20
0.41
0.20'
0.60
0.27
0.68
0.20
0.80
0.34
1.01
0.20
1.00
0.41
1.42
0.20
1.19
0.47
1.89
0.20
1.39
0.54
2.43
0.20
1.59
0.61
3.04
0.20
1.79
0.68
3.72
0.20
1.99
0.74
4.46
0.20
2.19
0.81
5.27
0.20
2.39
0.88
6.15
0.20
2.59
0.95
7.10
0.20
2.79
1.01
8.11
0.20
2.99
1.08
9.19
0.20
3.18
1.15
10.34
0.20
3.38
I
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I
11
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1
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Appendix C
1
Developed Condition
100-Yr Runoff Computations
Fort Collins. Colorado
Overland Flow Time of Concentration:
Ti= 1.8(1.1-05)L112 / S1r3
Gutter/Swale Flow. Time of Concentration:
Tt= L / 60V
To= Ti + Tt (5 minute min.)
To= (L/180) + 10 (For the first design point in a series if TC= Ti + Tt yields a larger value)
Intensity, (i) taken from Figure 3-1a of the City of Fort Collins
Storm Drainage Design Criteria and Construction Standards
Calculations BY: J. Miller
Velocity, (V) taken from Figure 3-1
Project: Clock Tower Apartments
Rational Equation: Q= ciA
Date: November 27, 2002
C � "�"���ti��" G�n�nl �luvv
Swwla h'.00 ,b'alloy perl 1
Upstream
�' �•�x '�
Length,L
Slope T, Length,L
Slope's
Velocity,
V
T,
Length,L
Slope,S
N
velocity.v T T,
(fps)
Design
Point
Basins
Time of
Concentration Area, A
(acres)
Runoff
Coefficient
Inlanairy,l
(in/hr)
Flow,p
(cfe)
T.
c
C.
(ft)
N (min) (ft)
N
(fps)
(min)
(1t)
Irw m.v
1
1
0.84
0.82
0.15
20
2.0 230
0.6
1.25
0.0
0,0
0.00 9.1
IBM
3.6
2
2
0,48
0.74
0.15
10
2.0 430
0.5
1.14
0.0
0.0
0.00 10.6
7.54
2.7
y
1-2
1.02
0.78
0.15
0
0.0 0
O.D
0.00
0.0
0.0
0.00 10.8
7.54
8.0
NEW
NEW
D30
0.83
0,15
0
0.0 0
00
)00
0.0
0.0
0.00 g.1
8.00
2.2
F: \DMW %Projects\CTA1CTA-DEVQ.wpd
i M M M Ml it M IM
Page 2 of 2
M M M M a r I.l M =1 1=1 M
M 1101111111 M= M M M= M M a= s M= r M
Developed Condition
2-Yr Runoff Computations
Fort Collins, Colorado
Overland Flow, Time of Concentration:
TI= 1.8(1.1-05)L112 / S1f3
Gutter/Swale Flow, Time of Concentration:
T,= L / 60V
Tc= TI + Tt (5 minute min.)
To= (L/180) + 10 (For the first design point in a series if T,= TI + T, yields a larger value)
Intensity, (i) taken from Figure 3-1 a of the City of Fort Collins
Storm Drainage Design Criteria and Construction Standards
Calculations Bv: J. Miller
Velocity, (V) taken from Figure 3-1
Project: Clock Tower Apartments
Rational Equation: Q= ciA
Date: November 27, 2002
Oveilano Fl,w
Gdnt "Flow
Swale Flow (Vahay Pen)
upstream
-
T1me of
Design
Basins
Concentration
Area, A
Runoff
Velocity,
Point
T,
(acres)
Coefficient
Ce
Length,L
Slope,SJ7,Length,L
Slope.S
V
Lenglh,L
Slope's
VeloGty,V
T
Intenelty,l
mow,p
c
(ft)
(%)
(1t)
N
(fps)
(min)
M
(%)(IrUhr)
(cfe)
1
1
0,54
0.86
015
20
2.0230
0.6
125
��3:,'E
00
0.0
0.00
91
2.29
0.8
2
2
'"0,0
0.46
0.52
0.15
10
2.0430
0.5
114
00
0.0
0.00
10.6
2.16
0.5
2
1-2
10 6 ;
1 02
059
015
0
0.0
0
0.0
0 00
i
gt)'.
00
0.0
0.00
106
21 B
13
NEW
NEW
030
r-5015
0
00
00
COC
0.0•n.,.„�.
03
00
0.00
2.29 1
0.5
F.\DMW1ProjectslCTA\CTA-DEVQ.wpd Page 1 of 2
I
'
Character of Surface
Runoff
Project: Clock Tower Apartments
Coefficient
Calculations By: J. Miller
,
Streets 8 Parking Lots:
Date: November 27, 2002
Paved ...........................
0.93
Gravel ...........................
0.60
t
Drives & Walks .............
0.89
Roofs...........................
0.90
Lawns, Sandy Soil.
0.20
Lawns, Heavy Soil:
0.50
'
Runoff Coefficients are taken from the Urban Storm Drainage Criteria Manual, UDFCD Table 3-1
Basin
Basin
Area of
Area d
Area of Drives
Area of Roofs
Area of Lawn and
Weighted
'
ID
Area
Paved
Gravel
and Walks
Landscape
Runoff
streets
streets
Coefficient
(Acres)
(Acres)
(Acres)
(Acres)
(Acres)
(Acres)
1
0.54
0.23
0.00
0.05
0.13
0.13
0.82
,
2
0.48
0.06
0.00
0.06
0.17
0.19
0.74
1-2
1.02
0.29
0.00
0.11
0.30
0.32
0.78
,
NEW
0.30
0.26
0.00
-0.06
0.10
0.00
0.93
Page 2 of 2
Character of Surface
Runoff
Coefficient
Project: Clock Tower Apartments
Calculations By: J. Miller
Date: November 27, 2002
Streets S Parking Lots:
Paved ...........................
0.87
Gravel ...........................
0.40
Drives & Walks .............
0.87
Roofs ...........................
0.80
Lawns, Sandy Soil:
0.00
Lawns, Heavy Soil:
a05
Runoff Coefficients are taken from the Urban Storm Drainage Criteria Manual, UDFCD Table 3-1
Basin
ID
Basin
Area
(Acres)
Area of
Paved
Streets
(Acres)
Area of
Gravel
Streets
(Acres)
Area of Drives
and Walks
(Acres)
Area of Roots
(Acres)
Area of Lawn and
Landscape
(Acres)
Weighted
Runoff
Coefficient
1
0.54
0.23
0.00
0.05
0.13
0.13
0.66
2
0.48
0.06
0.00
0.06
0.17
0.19
0.52
1-2
1.02
0.29
0.00
0.11
0.30
0.32
0.59
NEW
0.30
0.26
0.00
-0.06
0.10
0.00
0.85
Page 1 of 2
I
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11
n
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I
Appendix B
1
M M r M M M M r M M111111W a M 1W M M r M
Historic Condition
100-Yr Runoff Computations
Fort Collins, Colorado
Overland Flow, Time of Concentration:
T,= 1.8(1.1-05)L112 / S1)3
Gutter/Swale Flow, Time of Concentration:
Tt= L / 60V
Tc= TI + Tt (5 minute min.)
T0= (L/180) + 10 (For the first design point in a series if Tc= Ti + T1 yields a larger value)
Intensity, (i) taken from Figure 3-1 a of the City of Fort Collins
Storm Drainage Design Criteria and Construction Standards
Calculations By: J. Miller
Velocity, (V) taken from Figure 3-1
Project: Clock Tower Apartments
Rational Equation: Q= ciA
Date: November 27, 2002
Overland Plow
Gutter Pow
h
$wale Flow (Val�ay Pon) +
Upstream
Tlme of
Design
Basins
Concentration
Area. A
Runoff
Velocity,
Point
(acres)
coefficientF01
Lengtn,L
Slope,S T,
Lengti
Slcpe,S
V
T
Lengtn,L
Slope,$ voice y,V T To
Intenslty,l
Flow
To
c
m)
N (min)
(it)
N
(fps)
(min)
(fp N (fps) ,,,�„ m+n
flni
(cfs)
1
1
%u. ';W
1.02
0.66
10
q
2.0
430
0.5
114
0,0
0.0
0.00
1G.6
7.54
5.1
OLD
OLD
x ,r `
0.72
0.69
0
0.0 �,
0
D.0
0.00
�
0.0
0.0
0.00
10.0
7.54
3.7
NEW
NEW
.a +!`
0.30
0.56
0
0.0
0
0.0
0000.
0.0
OA
0.00
10.6
7.64
1.3
F:1DMW1ProjectskCTA1CTA-HSTD.wpd Page 2 of 2
Historic Condition
2-Yr Runoff Computations
Fort Collins, Colorado
Overland Flow Time of Concentration:
Ti= 1.8(1.1-05)L1/2 / S1f3
Gutter/Swale Flow, Time of Concentration:
T,= L / 60V
Tc= T, + Tt (5 minute min.)
Tc= (L/180) + 10 (For the first design point in a series if Tc= TI + Tt yields a larger value)
Intensity, (i) taken from Figure 3-1 a of the City of Fort Collins
Storm Drainage Design Criteria and Construction Standards
Calculations Bv: J. Miller
Velocity, (V) taken from Figure 3-1
Project: Clock Tower Apartments
Rational Equation: Q= ciA
Date: November 27, 2002
'Ixr ?m1
FI
iuWF
+ '.,q„
Raw
"^
Upstream
iT,
,.' x, h-.
, 4,
NaT
,w
... -
Length,L
Slope's T,
Length,L
Slopes
Velocity,
V
T,
Length,L
velocity,v
T
Design
Point
Basins
Tlme of
Concentrallon
Area. A
(acres)
Runoff
Coefficient
Slopes
T.
Intenaity,i
Flow,Q
T,
c
C,
(ft)
N (min)
Ot)
N
(fps)
(min)
(ft)
N
(fps)
cmm
n,.n
(Inthr)
(cis)
1.02
0,36
0,15
10
2,0
430
05
1.14
'6.3
0.0
0.0
0.00
10.6
2.16
0.8
OLD
OLD
0.72
042
0,15
0
0,0
0
0.0
0.00
0.0
0.0
0.0
0.00
10.4
2.1E
0.7
NEW
NEN
n
v'a'� �. Q'dr
0.30
021
0.15
0
00 .-.v,d
0
00
000
00
0.0
0.0
000
PRIM
10.6
1 2.1E
0,1
F:\DMW\Projects\CTA\CTA-HSTQ.wpd
Page 1 of 2
M M M M M M M
Historic Condition - 100 Year
Character of Surface
Runoff
Coefficient
Project: Clock Tower Apartments
Calculations By: J. Miller
Date: November 27, 2002
Streets & Parking Lots:
Paved ...........................
0.93
Gravel ...........................
0,60
Drives & Walks .............
0.89
Roofs ...........................
0.90
Lawns, Sandy Soil:
0.20
Lawns, Heavy Soil:
0.50
Runoff Coefficients are taken from the Urban
Storm Drainage Criteria Manual, UDFCD Table 3-1
Basin
ID
Basin
Area
(Acres)
Area of
Paved
Streets
(Acres)
Area of
Gravel
Streets
(Acres)
Area of Drees
and Walks
(Acres)
Area of Rods
(Acres)
Area of Lawn and
Landscape
(Acres)
Weighted
Runoff
Coefficient
1
1.02
&03
0.00
0.17
0.20
0.62
0.66
Otte
0.72
0.03
0.00
0.11
0.20
0.38
0.69
NEW
0.30
0.00
0.00
0.06
0.00
0.24
0.58
Page 2 of 2
Historic Condition - 2 Year
_ i.o177f?osile
f'CCIn ol-F LOUT 10111VIVrit Laa7PNC.GiIdCAVY'fJ
Character of Surface
Runoff
Coefficient
Project: Clock Tower Apartments
Calculations By J. Miller
Date: November 27, 2002
Sheets & Parking Lots.
Paved ...........................
0.87
Gravel...........................
0.40
Drives & Walks .............
0.87
Roofs ...........................
0.80
Lawns, Sandy Soil:
0.00
Lawns, Heavy Soil:
0-05
Runoff Coefficients are taken from the Urban Storm Drainage Criteria Manual, UDFCD Table 3-1
Basin
ID
Basin
Area
(Acres)
Area of
Paved
Streets
(Acres)
Area of
Gravel
Streets
(Acres)
Area of Drives
and Walks
(Acres)
Area of Roofs
(Acres)
Area of lawn and
landscape
(Acres)
Weighted
Runoff
Coefficient
1
1.02
0.03
0.00
0.17
0.20
0.62
0.36
OLD
0.72
0.03
0-00
0.11
0.20
0.38
0.42
NEW
0.30
0.00
0.00
0.06
0.00
0.24
0.21
Page 1 of 2
f/20/02
216.00
d By -
I
0
a
0
e
0
�a
0
0
u
A
J
I 2 4 6 10 20
Average velocity (ft/sec)
(216VI-TR-6,9, Second Ed„ June 19M)
FIGURE 3-1
AVERAGE VELOCITIES
FOR SHALLOW
CONCENTRATED FLOW
EQUATION FOR FIGURE 3-1:
PAVED: V=16.1345(s)0.5
UNPAVED: V=20.3282(s)0.5
s= slope in ft/ft
i
DAVIS, MILLER & WOHNRADE
CIVIL ENGINEERS, INC. \
1� West 29th Stme ln�dond, Celmede, 90578
PN : (970}161-2B61, F. (970N61-2665
1
Sheet
1
Sheets
1
City of Fort Collins
Rainfall Intensity -Duration -Frequency Table
for using the Rational Method
(5 minutes - 30 minutes)
Figure 3-1a
M
ear
nsity
hr
10-yeas
Intensity
in/hr
100-rear
Intensity
in/hr85
4.87
9.95
67
4.56
9.31
7.00
2.52
4.31 1
8.80
8.00
2.40
4.10
8.38
9.00
2.30
3.93
8.03
10.00
2.21
3.78
7.72
11.00
2.13
3.63
7.42
12.00
2.05
3.50
7.16
13.00
1.98
3.39
6.92
14.00
1.92
3.29
6.71
15.-00
1.87
3.19
6.52
16.00
1.81
3.08
6.30
17.00
1.75
2.99
6.10
18.00
1.70
2.90
5.92
19.00
1.65
2.82
5.75
20.00
1.61
2.74
5.60
21.00
1.56
2.67
5.46
22.00
1.53
2.61
5.32
23.00
1.49
2.55
5.20
24.00
1.46
2.49
5.09
2.44
4.98
2.39
4.87
2.34
4,78
M
2.29
4.69
2.25
4.60
2.21
4.52
Table 3-3
RATICNAL MCTROD RC MY COEFFICIENTS FOR CCIVOS= ANALYSIS
Character of Surfacs Runoff Coefficient
Streets, Parking Lots, Drives:
Aspha;t......................................
0.95
Concrete .....................................
0.95
Gravel .......................................
0.50
Roofs ..........................................
0.95
Lawns, Sandy Soil:
Flat<2%.....................................
0.10
Average 2 to 7%..............................
0.15
Steep >7%....................................
0.20
Lawns, Heavy Soil:
Flat <2%.....................................
0.20
Average.2 to 7%..............................
0.25
Steep>7%.....................................
0.35
Table 3-i
RATIONAL METHM FREQUn= ADJUSTMENT FACTORS
Storm Return Period Frequency Factor
(years) Cr
2 to 10 1.00
11 to 25 1.10
26 to 50 1.20
51 to 100 1.25
Note: The product of C times Cr shall not exceed 1.00
No Text
B I R C H S T R E E T
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PROPOSED SU0D1
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Drainage Design Considerations
' Clock Tower Apartments
November 27, 2002
1 REFERENCES
DMW Civil Engineers, Inc.
1) Storm Drainage Desiqn Criteria and Construction Standards, City of Fort
Collins, Colorado, May, 1997, revised 1999
2) Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control
District, Wright McLaughlin Engineers, Denver, Colorado, March, 1969.
Page 5
I
Drainage Design Considerations
Clock Tower Apartments
November 27, 2002
DMW Civil Engineers, Inc.
VII. WATER QUALITY
7.1 Porous Landscape Detention
The porous landscape detention consists of a low lying vegetated area underlain
by a sand bed. This BMP allows water quality containment volume below the invert
of the detention pond outlet. Accumulated runoff ponds in the vegetated zone and
gradually infiltrates into the underlying sand bed and subgrade. A total water
quality containment volume of 434 cubic feet is provided for the added impervious
areas of the redeveloped site.
Vlll. CONCLUSIONS
8.1 Compliance with Standards
All drainage analyses have been performed according to the City of Fort Collins'
Storm Drainage Design Criteria and Construction Standards manual and the Urban
Storm Drainage Criteria Manual, Volume 3, by the Urban Drainage and Flood
Control District.
Page 4
I
Drainage Design Considerations
Clock Tower Apartments
November 27, 2002
DMW Civil Engineers, Inc.
V. DESIGN CRITERIA
5.1 Design References
Drainage design criteria specified in the City of Fort Collins Storm Drainage Design
Criteria and Construction Standards manual and the Urban Storm Drainage Criteria
Manual, Volume 3 by the Urban Drainage and Flood Control District have been
referenced in the preparation of this study.
5.2 Hydrologic Criteria
The rational method has been used to estimate peak stormwater runoff from the
project site. An initial 2-year and major 100-year design storms have been used to
evaluate the proposed drainage system. Calculations made as part of this
' investigation, along with other supporting material, are contained in AppendixA and
B.
Rainfall intensity data for the rational method has been taken from rainfall intensity
data tables contained in the City of Fort Collins Storm Drainage Design Criteria and
Construction Standards manual (see Figure 3-1a). Composite runoff coefficients
were generated using Table 3-3 and 3-4 of the City of Fort Collins Storm Drainage
Design Criteria and Construction Standards manual.
5.3 Hydraulic Criteria
The computer program "Flowmaster" has been used to analyze the capacity of
proposed pipes and chases for the site. Also, the computer program "Watershed
Modeling Module" by Eagle Point Software has been used in the design of
proposed detention ponds. Riprap proposed for the site was analyzed with the use
of the computer model "HY8" by the U.S. Department of Transportation, Federal
Highway Administration.
VI. EROSION CONTROL
6.1 Erosion Control Plan and Criteria
The erosion control plan presented here is intended to control rainfall erosion. The
Erosion Control Reference Manual for Construction Sites (ECRM), City of Fort
Collins, has been referenced for this erosion control plan.
The proposed rainfall erosion control plan during construction will consist of
temporary structural erosion control measures. Temporary sediment control
consisting of silt fencing will surround areas of the proposed construction. See the
Grading and Erosion Control Plan for locations of proposed erosion control
measures.
Page 3
P
Drainage Design Considerations DMW Civil Engineers, Inc.
Clock Tower Apartments
November 27, 2002
' 3.2 Historic Drainage Basins
The site contains one onsite historic drainage basin, Basin H1 (See Exhibit 1).
Basin H1 (1.02 acres) drains overland from southwest to northeast as described in
' the previous paragraph. The 2 and 100 year discharges at Design Point H 1 are 0.8
cfs and 5.1 cfs respectively.
VI. DEVELOPED CONDITIONS
4.1 Proposed Site Development
Development of the Clock Tower Apartments site will consist of conversion of the
existing fraternity house along with new construction to create a 24 unit, multi -family
residence. The proposed site infrastructure includes onsite parking and stormwater
utilities.
4.2 Developed Drainage Patterns
The developed site has been divided into two (2) onsite drainage basins.
Stormwater runoff will be conveyed overland to an onsite detention and water
quality pond and released into Wagner Drive. The peak 100-year developed
discharge from the new impervious area added to the site will be released at a
historic 2-year rate.
Runoff from Basin 1 (0.54 acres) drains overland and through concrete chases and
pans to Detention Pond 1. The peak 2 and 100-year inflows to Pond 1 are 0.8 and
3.5 cfs respectively.
Runoff from Basin 2 (0.48 acres) drains overland onto local streets. The peak 2
and 100-year flows from Basin 2 are 0.5 and 2.7 cfs respectively.
Added impervious areas are tabulated separately on the accompanying tables as
"New" and account for peak 2 and 100-year flows of 0.6 and 2.2 respectively. The
historic peak 2 and 100-year flows from these same areas were 0.1 and 1.3 cfs
respectively.
4.3 Detention Pond 1
Detention Pond 1 is located in the southeast corner of the site adjacent to Wagner
Drive. Pond 1 will utilize a single stage release consisting of an 8" diameter orifice.
In addition to water quality containment volume, Pond 1 detains the peak 100-year
developed discharge from the new impervious area added to the site and releases
it at the historic 2-year rate for that respective area. The maximum 100-year
release from Pond 1 is 1.4 cfs with an associated water surface elevation of
5031.54.
Page 2
Drainage Design Considerations
for
Clock Tower Apartments
Fort Collins, Colorado
November 27, 2002
I. INTRODUCTION
1.1 Objective
This study documents the results of a comprehensive hydrologic and hydraulic
analysis of both pre and post -development conditions for the proposed Clock Tower
Apartments development. The utility plans which accompany this report are entitled
Final Construction Plans for Clock Tower Apartments prepared by Davis, Miller &
Wohnrade Civil Engineers, Inc.
1.2 Project History and Previous Studies
The Clock Tower Apartments site was formerly the Sigma Nu Fraternity building.
The site is within the Old Town drainage basin but not within any regulatory
floodplains. The City has no drainage study on file for this site.
1.3 Mapping and Surveying
Field survey information and topographic mapping with a contour interval of 1-foot
was obtained by Davis, Miller & Wohnrade Civil Engineers from Stewart &
Associates, Fort Collins, Colorado. Additional topography outside of the project
boundary was taken from USGS topographic mapping with a ten (10) foot contour
interval.
II SITE LOCATION AND DESCRIPTION
2.1 Site Location
The site is located in the northeast quarter of Section 15, Township 7 North, Range
69 West of the 6th Principal Meridian in the Town of Fort Collins, Colorado and is
described as Lot 7, Wagner Fraternity Park. The site is bounded by Wagner Drive
on the east and Birch Street on the North (See Vicinity Map).
2.2 Site Description
The Clock Tower Apartments site is approximately 1.02 acres. The site has
historically been used as a fraternity building with appurtenances including a
volleyball pit and a courtyard.
111. HISTORIC CONDITIONS
3.1 Historic Drainage Patterns
Stormwater runoff from the Clock Tower Apartments site drains overland generally
from southwest to northeast at slopes ranging from 0.5% to 25% toward existing
roadways. Stormwater runoff is conveyed from the site towards the east in roadway
gutters.
Clods Tower Apartments - Fort Collins, Colorado
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Drainage Design Considerations
for
Clock Tower Apartments
EXHIBITS
Exhibit 1 Clock Tower Apartments Historic Condition Plan
Exhibit 2 Clock Tower Apartments Drainage Plan
APPENDICES
Appendix A:
Historic Condition Hydrology
Appendix B:
Developed Condition Hydrology
Appendix C:
Detention Pond Rating and Routing
Appendix D:
Erosion Control Calculations
Appendix E:
Water Quality Calculations
Drainage Design Considerations for
Clock Tower Apartments
TABLE OF CONTENTS
VICINITY MAP
I
INTRODUCTION Page No.
1.1 Objective.........................................................__...........................
1.2 Project History and Previous Studies
1
..............................................
1.3 Mapping and Surveying
1
...................................................................
1
II
SITE LOCATION AND DESCRIPTION
2.1 Site Location
....................................................................................
2.2 Site Description
1
...............................................................................
1
III
HISTORIC CONDITIONS
3.1 Historic Drainage Patterns
...............................................................
3.2 Historic Drainage Basins.................................................................
1
2
IV
DEVELOPED CONDITIONS
4.1 Proposed Site Development
............................................................
4.2 Developed Drainage Patterns
2
.........................................................
4.3 Detention Pond 1
2
.............................................................................
2
V
DESIGN CRITERIA
5.1 Design References
..........................................................................
5.2 Hydrologic Criteria
3
.......................
5.3 Hydraulic Criteria
.............................................................................
3
VI
EROSION CONTROL
6.1 Erosion Control Plan and Criteria
....................................................
3
VII
WATER QUALITY
7.1 Porous Landscape Detention
..........................................................
4
VIII
CONCLUSIONS
8.1 Compliance with Standards
................. .........................
4
REFERENCES...........................................................................................
5
I
DMW
Davis, M/ller * Wohnrade Civil Engineers, Inc
November 27, 2002
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
Re: Drainage Design Considerations for
Clock Tower Apartments
Fort Collins, Colorado
Dear Staff:
1 435 W. 29'h Street, Loveland, Colorado 80538
Phone: 970-46 1-2661 , Fax: 970-46 I -2665
Davis, Miller & Wohnrade Civil Engineers, Inc. (DMW) is pleased to submit this drainage
study for Clock Tower Apartments for your review. This report complies with technical
criteria set forth in the City of Fort Collins' Storm Drainage Design Criteria and
Construction Standards manual and the Urban Storm Drainage Criteria Manual, Volume
3, by the Urban Drainage and Flood Control District.
We acknowledge that the City of Fort Collins' review of this study is only for general
conformance with submittal requirements, current design criteria and standard engineering
principles and practices.
If you should have any questions or comments as you review this report, please feel free
to contact me at your convenience.
Sincerely,
DAVIS, MILLER & WOHNRADE CIVIL ENGINEERS, INC.
W,affial
Jade P. Miller, P.E. (CO #33885)
Project Manager
Drainage Design Considerations
for
Clock Tower Apartments
Fort Collins, Colorado
November 27, 2002
Prepared for:
Barbara Seik
P.O. Box 1613
Fort Collins, Colorado 80522
Prepared by:
DMW
Davis, Miller & Wohnrade Civil Engineers, Inc.
1435 W. 29' Street
Loveland, Colorado 80538
Phone: (970)461-2661
Fax: (970)461-2665
I
Project Number: 0218.00-CTA
I