HomeMy WebLinkAboutFRONT RANGE COMMUNITY COLLEGE SOUTH PARKING LOT EXPANSION - SPAR - SPA130004 - REPORTS - DRAINAGE REPORTBOULDER I FORT COLLINS I WINTER PARK
JVA, Incorporated
25 Old Town Square
Suite 200
Fort Collins, CO 80524
Ph: 970.225.9099
Fax: 970.225.6923
Toll Free: 877.444.1951
Web site:
www.jvajva.com
E-mail:
info@jvajva.com
October 15, 2013 (Updated 11/2/13)
Mr. Derek Brown
AVP Facilities Planning and Management
Front Range Community College
RE: FRCC Larimer Campus – South Parking Lot
Drainage Intent Letter for SPAR (Updated)
JVA Job No. 1990.3c
Dear Derek:
In our previous drainage intent letter, we made reference to the addendum to FRCC’s Master
Drainage Study prepared by Interwest. Upon further review and comments received, two errors
in the previous intent letter should be noted. First being that the referenced water quality and
detention volumes were associated with the proposed improvements north of the existing
irrigation ditch, which was referenced in error as the south side of the irrigation ditch. The
second correction that came to our attention was that the interim/ultimate conditions described in
the addendum were both in reference to the improvements to the north side of the irrigation
ditch. So the water quality and detention volumes were referenced in error to be the interim
conditions, and the design will require additional volume to achieve the City of Fort Collins
Drainage criteria. For the purposes of this letter and response to Clarendon Hills HOA
comments, we have completed additional detailed calculations to confirm the necessary drainage
infrastructure required.
Similarly as previously stated, JVA is currently in process of working with Oz Architecture and
Front Range Community College (FRCC) on the design of a parking lot located within the
vacant lot at the northeast corner of Clarendon Hills Drive and South Shields Street. The parking
lot is proposed to be constructed in two phases; both being located north of the existing private
irrigation lateral crossing the property. The first phase will approximately consist of 256 parking
spaces and the second phase approximately consisting of 148 parking spaces. FRCC’s intent is
to construct the first phase of parking in the near future, possibly spring of 2014. The second
phase of parking is not currently budgeted and does not have an anticipated schedule, to our
knowledge, at this time. For the consideration of future planning, FRCC has submitted both
phases of parking improvements with the SPAR submittal.
The intent of this parking lot project is to provide detention such that the runoff associated
proposed parking lot improvements will be detained, treated for water quality, and released at the
2-yr historic release rate. This would be achieved by creating a detention pond, proposed to be
located on the existing FRCC campus, south of the existing parking lot. The detained runoff
would be released to the existing swale that runs along the south side of the existing parking lot,
to the regional (campus regional) detention facility. We anticipate achieving the necessary
volume within the proposed pond without any modifications to the existing regional pond. The
existing site currently drains from the southwest to the northeast and the proposed improvements
will not alter the historic drainage path. We have performed additional conceptual analysis to
FRCC Larimer Campus – South Parking Lot
October 15, 2013 (Updated 11/2/13)
Page 2 of 2
estimate the required water quality and detention volumes. In reference to these calculations, the
parking lot project would need to provide 0.11 acre-ft of water quality volume and 1.0 acre-ft of
detention volume. Permeable pavers are proposed within the parking lot. The City of Fort
Collins allows up to 40% of the drainage course volume below the permeable pavers to account
for detention volume. Based on our early assumptions, the permeable pavers would provide 0.19
acre-ft of storage. Reducing this from the 100-yr detention volume, 0.81 acre-ft of detention
volume will need to be provided in the water quality/detention pond. With the incorporation of
the permeable pavers and the porous landscape detention swale, we anticipate combining the
water quality and detention volumes, rather than adding the two to determine the pond volume.
To achieve the necessary detention volumes, two interconnected ponds are proposed. The
preliminary calculations are attached for reference. All computations will be confirmed with the
final design.
The design team and FRCC’s intend to implement Low Impact Development techniques where
reasonably achievable. Conceptually we are proposing utilizing permeable pavers within the
parking lot and will be located to collect and treat as much parking lot runoff as possible. In
addition, we are anticipating utilizing an area between parking for Porous Landscape Detention
for additional water quality treatment. This is in addition to the water quality/detention pond that
will be design with a controlled outlet structure per City of Fort Collins and Urban Drainage
design criteria.
All final computations will be available for reference when the project is complete. Please let us
know if you have any additional concerns with the drainage intent for this project that we should
anticipate incorporating.
As always, we appreciate your assistance and please do not hesitate to call if you have any
questions/comments/concerns.
Sincerely,
JVA, INCORPORATED
By: ____________________________________
Jason T. Claeys, PE, LEED AP
Project Manager
Attachments: Preliminary % impervious calculations
Historic runoff calculations (UD_Detention.xls)
Developed runoff and detention volume calculations (UD_Detention.xls)
Water Quality Volume Calculation
Proposed Pond Stage Storage Calculations.
South Parking Lot Basin
Boundary (4.81 Acres)
Permeable
Pavers (typ)
Porous Landscape
Detention
Water Quality/
Detention Ponds
Existing Irrigation Ditch
Existing Drainage Swale
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Hydrologic Soil Group—Larimer County Area, Colorado
(FRCC South Parking Lot Expansion)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2013
Page 1 of 4
4485330 4485360 4485390 4485420 4485450 4485480 4485510
4485330 4485360 4485390 4485420 4485450 4485480 4485510
491840 491870 491900 491930 491960 491990 492020 492050 492080 492110 492140
491840 491870 491900 491930 491960 491990 492020 492050 492080 492110 492140
40° 31' 13'' N
105° 5' 47'' W
40° 31' 13'' N
105° 5' 33'' W
40° 31' 6'' N
105° 5' 47'' W
40° 31' 6'' N
105° 5' 33'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 20 40 80 120
Meters
Map Scale: 1:1,480 if printed on A landscape (11" x 8.5") sheet.
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
4 Altvan-Satanta loams, 3
to 9 percent slopes
B 2.7 45.1%
56 Kim-Thedalund loams, 3
to 15 percent slopes
B 0.8 12.9%
74 Nunn clay loam, 1 to 3
percent slopes
C 0.1 1.4%
76 Nunn clay loam, wet, 1 to
3 percent slopes
C 2.4 40.6%
Totals for Area of Interest 5.9 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer
at or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Hydrologic Soil Group—Larimer County Area, Colorado FRCC South Parking Lot Expansion
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2013
Page 3 of 4
FRCC South Parking Lot Expansion
COMPOSITE C AND IMPERVIOUS AREA CALCULATION
Project Number: 1990c
Design Engineer: JTC
Date: 11/2/2013
DESIGN CRITERIA:
Urban Storm Drainage Criteria Manual by Urban Drainage and Flood Control District, June 2001
City of Fort Collins
BASINS:
Composite C values obtained from Table RO-11 in the City of Fort Collins Storm Drainage Criteria Manual Ammendments
Hydrologic Soil Group (HSG) Type C
C2
C10
C100
% Impervious
2-year &
5-year
100-year
Sub-basin Atotal
Atotal
Apaved
Aroof
Apasture/grass
Apavers/Gravel
Agreenbelt
Percent
Designation (acres) (sq. ft) (acres) (acres) (acres) (acres) (acres) C2
C10
C100
Impervious
South Parking 4.81 209,598 2.87 0.00 1.63 0.32 0.00 0.68 0.68 0.74 62.21%
Permeable Pavers 0.50 0.50 0.63 40.0%
COMPOSITE
Lawns (Heavy, 2-7%)
Historic Flow Analysis
0.25 0.25 0.31 2.0%
C VALUE
Paved Areas
Lawns (Heavey 2-7%)
0.95
0.25
Roofs 0.95
0.25
0.95
0.95
0.31
1.00 100.0%
0.0%
1.00 90.0%
Return Period
Frequency Adjustment
Factor (Cf
)
1.00
1.25
1990c Rational - South Parking Lot-CoFC Runoff Coef.xlsx - COMPOSITE C
Page 1 of 1
JVA, Inc.
Project:
Basin ID:
Design Information (Input): Design Information (Input):
Catchment Drainage Imperviousness Ia = 2.00 percent Catchment Drainage Imperviousness Ia = 2.00 percent
Catchment Drainage Area A = 4.810 acres Catchment Drainage Area A = 4.810 acres
Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C A, B, C, or D
Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc = 10 minutes Time of Concentration of Watershed Tc = 10 minutes
Allowable Unit Release Rate q = 0.13 cfs/acre Allowable Unit Release Rate q = 0.13 cfs/acre
One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P1 = 2.86 inches
Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3
Coefficient One C1 = 28.50 Coefficient One C1 = 28.50
Coefficient Two C2 = 10 Coefficient Two C2 = 10
Coefficient Three C3 = 0.787 Coefficient Three C3 = 0.787
Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C = 0.06 Runoff Coefficient C = 0.51
Inflow Peak Runoff Qp-in = 0.64 cfs Inflow Peak Runoff Qp-in = 18.94 cfs
Allowable Peak Outflow Rate Qp-out = 0.64 cfs Allowable Peak Outflow Rate Qp-out = 0.64 cfs
Mod. FAA Minor Storage Volume = 48 cubic feet Mod. FAA Major Storage Volume = 33,585 cubic feet
Mod. FAA Minor Storage Volume = 0.001 acre-ft Mod. FAA Major Storage Volume = 0.771 acre-ft
5 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet
(input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output)
5 2.78 0.006 1.00 0.64 0.004 0.001 5 9.68 0.164 1.00 0.64 0.004 0.159
10 2.21 0.009 1.00 0.64 0.009 0.000 10 7.72 0.261 1.00 0.64 0.009 0.252
15 1.86 0.011 0.83 0.53 0.011 0.000 15 6.48 0.328 0.83 0.53 0.011 0.317
20 1.61 0.013 0.75 0.48 0.013 0.000 20 5.61 0.379 0.75 0.48 0.013 0.366
25 1.43 0.014 0.70 0.45 0.015 -0.001 25 4.97 0.420 0.70 0.45 0.015 0.405
30 1.28 0.015 0.67 0.43 0.018 -0.002 30 4.48 0.454 0.67 0.43 0.018 0.436
35 1.17 0.016 0.64 0.41 0.020 -0.004 35 4.08 0.483 0.64 0.41 0.020 0.463
40 1.08 0.017 0.63 0.40 0.022 -0.005 40 3.76 0.508 0.63 0.40 0.022 0.486
45 1.00 0.018 0.61 0.39 0.024 -0.006 45 3.48 0.530 0.61 0.39 0.024 0.506
50 0.93 0.019 0.60 0.38 0.026 -0.008 50 3.25 0.550 0.60 0.38 0.026 0.523
55 0.88 0.019 0.59 0.38 0.029 -0.010 55 3.06 0.568 0.59 0.38 0.029 0.539
60 0.83 0.020 0.58 0.37 0.031 -0.011 60 2.88 0.584 0.58 0.37 0.031 0.554
65 0.78 0.020 0.58 0.37 0.033 -0.013 65 2.73 0.600 0.58 0.37 0.033 0.567
70 0.74 0.021 0.57 0.37 0.035 -0.015 70 2.60 0.614 0.57 0.37 0.035 0.579
75 0.71 0.021 0.57 0.36 0.037 -0.016 75 2.47 0.627 0.57 0.36 0.037 0.590
80 0.68 0.022 0.56 0.36 0.040 -0.018 80 2.37 0.639 0.56 0.36 0.040 0.600
85 0.65 0.022 0.56 0.36 0.042 -0.020 85 2.27 0.651 0.56 0.36 0.042 0.609
90 0.62 0.022 0.56 0.36 0.044 -0.022 90 2.18 0.662 0.56 0.36 0.044 0.618
95 0.60 0.023 0.55 0.35 0.046 -0.024 95 2.10 0.673 0.55 0.35 0.046 0.626
100 0.58 0.023 0.55 0.35 0.049 -0.025 100 2.02 0.683 0.55 0.35 0.049 0.634
105 0.56 0.023 0.55 0.35 0.051 -0.027 105 1.95 0.692 0.55 0.35 0.051 0.641
110 0.54 0.024 0.55 0.35 0.053 -0.029 110 1.89 0.701 0.55 0.35 0.053 0.648
115 0.52 0.024 0.54 0.35 0.055 -0.031 115 1.83 0.710 0.54 0.35 0.055 0.655
120 0.51 0.024 0.54 0.35 0.057 -0.033 120 1.77 0.718 0.54 0.35 0.057 0.661
125 0.49 0.024 0.54 0.35 0.060 -0.035 125 1.72 0.726 0.54 0.35 0.060 0.667
130 0.48 0.025 0.54 0.34 0.062 -0.037 130 1.67 0.734 0.54 0.34 0.062 0.672
135 0.47 0.025 0.54 0.34 0.064 -0.039 135 1.63 0.741 0.54 0.34 0.064 0.678
140 0.45 0.025 0.54 0.34 0.066 -0.041 140 1.58 0.749 0.54 0.34 0.066 0.683
145 0.44 0.025 0.53 0.34 0.068 -0.043 145 1.54 0.756 0.53 0.34 0.068 0.687
150 0.43 0.026 0.53 0.34 0.071 -0.045 150 1.50 0.762 0.53 0.34 0.071 0.692
155 0.42 0.026 0.53 0.34 0.073 -0.047 155 1.47 0.769 0.53 0.34 0.073 0.696
160 0.41 0.026 0.53 0.34 0.075 -0.049 160 1.43 0.775 0.53 0.34 0.075 0.700
165 0.40 0.026 0.53 0.34 0.077 -0.051 165 1.40 0.782 0.53 0.34 0.077 0.704
170 0.39 0.027 0.53 0.34 0.079 -0.053 170 1.37 0.788 0.53 0.34 0.079 0.708
175 0.38 0.027 0.53 0.34 0.082 -0.055 175 1.34 0.794 0.53 0.34 0.082 0.712
Project:
Basin ID:
Design Information (Input): Design Information (Input):
Catchment Drainage Imperviousness Ia = 62.21 percent Catchment Drainage Imperviousness Ia = 62.21 percent
Catchment Drainage Area A = 4.810 acres Catchment Drainage Area A = 4.810 acres
Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C A, B, C, or D
Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc = 10 minutes Time of Concentration of Watershed Tc = 10 minutes
Allowable Unit Release Rate q = 0.13 cfs/acre Allowable Unit Release Rate q = 0.13 cfs/acre
One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P1 = 2.86 inches
Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3
Coefficient One C1 = 28.50 Coefficient One C1 = 28.50
Coefficient Two C2 = 10 Coefficient Two C2 = 10
Coefficient Three C3 = 0.787 Coefficient Three C3 = 0.787
Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C = 0.42 Runoff Coefficient C = 0.64
Inflow Peak Runoff Qp-in = 4.47 cfs Inflow Peak Runoff Qp-in = 23.77 cfs
Allowable Peak Outflow Rate Qp-out = 0.64 cfs Allowable Peak Outflow Rate Qp-out = 0.64 cfs
Mod. FAA Minor Storage Volume = 4,909 cubic feet Mod. FAA Major Storage Volume = 43,688 cubic feet
Mod. FAA Minor Storage Volume = 0.113 acre-ft Mod. FAA Major Storage Volume = 1.003 acre-ft
5 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet
(input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output)
5 2.78 0.039 1.00 0.64 0.004 0.034 5 9.68 0.205 1.00 0.64 0.004 0.201
10 2.21 0.062 1.00 0.64 0.009 0.053 10 7.72 0.327 1.00 0.64 0.009 0.319
15 1.86 0.078 0.83 0.53 0.011 0.067 15 6.48 0.412 0.83 0.53 0.011 0.401
20 1.61 0.090 0.75 0.48 0.013 0.076 20 5.61 0.476 0.75 0.48 0.013 0.463
25 1.43 0.099 0.70 0.45 0.015 0.084 25 4.97 0.527 0.70 0.45 0.015 0.512
30 1.28 0.107 0.67 0.43 0.018 0.090 30 4.48 0.569 0.67 0.43 0.018 0.552
35 1.17 0.114 0.64 0.41 0.020 0.094 35 4.08 0.606 0.64 0.41 0.020 0.586
40 1.08 0.120 0.63 0.40 0.022 0.098 40 3.76 0.637 0.63 0.40 0.022 0.615
45 1.00 0.125 0.61 0.39 0.024 0.101 45 3.48 0.665 0.61 0.39 0.024 0.641
50 0.93 0.130 0.60 0.38 0.026 0.103 50 3.25 0.690 0.60 0.38 0.026 0.663
55 0.88 0.134 0.59 0.38 0.029 0.105 55 3.06 0.713 0.59 0.38 0.029 0.684
60 0.83 0.138 0.58 0.37 0.031 0.107 60 2.88 0.733 0.58 0.37 0.031 0.702
65 0.78 0.142 0.58 0.37 0.033 0.109 65 2.73 0.752 0.58 0.37 0.033 0.719
70 0.74 0.145 0.57 0.37 0.035 0.110 70 2.60 0.770 0.57 0.37 0.035 0.735
75 0.71 0.148 0.57 0.36 0.037 0.111 75 2.47 0.787 0.57 0.36 0.037 0.749
80 0.68 0.151 0.56 0.36 0.040 0.111 80 2.37 0.802 0.56 0.36 0.040 0.763
85 0.65 0.154 0.56 0.36 0.042 0.112 85 2.27 0.817 0.56 0.36 0.042 0.775
90 0.62 0.156 0.56 0.36 0.044 0.112 90 2.18 0.831 0.56 0.36 0.044 0.787
95 0.60 0.159 0.55 0.35 0.046 0.113 95 2.10 0.844 0.55 0.35 0.046 0.798
100 0.58 0.161 0.55 0.35 0.049 0.113 100 2.02 0.857 0.55 0.35 0.049 0.808
105 0.56 0.163 0.55 0.35 0.051 0.113 105 1.95 0.868 0.55 0.35 0.051 0.818
110 0.54 0.166 0.55 0.35 0.053 0.113 110 1.89 0.880 0.55 0.35 0.053 0.827
115 0.52 0.168 0.54 0.35 0.055 0.112 115 1.83 0.891 0.54 0.35 0.055 0.836
120 0.51 0.170 0.54 0.35 0.057 0.112 120 1.77 0.901 0.54 0.35 0.057 0.844
125 0.49 0.171 0.54 0.35 0.060 0.112 125 1.72 0.911 0.54 0.35 0.060 0.852
130 0.48 0.173 0.54 0.34 0.062 0.112 130 1.67 0.921 0.54 0.34 0.062 0.859
135 0.47 0.175 0.54 0.34 0.064 0.111 135 1.63 0.930 0.54 0.34 0.064 0.867
140 0.45 0.177 0.54 0.34 0.066 0.111 140 1.58 0.940 0.54 0.34 0.066 0.873
145 0.44 0.178 0.53 0.34 0.068 0.110 145 1.54 0.948 0.53 0.34 0.068 0.880
150 0.43 0.180 0.53 0.34 0.071 0.109 150 1.50 0.957 0.53 0.34 0.071 0.886
155 0.42 0.182 0.53 0.34 0.073 0.109 155 1.47 0.965 0.53 0.34 0.073 0.892
160 0.41 0.183 0.53 0.34 0.075 0.108 160 1.43 0.973 0.53 0.34 0.075 0.898
165 0.40 0.185 0.53 0.34 0.077 0.107 165 1.40 0.981 0.53 0.34 0.077 0.904
170 0.39 0.186 0.53 0.34 0.079 0.107 170 1.37 0.988 0.53 0.34 0.079 0.909
175 0.38 0.187 0.53 0.34 0.082 0.106 175 1.34 0.996 0.53 0.34 0.082 0.914
FRCC South Parking Lot Expansion
Water Quality Pond and Outlet Sizing (Per USDCM)
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA:
REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV):
Tributary Area, A 4.5 acres
Composite. Imperviousness, I 62.2%
WQCV (watershed inches) 0.244 inches 40-Hour Drain Time (Fig SQ-2)
Required WQCV 0.110 acre-feet Including 20% for Sedimentation
WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3):
Design Water Quality Depth, DWQ
2.72 ft
Determine K40
K40
= 0.013DWQ
2
+ 0.22DWQ
- 0.10 0.596
Maximum Area per Row, a a = WQCV / K40
0.184 square inches
Number of Rows, nr 8 rows
Number of Columns, nc (See Table 6a-1 for Max.) 1 columns
Choose Hole Diameter 3/8 inches
Use USDCM Volume 3, Figure 5 0.375 inches
Total Area per Row, Ao
0.11 square inches
Total Outlet Area, A 0.88 square inches
Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001
Circular Perforation Sizing
J.Claeys
JVA, Inc.
1990c
November 2, 2013
* * 1 . 2
12
Area
WQCV
Volume
=
Total Outlet Area, Aot
0.88 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
(Not Used)
Number of Rows, nr 4 rows
Choose Rectangular Hole Width (w/ 2" Height) 0 inches
Use USDCM Volume 3, Figure 5 0.000 inches
Total Outlet Area, Aot
0.00 square inches
Does design work? Yes
Minimum Steel Plate Thickness 1/4 inch
Rectangular Perforation Sizing
FRCC South Parking Lot Expansion
Water Quality Pond and Outlet Sizing (Per USDCM)
Design Engineer:
Design Firm:
Project Number:
Date:
J.Claeys
JVA, Inc.
1990c
November 2, 2013
WATER QUALITY TRASH RACK SIZING (Per USDCM, Volume 3)
Required Open Area, At
At
=0.5*[77(e
-0.124D
)]*Aot
32 square inches
Min. Distance between Columns, Sc
2 inches
Width of Trash Rack and Concrete Opening per Column 6 inches This is widened to 6" to incorporate 100-yr Orifice
Use USDCM Volume 3, Table 6a-1
Total Width, Wconc
6 inches
Height of Trash Rack Screen, Htr
32 11/16 inches Check - Larger than Required
Type of Screen S.S. #93 VEE Wire (US Filter)
Screen Opening Slot Dimension 0.139" (US Filter)
Support Rod Type (See Table 6a-2)
Spacing of Support Rod (O.C.) 3/4 inches O.C.
Total Screen Thickness (See Table 6a-2) 0.31 inches
Carbon Steel Frame Type (See Table 6a-2)
(Not Used)
Required Open Area, At
(including 50% clogging)
At
=0.5*[77(e
-0.124D
)]*Aot
0 square inches
Width of Trash Rack Opening, Wopening
1 inches
Use USDCM Volume 3, Table 6b-1
Rectangular Perforation Trash Rack Sizing
#156 VEE
3/8in x 1.0in flat bar
Circular Perforation Trash Rack Sizing
Use USDCM Volume 3, Table 6b-1
Width of Concrete Opening, Wconc
12 inches
Min Height of Trash Rack Screen, Htr
(including 2' 4" below lowest openings) 28.00 inches
Type of Screen Kelmp KRP Series Aluminum Bar Gate (or Equal)
Screen Opening Slot Dimension 3/16" Bars on 1-3/16" Centers
Minimum Bearing Bar Size (See Table 6b-2) 1-1/4 in x 3/16 in
1990c PondCalcs.xls - WQCV & Outlet Structure Page 2 of 2 JVA, Inc.
FRCC South Parking Lot Expansion
Critical Pond Elevations
Design Engineer:
Design Firm:
Project Number:
Date:
DESIGN CRITERIA
Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001
Stage Storage
Volume (pond volume calculated using the prismoidal formula):
Premeable Paver Storage Volume
Total Paver
Area (ft2)
Paver Drainage
Course Depth
(ft)
Allowed Paver
Detention (%)
Paver Detention
Volume (ft3)
Paver Detention
Volume (acre-ft)
13837.5 1.5 40% 8302.5 0.19
Pond StageStorage
CONTOUR (FT)
West Pond
AREA (FT2)
East Pond
AREA (FT2)
West/East
Pond AREA
(ACRE)
VOLUME
(ACRE-FT)
DEPTH (FT)
CUMULATIVE VOLUME
(ACRE-FT)
5066.20 0.000 0.000 0.00 0.000
5067.0 16.92 0.000 0.000 0.80 0.000
5068.0 563.23 2362.25 0.067 0.024 1.80 0.024
5069.0 1436.78 4358.99 0.133 0.098 2.80 0.123
5070.0 2678.47 6594.09 0.213 0.171 3.80 0.294
5071.0 4248.74 9047.85 0.305 0.258 4.80 0.552
5072.0 6183.81 11659.67 0.410 0.356 5.80 0.908
J.Claeys
JVA, Inc.
1990c
November 2, 2013
( )
3
AAAADepth 1 2 1 2
V
+ +
=
1990c PondCalcs.xls - Pond Stage Storage Page 1 of 1 JVA, Inc.
5072.0 6183.81 11659.67 0.410 0.356 5.80 0.908
0.11 5068.92 ft
0.81 Acre-Ft Interpolates to an Elev. of 5071.73 ft
Acre-Ft Interpolates to an Elev. of
Required Water Quality Capture Volume =
Required 100-yr Detention Volume (including WQCV) =
1990c PondCalcs.xls - Pond Stage Storage Page 1 of 1 JVA, Inc.
1990c PondCalcs.xls - WQCV & Outlet Structure Page 1 of 2 JVA, Inc.
180 0.38 0.189 0.53 0.34 0.084 0.105 180 1.31 1.003 0.53 0.34 0.084 0.919
185 0.37 0.190 0.53 0.34 0.086 0.104 185 1.29 1.010 0.53 0.34 0.086 0.924
190 0.36 0.191 0.53 0.34 0.088 0.103 190 1.26 1.017 0.53 0.34 0.088 0.929
195 0.35 0.193 0.53 0.34 0.090 0.102 195 1.24 1.024 0.53 0.34 0.090 0.933
200 0.35 0.194 0.53 0.34 0.093 0.101 200 1.21 1.030 0.53 0.34 0.093 0.937
205 0.34 0.195 0.52 0.34 0.095 0.100 205 1.19 1.036 0.52 0.34 0.095 0.942
210 0.34 0.196 0.52 0.34 0.097 0.099 210 1.17 1.043 0.52 0.34 0.097 0.946
215 0.33 0.197 0.52 0.33 0.099 0.098 215 1.15 1.049 0.52 0.33 0.099 0.950
220 0.32 0.198 0.52 0.33 0.101 0.097 220 1.13 1.055 0.52 0.33 0.101 0.953
225 0.32 0.200 0.52 0.33 0.104 0.096 225 1.11 1.061 0.52 0.33 0.104 0.957
230 0.31 0.201 0.52 0.33 0.106 0.095 230 1.09 1.066 0.52 0.33 0.106 0.961
235 0.31 0.202 0.52 0.33 0.108 0.094 235 1.08 1.072 0.52 0.33 0.108 0.964
240 0.30 0.203 0.52 0.33 0.110 0.093 240 1.06 1.078 0.52 0.33 0.110 0.967
245 0.30 0.204 0.52 0.33 0.112 0.091 245 1.04 1.083 0.52 0.33 0.112 0.971
250 0.29 0.205 0.52 0.33 0.115 0.090 250 1.03 1.088 0.52 0.33 0.115 0.974
255 0.29 0.206 0.52 0.33 0.117 0.089 255 1.01 1.094 0.52 0.33 0.117 0.977
260 0.29 0.207 0.52 0.33 0.119 0.088 260 1.00 1.099 0.52 0.33 0.119 0.980
265 0.28 0.208 0.52 0.33 0.121 0.086 265 0.98 1.104 0.52 0.33 0.121 0.983
270 0.28 0.209 0.52 0.33 0.123 0.085 270 0.97 1.109 0.52 0.33 0.123 0.985
275 0.27 0.210 0.52 0.33 0.126 0.084 275 0.96 1.114 0.52 0.33 0.126 0.988
280 0.27 0.210 0.52 0.33 0.128 0.083 280 0.94 1.119 0.52 0.33 0.128 0.991
285 0.27 0.211 0.52 0.33 0.130 0.081 285 0.93 1.123 0.52 0.33 0.130 0.993
290 0.26 0.212 0.52 0.33 0.132 0.080 290 0.92 1.128 0.52 0.33 0.132 0.996
295 0.26 0.213 0.52 0.33 0.134 0.079 295 0.91 1.133 0.52 0.33 0.134 0.998
300 0.26 0.214 0.52 0.33 0.137 0.077 300 0.89 1.137 0.52 0.33 0.137 1.001
305 0.25 0.215 0.52 0.33 0.139 0.076 305 0.88 1.142 0.52 0.33 0.139 1.003
Mod. FAA Minor Storage Volume (cubic ft.) = 4,909 Mod. FAA Major Storage Volume (cubic ft.) = 43,688
Mod. FAA Minor Storage Volume (acre-ft.) = 0.1127 Mod. FAA Major Storage Volume (acre-ft.) = 1.0029
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.33, Released August 2013
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
FRCC South Parking Lot
100-yr Developed Detained to 2-yr Historic
FRCC South Parking Lot - UD-Detention_v2.33.xls, Modified FAA 11/2/2013, 1:10 PM
Require Detention
Storage w/ 2-yr
Historic Release Rate
180 0.38 0.027 0.53 0.34 0.084 -0.057 180 1.31 0.799 0.53 0.34 0.084 0.715
185 0.37 0.027 0.53 0.34 0.086 -0.059 185 1.29 0.805 0.53 0.34 0.086 0.719
190 0.36 0.027 0.53 0.34 0.088 -0.061 190 1.26 0.810 0.53 0.34 0.088 0.722
195 0.35 0.028 0.53 0.34 0.090 -0.063 195 1.24 0.816 0.53 0.34 0.090 0.725
200 0.35 0.028 0.53 0.34 0.093 -0.065 200 1.21 0.821 0.53 0.34 0.093 0.728
205 0.34 0.028 0.52 0.34 0.095 -0.067 205 1.19 0.826 0.52 0.34 0.095 0.731
210 0.34 0.028 0.52 0.34 0.097 -0.069 210 1.17 0.831 0.52 0.34 0.097 0.734
215 0.33 0.028 0.52 0.33 0.099 -0.071 215 1.15 0.836 0.52 0.33 0.099 0.737
220 0.32 0.028 0.52 0.33 0.101 -0.073 220 1.13 0.841 0.52 0.33 0.101 0.739
225 0.32 0.029 0.52 0.33 0.104 -0.075 225 1.11 0.845 0.52 0.33 0.104 0.742
230 0.31 0.029 0.52 0.33 0.106 -0.077 230 1.09 0.850 0.52 0.33 0.106 0.744
235 0.31 0.029 0.52 0.33 0.108 -0.079 235 1.08 0.854 0.52 0.33 0.108 0.746
240 0.30 0.029 0.52 0.33 0.110 -0.081 240 1.06 0.859 0.52 0.33 0.110 0.749
245 0.30 0.029 0.52 0.33 0.112 -0.083 245 1.04 0.863 0.52 0.33 0.112 0.751
250 0.29 0.029 0.52 0.33 0.115 -0.085 250 1.03 0.867 0.52 0.33 0.115 0.753
255 0.29 0.029 0.52 0.33 0.117 -0.087 255 1.01 0.872 0.52 0.33 0.117 0.755
260 0.29 0.030 0.52 0.33 0.119 -0.090 260 1.00 0.876 0.52 0.33 0.119 0.757
265 0.28 0.030 0.52 0.33 0.121 -0.092 265 0.98 0.880 0.52 0.33 0.121 0.758
270 0.28 0.030 0.52 0.33 0.123 -0.094 270 0.97 0.884 0.52 0.33 0.123 0.760
275 0.27 0.030 0.52 0.33 0.126 -0.096 275 0.96 0.888 0.52 0.33 0.126 0.762
280 0.27 0.030 0.52 0.33 0.128 -0.098 280 0.94 0.891 0.52 0.33 0.128 0.764
285 0.27 0.030 0.52 0.33 0.130 -0.100 285 0.93 0.895 0.52 0.33 0.130 0.765
290 0.26 0.030 0.52 0.33 0.132 -0.102 290 0.92 0.899 0.52 0.33 0.132 0.767
295 0.26 0.030 0.52 0.33 0.134 -0.104 295 0.91 0.903 0.52 0.33 0.134 0.768
300 0.26 0.031 0.52 0.33 0.137 -0.106 300 0.89 0.906 0.52 0.33 0.137 0.770
305 0.25 0.031 0.52 0.33 0.139 -0.108 305 0.88 0.910 0.52 0.33 0.139 0.771
Mod. FAA Minor Storage Volume (cubic ft.) = 48 Mod. FAA Major Storage Volume (cubic ft.) = 33,585
Mod. FAA Minor Storage Volume (acre-ft.) = 0.0011 Mod. FAA Major Storage Volume (acre-ft.) = 0.7710
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.33, Released August 2013
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
FRCC South Parking Lot
2-yr Historic Runoff Rate
FRCC South Parking Lot - UD-Detention_v2.33.xls, Modified FAA 11/2/2013, 1:11 PM
2-yr Historic Release
Rate (0.13 cfs/acre)
C3 Adjusted to fit
CoFC IDF Curve