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| Board/Commission | Planning & Zoning Commission |
|---|---|
| Meeting Date | March 28, 2023 |
| Pages | 211 |
| File Size | 3.1 MB |
| OCR Status | Searchable (OCR processed) |
| Source URL | Original |
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CLA Engineers, Inc
DRAINAGE CALCULATIONS,
HYDRAULICS & HYDROLOGY REPORT
STONE RIDGE BUSINESS PARK
21 GURLEY ROAD
OCTOBER 2022
JULY 2022
APRIL 2022
MARCH 2022
JUNE 2021
H-1
DRAINAGE HYDRAULICS AND HYDROLOGY REPORT
STONE RIDGE BUSINESS PARK
EXISTING CONDITIONS
The site is approximately 22.19 acres in area and is shown on the Existing
Conditions Survey (Sheet 1 of the site plans). The site has frontage on Oil Mill Road and
Gurley Road. There are approximately 3.75 acres of wetlands on the site.
PROPOSED DEVELOPMENT
The project proposes six new free standing buildings that will each be divided
into multiple units. Half of the units will be used as office space, while the other half will
be used as warehouse space. All buildings will have metal roofs treated with an
elastomeric coating to prevent metals from leaching into stormwater runoff. The proper
amount of parking has been provided for each building.
Building Number
Area (SF)
1
10,800
2
12,800
3
10,400
4
6,880
5
14,400
6
10,400
The approximately 22 acre site contains wetlands as shown on sheet 1. Of the
22.19 acres only 9.58 acres of the site will be disturbed during construction, leaving
12.61 acres of totally undisturbed land. And of the 9.58 acres of disturbance, half of that
will be landscaped and planted, as shown on the landscape plan, once construction is
completed. The site proposes only 4.6 acres of development area on a 22.19 acre site.
H-2
EXISTING AND PROPOSED HYDRAULICS
The stormwater management system has been designed to provide for zero
increase in peak stormwater discharge from the site. The project has been designed to
actually result in a relatively small decrease in the peak stormwater rates leaving the
project site. The proposed stormwater forebays, water quality basins, rain gardens, and
infiltration galleries will provide treatment of the runoff from the proposed pavement and
roof areas.
The current site is divided into three, existing, drainage areas:
Existing Drainage Area 1
13.96 Acres
Existing Drainage Area 2
3.92 Acres
Existing Drainage Area 3
4.30 Acres
The development of the proposed site will result in three, similarly sized, drainage
areas:
Proposed Drainage Area 1
11.60 Acres
Proposed Drainage Area 2
5.38 Acres
Proposed Drainage Area 3
4.27 Acres
Proposed Drainage Area 1 was divided into four separate sub catchment areas:
Proposed Drainage Area 1A
0.95 Acres
Proposed Drainage Area 1B
5.93 Acres
Proposed Drainage Area 1C
3.07 Acres
Proposed Drainage Area 1D
1.83 Acres
Proposed Drainage Area 1A contains the parking lot for Building 1. The runoff
from the parking lot will be treated by a stormwater management system that consist of a
forebay followed by a water quality basin. To reduce the volume of stormwater flowing
into the stormwater management system, the roof leaders from Building 1 will flow into
underground concrete leaching galleries. There will not be any roof top units.
H-3
Proposed Drainage Area 1B contains undeveloped land and grass on the east and
west side of the access drive between Buildings 2 and 3. The stormwater runoff from the
east side of the access drive will flow west towards the western most wetland into a rain
garden. Three 12” HDPE culverts will act as outlets from the rain garden to allow the
overflow water that does not infiltrate, to flow under the access drive without being
contaminated. Because there is no impervious cover and ample overland flow over grass
and wooded area, a stormwater treatment system is not necessary.
Proposed Drainage Area 1C contains the parking lots for Buildings 2 and 3 and
the access drive that connects them. The runoff will be treated by a stormwater
management system that consists of a forebay followed by a water quality basin. Several
rain gardens and landscape patches are also to be installed throughout the parking area to
decrease the amount of impervious cover. To reduce the volume of stormwater flowing
into the stormwater management system, roof leaders from Buildings 2 and 3 will flow
into underground concrete leaching galleries. There will be no roof top units.
Proposed Drainage Area 1D contains the shared parking lot between Buildings 4
and 5, the shared parking lot between Buildings 2 and 3, and half of the roof drainage
from Building 5. The stormwater runoff will be treated by a stormwater management
system that consists of a forebay and a water quality basin. After leaving the basin, the
water has substantial overland travel over an undisturbed area before leaving the site.
Several rain gardens and landscaped patches are also to be installed throughout the
parking area to decrease the amount of impervious cover. In order to reduce the basin
inflow, roof leaders for Building 4 will flow into underground concrete leaching galleries.
There will be no roof top units.
All water quality basins, rain gardens, and infiltration galleries will be inspected
annually by the design soil scientist and a report will be provided to the Town Planning
Department.
H-4
Like Drainage Area 1, Proposed Drainage Area 2 was divided into several sub
catchment areas:
Proposed Drainage Area 2A
2.45 Acres
Proposed Drainage Area 2B
0.85 Acres
Proposed Drainage Area 2C
1.91 Acres
Proposed Drainage Area 2A contains the parking lot shared by Buildings 5 and 6,
along with half of the roof drainage from Buildings 5, the roof drainage from Building 6,
and the parking lot to the east of Building 6. The stormwater runoff will be treated by a
forebay followed by a water quality basin. Several rain gardens and landscape patches are
also to be installed throughout the parking area to decrease the amount of impervious
cover. Underground leaching galleries could not be used due to the elevation of mottling
and ledge. There will be no roof top units.
Proposed Drainage Area 2B contains the eastern-most access drive on the site,
which leads to the parking lot to the east of Building 6. The stormwater runoff will be
treated by a forebay followed by a water quality basin. Several rain gardens and
landscape patches are also to be installed throughout the parking area to decrease the
amount of impervious cover. Like Drainage Area 2A, underground leaching chambers
could not be used due to the elevation of mottling and ledge. There will be no roof top
units.
Proposed Drainage Area 2C contains undeveloped land. There is no development
occurring in this area so no stormwater treatment measures are required. Runoff from
Drainage Areas 2A and 2B will be treated by water quality basins before flowing into
Drainage Area 2C.
H-5
Proposed Drainage Area 3 contains all undeveloped land. The construction of the
proposed development will reduce the size of Drainage Area 3 by about 0.03 acres, which
will slightly reduce the amount of stormwater leaving the site. The undeveloped land and
reduction in area allow for there to be no stormwater storage or treatment systems in this
area.
Both the existing and the proposed conditions for the development site have been
analyzed for the 2-year, 10-year, 25-year, 50-year, and 100 year design storms using the
TR-55 SCS Runoff Method. The following is the summary table for the 2-year, 10-year,
25-year, 50-year, and 100-year design storms showing first the existing conditions and
proposed conditions, after passing through the existing detention basin located within the
wetland:
Drainage Area 1
2 Year
10 Year
25 Year
50 Year
100 Year
Existing
1.44 cfs
6.99 cfs
11.84 cfs
15.83 cfs
20.44 cfs
Proposed Area 1A
(WQ Basin 1)
0.00 cfs
0.00 cfs
0.00 cfs
0.00 cfs
0.00 cfs
Proposed Area 1B
(No Basins)
0.56 cfs
2.44 cfs
4.06 cfs
5.40 cfs
6.93 cfs
Proposed Area 1C
(WQ Basin 2)
0.00 cfs
0.19 cfs
0.79 cfs
1.73 cfs
3.16 cfs
Proposed Area 1D
(WQ Basin 3)
0.00 cfs
0.00 cfs
0.00 cfs
0.12 cfs
0.35 cfs
Proposed
0.56 cfs
2.44 cfs
4.06 cfs
5.40 cfs
7.67 cfs
H-6
Drainage Area 2
2 Year
10 Year
25 Year
50 Year
100 Year
Existing
0.45 cfs
2.21 cfs
3.73 cfs
4.98 cfs
6.43 cfs
Proposed Area 2A
(WQ Basin 4)
0.00 cfs
0.00 cfs
0.33 cfs
2.06 cfs
4.53 cfs
Proposed Area 2B
(WQ Basin 5)
0.00 cfs
0.00 cfs
0.00 cfs
0.00 cfs
0.00 cfs
Proposed Area 2C
(No Basin)
0.24 cfs
1.16 cfs
1.95 cfs
2.61 cfs
3.37 cfs
Proposed
0.24 cfs
1.16 cfs
1.95 cfs
2.97 cfs
6.36 cfs
Drainage Area 3
2 Year
10 Year
25 Year
50 Year
100 Year
Existing
0.61 cfs
2.99 cfs
5.06 cfs
6.77 cfs
8.74 cfs
Proposed
0.60 cfs
2.97 cfs
5.03 cfs
6.72 cfs
8.68 cfs
EROSION & SEDIMENTATION CONTROL
The 2002 CT Guidelines for Soil Erosion & Sedimentation Control applies to the
construction phase of the project. A detailed erosion and sediment control plan has been
provided in the site development plans. The proposed stormwater forebays and water
quality basins have been designed to function as sedimentation traps during stabilization.
When constructed, the five forebays are to be constructed to their intended depth.
However, during construction, the 5 basins are to be constructed 2 ft shallower than the
intended depth of the water quality basins. This will ensure that the water quality basins
will function properly after the site development is complete.
H-7
The first calculation required by the Guidelines is for the sediment storage volume
(SSV). The sediment storage volume is the calculation for one year of predicted sediment
load. The required SSV calculations for the temporary sediment traps in each drainage
area are shown below.
Drainage Area 1A
Drainage Area 1C
SSV = A(134CY/Acre)
SSV = A(134CY/Acre)
A = 0.95 ACRE
A = 3.07 ACRES
SSV = 127.3 CY = 3,440 CF
SSV = 411.4 CY = 11,110 CF
Drainage Area 1D
SSV = A(134CY/Acre)
A = 1.83 ACRE
SSV = 245.2 CY = 6,620 CF
Drainage Area 2A
Drainage Area 2B
SSV = A(134CY/Acre)
SSV = A(134CY/Acre)
A = 2.45 ACRE
A = 0.85 ACRES
SSV = 328.3 CY = 8,865 CF SSV = 113.9 CY = 3,075 CF
The second calculation required by the Guidelines is for wet storage volume
(WSV). The wet storage volume is the volume in the basin that is located below the
bottom of the riprap for the level spreader outlet of the basin. The volume of the wet
storage is required to be half of the required SSV. The required wet storage volumes for
each drainage area are shown below along with the dry storage volumes (DSV).
H-8
Drainage Area 1A
Drainage Area 1C
WSV = DSV = SSV/2
WSV = DSV = SSV/2
= 1,720.0 CF
= 5,555.0 CF
Drainage Area 1D
WSV = DSV = SSV/2
= 3,310.0 CF
Drainage Area 2A
Drainage Area 2B
WSV = DSV = SSV/2
WSV = DSV = SSV/2
= 4,432.5 CF
= 1,537.5 CF
The required and provided storage for each basin are as follows:
Drainage Area 1A
(Bottom of Riprap Elev. = 26.5)
Sedimentation Trap 1
1,720 CF of Wet Storage Volume Required
11,315 CF Provided
1,720 CF of Dry Storage Volume Required
16,285 CF Provided
3,440 CF of Sediment Storage Volume Required
27,600 CF Total Provided
Drainage Area 1C
(Outlet Elev. = 26.0)
Sedimentation Trap 2
5,555 CF of Wet Storage Volume Required
10,045 CF Provided
5,555 CF of Dry Storage Volume Required
13,930 CF Provided
11,110 CF of Sediment Storage Volume Required
23,975 CF Total Provided
H-9
Drainage Area 1D
(Bottom of Riprap Elev. = 36.5)
Sedimentation Trap 3
3,310 CF of Wet Storage Volume Required
15,160 CF Provided
3,310 CF of Dry Storage Volume Required
7,620 CF Provided
6,620 CF of Sediment Storage Volume Required
22,780 CF Total Provided
Drainage Area 2A
(Bottom of Riprap Elev. = 56.5)
Sedimentation Trap 5
4,432.5 CF of Wet Storage Volume Required
18,720 CF Provided
4,432.5 CF of Dry Storage Volume Required
12,240 CF Provided
8,865 CF of Sediment Storage Volume Required
30,960 CF Total Provided
Drainage Area 2B
(Bottom of Riprap Elev. = 66.5)
Sedimentation Trap 6
1,537.5 CF of Wet Storage Volume Required
3,070 CF Provided
1,537.5 CF of Dry Storage Volume Required
7,685 CF Provided
3,075 CF of Sediment Storage Volume Required
10,755 CF Total Provided
CONNECTICUT STORMWATER QUALITY MANUAL
The Connecticut 2004 Stormwater Quality Manual (Manual) applies to the post
construction phase, for the operation of the facility. The temporary sediment traps have
been designed to function as water quality basins after the site is stabilized. They all
meet the criteria of the Connecticut Stormwater Quality Manual for a Water Quality
Basin.
H-10
Drainage Area 1A
(Forebay & WQ Basin 1)
WQV = (1")(R)(A)/12
A = 0.95 Acre
R = 0.05 + 0.009(I)
I = 0.31 Acres / 0.95 Acres = 0.326 (32.6%)
R = 0.344
WQV = 0.027 Ac-Ft = 1,185 CF (Required)
13,130 CF (Provided)
Drainage Area 1C
(Forebay & WQ Basin 2)
WQV = (1")(R)(A)/12
A = 3.07 Acres
R = 0.05 + 0.009(I)
I = 1.06 Acres / 3.07 Acres = 0.345 (34.5%)
R = 0.361
WQV = 0.092 Ac-Ft = 4,020 CF (Required)
13,435 CF (Provided)
H-11
Drainage Area 1D
(Forebay & WQ Basin 3)
WQV = (1")(R)(A)/12
A = 1.83 Acres
R = 0.05 + 0.009(I)
I = 1.01 Acres / 1.83 Acres = 0.552 (55.2%)
R = 0.547
WQV = 0.083 Ac-Ft = 3,630 CF (Required)
17,890 CF (Provided)
Drainage Area 2A
(Forebay & WQ Basin 4)
WQV = (1")(R)(A)/12
A = 2.45 Acres
R = 0.05 + 0.009(I)
I = 1.09 Acres / 2.45 Acres = 0.445 (44.5%)
R = 0.450
WQV = 0.092 Ac-Ft = 4,005 CF (Required)
24,860 CF (Provided)
H-12
Drainage Area 2B
(Forebay & WQ Basin 5)
WQV = (1")(R)(A)/12
A = 0.85 Acres
R = 0.05 + 0.009(I)
I = 0.15 Acres / 0.85 Acres = 0.176 (17.6%)
R = 0.209
WQV = 0.015 Ac-Ft = 644.3 CF (Required)
8,180 CF (Provided)
Once development of the site is completed, there will be a relatively small
decrease in runoff from the site. All of the temporary sedimentation basins provide ample
wet and dry volume storage to meet and exceed the requirements of the 2002 CT
Guidelines for Soil & Sedimentation Control. Likewise, the five permanent Water
Quality Basins meet and exceed the post construction requirements of the Connecticut
2004 Stormwater Quality Manual.
The CTDEEP 2004 Stormwater Manual prescribes means by which stormwater runoff
from developed sites can be adequately treated. The method outlined in section 7.4.1 of the
2004 Manual, treating the WQV is employed on this site. As indicated in the calculations of
WQV within this report, the stormwater treatment design exceeds treatment of the WQV
required by the 2004 Manual for each stormwater treatment basin,. The range of over-
treatment runs from three times that required for Basin 2 to nine times that required for Basin
1. Thus it is anticipated that the stormwater basins will provide a higher level of water quality
renovation than required by CTDEEP. All of the basins are designed as wet bottom basins that
will function as stormwater wetlands.
Also note that per the calculations in this report none of the stormwater basins will
discharge in the 2 year storm event. Appendix D of wetland report includes data from the
H-13
University of New Hampshire Stormwater Center that indicate that retaining the two year
storm provides extremely high levels of removal of pollutants of concern for commercial and
industrial sites. Based on the UNH data, CLA anticipates levels of renovation that will be
protective of water quality within local water bodies as well as the Niantic River,
CLA has reviewed the Niantic River watershed management plans to ensure that the site plans
are consistent with those documents. Based on that review, additional measures beyond the
water quality basins described above have been incorporated into the site plans.
1. There will be a 50 foot undisturbed vegetative buffer left in place around all wetlands
and watercourses on the site. This will provide shade over streams, wildlife habitat and
further treat discharge from the treatment basins.
2. Low Impact Development (LID) measures such as rain gardens have been
incorporated. In total, nine rain gardens are proposed and each will provide bio-
filtration to stormwater runoff before is enters the ground. This will provide treatment
not accounted for in the WQV calculations and is described further in the wetland
report.
3. Infiltration of stormwater is used whenever practical, in both the rain gardens and
Basin 1, 2, and 3.
4. The plans are consistent with the CTDEEP 2002 and 2004 Manuals.
Based on the stormwater treatment design and the measures incorporated to be consistent
with the watershed management plans, CLA believes that the design is protective of both
onsite resources and the Niantic River.
Hydrograph Summary Report
1
Hyd.
Hydrograph
Peak
Time
Time to
Hyd.
Inflow
Maximum
Total
Hydrograph
No.
type
flow
interval
peak
volume
hyd(s)
elevation
strge used
description
(origin)
(cfs)
(min)
(min)
(cuft)
(ft)
(cuft)
1
SCS Runoff
1.438
1
767
16,593
------
------
------
Existing Area 1
2
SCS Runoff
1.268
1
717
3,010
------
------
------
Building 1
3
Reservoir(i)
0.000
1
n/a
0
2
33.83
1,110
Leaching Gallery 1
4
SCS Runoff
0.713
1
741
3,782
------
------
------
Proposed Area 1A
5
Combine
0.713
1
741
3,782
3, 4
------
------
Roof overflow and Area 1A
6
Reservoir
0.000
1
n/a
0
5
25.18
3,782
Basin 1 Forebay
7
Reservoir
0.000
1
n/a
0
6
22.00
0.000
Basin 1
8
SCS Runoff
0.560
1
786
7,778
------
------
------
Proposed Area 1B
9
SCS Runoff
1.471
1
717
3,492
------
------
------
Building 2
10
Reservoir(i)
0.000
1
n/a
0
9
35.12
1,268
Leaching Gallery 2
11
SCS Runoff
1.218
1
717
2,890
------
------
------
Building 3
12
Reservoir(i)
0.000
1
n/a
0
11
39.37
1,033
Leaching Gallery 3
13
SCS Runoff
1.703
1
757
12,076
------
------
------
Proposed Area 1C
14
Combine
1.703
1
757
12,076
10, 12, 13
------
------
BLDG 2&3 & Area 1C
15
Reservoir(i)
0.074
1
1378
1,588
14
26.11
11,122
Basin 2 Forebay
16
Reservoir
0.000
1
n/a
0
15
23.14
1,588
Basin 2
17
SCS Runoff
0.913
1
717
2,167
------
------
------
Building 4
18
Reservoir(i)
0.000
1
n/a
0
17
44.07
727
Leaching Gallery 4
19
SCS Runoff
2.434
1
735
11,188
------
------
------
Proposed Area 1D
20
Combine
2.434
1
735
11,188
18, 19
------
------
BLDG 4 & AREA 1D
21
Reservoir(i)
0.000
1
n/a
0
20
35.18
11,257
Basin 3 Forebay
22
Reservoir
0.000
1
n/a
0
21
30.00
0.000
Basin 3
23
Combine
0.560
1
786
7,778
7, 8, 16,
22
------
------
Proposed Area 1
24
SCS Runoff
0.450
1
760
4,682
------
------
------
Existing Area 2
25
SCS Runoff
2.045
1
746
11,821
------
------
------
Proposed Area 2A
26
Reservoir
2.038
1
748
10,947
25
53.18
1,124
Basin 4 Forebay
27
Reservoir
0.000
1
750
0
26
53.57
4,711
Basin 4
28
SCS Runoff
0.515
1
735
2,508
------
------
------
Proposed Area 2B
29
Reservoir
0.072
1
842
1,336
28
66.33
1,289
Basin 5 Forebay
30
Reservoir
0.000
1
947
0
29
64.16
369
Basin 5
31
SCS Runoff
0.236
1
756
2,281
------
------
------
Proposed Area 2C
32
Combine
0.236
1
756
2,281
27, 30, 31
------
------
Proposed Area 2
33
SCS Runoff
0.608
1
749
5,185
------
------
------
Existing Area 3
34
SCS Runoff
0.603
1
749
5,149
------
------
------
Proposed Area 3
GSD 60 Drainage V13.gpw
Return Period: 2 Year
Monday, Oct 3, 2022
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 1
Existing Area 1
Hydrograph type
= SCS Runoff
Peak discharge
= 1.438 cfs
Storm frequency
= 2 yrs
Time to peak
= 767 min
Time interval
= 1 min
Hyd. volume
= 16,593 cuft
Drainage area
= 13.960 ac
Curve number
= 55
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 43.30 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
2
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Existing Area 1
Hyd. No. 1 -- 2 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 2
Building 1
Hydrograph type
= SCS Runoff
Peak discharge
= 1.268 cfs
Storm frequency
= 2 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 3,010 cuft
Drainage area
= 0.250 ac
Curve number
= 98
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.45 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
3
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Building 1
Hyd. No. 2 -- 2 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 3
Leaching Gallery 1
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Upper Pond
Lower Pond
Pond name
= Leaching Gallery 1
Pond name
= Basin 1 Forebay
Inflow hyd.
= 2 - Building 1
Other Inflow hyd.
= None
Max. Elevation
= 33.83 ft
Max. Elevation
= 22.00 ft
Max. Storage
= 1,110 cuft
Max. Storage
= 0 cuft
Interconnected Pond Routing. Storage Indication method used.
4
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Leaching Gallery 1
Hyd. No. 3 -- 2 Year
Hyd No. 3
Hyd No. 2
Total storage used = 1,110 cuft
Outflow Pond 11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 4
Proposed Area 1A
Hydrograph type
= SCS Runoff
Peak discharge
= 0.713 cfs
Storm frequency
= 2 yrs
Time to peak
= 741 min
Time interval
= 1 min
Hyd. volume
= 3,782 cuft
Drainage area
= 0.950 ac
Curve number
= 72*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 26.10 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.190 x 55) + (0.450 x 61) + (0.310 x 98)] / 0.950
5
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Proposed Area 1A
Hyd. No. 4 -- 2 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 5
Roof overflow and Area 1A
Hydrograph type
= Combine
Peak discharge
= 0.713 cfs
Storm frequency
= 2 yrs
Time to peak
= 741 min
Time interval
= 1 min
Hyd. volume
= 3,782 cuft
Inflow hyds.
= 3, 4
Contrib. drain. area = 0.950 ac
6
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Roof overflow and Area 1A
Hyd. No. 5 -- 2 Year
Hyd No. 5
Hyd No. 3
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 6
Basin 1 Forebay
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 5 - Roof overflow and Area 1A
Max. Elevation
= 25.18 ft
Reservoir name
= Basin 1 Forebay
Max. Storage
= 3,782 cuft
Storage Indication method used.
7
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Basin 1 Forebay
Hyd. No. 6 -- 2 Year
Hyd No. 6
Hyd No. 5
Total storage used = 3,782 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 7
Basin 1
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 6 - Basin 1 Forebay
Max. Elevation
= 22.00 ft
Reservoir name
= Basin 1 Forebay
Max. Storage
= 0 cuft
Storage Indication method used.
8
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
Q (cfs)
0.00
0.00
0.01
0.01
0.02
0.02
0.03
0.03
0.04
0.04
0.05
0.05
0.06
0.06
0.07
0.07
0.08
0.08
0.09
0.09
0.10
0.10
Q (cfs)
Time (min)
Basin 1
Hyd. No. 7 -- 2 Year
Hyd No. 7
Hyd No. 6
Total storage used = 0 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 8
Proposed Area 1B
Hydrograph type
= SCS Runoff
Peak discharge
= 0.560 cfs
Storm frequency
= 2 yrs
Time to peak
= 786 min
Time interval
= 1 min
Hyd. volume
= 7,778 cuft
Drainage area
= 5.930 ac
Curve number
= 56*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 69.10 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(5.120 x 55) + (0.810 x 61)] / 5.930
9
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Proposed Area 1B
Hyd. No. 8 -- 2 Year
Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 9
Building 2
Hydrograph type
= SCS Runoff
Peak discharge
= 1.471 cfs
Storm frequency
= 2 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 3,492 cuft
Drainage area
= 0.290 ac
Curve number
= 98
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.45 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
10
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Building 2
Hyd. No. 9 -- 2 Year
Hyd No. 9
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 10
Leaching Gallery 2
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Upper Pond
Lower Pond
Pond name
= Leaching Gallery 2
Pond name
= Basin 2 Forebay
Inflow hyd.
= 9 - Building 2
Other Inflow hyd.
= None
Max. Elevation
= 35.12 ft
Max. Elevation
= 22.00 ft
Max. Storage
= 1,268 cuft
Max. Storage
= 0 cuft
Interconnected Pond Routing. Storage Indication method used.
11
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Leaching Gallery 2
Hyd. No. 10 -- 2 Year
Hyd No. 10
Hyd No. 9
Total storage used = 1,268 cuft
Outflow Pond 12
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 11
Building 3
Hydrograph type
= SCS Runoff
Peak discharge
= 1.218 cfs
Storm frequency
= 2 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 2,890 cuft
Drainage area
= 0.240 ac
Curve number
= 98
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.45 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
12
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Building 3
Hyd. No. 11 -- 2 Year
Hyd No. 11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 12
Leaching Gallery 3
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Upper Pond
Lower Pond
Pond name
= Leaching Gallery 3
Pond name
= Basin 2 Forebay
Inflow hyd.
= 11 - Building 3
Other Inflow hyd.
= None
Max. Elevation
= 39.37 ft
Max. Elevation
= 22.00 ft
Max. Storage
= 1,033 cuft
Max. Storage
= 0 cuft
Interconnected Pond Routing. Storage Indication method used.
13
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Leaching Gallery 3
Hyd. No. 12 -- 2 Year
Hyd No. 12
Hyd No. 11
Total storage used = 1,033 cuft
Outflow Pond 13
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 13
Proposed Area 1C
Hydrograph type
= SCS Runoff
Peak discharge
= 1.703 cfs
Storm frequency
= 2 yrs
Time to peak
= 757 min
Time interval
= 1 min
Hyd. volume
= 12,076 cuft
Drainage area
= 3.070 ac
Curve number
= 72*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 48.50 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.740 x 55) + (1.060 x 98) + (1.270 x 61)] / 3.070
14
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Proposed Area 1C
Hyd. No. 13 -- 2 Year
Hyd No. 13
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 14
BLDG 2&3 & Area 1C
Hydrograph type
= Combine
Peak discharge
= 1.703 cfs
Storm frequency
= 2 yrs
Time to peak
= 757 min
Time interval
= 1 min
Hyd. volume
= 12,076 cuft
Inflow hyds.
= 10, 12, 13
Contrib. drain. area = 3.070 ac
15
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
BLDG 2&3 & Area 1C
Hyd. No. 14 -- 2 Year
Hyd No. 14
Hyd No. 10
Hyd No. 12
Hyd No. 13
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 15
Basin 2 Forebay
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.074 cfs
Storm frequency
= 2 yrs
Time to peak
= 1378 min
Time interval
= 1 min
Hyd. volume
= 1,588 cuft
Upper Pond
Lower Pond
Pond name
= Basin 2 Forebay
Pond name
= Basin 2
Inflow hyd.
= 14 - BLDG 2&3 & Area 1C
Other Inflow hyd.
= None
Max. Elevation
= 23.16 ft
Max. Elevation
= 26.11 ft
Max. Storage
= 477 cuft
Max. Storage
= 10,645 cuft
Interconnected Pond Routing. Storage Indication method used.
16
0
240
480
720
960
1200
1440
1680
1920
2160
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
Q (cfs)
Time (min)
Basin 2 Forebay
Hyd. No. 15 -- 2 Year
Hyd No. 15
Hyd No. 14
Total storage used = 11,122 cuft
Outflow Pond 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 16
Basin 2
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 15 - Basin 2 Forebay
Max. Elevation
= 23.14 ft
Reservoir name
= Basin 2
Max. Storage
= 1,588 cuft
Storage Indication method used.
17
0
240
480
720
960
1200
1440
1680
1920
2160
Q (cfs)
0.00
0.00
0.01
0.01
0.02
0.02
0.03
0.03
0.04
0.04
0.05
0.05
0.06
0.06
0.07
0.07
0.08
0.08
0.09
0.09
0.10
0.10
Q (cfs)
Time (min)
Basin 2
Hyd. No. 16 -- 2 Year
Hyd No. 16
Hyd No. 15
Total storage used = 1,588 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 17
Building 4
Hydrograph type
= SCS Runoff
Peak discharge
= 0.913 cfs
Storm frequency
= 2 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 2,167 cuft
Drainage area
= 0.180 ac
Curve number
= 98
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.45 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
18
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Building 4
Hyd. No. 17 -- 2 Year
Hyd No. 17
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 18
Leaching Gallery 4
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Upper Pond
Lower Pond
Pond name
= Leaching Gallery 4
Pond name
= Basin 3 Forebay
Inflow hyd.
= 17 - Building 4
Other Inflow hyd.
= None
Max. Elevation
= 44.07 ft
Max. Elevation
= 32.00 ft
Max. Storage
= 727 cuft
Max. Storage
= 0 cuft
Interconnected Pond Routing. Storage Indication method used.
19
0
120
240
360
480
600
720
840
960
1080
1200
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Leaching Gallery 4
Hyd. No. 18 -- 2 Year
Hyd No. 18
Hyd No. 17
Total storage used = 727 cuft
Outflow Pond 14
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 19
Proposed Area 1D
Hydrograph type
= SCS Runoff
Peak discharge
= 2.434 cfs
Storm frequency
= 2 yrs
Time to peak
= 735 min
Time interval
= 1 min
Hyd. volume
= 11,188 cuft
Drainage area
= 1.830 ac
Curve number
= 81*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 21.50 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(1.010 x 98) + (0.820 x 61)] / 1.830
20
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
Proposed Area 1D
Hyd. No. 19 -- 2 Year
Hyd No. 19
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 20
BLDG 4 & AREA 1D
Hydrograph type
= Combine
Peak discharge
= 2.434 cfs
Storm frequency
= 2 yrs
Time to peak
= 735 min
Time interval
= 1 min
Hyd. volume
= 11,188 cuft
Inflow hyds.
= 18, 19
Contrib. drain. area = 1.830 ac
21
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
BLDG 4 & AREA 1D
Hyd. No. 20 -- 2 Year
Hyd No. 20
Hyd No. 18
Hyd No. 19
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 21
Basin 3 Forebay
Hydrograph type
= Reservoir (Interconnected)
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Upper Pond
Lower Pond
Pond name
= Basin 3 Forebay
Pond name
= Basin 3
Inflow hyd.
= 20 - BLDG 4 & AREA 1D
Other Inflow hyd.
= None
Max. Elevation
= 33.21 ft
Max. Elevation
= 35.18 ft
Max. Storage
= 248 cuft
Max. Storage
= 11,009 cuft
Interconnected Pond Routing. Storage Indication method used.
22
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
Basin 3 Forebay
Hyd. No. 21 -- 2 Year
Hyd No. 21
Hyd No. 20
Total storage used = 11,257 cuft
Outflow Pond 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 22
Basin 3
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= n/a
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 21 - Basin 3 Forebay
Max. Elevation
= 30.00 ft
Reservoir name
= Basin 3
Max. Storage
= 0 cuft
Storage Indication method used.
23
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
Q (cfs)
0.00
0.00
0.01
0.01
0.02
0.02
0.03
0.03
0.04
0.04
0.05
0.05
0.06
0.06
0.07
0.07
0.08
0.08
0.09
0.09
0.10
0.10
Q (cfs)
Time (min)
Basin 3
Hyd. No. 22 -- 2 Year
Hyd No. 22
Hyd No. 21
Total storage used = 0 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 23
Proposed Area 1
Hydrograph type
= Combine
Peak discharge
= 0.560 cfs
Storm frequency
= 2 yrs
Time to peak
= 786 min
Time interval
= 1 min
Hyd. volume
= 7,778 cuft
Inflow hyds.
= 7, 8, 16, 22
Contrib. drain. area = 5.930 ac
24
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Proposed Area 1
Hyd. No. 23 -- 2 Year
Hyd No. 23
Hyd No. 7
Hyd No. 8
Hyd No. 16
Hyd No. 22
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 24
Existing Area 2
Hydrograph type
= SCS Runoff
Peak discharge
= 0.450 cfs
Storm frequency
= 2 yrs
Time to peak
= 760 min
Time interval
= 1 min
Hyd. volume
= 4,682 cuft
Drainage area
= 3.920 ac
Curve number
= 55
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 35.00 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
25
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.05
0.05
0.10
0.10
0.15
0.15
0.20
0.20
0.25
0.25
0.30
0.30
0.35
0.35
0.40
0.40
0.45
0.45
0.50
0.50
Q (cfs)
Time (min)
Existing Area 2
Hyd. No. 24 -- 2 Year
Hyd No. 24
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 25
Proposed Area 2A
Hydrograph type
= SCS Runoff
Peak discharge
= 2.045 cfs
Storm frequency
= 2 yrs
Time to peak
= 746 min
Time interval
= 1 min
Hyd. volume
= 11,821 cuft
Drainage area
= 2.450 ac
Curve number
= 76*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 34.80 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(1.090 x 98) + (0.870 x 61) + (0.490 x 55)] / 2.450
26
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
Proposed Area 2A
Hyd. No. 25 -- 2 Year
Hyd No. 25
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 26
Basin 4 Forebay
Hydrograph type
= Reservoir
Peak discharge
= 2.038 cfs
Storm frequency
= 2 yrs
Time to peak
= 748 min
Time interval
= 1 min
Hyd. volume
= 10,947 cuft
Inflow hyd. No.
= 25 - Proposed Area 2A
Max. Elevation
= 53.18 ft
Reservoir name
= Basin 4 Forebay
Max. Storage
= 1,124 cuft
Storage Indication method used.
27
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
Basin 4 Forebay
Hyd. No. 26 -- 2 Year
Hyd No. 26
Hyd No. 25
Total storage used = 1,124 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 27
Basin 4
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= 750 min
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 26 - Basin 4 Forebay
Max. Elevation
= 53.57 ft
Reservoir name
= Basin 4
Max. Storage
= 4,711 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
28
0
240
480
720
960
1200
1440
1680
1920
2160
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
Q (cfs)
Time (min)
Basin 4
Hyd. No. 27 -- 2 Year
Hyd No. 27
Hyd No. 26
Total storage used = 4,711 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 28
Proposed Area 2B
Hydrograph type
= SCS Runoff
Peak discharge
= 0.515 cfs
Storm frequency
= 2 yrs
Time to peak
= 735 min
Time interval
= 1 min
Hyd. volume
= 2,508 cuft
Drainage area
= 0.850 ac
Curve number
= 67*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 17.10 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.150 x 98) + (0.640 x 61) + (0.060 x 55)] / 0.850
29
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Proposed Area 2B
Hyd. No. 28 -- 2 Year
Hyd No. 28
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 29
Basin 5 Forebay
Hydrograph type
= Reservoir
Peak discharge
= 0.072 cfs
Storm frequency
= 2 yrs
Time to peak
= 842 min
Time interval
= 1 min
Hyd. volume
= 1,336 cuft
Inflow hyd. No.
= 28 - Proposed Area 2B
Max. Elevation
= 66.33 ft
Reservoir name
= Basin 5 Forebay
Max. Storage
= 1,289 cuft
Storage Indication method used.
30
0
180
360
540
720
900
1080
1260
1440
1620
1800
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Basin 5 Forebay
Hyd. No. 29 -- 2 Year
Hyd No. 29
Hyd No. 28
Total storage used = 1,289 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 30
Basin 5
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= 947 min
Time interval
= 1 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 29 - Basin 5 Forebay
Max. Elevation
= 64.16 ft
Reservoir name
= Basin 5
Max. Storage
= 369 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
31
0
180
360
540
720
900
1080
1260
1440
1620
1800
1980
Q (cfs)
0.00
0.00
0.01
0.01
0.02
0.02
0.03
0.03
0.04
0.04
0.05
0.05
0.06
0.06
0.07
0.07
0.08
0.08
0.09
0.09
0.10
0.10
Q (cfs)
Time (min)
Basin 5
Hyd. No. 30 -- 2 Year
Hyd No. 30
Hyd No. 29
Total storage used = 369 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 31
Proposed Area 2C
Hydrograph type
= SCS Runoff
Peak discharge
= 0.236 cfs
Storm frequency
= 2 yrs
Time to peak
= 756 min
Time interval
= 1 min
Hyd. volume
= 2,281 cuft
Drainage area
= 1.910 ac
Curve number
= 55*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 29.00 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(1.850 x 55) + (0.060 x 61)] / 1.910
32
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.05
0.05
0.10
0.10
0.15
0.15
0.20
0.20
0.25
0.25
0.30
0.30
0.35
0.35
0.40
0.40
0.45
0.45
0.50
0.50
Q (cfs)
Time (min)
Proposed Area 2C
Hyd. No. 31 -- 2 Year
Hyd No. 31
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 32
Proposed Area 2
Hydrograph type
= Combine
Peak discharge
= 0.236 cfs
Storm frequency
= 2 yrs
Time to peak
= 756 min
Time interval
= 1 min
Hyd. volume
= 2,281 cuft
Inflow hyds.
= 27, 30, 31
Contrib. drain. area = 1.910 ac
33
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.05
0.05
0.10
0.10
0.15
0.15
0.20
0.20
0.25
0.25
0.30
0.30
0.35
0.35
0.40
0.40
0.45
0.45
0.50
0.50
Q (cfs)
Time (min)
Proposed Area 2
Hyd. No. 32 -- 2 Year
Hyd No. 32
Hyd No. 27
Hyd No. 30
Hyd No. 31
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 33
Existing Area 3
Hydrograph type
= SCS Runoff
Peak discharge
= 0.608 cfs
Storm frequency
= 2 yrs
Time to peak
= 749 min
Time interval
= 1 min
Hyd. volume
= 5,185 cuft
Drainage area
= 4.300 ac
Curve number
= 55
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 21.00 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
34
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Existing Area 3
Hyd. No. 33 -- 2 Year
Hyd No. 33
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 34
Proposed Area 3
Hydrograph type
= SCS Runoff
Peak discharge
= 0.603 cfs
Storm frequency
= 2 yrs
Time to peak
= 749 min
Time interval
= 1 min
Hyd. volume
= 5,149 cuft
Drainage area
= 4.270 ac
Curve number
= 55
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 21.00 min
Total precip.
= 3.45 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
35
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
0.10
0.10
0.20
0.20
0.30
0.30
0.40
0.40
0.50
0.50
0.60
0.60
0.70
0.70
0.80
0.80
0.90
0.90
1.00
1.00
Q (cfs)
Time (min)
Proposed Area 3
Hyd. No. 34 -- 2 Year
Hyd No. 34
Hydrograph Summary Report
36
Hyd.
Hydrograph
Peak
Time
Time to
Hyd.
Inflow
Maximum
Total
Hydrograph
No.
type
flow
interval
peak
volume
hyd(s)
elevation
strge used
description
(origin)
(cfs)
(min)
(min)
(cuft)
(ft)
(cuft)
1
SCS Runoff
6.988
1
757
52,978
------
------
------
Existing Area 1
2
SCS Runoff
1.900
1
717
4,588
------
------
------
Building 1
3
Reservoir(i)
0.000
1
n/a
0
2
34.35
2,201
Leaching Gallery 1
4
SCS Runoff
1.591
1
739
8,015
------
------
------
Proposed Area 1A
5
Combine
1.591
1
739
8,015
3, 4
------
------
Roof overflow and Area 1A
6
Reservoir
0.000
1
n/a
0
5
27.09
8,015
Basin 1 Forebay
7
Reservoir
0.000
1
n/a
0
6
22.00
0.000
Basin 1
8
SCS Runoff
2.439
1
775
23,919
------
------
------
Proposed Area 1B
9
SCS Runoff
2.204
1
717
5,323
------
------
------
Building 2
10
Reservoir(i)
0.194
1
745
172
9
35.75
2,274
Leaching Gallery 2
11
SCS Runoff
1.824
1
717
4,405
------
------
------
Building 3
12
Reservoir(i)
0.000
1
n/a
0
11
40.80
1,851
Leaching Gallery 3
13
SCS Runoff
3.807
1
754
25,590
------
------
------
Proposed Area 1C
14
Combine
3.926
1
752
25,762
10, 12, 13
------
------
BLDG 2&3 & Area 1C
15
Reservoir(i)
1.205
1
802
15,274
14
26.53
13,152
Basin 2 Forebay
16
Reservoir
0.185
1
1198
5,158
15
26.19
10,998
Basin 2
17
SCS Runoff
1.368
1
717
3,304
------
------
------
Building 4
18
Reservoir(i)
0.000
1
n/a
0
17
45.69
1,165
Leaching Gallery 4
19
SCS Runoff
4.556
1
735
20,854
------
------
------
Proposed Area 1D
20
Combine
4.556
1
735
20,854
18, 19
------
------
BLDG 4 & AREA 1D
21
Reservoir(i)
0.308
1
917
5,022
20
36.55
16,138
Basin 3 Forebay
22
Reservoir
0.000
1
n/a
0
21
33.04
5,022
Basin 3
23
Combine
2.439
1
775
29,077
7, 8, 16,
22
------
------
Proposed Area 1
24
SCS Runoff
2.207
1
751
14,948
------
------
------
Existing Area 2
25
SCS Runoff
4.190
1
744
23,580
------
------
------
Proposed Area 2A
26
Reservoir
4.180
1
746
22,706
25
53.30
1,282
Basin 4 Forebay
27
Reservoir
0.000
1
725
0
26
55.56
12,474
Basin 4
28
SCS Runoff
1.322
1
733
5,799
------
------
------
Proposed Area 2B
29
Reservoir
0.841
1
747
4,628
28
66.77
1,736
Basin 5 Forebay
30
Reservoir
0.000
1
802
0
29
64.68
1,556
Basin 5
31
SCS Runoff
1.158
1
747
7,283
------
------
------
Proposed Area 2C
32
Combine
1.158
1
747
7,283
27, 30, 31
------
------
Proposed Area 2
33
SCS Runoff
2.988
1
740
16,555
------
------
------
Existing Area 3
34
SCS Runoff
2.967
1
740
16,439
------
------
------
Proposed Area 3
GSD 60 Drainage V13.gpw
Return Period: 10 Year
Monday, Oct 3, 2022
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 1
Existing Area 1
Hydrograph type
= SCS Runoff
Peak discharge
= 6.988 cfs
Storm frequency
= 10 yrs
Time to peak
= 757 min
Time interval
= 1 min
Hyd. volume
= 52,978 cuft
Drainage area
= 13.960 ac
Curve number
= 55
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 43.30 min
Total precip.
= 5.14 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
37
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
Q (cfs)
0.00
0.00
1.00
1.00
2.00
2.00
3.00
3.00
4.00
4.00
5.00
5.00
6.00
6.00
7.00
7.00
Q (cfs)
Time (min)
Existing Area 1
Hyd. No. 1 -- 10 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Monday, Oct 3, 2022
Hyd. No. 2
Building 1
Hydrograph type
= SCS Runoff
Peak discharge
= 1.900 cfs
Storm frequency
= 10 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 4,588 cuft
Drainage area
= 0.250 ac
Curve number
= 98
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
To