SW6200401_2020-09-11 DSI Submittal Documents_20201007

jjl!�ENGINEERING - SURVEYING - DESIGNING - DRAFTING
Larry King & Associates, R.L.S., P.A.
P.O. Box 53787
1333 Morganton Road, Suite 201
Fayetteville, North Carolina 28305
P. [phone] F. [phone]
vwwv.LKandA.com
TRANSMITTAL
Steven C. Anen, PE
512 N. Salisbury Street
91" Floor
Raleigh, NC 27604
1612 Mail Service Center
Raleigh, NC 27699-1612
1 /2020
NC Div. of Energy, Mineral and Land
ampany: Resources
Re: DSI Properties
CC:
We are
El
HAND DELIVERY
®
OVERNIGHT
El
US MAIL
❑
PICKUP AT OUR
send Ing Via:
DELIVERY
OFFICE
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SURVEY
DRAWING(S)
❑
PLOT PLAN(S) ❑
CHANGE ORDER
❑
The following:
CONCEPTUAL
PRELIMINARY
FINAL
❑
DRAWING(S)
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CONSTRUCTION
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OTHER
DRAWINGS
DRAWING(S)
For your:
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REVIEW
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COMMENTS
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SIGNATURE
OTHER
COPIES
DATE
NO.
DESCRIPTION
2
Revised Drawing Sheets C-04 & C-10
1
Revised Drawdown Calculation
1
Revised Supplement EZ Form
1
Revised SWU-101 (Page 3 Only)
Notes:
From:
C\A/\-
Jeffrey Nob s, PE
Please notify us at once if any items are missing.

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
BRIAN WRENN
Acting Dire, tot
Jeffrey A. Nobles, PE
Larry King & Associates, RLS, PA
P.O. Box 53787
Fayetteville, NC 28305
NORTH CAROLINA
Environmental Quality
July 13, 2020
Subject: Request for Additional Information
Stormwater Permit No. SW6200401
DSI Properties, LLC
Cumberland County
Dear Mr. Nobles:
The Division of Energy, Mineral and Land Resources MI :N I [ .R), received a Stormwater
Management Permit Application for the subject project on June 19, 2020. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
1. The SWU-101 application and Supplement EZ form list the project density as 34.39%,
however, the provided project area and built -upon area show the density to be
approx;rr,atPl-,, 790i Ph-ncr avninin and/nr rnrrart the rlicrrt-nanry
Total Project Area is mislabeled. Should be 3.64 acres. Project Impervious area (8) is correct at 33.394o. Drainage area impervious area
has been updated to 79.389u.
2. Please delineate all wetlands on the plan sheets or add a note that none exist [15A NCAC
02H .1042(2)(g)(3)]. Note added.
3. The bottom area of the infiltration system as shown in the Supplement EZ form and used
in the calculations should include only the main infiltration area and not the forebay.
This area has been updated in the EZ.
4. The drawdown calculations should be based on the bottom area of the infiltration system
and not the entire contour area at the maximum water level.
Drawdown has been recalculated as 31 hours. EZ has been updated.
Please provide complete grading showing the tinal contours of all new built upon area
and any other grading that will occur. Final contours have been add
6. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcop) of other
documents. Please only submit those plan sheets which have been revised as a result
of these comments. Pdfs must be uploaded using the form at:
https:Hedocs.deg.nc.gov/Forms/SW Project Submittal
North Carolina Depart ment of Environmental Quality I Division of Energy, Mineral and Land Resources
e��—D_EQ> 512 North Salisbury Street 1 1612 Mail Service Center 1 Raleigh, North Carolina 27649 1612
NVF r 919.707.9200

Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to August 12, 2020, or
the application will be returned as incomplete. The return of a project will necessitate
resubmittal of all required items, including the application fee. Please reference the State
assigned project number SW6200401 on all correspondence.
If you need additional time to submit the information, please submit your request for a time
extension to the Division at the contact below. The request must indicate the date by which you
expect to submit the required information. The Division is allowed 90 days from the receipt of
a completed application to issue the permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.
If you have any questions concerning this matter please feel free to contact me at
[e-mail] or [phone]. Please note that due to the ongoing Covid-19
pandemic, I will be teleworking and will be most easily reached by email.
Sincerely,
Steven C. Anen, PE
Environmental Engineer
Stormwater Program
cc: Fayetteville Regional Office
NOTE:
To adjust for reducing the surface area to main pool only, the overflow pipe was lowered to reduce the
drawdown times and reduce the volume to be infiltrated.

IV. PROJECT INFORMATION
1. In the space provided below, briefly summarize how the stormwater runoff will be treated.
Runoff from the proposed development will be diverted by 12ipe to a prposed infiltration basin
2. a. If claiming vested rights, identify the supporting documents provided and the date they were approved:
❑ Approval of a Site Specific Development Plan or PUD Approval Date:
❑ Valid Building Permit Issued Date:
❑ Other: Date:
b. If claiming vested rights, identify the regulation(s) the project has been designed in accordance with:
❑ Coastal SW - 1995 ❑ Ph II - Post Construction
3. Stormwater runoff from this project drains to the Cape Fear River basin.
4. Total Property Area: 3.60 acres
5. Total Coastal Wetlands Area: acres
6. Total Surface Water Area: acres
7. Total Property Area (4) - Total Coastal Wetlands Area (5) - Total Surface Water Area (6) = Total Project
Area+:3.60 acres
+ Total project area shall be calculated to exclude the following: the normal pool of impounded structures, the area
between the batiks of streams and rivers, the area below the Normal High Water (NHVV) line or Mean High Water
(MHM line, and coastal wetlands landward from the NHW (or MHV1>) line. The resultant project area is used to
calculate overall percent built upon area (BUA). Non -coastal wetlands landward of the NHW (or MHM line may
be included in the total project area.
8. Project percent of impervious area: (Total Impervious Area / Total Project Area) X 100 = 34.39 %
9. How many drainage areas does the project have?1 (For high density, count 1 for each proposed engineered
stormwater BMP. For low density and other projects, use 1 for the whole property area)
10. Complete the following information for each drainage area identified in Project Information item 9. If there
are more than four drainage areas in the project, attach an additional sheet with the information for each area
provided in the same format as below.
Basin Information
Drainage Area 1
Drainage Area _
Drainage Area
Drainage Area _
Receiving Stream Name
Rockfish Creek
Stream Class *
C
Stream Index Number *
18-31-(23)
Total Drainage Area (sf)
68,691
On -site Drainage Area (so
68,691
Off -site Drainage Area (so
0
Proposed Impervious Area** (sf)
54,528
% Impervious Area** total
79.38
Impervious— Surface Area
Drainage Area 1
Drainage Area
Drainage Area _
Drainage Area _
On -site Buildings/Lots (sf)
12,000
On -site Streets (sf)
On -site Parking (so
32,139
On -site Sidewalks (so
2139
Other on -site (sf)
8,250
Future (sf)
0
Off -site (sf)
0
Existing BUA*** (sf)
0
Total (so:
54,528
* Stream Class and Index Number can be determined at: littp. portal.ttcdettr.org/webAtyq&s/cstl/classiflcatiotts
Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
Form SWU-101 Version Oct. 31, 2013 Page 3 of 6

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 .Project Name
DSI Properties
2 Project Area (ac)
1.6
3 Coastal Wetland Area ac
0
4 Surface Water Area ac
0
5
Is this project High or Low Density?
High
6
Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H .1003(4)
7
Width of vegetated setbacks provded feet
8
Will the vegetated setback remain vegetated?
Yes
9
Is BUA other that as listed in .1003 4 c-d out of the setback?
Yes
10
Is streambank stabilization proposed on this project?
No
NUMBER AND TYPE OF SCMs:
11
Infiltration System
1
12
_
Bioretention Cell
0
13
Wet Pond
0
14
_
Stormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
0
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level Spreader -Filter Strip (IS-FS
0
20
Disconnected Impervious Surface DI5
0
21
_
Treatment Swale
0
22
Dry Pond
0
23
StormFilter
0
24
Silva Cell
0
25
Bayfifter
0
26
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Or anization:
Street address
City, State, Zips
Phone number::; 1:
Email:
Jeffre A. Nobles, PE
28
Larry King & Associates, RLS, PA
29
1333 Morganton Road, Suite 201
30
Fayetteville, NC 28305
31
910-4_83-4300
[e-mail]
32
Certification Statement.
I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or
supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and
that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent
with the information provided here
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Date

DRAINAGE AREAS
1
Is this a high densitproject?
Yes
2
If so, number of drainage areas/SCMs
1
3
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
d Type of SCM
5 Total BUA in project sq ft
Entire Site
9
Info Basin
54528 sf
54528 sf
New BUA on subdivided lots (subject to permitting)
6 1 (sq ft
7permitting)
New BUA outside of subdivided lots (subject to
Offsite - total area (sq ft
Offsite BUA sq ft
8
9
10
Breakdown of new BUA outside subdivided lots:
Parking (sq €t
32139 sf
32139 sf
Sidewalk N ft
2139 s€
2139 sf
Roof (sq ft
12000 sf
12000 sf
Roadway ft
Future (sq ft
Other, please specify in the comment box
below (sq ft
8250 sf
8250 sf
11
New infiltrating permeable pavement on
subdivided lots (sq ft
12
New infiltrating permeable pavement outside of
subdivided lots (sq ft
13permitting)
Exisitng BUA that will remain (not subject to
s ft
14
1 Existin 6UA that is aire ad ermitted (sq ff
sf
sf
15
Existing BUA that will be removed (sq ft
sf
sf
18
Percent BUA
34%
34%
17
Design storm inches
1 in
1 in
18
Design volume of SCM cu ft
4734 cf
4734 cf
19
Calculation method for design volume
1 Simple Method
Simple Method
ADDITIONAL INFORMATION
20
Please use this space to provide any additional information about the
drainage area(s):

INFILTRATION SYSTEM
1 Drainage area number 1
2 Design volume of SCM (cu ft) L 4?34 cf
GLNERAL MD[ FROM p2H ,1050
3 'Is the SCM sized to treat the SW from all surfaces at build -out? Yes
4
Is the SCM located away from contaminated soils?
Yes
5
What are the side slopes of the SCM (H:V)?
3:1
6
Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
Yes
7
jAre the inlets, outlets. and receiving stream protected from erosion (10-year storm)?
Is there an overflow or bypass for inflow volume in excess of the design volume?
8
Yes
9
What is the method for dewatering the SCM for maintenance?
Pump (preferred)
10
If applicable, will the SCM be cleaned out after construction?
Yes
11
Does the maintenance access comply with General MDC (8)?
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with General MDC
(10)?
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
15
Is there an O&M Plan that complies with General MDC (12)?
Yes
16
Does the SCM follow the device specific MDC?
Yes
17 Was the SCM designed by an NC licensed professional?
INFILTFIATI0N SYSTEM Mnr FRAM WN .7AS1
Yes
18
Proposed slope of the subgrade surface (%)
19
Are terraces or baffles provided?
No
20
IType of pretreatment:
Forebay
Solis Data
21
Was the soil investigated in the footprint and at the elevation of the infiltration
system?
SHWT elevation (fmsl)
Depth to SHWT per soils report (in)
Ground elevation at boring in soils report (fmsh
Is a detailed hydrogeologic study attached if the separation is between 1 and 2 feet?
Soil infiltration rate (inlhr)
Factor of safety (FS) (2 is recommended):
Bottom elevation (fmsl)
Yes
22
<105
23
144.00
24
117.00
25
Yes
26
2.00
27
2.00
Elevations
29
107 ft
30
Storage elevation (fmsl)
108. ft
31
jBypass elevation (fmsl)
111 ft
For Basins
Only
32
113ottom surface area, ft':
4600 ft
33
1 storage elevation surface area (ft)
5284. ft
rvr irrrfcnrs ver
34 Length (ft)
35 Width (ft)
36 Perforated pipe diameter, if applicable (in
37 Number of laterals
38 Total length of perforated piping
39 Stone type, if applicable
40 Stone void ratio (%)
41 Is stone free of fines?
42 Is the stone wrapped in geotextile fabric?
43 Has at least one infiltration port been pro,
VolumeslDrawdown
44 Design volume of SCM (cu ft)
45 Time to drawdown (hours)
ADDITIONAL INFORMATION
Please use this space to provide any add
46 system(s):
Infiltration 1 10:30 AM 9/11/2020

ENGINEERING - SURVEYING - DESIGNING - DRAFTING
Larry King & Associates, R.L.S., P.A.
P. [phone] www.LKandA.com F. [phone]
Anti -Flotation Sizing Calculations
Project Name: P19-039 DSI Properties
Outlet. 1
Min. Surface Area Required for Infiltration System
SA=FS*(DV*12) / (K+T)
SA= Required Surface Area (sf)
FA= Factor of Safety 2
DV= Design Volume (cf)
K= Infiltration Rate
T= Max Dewatering Time (hrs 72 hr
DA= 1.6 ac
68,691 sf
Water Quality Volume Required (by Simple Method)
VQV (DV)= 4,942 cf
Ksat= 2 in/hr
Surface Area Required to Achieve 3 Day Drawdown
SA= 1603 sf
Drawdown Time for WQV (Main Basin Area)
T= 30.8 hr
SA= 3,613 sf
Drawdown Time Below Overflow (Main Basin Area)
T= 68.3 hr
SA= 3,613 sf
DV= 10,588 cf
SC-5

Table of Contents
INFIL POND-TESTgpw
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:41 AM
Hydrograph Return Period Recap...................................................................... 1
1 -Year
SummaryReport................................................................................................................. 2
HydrographReports........................................................................................................... 3
Hydrograph No. 2, Reservoir, POST INFIL....................................................................... 3
PondReport................................................................................................................. 4
10 -Year
SummaryReport................................................................................................................. 5
HydrographReports........................................................................................................... 6
Hydrograph No. 2, Reservoir, POST INFIL....................................................................... 6
PondReport...........................................................
25 - Year
SummaryReport................................................................................................................. 8
HydrographReports........................................................................................................... 9
Hydrograph No. 2, Reservoir, POST INFIL....................................................................... 9
PondReport ............................................................................................................... 10
100 -Year
SummaryReport............................................................................................................... 11
HydrographReports......................................................................................................... 12
Hydrograph No. 2, Reservoir, POST INFIL..................................................................... 12
PondReport ............................................................................................................... 13
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Hydrograph Return Period Recap
Hyd.
Hydrograph
Inflow
Peak Outflow
(cfs)
Hydrograph
No.
type
Hyd(s)
description
(origin)
1-Yr
2-Yr
3-Yr
5-Yr
10-Yr
25-Yr
50-Yr
100-Yr
POST
1
Rational
-------
6.77
-------
-------
-------
10.43
11.70
-------
13.51
2
Reservoir
1
2.01
-------
-------
-------
2.67
2.84
-------
3.07
POST INFIL
3
Rational
-------
2.39
-------
----
-------
3.68
4.13
-------
4.77
PRE-
Proj. file: INFIL POND-TEST.gpw
Friday, Sep 11 2020, 9:40 AM
Hydraflow Hydrographs by Intelisolve

Hydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum 1 Hydrograph
storage description
(cuft)
1
Rational
6.77
1
57
30,667
----
------
------
POST
2
Reservoir
2.01
1
123
30,428
1
110.67
21,800
POST INFIL
3
Rational
2.39
1
6
860
----
------
------
PRE-
INFIL POND-TEST.gpw
Return Period: 1 Year
Friday, Sep 11 2020, 9:40 AM
Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:40AM
Hyd. No. 2
POST INFIL
Hydrograph type
= Reservoir
Peak discharge
= 2.01 cfs
Storm frequency
= 1 yrs
Time interval
= 1 min
Inflow hyd. No.
= 1
Max. Elevation
= 110.67 ft
Reservoir name
= INFIL BASIN
Max. Storage
= 21,800 cuft
Storage Indication method used.
M
5.00
4.00
3.00
NOR
1.00
0.00
0 3 5
— Hyd No. 2
POST INFIL
Hyd. No. 2 -- 1 Yr
Hydrograph Volume = 30,428 cuft
Q (cfs)
7.00
H. W
5.00
4.00
3.00
2.00
1.00
0.00
8 10 13 15 18 20 23 25 28
— Hyd No. 1 Time (hrs)
3

Pond Report
4
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:40AM
Pond No. 1 - INFIL BASIN
Pond Data
Pond storage is based on known contour areas. Average end area method used.
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cuft)
Total storage (cult)
0.00 107.00
4,600
0
0
1.00 108.00
5,284
4,942
4,942
2.00 109.00
6,008
5,646
10,588
3.00 110.00
6,772
6,390
16,978
4.00 111.00
7,575
7 174
24.152
5.00 112.00
9,299
8,437
32,589
6.00 113.00
10,220
9,760
42,348
7.00 114.00
11,180
10,700
53,048
8.00 115.00
11,180
11,180
64,228
9.00 116.00
12,180
11,680
75,908
Culvert / Orifice Structures
Weir Structures
[A] [B]
[C]
[D]
[A] [B]
[C]
[D]
Rise (in) = 8.00 0.00
0.00
0.00
Crest Len (ft)
= 0.00 0.00
0.00
0.00
Span (in) = 8.00 0.00
0.00
0.00
Crest El. (ft)
= 0.00 0.00
0.00
0.00
No. Barrels = 1 0
0
0
Weir Coeff.
= 3.33 0.00
0,00
0.00
Invert El. (ft) = 109.00 0.00
0.00
0.00
Weir Type
= --- ---
---
---
Length (ft) = 70.00 0.00
0.00
0.00
Multi -Stage
= No No
No
No
Slope (%) = 1.21 0.00
0.00
0.00
N-Value = .013 .000
.000
.000
Orif. Coeff. = 0.60 0.00
0.00
0.00
Multi -Stage = n/a No
No
No
Exfiltration = 2.000 in/hr (Contour) Tailwater Elev. = 0.00 ft
Note: Culvert/Orifice outflows have been analyzed under inlet and outlet control. Weir riser checked for orifice conditions
Stage (ft)
10.00
8.00
6.00
4.00
2.00
0.00
0.00 0.50 1.00 1.50
Total Q
Stage / Discharge
2.00
Stage (ft)
10.00
8.00
6.00
4.00
2.00
- 0.00
2.50 3.00 3.50 4.00
Discharge (cfs)

Hydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
POST
1
Rational
10.43
1
57
47,262
----
------
------
2
Reservoir
2.67
1
127
46,904
1
112.15
34,044
POST INFIL
3
Rational
3,68
1
6
1,325
----
------
------
PRE-
INFIL POND-TEST.gpw
Return Period: 10 Year
Friday, Sep 11 2020, 9:40 AM
Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
POST INFIL
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Inflow hyd. No. = 1
Reservoir name = INFIL BASIN
Storage Indication method used
10.00
8.00
6.00
4.00
2.00
0.00
0 3 5 8
Hyd No. 2
Friday, Sep 11 2020, 9:40 AM
Peak discharge
= 2.67 cfs
Time interval
= 1 min
Max. Elevation
= 112.15 ft
Max. Storage
= 34,044 cuft
POST INFIL
Hyd. No. 2 -- 10 Yr
Hydrograph Volume = 46,904 cuft
Q (cfs)
12.00
10.00
e
we]
4.00
2.00
0.00
10 13 15 18 20 23 25 28
Hyd No. 1 Time (hrs)
6

Pond Report
7
Hydraflow Hydrographs by Intelisolve
Pond No. 1 - INFIL BASIN
Pond Data
Pond storage is based on known contour areas. Average end area method used.
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cult)
Total storage (cuft)
0.00 107.00
4,600
0
0
1.00 108.00
5,284
4,942
4,942
2.00 109.00
6,008
5,646
10,588
3.00 110.00
6,772
6,390
16,978
4.00 111.00
7,575
7,174
24,152
5.00 112.00
9,299
8,437
32,589
6.00 113.00
10,220
9,760
42,348
7.00 114.00
11,180
10,700
53,048
8.00 115.00
11,180
11,180
64,228
9.00 116.00
12,180
11,680
75,908
Friday, Sep 11 2020, 9:40 AM
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[D]
[A]
[B]
[C]
[D]
Rise (in)
= 8.00
0.00
0.00
0.00
Crest Len (ft)
= 0.00
0.00
0.00
0.00
Span (in)
= 8.00
0.00
0.00
0.00
Crest El. (ft)
= 0.00
0.00
0.00
0.00
No. Barrels
= 1
0
0
0
Weir Coeff.
= 3.33
0.00
0.00
0.00
Invert El. (ft)
= 109.00
0.00
0.00
0.00
Weir Type
= ---
---
---
---
Length (ft)
= 70.00
0.00
0.00
0.00
Multi -Stage
= No
No
No
No
Slope (%)
= 1.21
0.00
0.00
0.00
N-Value
= .013
0111)
.000
.000
Orif. Coeff.
= 0.60
0.00
0.00
000
Multi -Stage = n/a No No No Exfiltration = 2.000 in/hr (Contour) Tailwater Elev. = 0.00 ft
Stage (ft)
10.00
8.00
6.00
4.00
2.00
0.00
Note: Culvert/Orifice outflows have been analyzed under ::let and outlet control. Weir riser checked for orifice conditions.
Stage / Discharge
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50
Total Q
Stage (ft)
10.00
8.00
6.00
4.00
2.00
-1- 0.00
4.00
Discharge (cfs)

Hydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
I Peak
flow
(cfs)
11.70
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
POST
1
Rational
1
57
53,044
----
------
------
2
Reservoir
2.84
1
128
52,644
1
112.61
38,583
POST INFIL
3
Rational
4.13
1
6
1,487
----
------
------
PRE-
INFIL POND-TEST.gpw
Return Period: 25 Year
Friday, Sep 11 2020, 9:40 AM
Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:40 AM
Hyd. No. 2
POST INFIL
Hydrograph type
= Reservoir
Peak discharge
= 2.84 cfs
Storm frequency
= 25 yrs
Time interval
= 1 min
Inflow hyd. No.
= 1
Max. Elevation
= 112.61 ft
Reservoir name
= INFIL BASIN
Max. Storage
= 38,583 cuft
Storage Indication method used.
10.00
8.00
&00
4.00
2.00
0.00
0 3 5 8
Hyd No. 2
POST INFIL
Hyd. No. 2 -- 25 Yr
Hydrograph Volume = 52,644 cuft
Q (cfs)
12.00
10.00
M
4.00
2.00
0.00
10 13 15 18 20 23 25 28
Hyd No. 1 Time (hrs)
9

Pond Report
10
Hydraflow Hydrographs by Intelisolve
Pond No. 1 - INFIL BASIN
Pond Data
Pond storage is based on known contour areas. Average end area method used.
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cult)
Total storage (cult)
0.00 107.00
4,600
0
0
1.00 108.00
5,284
4,942
4,942
2.00 109.00
6,008
5,646
10,588
3.00 110.00
6,772
6,390
16,978
4.00 111.00
7,575
7.174
24,152
5.00 112.00
9,299
8,437
32,589
6.00 113.00
10,220
9,760
42,348
7.00 114.00
11,180
10,700
53,048
8.00 115.00
11,180
11,180
64,228
9.00 116.00
12,180
11,680
75,908
Friday, Sep 11 2020, 9:41 AM
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[D]
[A]
[B]
[C]
[D]
Rise (in)
= 8.00
0.00
0.00
0.00
Crest Len (ft)
= 0.00
0.00
0.00
0.00
Span (in)
= 8.00
0.00
0.00
0.00
Crest El. (ft)
= 0.00
0.00
0.00
0.00
No. Barrels
= 1
0
0
0
Weir Coeff.
= 3.33
0.00
0.00
0.00
Invert El. (ft)
= 109.00
0.00
0.00
0.00
Weir Type
= ---
---
---
---
Length (ft)
= 70.00
0.00
0.00
0.00
Multi -Stage
= No
No
No
No
Slope (%)
= 1.21
0.00
0.00
0.00
N-Value
= .013
.000
.000
.000
Orif. Coeff.
= 0.60
0.00
0.00
0.00
Multi -Stage = n/a No No No Exfiltration = 2.000 in/hr (Contour) Tailwater Elev. = 0.00 ft
Stage (ft)
10.00
8.00
6.00
4.00
2.00
0.00 -1
0.00
0.50 1.00
Total Q
Note: Culvert/Orifice outflows have been analyzed under inlet and outlet control. Weir riser checked for orifice conditions.
Stage / Discharge
1.50 2.00 2.50 3.00 3.50
Stage (ft)
10.00
8.00
6.00
4.00
2.00
___L_ 0.00
4.00
Discharge (cfs)

11
Hydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
POST
1
Rational
13.51
1
57
61,228
----
------
------
2
Reservoir
3.07
1
130
60 770
1
113.26
45,160
POST INFIL
3
Rational
4.77
1
6
1,716
----
------
------
PRE-
INFIL POND-TEST.gpw
Return Period: 100 Year
Friday, Sep 11 2020, 9:41 AM
Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:41 AM
Hyd. No. 2
POST INFIL
Hydrograph type
= Reservoir
Peak discharge
= 3.07 cfs
Storm frequency
= 100 yrs
Time interval
= 1 min
Inflow hyd. No.
= 1
Max. Elevation
= 113.26 ft
Reservoir name
= INFIL BASIN
Max. Storage
= 45,160 cuft
Storage Indication method used. Hydrograph Volume = 60,770 cult
12.00
10.00
M
Mr
4.00
2.00
POST INFIL
Hyd. No. 2 -- 100 Yr
3 5 8 11 13
Hyd No. 2 Hyd No. 1
Q (cfs)
14.00
12.00
10.00
M
M
4.00
2.00
0.00
16 19 21 24 27
Time (hrs)
12

Pond Report
13
Hydraflow Hydrographs by Intelisolve
Friday, Sep 11 2020, 9:41 AM
Pond No. 1 - INFIL BASIN
Pond Data
Pond storage is based on known contour areas. Average end area method used.
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cuft)
Total storage (cuft)
0.00 107.00
4,600
0
0
1.00 10800
5,284
4,942
4,942
2.00 109.00
6,008
5,646
10,588
3.00 110.00
6,772
6,390
16,978
4.00 111.00
7,575
7,174
24,152
5.00 112.00
9,299
8,437
32,589
6.00 113.00
10,220
9,760
42,348
7.00 114.00
11,180
10,700
53,048
8.00 115.00
11,180
11,180
64,228
9.00 116.00
12,180
11,680
75,908
Culvert / Orifice Structures
Weir Structures
[A] [B]
[C]
[D]
[A►] [B]
[C]
[D]
Rise (in) = 8.00 0.00
0.00
0.00
Crest Len (ft)
= 0.00 0.00
0.00
0.00
Span (in) = 8.00 0.00
0.00
0.00
Crest El. (ft)
= 0.00 0.00
0.00
0.00
No. Barrels = 1 0
0
0
Weir Coeff.
= 3.33 0.00
0.00
0.00
Invert El. (ft) = 109.00 0.00
0.00
0.00
Weir Type
= ---
---
---
Length (ft) = 70.00 0.00
0.00
0.00
Multi -Stage
= No No
No
No
Slope (%) = 1.21 0.00
0.00
0.00
N-Value = .013 000
000
.000
Orif. Coeff. = 0.60 0.00
0.00
0.00
Multi -Stage = n/a No
No
No
Exfiltration = 2.000 in/hr (Contour) Tailwater Elev. = 0.00 ft
Note: Culvert/Orifice outflows have been analyzed under inlet and outlet control. Weir riser checked for orifice conditions
Stage (ft)
10.00
8.00
6.00
4.00
2.00
0.00
0.00 0.50 1.00 1.50
Total Q
Stage / Discharge
2.00
Stage (ft)
10.00
8.00
6.00
4.00
2.00
0.00
2.50 3.00 3.50 4.00
Discharge (cfs)