SW8941008_HISTORICAL FILE_19941118 (2)

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8 �IkA IUO S
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
�T HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
01014 l 1 1 8
YYYYMMDD

A
State of North Carolina
Department of Environment, Health, and Natural Resources
Wilmington Regional Office
James B. Hunt, Jr., Governor DIVISION OF ENVIRONMENTAL MANAGEMENT Bob Jamieson
Jonathan B. Howes, Secretary WATER QUALITY SECTION Regional Manager
November 18, 1994
Mr. Mark Maynard
Mark Maynard Construction Co.
Post Office Box 5601
Wilmington, North Carolina 28403
Subject: CERTIFICATION OF COMPLIANCE
with Stormwater Regulations
Stormwater Project No. SW8 941008
Meridian Village Apartments-NorthChase
New Hanover County
Dear Mr. Maynard:
This Certification is pursuant to the application for the Meridian Village Apartments-NorthChase
received on October 7, 1994, with additional information received on November 7, 1994. Staff review
of the project plans and specifications has determined that the stormwater control system as proposed for
Meridian Village Apartments-NorthChase will comply with the Stormwater Regulations set forth in Title
15A NCAC 2H.1003(i). The runoff from 129,390 square feet of impervious surface will be treated in
a detention pond sized to achieve 90% reduction in Total Suspended Solids.
Any modification of the plans submitted to and approved by this Office or further development
of this site regardless of the fact that the modification may be less than 1 acre, will require an additional
Stormwater Submittal/Modification and approval prior to initiation of construction. Modifications include
but are not limited to; project name changes, transfer of ownership, redesign of built -upon surfaces,
addition of built -upon surfaces, redesign or further subdivision of the project area.
This Certification shall be effective from the date of issuance until rescinded. The project shall
be constructed and maintained in accordance with the plans and specifications approved by the
Wilmington Regional Office. This Certification does not supersede any other permit or approval. The
developer is responsible for obtaining any and all permits and approvals necessary for the development
of this project. This could include the Division of Coastal Management under CAMA requirements, the
Division of Environmental Management under Wetland 401 Water Quality Certification and/or a Dredge
and Fill Permit and/or a Sewer Extension/Collection Permit, U.S. Army Corps of Engineers 404 Wetland
Permit, NPDES Stormwater Permit if disturbing five acres or more, local County or Town Agency
permits under their local ordinances, or others that may be required.
127 Cardinal Drive Extension, Wilmington, N.C. 28405-3845 • Telephone [phone] • Fax [phone]
An Equal Opportunity Affirmative Action Employer

Mr. Maynard
November 18, 1994
Stormwater Project No. SW8 941008
A professional engineer must certify that the stormwater system has been installed in accordance
with the approved plans and specifications upon completion of construction. The attached certification
should be received by this Office within 30 days of completion of construction.
The detention pond must be constructed in it's entirety, operational for it's intended use, and
permanently vegetated prior to the construction of any impervious surfaces proposed as a part of the
project, except roads.
If you have any questions concerning this matter, please call Ms. Linda Lewis or me at (910) 395-
3900.
Sincerely,
Dave Adkins
Water Quality Supervisor
DA/arl: S:\WQS\STORMWAT\CERTIFIC\941008.NOV
cc: Jim Honeycutt, P.E.
Sky Conklin, New Hanover County Inspections
Bradley Bennett
Beth Easley, New Hanover County
Linda Lewis
Wilmington Regional Office
Central Files

DIVISION OF ENVIRONMENTAL MANAGEMENT
PROJECT DATA
Project Name: Meridian Village Apartments-NorthChase
Project Number: SW8 941008
Location:
Applicant:
Mailing Address:
Submittal Date:
Water Body Receiving Stormwater Runoff:
Classification of Water Body:
If Class SA, chloride sampling results:
Pond Depth:
Permanent Pool Elevation:
Total Impervious Surfaces Allowed:
Offsite Area entering Pond:
Green Area entering Pond:
Required Surface Area:
Provided Surface Area:
Required Storage Volume:
Provided Storage Volume:
Temporary Storage Elevation:
Controlling Orifice Type/Diameter:
New Hanover County
Mr. Mark Maynard
Mark Maynard Construction Co.
Post Office Box 5601
Wilmington, North Carolina 28403
October 7, 1994
Smith Creek
"C Sw"
N/A
7.5 feet
30.05 MSL
129,390 square feet
N/A square feet
85852 square feet
4,100 square feet
4,200 square feet
11,800 cubic feet
11,800 cubic feet
32.29 MSL
1.5" pipe

WET DETENTION POND EVALUATION
1. Yes No The design storage is for the runoff from all impervious surfaces resulting from
1-inch of rainfall and is located above the permanent pool.
2. Yes No The permanent pool is designed for 90% total suspended solid (TSS) removal.
Therefore, no vegetative filter is required.
3. Yes No The runoff completely draws down to the permanent pool in 5 days, but not less
than 2 days.
4. Yes No The mean depth of the permanent pool is a minimum of 3 feet.
5. Yes No The inlet stnicture is designed to minimize turbulence and short circuiting.
6. Yes No An appropriate operation and maintenance plan has been provided for the
system.
7. Yes No THIS PROJECT MEETS THE STORMWATER CONTROL REQUM04EN1'S
OF 15A NCAC 2H.1003 (g), (i), (k), and (1) (For Yes, 1 through 7 must all
be highlighted Yes.)
Brief Explanation: This detention pond is designed to remove 90% total suspended solids without the
aide of a vegetative filter.
DIVISION OF ENVIRONMENTAL MANAGEMENT SIGN -OFF
Wilmington Regional Office
Date
Individual Evaluating Form/Plans
Date—Rdgio`nal Water Quality Supervisor
cc: Applicant/Bradley Bennett/arl/WiRO/CF

Meridian Village Apartments-NorthChase
New Hanover County
Stormwater Project No. SW8 941008
Engineer's Certification
I,
as a duly registered Professional Engineer in the State
of North Carolina, having been authorized to observe (periodically/weekly/full time) the construction of
the project,
(Project)
for (Project Owner) hereby state that, to the best of my abilities,
due care and diligence was used in the observation of the project construction such that the construction
was observed to be built within substantial compliance and intent of the approved plans and specifications.
Signature
Registration Number
Date

POND MAINTENANCE REQUHLEMENTS
Project Name: /1,r/71G1,9.✓ (/,//#&I- L.L. C. Project No. 5w5 R4/ODE
Responsible Party: /%4ef&oA1 (/,(I~ L. L. G. Phone No. 799- .f 1 G y
yo ^fA& tadsn co.
Address:_14 p. dlox ,s/ p/ , u�� /.,�..o-io .i iY c
L Monthly, or after every runoff producing rainfall event, whichever comes first:
A. Inspect the trash rack; remove accumulated debris, repair/replace if it is not functioning.
B. Inspect and clear the orifice of any obstructions. If a pump is used as the drawdown
mechanism, pump operation will be checked. A log of test runs of the pump will be kept
on site and made available to DEM personnel upon request.
C. Inspect the pond side slopes and grassed inlet swales; remove trash, and repair eroded
areas before the next rainfall event.
D. If the pond is operated with a vegetated filter, the filter will be checked for sediment
accumulation, trash accumulation, erosion and proper operation of the flow spreader
mechanism. Repairs/cleaning will be done as necessary:,
II. Quarterly:
A. Inspect the collection system (ie. catch basins, piping, grassed swales) for proper
functioning. Accumulated trash will be cleared from basin grates, basin bottoms, and
piping will be checked for obstructions and cleared as required.
B. Pond inlet pipes will be checked for undercutting, riprap or other energy dissipation
structures will be replaced, and broken pipes will be repaired.
M. Semi-annually:
A. Accumulated sediment from the bottom of the outlet structure will be removed.
B. The pond depth will be checked at various points. If depth is reduced to 75 % of original
design depth or 3 feet whichever is greater, sediment will be removed to at least the
original design depth.
C. Grassed swales, including the vegetated filter if applicable, will be reseeded twice a year
as necessary.
YY
i � F' �,
APPROVED `1 2` jr♦" d LK
NORTH CAROUNA Fq" (IRONMEfJTAL I nl E C E OWE UD
MANAGEMEr ' r.'.:,.tiSSION
DIVISION OF ENVIHGNMENTAL MANAGEMENT
Date 18 NOV 1994 NOV 0 ? 1994
StormwaterCee,iticationNo.Slw? 0(4100$ D E M
VRoJ # 5Gu8g4/00F

POND MAINTENANCE REQUIREMENTS
PAGE 2
IV. General:
A. Mowing of the side slopes will be accomplished according to the season. Maximum grass
height will be 6".
B. Cattails are encouraged along the pond perimeter, however they will be removed when they
cover more than 1/2 the surface area of the pond.
C. The orifice/pump is designed to draw down the pond in 2-5 days. If drawdown is not
accomplished in that time, the system will be checked for clogging. The source of the
clogging will be found and eliminated.
D. All components of the detention pond system will be kept in good working order. Repair
or replacement components will meet the original design specifications as per the approved
stormwater plan.
V. Special Requirements:
I, A-4-4x G• ^4YA AR hereby acknowledge that I am the financially
responsible party for maintenance of this detention pond. I will perform the maintenance as outlined
above, as part of the Certification of Compliance with Stormwater Regulations received for this project.
Signature: Date:
NuTtePy a Notary Public fortheStateof /VuRiN C'6 (ZoL�Nii
County of No Ui5r do hereby certify that MARK L, M,4� A
personally appeared before me this -1 day of 1911 q- , and acknowledge the
due execution of the foregoing instrument. Witness my hand and official seal,
�CSEAL r h
My commission ex ires '
MY COMMISSION EX IRES
MAY 18, 1997 :�fiy .. • • .. • ' `
DA/arl: S:\WQS\STORMWAT\FORMS\O&M-POND. FOR ygNOVER CO��.''

DIVISION OF ENVIRONMENTAL MANAGEMENT
DENSITY ENGINEERED
PROJECT DATA
Project Name N D RTNGiftYfE ROi4RT na EfJTS
i
Location (County, Township/Municipality, Address, State Road) No ATNCilA-SF PARKwAy
SOUT/FE/tT% , NEW hHWOVEl2 C_ou/JT-/ ;.'
Owner's Name MARK MP,'4rJ fAD C.oiJSTRucTioN C.O.
MailineAddress P• o . g oX S/oo 1
Phone Number -7 e 9 - 572. (6 4 Submittal Date
Brief Description (include map and appropriate drawings) co n(STRv cT 104 APA-RTMeNTS
Name of Water Body, Receiving Stormwater Runoff 1) AII1Q TRia) i/iR.Y -M SlvI1TH C12EEK
ND CA FEAp_ RIVED— SI
Classification of Water Body C— SW If SA waters, engineered system, and distance is <0.5
miles, attach report of chloride sampling results mg/I _
State/Federal Permits/Approvals Required (Check appropriate blanks)
CAMA Major Sedimentation/Erosion Control
404 Permit DEM/DHS Sewage Disposal
Other (Specify) SEW Erg Ex-M N s t o u, w A TIF-2 u ^/ E 6XTEWSi o tJ
CALCULATION OF BUILT UPON AREA
Built upon area means that portion of a development that is covered by impervious or partially pervious -cover
including buildings, pavement, recreation facilities, gravel, etc., but not including wood decking. If the project
includes areas draining to different water classifications, please note them separately below.
Subwatershed Subwatershed
Classification
CS lid
Built upon area
Z 6q A cRrFS
Total Project Area
7 3z4 rrcR03
% Built upon Area
3 6. 8 `70
Allowable B/U Area 2.'2-0 AcizL3
Is the Project B/U Area 5 the Allowable B/U Area? N O (If no, an engineere
% Built upon area = (built upon area / total project area) • 100
Built upon area limits for projects to meet density: SA waters — 25%, Other —30%
STORMWATER COLLECTION SYSTEM
Describe how the runoff will be treated tN E r D E"rrW T101'J Po N 9
i system is requtrea.)
Office use only
Inl��U�
OCT 0 71994 U
DEM-
'ROJ 0s 8 94100 •

BUFFER AREA'
Is the built upon area at least 30 feet from mean high water of all surface waters? E-5� If no, please
provide a description N/A
(Note: Only boat ramps, public roads, public bridges, and walkways to water related facilities are whew•_
within 30. feet of the mean high water line if the project is intended to meet stormwater control
requirements through density limits.)
DEED RESTRICTIONS AND PROTECTIVE COVENANTS
By my signature below, I certify that the recorded deed restrictions and protective covenants for this project
shall limit the allowable built -upon area per lot to r4I A square feet inclusive of right-of-way,
structures, pavement, walkways or patios of brick, stone, or slate, not including wood decking, state that
the covenants will be binding on all parties and persons claiming under them, that they will run with the
land, and that benefits may be enforced by the State of North Carolina, therefore, the covenant cannot be
changed or deleted without consent of the State.
CERTIFICATION
I, ftpr 1.. /-to-ymnaN , certify that the information included on this
submittal form is correct, that the project will be constructed in conformance with this information, and
that to the best of my knowledge, the proposed project complies with the requirements of 15 NCAC
2H.1003 (b). I authorize the below named person or firm to submit stormwater plans on my behalf, and
agree to abide by the deed restriction statement above.
Owner's Signature D to
Provide authorized person or firm name and address below:
1MPRcT EN61�/t�n1NG1 P.C.
38o5r W1Q146t+TSVIILL /NVE, vn 1T /-7
W1t.M/rV6rbr/ / n1G 2-S4o3
I, ,a Notary Public fo eStateo
County of do ereb certi that [ personally
appear d befbfe.me this day of 19 acknowledges the due execution
o¢ rapn� ru nt. Witness my h ' and official seal,
�. l�
ivly cosrmdssica ex
DIVISION OF ENVIRONMENTAL MANAGEMENT SIGN -OFF
Regional Office
16 Nvv 94
Date
10lo,,&K I45/
Date 11
et,"C(rL
Individual Evaluating Forms/Plans
�... ellh
cc: Applicant/WiRO/Bradley Bennett/Central Files
Quality Supervisor
4

Dec-09-97 05:20P HONEYCUTT ENGINEERING CO. 910 350-0631 11.03
Meridian Village Apartments FILE
New Hanover County
Stormwater Project No. SW8 941008
Engineer's Certification
I, . AAO R• RO.OYC, it ,. ,%R__0F. , as a duly registered Professional Engineer in the State
of North Carolina, having been autholized to observe (periodically/weekly/full time) the construction of the
project,
MERIDIAN v/tc,*af STORM tv.4TER (Project)
for M EZO dq tj v r L L A C, E L (_ C (Project Owner) hereby state that, to the best of my abilities,
due care and diligence was used in the observation of the project construction such that the construction was
observed to be built within substantial compliance and intent of the approved plans and specifications.
Please note any deviations from the approved plans below:
Signature
Registratil
Date

C
Drainage Calculations for Northchase Apts., Wilmington, NC
Project IEE4076 9/2/94 -Revised 10/29/94
A _ 215095 A = 4.9379 acres ...total drainage area
total 43560 total 9
A 67939
paved'- 43560
11743
A side 43560
49344
A bidg - 43560
3.64
A misc 43560
A paved = 1.56
A side = 0.27
A bidg = 1.133
acres ...parking area minus interior landscaping
acres
A misc = 0.004 acres
...sidewalk area
acres ...Total area of buildings
Dumpster pads
A imp A paved + A misc + A side A imp = 1.834 acres - total impervious area excl.
bldgs
A other A total - A Imp - A bidg A other = 1.971
C pre := .20 ...predevelopment C C bldg '= 1.00
C Imp := .95 ...paved area C
11 :�
C comp - C pre.
re q ototalr J + C imp (A total, + C bidg' �Atotal/ 3
C comp = 0.66 ...composite C (post -development)
L := 500 ft
H := 3.5ft
( 3 385
T :- `H�
c 128
T c = 6.3 minutes
Intensity -Duration -Frequency Relationships:
Values of G and H•
R G H
10 252 30
50 338 33
R= Return Period
`Source: Master Drainage Plan for City of Wilmington
...hydraulic length
...height
...time of concentration
SEAL
9524
iD)E C EuuL�nl
W NOV 0 7 1994 U
D.EM
PROJ #

0
T := T c Time of duration
G 10:= 252
H 10 := 30
1 10 := G 10 1 10 = 6.94 in/hr
(H 10 + T)
G 50 := 338 H 50 := 33
50 (H o50 T) 150 = 8.596 irVhr
Compute runoff rates:
10 year storm intensity
...50 year storm
Q pre C pre' 110' A total
Q pre = 6.85 cfs ...pre -development runoff from 10 yr. storm
Page 2
Q 10 C comp' 1 10, A total
Q 10 = 22.68 cis ...post -development discharge rate to pond from 10 yr. storm
Q 50 = C comp' 150, A total
Q 50 = 28.1 cis ...past -development discharge rate to pond from 50 yr. stone
Volume of runoff from developed area of site:
P := 4.8 in
Soil type = Seagate
CN := 70 Curve No.
S.=(C�)-10 S=4.286
R de th _ (P - 0.2• S )2 R de th = 1.889 in.
p P i .8 S p
R vol '= R depth' (A total)' 43560• 12 R Vol = 33865
T - R depth' `A total 1 43560 1
p 1.39•(a10) (12) 60
T p = 17.9
...runoff depth
cubic feet ...total runoff volume
time to peak flow

Determine size of 7.5' deep pond without vegetative filter: Page 3
IMP% := A imp + A bid g IMP% = 0.601
A total
IMP% 6o := .019
IMP% 70 := .023
IMP := IMP% 60 + IMP% 70 - IMP% 60)..1
IMP = 0.0194
DA := A total'43560
SA := ( IMP)• DA
SA = 4173
Determine storage volume required for treatment of first Inch of runoff:
C comp = 0.662
V :_ 1 12 .A total' 43560•C comp
V = 11867 cubic feet
Assume 37.5' x 112' pond. Solve for depth "d" to provide required storage:
I .= 112 w := 37.5 w• I = 4200
d := 1.5 ...guess value
f(d) .= I.w+(I t6•d).(w+6•d) d
2
g(d) := V
d.= root((f(d) - g(d)).d)
...function of d for rectangular pond w/3:1 side slopes
d = 2.24 ft. - depth required to provide required storage for 1 inch
Determine size of orifice for drawdown of first inch:
Q Q 2day = 0.0687 cis ... Max discharge for 2 day drawdown with site
2day 2 24 60 60
fully developed
_ V
5day 5.24-60-60 Q 5day = 0.0275 cis ...Max discharge for 5 day drawdown with site
fully developed
g := 32.2 C d 6 ...orifice coefficient
h := 2 h = 1.12 ft ...avg. head
A onfic Q 2day A orifice = 0.013 Square ft.
Cd(2gh).s

5
D = (4-- A orifice 12
3.14 )
Q 5day = 0.0275 cis
A
Q 5day
orifice _
Cd.(2 g h).s
A orifice s
D := 4. 12
3.14 ),
D = 1.57 in. - for 2 day drawdown
A orifice = 0.005 Square ft.
D = 0.994 in - for 5 day drawdown
Use 1.5 Inch diameter pipe In routing chart
Check capacity of emergency spillway to pass 50 year peak flow:
L := 10 ft ...Length of weir
H :_ 12 ft ...Driving head C w .= 3.0 ...Weir coefficient
Q C w L. 1-11'5 ...Weir capacity
Q = 30 must be => Q 50 = 28.1 O.K
Page 4
Find normal depth in spillway channel with grass as a permanent lining:
Q 28.1 ..flow in channel in cis
B := 10 ...bottom width of channel (ft)
M .= 3 ...side slopes
s = 34.253- 27.0 s = 0.186 ...channel slope
n := 0.043 ...roughness coeff. for grass lined channels Retardance Class D (cut) based on V x R
below
Z req .= Q-n Z req = 1.881 ..Z required (from R. Malcolm)
1.49 Ns
y :_ .36 ...depth of flow (ft.) - vary this number until Zav (below) is approx. equal to Z.req
(above) when n (above) is appropriate for V x R (below)
A := B• y + M• (y)2 ...Cross -sectional area of flow (sq.ft.) at depth y
P := B + 2. y 1 + M2 ... Wetted perimeter (ft.) at depth y
R := P ...Hydraulic radius (ft.) at depth y
2
Z av A. (R) 3 Z av - 1.885 ...Z available

Compute velocity at this depth:
Page 5
2 1
V := 1.49 R3 s2 V = 7.061 fps
n
V. R = 2.294 Using this value, choose n from Figure 8.05c page 8.05.7 and adjust n above until
consistent
From Table 8.O5a page 8.05A.
V p := 3.5 fps - Permissible Velocity for channels lined with bernudagrass with slopes >10% in
easily erodible non -plastic soils
Since V>Vg. another channel lining will have to be used
Determine normal depth in channel using riprep as a permanent lining:
Q = 28.1 ..flow in channel in cfs
B = 10 ...bottom width of channel (ft)
M = 3 ...side slopes
s = 0.186 ...channel slope
n :_ .078 ...roughness coeff. for 12" riprap with flow = .5 ft. (must be consistent with depth of flow)
Z req := Q-n� Z req = 3.412 ...Z required (from R.Malcolm)
1.49 Ns
y :_ .509 ...depth of flow (tt) - vary this number until Zav (below) is approx equal to Z.req
(above) - may also have to vary n above to be consistent with this depth
A := 8- y + M• (y )2 ...Cross -sectional area of flow (sq.ft.) at depth y
P :_ !3 + 2 y 1 + M2 ...Wetted perimeter (ft.) at depth y
R := P ...Hydraulic radius (ft.) at depth y
2
Z av := A. (R) 3 Z av = 3.414 ...Z available
Compute velocity at this depth:
2 1
V := 1.49 R3•s2 V =4.792 fps
n
Size riprap using Tractive Force Procedure:
T d := 6.00 ...permissible shear stress in Ib/sq.ft for 12" riprap
y := 62.4 ...unit weight of water, Ib/cu.ft.
s = 0.186 ...channel slope, ft/ft
d := y ...flow depth, ft
T := r d• s
T=5.904 < Td=6 O.K
d 50 := 1 ft - minimum

0
dmax:= 1.5.d5o.12
d max = 18 inches maximum riprap size
depth := 1.5 d max
depth = 27 inches minimum depth of riprep
Using a 15" barrel, check velocity at outlet:
D := 1.25ft q := 6.82 ...max barrel discharge from routing sheets
A pipe xx 4D2 A pipe = 1.227
V outlet A q V outlet = 5.56 fps
pipe
Page 6
Determine outlet apron dimensions and riprap size for discharge from pond:
Since invert of pipe is discharging into the bottom of an existing drainage ditch, assume maximum
taiiwater conditions.
L a := 9 ft - minimum length of apron from figure 8.06b
d 50 :_ .33 ft -minimum -from figure 8.06b
d max := 1.5•d 50.12
d max = 5.94 use d max := 6 inches maximum riprap size
depth := 1.5. d max
depth = 9 inches minimum depth of riprap
Determine outlet apron dimensions and riprap size for discharge into pond:
D := 2 ft q := 17.4 ds V := 5.6 fps ...outlet discharge from pipe chart
Since invert of pipe is discharging below the max. stage of the pond, assume maximum tailwater
conditions.
L a := 10 ft - minimum length of apron from figure 8.06b
d 50 : _ .33 ft - minimum - from figure 8.06b
d max := 1.5 d 50.12
d max = 5.94 use d max := 6 inches maximum riprap size
depth := 1.5•d max
depth = 9 inches minimum depth of riprap
REFER TO ATTACHED SHEETS FOR ROUTING RESULTS
Note: References to chart nos., table nos., and page nos. refer to Erosion and Sediment Control
Planning and Design Manual unless noted otherwise

S Z
CONTOUR INCR ACCUN
CONTOUR AREA VOL VOL STAGE In S In Z Z eat
29.00
4200
0 0
0.00
0.00
30.30
4657
2214 2214
0.50
7.7027
-0.6931
0.51
30.80
5133
2448 4662
1.00
8.4471
0.0000
0.90
31.30
5627
2690 7352
1.50
8.9027
0.4055
1.46
31.80
6138
2941 10293
2.00
9.2392
0.6931
1.96
32.04
6390
1503 11796
2.24
9.3755
0.8065
2.21
32.80
7215
5170 16966
3.00
9.7390
1.0986
3.04
33.20
7781
2999 19965
3.40
9.9017
1.2238
3.50
Regression
Output:
Constant
8.4654
Rs- 4748
Std Err of Y Eat
0.0294
b- 1.15
R Squared
0.9900
No. of Observations
7
X Coefficient(s)
1.14697
Std Err of Coef.
0.01777

STAGE -DISCHARGE FOR RISER/BARREL SPILLWAY WITH EMERGENCY WEIR
RISER/BARREL:
7.5
Q.pre-6.85
Dr
-
3.516
Area of grate openings
6.82
Etop
-
33.01
Elev. top riser (ft)
34.26
Cwr
-
3
Riser weir coefficient
Cdr
-
0.59
Riser orifice coefficient
Do
-
1.50
Orifice dia.(in)
Einv
-
29.80
Elev inv. orifice (ft)
Co
-
0.6
Orifice coeff.
Db
-
1.25
ft.
Binv
-
27.5
Barrel invert
Cdb
-
0.6
EMERGENCY
WEIR:
Cw
-
3
Weir coefficient
Ecr
-
34.5
Elev. weir crest (ft)
Lw
-
10
Weir length (ft)
1
2
3
4
5
6 7
8
Stage
Riser
Riser
Barrel
1.50
Princ. Emerg.
Total
(weir)
(orifice)
orifice
Spillway Weir
Outflow
[ft]
[cfe]
fare]
[ere]
[ere]
[erg] [ere]
[erg)
29.80
0.00
0.00
0.00
0.00
0.00 0.00
0.00
30.30
0.00
0.00
0.00
0.04
0.00 0.00
0.04
30.80
0.00
0.00
0.00
0.06
0.00 0.00
0.06
31.30
0.00
0.00
0.00
0.07
0.00 0.00
0.07
31.60
0.00
0.00
0.00
0.08
0.00 0.00
0.08
32.30
0.00
0.00
0.00
0.09
0.00 0.00
0.09
32.80
0.00
0.00
0.00
0.10
0.00 0.00
0.10
33.30
0.00
0.00
0.00
0.11
0.00 0.00
0.11
33.80
0.00
0.00
0.00
0.12
0.00 0.00
0.12
34.30
7.72
11.65
15.40
0.13
7.72 0.00
7.84
34.80
22.16
16.56
15.96
0.13
15.96 4.93
21.02
35.30
40.92
20.32
16.49
0.14
16.49 21.47
38.10
35.80
63.16
23.48
17.01
0.14
17.01 44.47
61.63
36.30
88.41
26.27
17.52
0.15
17.52 72.45
90.12
36.80
116.33
28.79
18.01
0.16
18.01 104.64
122.81
37.30
146.70
31.10
18.49
0.16
18.49 140.56
159.21
37.80
179.33
33.25
18.95
0.17
18.95 179.84
198.96

C
COMPOSITE STAGE DISCHARGE
40
0.00
29.80 31.80 33.80 35.80 37.80
STAGE
-11—R(W) — —R(0) --♦-BARREL t1"OFURC E tEw

NET STAGE DISCHARGE
Em
N 20.00
v
W
p 10.00
�m
29.80 31.80 33.80 35.80 37.80
STAGE

9/3Z94
CHAINSAW ROUTING
Input data:
Northchase Apartments
Qp- 22.68 RESULTS:
Tp- 17.9 OUTFLOW PEAR- 6.02
MAX STAOE- 34.26
dT- 1.8
Rs-
4740
b-
1.15
7.5
Etop -
33.01
Top of riser
Dr -
3.516
Area of grate openings
Db-
1.25
Binv-
27.5
N-
1
No. of orif.
Cd-
0.6
Orifice coeff.
D-
1.5
Din. of orifice
2i-
29.8
Inv. elevation
Cw- 3 Weir Coefficient
L- 10 Length of overflow weir
2cr- 34.5 Elev. of overflow weir

1 2 3 4 5 6 7 8
TIME INFLOW STORAGE STAGE OUTFLOWORIFICE WEIR RISER/
[min) [cfs] [cu ft] [ft] [cfs] [cfs] [cfs] BARREL
0
0.00
0
29.0
0.00
0.000
0.09
0.00
1.8
0.56
0
29.80
0.00
0.000
0.00
0.00
3.6
2.19
61
29.82
0.00
0.000
0.00
0.00
5.4
4.72
297
29.89
0.00
0.000
0.00
0.00
7.2
7.91
807
30.01
0.02
0.023
0.00
0.00
9
11.44
1659
30.20
0.03
0.034
0.00
0.00
10.8
14.96
2891
30.45
0.05
0.045
0.00
0.00
12.6
18.12
4501
30.75
0.06
0.056
0.00
0.00
14.4
29.61
6452
31.11
0.07
0.066
0.00
0.00
16.2
22.18
8671
31.49
0.O8
0.075
0.00
0.00
18
22.68
11050
31.09
0.08
0.084
0.00
0.00
19.8
22.06
13490
32.29
0.09
0.092
0.00
0.00
21.6
20.37
15870
32.66
0.10
0.099
0.00
0.00
23.4
17.99
16059
33.01
0.10
0.105
0.00
0.00
25.2
15.79
19991
33.30
0.11
0.110
0.00
0.00
27
13.05
21684
33.56
0.11
0.114
0.00
0.00
28.0
12.15
23160
33.78
0.12
0.117
0.00
0.00
30.6
10.67
24460
33.90
1.66
0.120
0.00
1.54
32.4
9.36
25441
34.12
4.04
0.122
0.00
3.91
34.2
8.21
26016
34.21
5.74
0.123
0.00
5.62
36
7.21
26283
34.25
6.60
0.124
0.00
6.40
37.8
6.32
26348
34.26
6.82
0.124
0.00
6.69
39.6
5.55
26295
34.25
6.64
0.124
0.00
6.52
41.4
4.07
26177
34.23
6.25
0.123
0.00
6.13
43.2
4.27
26027
34.21
5.78
0.123
0.00
5.65
45
3.75
25864
34.18
5.27
0.123
0.00
5.15
46.8
3.29
25700
34.16
4.78
0.122
0.00
4.66
48.6
2.89
25539
34.14
4.31
0.122
0.00
4.19
50.4
2.53
25385
34.11
3.B8
0.122
0.00
3.76
52.2
2.22
25239
34.09
3.49
0.121
0.00
3.36
54
1.95
25103
34.07
3.13
0.121
0.00
3.01
57
1.57
24891
34.04
2.60
0.121
0.00
2.48
60
1.26
24705
34.01
2.17
0.120
0.00
2.05
63
1.01
24541
33.99
1.81
0.120
0.00
1.69
66
0.82
24398
33.97
1.52
0.120
0.00
1.40
69
0.66
24272
33.95
1.27
0.119
0.00
1.15
72
0.53
24161
33.93
1.07
0.119
0.00
0.95
75
0.42
24063
33.92
0.90
0.119
0.00
0.79
80
0.30
23919
33.90
0.60
0.119
0.00
0.56
85
0.21
23804
33.88
0.52
0.118
0.00
0.40
90
0.14
23710
33.86
0.40
0.118
0.00
0.28
95
0.10
23633
33.85
0.32
0.116
0.00
0.20
100
0.97
23568
33.64
0.25
0.118
0.00
0.13
105
0.05
23513
33.83
0.20
0.118
0.00
0.09
110
0.03
23466
33.83
0.17
0.118
0.00
0.05
115
0.02
23425
33.82
0.15
0.116
0.00
0.03
120
0.02
23389
33.82
0.13
0.117
0.00
0.01
125
0.01
23355
33.81
0.12
0.117
0.00
0.00
130
0.01
23323
33.81
0.12
0.117
0.00
0.00
135
0.01
23290
33.80
0.12
0.117
0.00
0.00
140
0.00
23257
33.80
0.12
0.117
0.00
0.00
145
0.00
23223
33.79
0.12
0.117
0.00
0.00
150
0.00
23188
33.79
0.12
0.117
0.00
0.00

1 2 3 4 5 6 7 8
TIME INFLOW STORAGE STAGE OUTFLOWORIFICE WEIR RISER/
[min) [cfs) [cu ft) [ft] [cfs) [cfs] [cfs) BARREL
155
0.00
23154
33.78
0.12
0.117
0.00
0.00
160
0.00
23119
33.78
0.12
0.117
0.00
0.00
165
0.00
23084
33.77
0.12
0.117
0.00
0.00
170
0.00
23049
33.77
0.12
0.117
0.00
0.00
175
0.00
23015
33.76
0.12
0.117
0.00
0.00
180
0.00
22980
33.75
0.12
0.117
0.00
0.00
185
0.00
22945
33.75
0.12
0.116
0.00
0.00
190
0.00
22910
33.74
0.12
0.116
0.00
0.00
195
0.00
22875
33.74
0.12
0.116
0.00
0.00
200
0.00
22840
33.73
0.12
0.116
0.00
0.00
205
0.00
22805
33.73
0.12
0.116
0.00
0.00
210
0.00
22771
33.72
0.12
0.116
0.00
0.00
215
0.00
22736
33.72
0.12
0.116
0.00
0.00
220
0.00
22701
33.71
0.12
0.116
0.00
0.00
225
0.00
22666
33.71
0.12
0.116
0.00
0.00
230
0.00
22631
33.70
0.12
0.116
0.00
0.00
235
0.00
22597
33.70
0.12
0.116
0.00
0.00
240
0.00
22562
33.69
0.12
0.116
0.00
0.00
245
0.00
22527
33.69
0.12
0.115
0.00
0.00
250
0.00
22493
33.68
0.12
0.115
0.00
0.00
255
0.00
22458
33.68
0.12
0.115
0.00
0.00
260
0.00
22423
33.67
0.12
0.115
0.00
0.00
265
0.00
22389
33.67
0.12
0.115
0.00
0.00
270
0.00
22354
33.66
0.12
0.115
0.00
0.00
275
0.00
22320
33.66
0.12
0.115
0.00
0.00
280
0.00
22285
33.65
0.11
0.115
0.00
0.00
285
0.00
22251
33.65
0.11
0.115
0.00
0.00
315
0.00
22044
33.61
0.11
0.114
0.00
0.00
345
0.00
21838
33.58
0.11
0.114
0.00
0.00
375
0.00
21633
33.55
0.11
0.113
0.00
0.00
405
0.00
21429
33.52
0.11
0.113
0.00
0.00
435
0.00
21226
33.49
0.11
0.112
0.00
0.00
465
0.00
21023
33.46
0.11
0.112
0.00
0.00
495
0.00
20822
33.43
0.11
0.112
0.00
0.00
525
0.00
20621
33.40
0.11
0.111
0.00
0.00
555
0.00
20421
33.37
0.11
0.111
0.00
0.00
585
0.00
20222
33.34
0.11
0.110
0.00
0.00
615
0.00
20024
33.31
0.11
0.110
0.00
0.00
645
0.00
19826
33.28
0.11
0.109
0.00
0.00
675
0.00
19630
33.25
0.11
0.109
0.00
0.00
705
0.00
19434
33.22
0.11
0.108
0.00
0.00
765
0.00
19045
33.16
0.11
0.107
0.00
0.00
825
0.00
18659
33.10
0.11
0.106
0.00
0.00
005
0.00
10277
33.04
0.11
0.105
0.00
0.00
945
0.00
17898
32.98
0.10
0.104
0.00
0.00
1005
0.00
17522
32.92
0.10
0.103
0.00
0.00
1065
0.00
17150
32.86
0.10
0.102
0.00
0.00
1125
0.00
16782
32.81
0.10
0.101
0.00
0.00
1105
0.00
16417
32.75
0.10
0.100
0.00
0.00
1245
0.00
16056
32.69
0.10
0.099
0.00
0.00
1305
0.00
15698
32.64
0.10
0.098
0.00
0.00
1365
0.00
15344
32.58
0.10
9.097
0.00
0.00
1425
0.00
14994
32.53
0.10
0.096
0.00
0.00

1 2 3 4 5 6 7 8
TIME INFLOW STORAGE STAGE OUTFLOWORIFICE WEIR RISER/
[min] [cfs] [cu ft] [ft] [cfs] [cfs] [cfs] BARREL
1485
0.00
14647
32.47
0.10
0.095
0.00
0.00
1545
0.00
14303
32.42
0.09
0.094
0.00
0.00
1605
0.00
13964
32.36
0.09
0.093
0.00
0.00
1665
8.00
13627
32.31
0.09
0.092
0.00
0.00
1725
0.00
13295
32.25
0.09
0.091
0.00
0.00
1785
0.00
12966
32.20
0.09
0.090
0.00
0.00
1845
0.00
12641
32.15
0.09
0.089
0.00
0.00
1905
0.00
12320
32.10
0.09
0.088
0.00
0.00
1965
0.00
12002
32.04
0.09
0.087
0.00
0.00
2025
0.00
11688
31.99
0.09
0.006
0.00
0.00
2085
0.00
11377
31.94
0.09
0.085
0.00
0.00
2145
0.00
11071
31.89
0.08
0.064
0.00
0.00
2205
0.00
10760
31.04
0.08
0.083
0.00
0.00
2265
0.00
10469
31.79
0.08
0.082
0.00
0.00
2325
0.00
10173
31.74
0.08
0.001
0.00
0.00
2305
0.00
9882
31.69
0.08
0.080
0.00
0.00
2865
0.00
7579
31.30
0.07
0.071
0.00
0.00
3345
0.00
5537
30.94
0.06
0.061
0.00
0.00

CHAINSAW ROUTING
30.00
LL 2000.
w
10.00
C
0.00
0 7.2 14 22 29
36 43
TIME (MINS)
1-0--INFLOW :i-OUTFLOW
50 60 72 90

PIPE SIZING CHART
Pagel

State of North Carolina
Department of Environment, Health, and Natural Resources
Wilmington Regional Office
James B. Hunt, Jr., Governor DIVISION OF ENVIRONMENTAL MANAGEMENT Bob Jamieson
Jonathan B. Howes, Secretary WATER QUALITY SECTION Regional Manager
October 19, 1994
Mr. Jim Honeycutt, P.E.
Impact Engineering
3805 Wrightsville Avenue, Unit 17
Wilmington, North Carolina 28406
Subject: ADDITIONAL INFORMATION
Stormwater Project No. SW8 941008
NorthChase Apartments
New Hanover County
Dear Mr. Honeycutt:
The Wilmington Regional Office received a Stormwater Submittal for the NorthChase Apartments
on October 7, 1994. A preliminary review of that information has determined that the submittal for the
subject project is not complete. The following information is needed to continue the stormwater review:
✓1. Sign and seal the calculations.
✓2. Delineate the 4.938 acres of drainage area you use.
,/3. A signed and notarized Operation and Maintenance Plan for the stormwater detention
pond.
127 Cardinal Drive Extension, Wilmington, N.C. 28405-3845 • Telephone [phone] • Fax [phone]
An Equal opportunity Affirmative Action Employer

Mr. Honeycutt
October 19, 1994
Stormwater Project No. SW8 941008
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 November 19, 1994, or the submittal
will be returned as incomplete.
If you have any questions concerning this matter please feel free to call me at [phone].
Sincerely,
Ms. Linda Lewis
Environmental Engineer
DA/arl: S:\WQS\STORMWAT\ADDINFO\941008.00T
cc: (2) Linda Lewis
Central Files
A

i
51v8 `t4-1005 AlhrfhChose korhrien
V
R¢--�lee%CzlGs Z
-f (Z& x41) k
2G
X 20
2 /
��yi�JeP.,- vse s 7.3 2� lff — �, 93�
cue�la�c✓s e,�c%1e�i
-(-►'..-) v`ty
13( 5'711 = 4 S(RIo
3Ce 4 8
4q 544
a ,
II 1

Drainage Calculations for Northchase Apts., Wilmington, NC
ProjectIE-4076
_ 215095
A total 43560 A total = 4.9379 acres
43560
O� A paved := 67939 A pav 56 acres
11743
v�p� Aside 43560
_ 49344
OX A bidg ' 43560
3.64
(PIA misc:- 43560
A side 0.27 acres
Awbi
0.004 acre
...total drainage area
...parking area minus interior landscaping
area
acres ...Total area of buildings
Dumpster pads
A impA ed + A misc + side AiYp 834 acres - total impervious area excl.
bldgs
A other to I - A imp - bidg Aer = 1.971
C pre '_ .
development C
C bidg := 1.00
C imp :_ .9
...paved area C
C com - C
A other
+ C i P.+ C bidg'
�q
total) A total)
total„
C comp = 0.66
...composite ' post -development)
L :- 500 ft
...hydraulic length
H := 3.5ft
...height
3 385
T = 1H/
c
128
T c = 6.3
tes
...time of concentration
Intensity-Durati
-Frequency Relationships:
STORNATE iN
Values of G
R G
d H'
u V
I4�J�nJ�(J
10 252 0
50 338 33
OCT O 7 1994
R= Return Period
O E M
'Source: Master Drainage Plan for City of Wilmington
-Rol # 8 941WZ

n
T := T c Time of duration
G 10 := 252
H 10 := 30
10 := G 10 1 10 = 8.94 in/hr
(H 10 + T)
G 50 : = 338 H 50 : = 33
50 '= G 50 150 = 8.596 in/hr
(H 50 + T)
Compute runoff rates:
...10 year storm intensity
50 year storm
Q pre '= C pre' 110'A total
Q pre = 6.85 ofs ...pre -development runoff from 10 yr: storm
Page 2
Q 10 = C comp' 1 10' A total
Q 10 = 22.68 cfs post -development discharge rate to pond from 10 yr. storm
Q 50 C comp' 1 50-A total
Q 50 = 28.1 cfs ...post -development discharge rate to pond from 50 yr. stone
Volume of runoff from developed area of site:
P := 4.8 in
Soil type = Seagate
CN := 70 Curve No.
S . (1CN0) - 10 S = 4.286
R depth .= (P +0.8. S )2 R depth = 1.889 in.
R vol R depth' (A total) '43560- 12 R vol = 33865
T ._ R depth' (A total) 1
1 .43560
p 1.39 (Q 10) (12) 60
Tp=17.9
.runoff depth
cubic feet ...total runoff volume
time to peak flow

Determine size of 7.5' deep pond without vegetative filter. Page 3
IMP% := A imp + A btdg IMP% = 0.601
A total
IMP%60 .= .019
IMP%70:= .023
IMP := IMP% 60 + IMP% 70 - IMP% 60)-.1
IMP = 0.0194
DA := A total' 43560
SA :_ ( IMP) DA
SA = 4173
Determine storage volume required for treatment of first inch of runoff:
V 1 12 .A total* 43560•C comp
V = 11867 cubic feet
Assume 37.5' x 112' pond. Solve for depth "T to provide required storage:
I 112 w := 37.5 w• I = 4200
d := 1.5 ...guess value
f(d) = I•w+(I+6d)•(w+6•d) d
2
g(d) := V
d := root((f(d) - g(d) ), d)
...function of d for rectangular pond wl3:1 side slopes
d = 2.24 ft. - depth required to provide required storage far 1 inch
Determine size of orifice for drawdown of first inch:
_ V
2day 2.24 60 60 Q 2dey = 0.0687 cfs
... Max discharge for 2 day drawdown with site
fully developed
V
Q 5day _ 5 24-60 60 Q 5day = 0.0275 cfs ...Max discharge for 5 day drawdown with site
fully developed
g := 32.2 C d := .6 ...orifice coefficient
h := d h = 1.12 ft ...avg. head
2
A orifice ;= Q 2day A orifice = 0.013 Square ft.
Cd.(2.g.h).5

\ S
D .= (4.
A orifice 12
3.14
Q 6day = 0.0275 cfs
A orifice �_ Q 5day
Cd•(2•g'h).s
s
D := (4.
A orifice)'. 12
3.14
D = 1.57 in. - for 2 day drawdown
A orifice = 0.005 Square ft.
D = 0.9W in - for 5 day drawdown
Use 1.5 Inch diameter pipe In routing chart
Check capacity of emergency spilhvay to pass 50 year peak flow:
L 15 ft ...Length of weir
H .= 9 ft ...Driving head C W := 3.0 ...Weir coefficient
12
Q := C w L• H1.s ... Weir capacity
Q = 29.23 must be => Q W = 28.1 OX
Assuming 15" barrel, check velocity at outlet:
D := 1.25ft q := 6.84 ...max barrel discharge from routing sheets
A pipe z• DZ 4 A pipe = 1.227
V outlet '= q V outlet = 5.574 fps
A pipe
REFER TO ATTACHED SHEETS FOR ROUTING RESULTS
Page 4

S
Z
CONTOUR
INCR ACCUM
CONTOUR
AREA
VOL VOL
STAGE
In S
In Z
Z set
39.05
4200
0 0
0.00
0.00
30.55
4657
2214 2214
0.50
7.7027
-0.6931
0.51
31.05
5133
2448 4662
1.00
8.4471
0.0000
0.90
31.55
5627
2690 7352
1.50
8.9027
0.4055
1.46
32.05
6138
2941 10293
2.00
9.2392
0.6931
1.96
32.29
639 1503 11796
2.24
9.3755
0.6065
2.21
33.05
7215
5179 16965
3.00
9.7390
1.0986
3.04
33.55
7781
3749 20715
3.50
9.9386
1.2528
3.61
Regression
Output:
Constant
0.4654
Ks- 4746
Std Err of Y Eat
0.0294
b- 1.15
R Squared
0.9988
No. of Observations
7
X Coefficient(s)
1.14697
Std Err of Coef.
0.01777

STAGE -DISCHARGE FOR RISER/BARREL SPILLWAY WITH EMERGENCY WEIR
RISER/BARREL:
7.5
Q.pre-6.85
Dr
-
3.516
Area of grate openings
6.84
Etop
-
34.06
Elev. top riser (ft)
34.51
Cwr
-
3
Riser weir coefficient
Cdr
-
0.59
Riser orifice coefficient
Do
-
1.50
Orifice dia.(in)
Einv
-
30.05
Elev inv. orifice
(ft)
cc
-
0.6
Orifice coeff.
Db
-
1.25
ft.
Binv
-
30.05
Barrel invert
Cdb
-
0.6
EMERGENCY
WEIR:
Cw
-
3
Weir coefficient
Ear
-
34.5
Elev. weir crest (ft)
Lw
-
15
Weir length (ft)
1
2
3
4
5
6 7
8
Stage
Riser
Riser
Barrel
1.5"
Princ. Emerg.
Total
(weir)
(orifice)
orifice
Spillway Weir
Outflow
[ft]
[cfe]
[cfe]
[cfs]
[cfe]
[cfs] [cfe]
[cfe]
30.05
0.00
0.00
0.00
0.00
0.00 0.00
0.00
30.55
0.00
0.00
0.00
0.04
0.00 0.00
0.04
31.05
0.00
0.00
0.00
0.06
0.00 0.00
0.06
31.55
0.00
0.00
0.00
0.07
0.00 0.00
0.07
32.05
0.00
0.00
0.00
0.08
0.00 0.00
0.00
32.55
0.00
0.00
0.00
0.09
0.00 0.00
0.09
33.05
0.00
0.00
0.00
0.10
0.00 0.00
0.10
33.55
0.00
0.00
0.00
0.11
0.00 0.00
0.11
34.05
0.00
0.00
0.00
0.12
0.00 0.00
0.12
34.55
7.72
11.65
12.53
0.13
7.72 0.50
8.35
35.05
22.16
16.56
13.21
0.13
13.21 18.36
31.69
35.55
40.92
20.32
13.85
0.14
13.85 48.42
62.41
36.05
63.16
23.48
14.47
0.14
14.47 86.04
101.45
36.55
88.41
26.27
15.06
0.15
15.06 132.08
147.29
37.05
116.33
28.79
15.63
0.16
15.63 183.24
199.02
37.55
146.70
31.10
16.17
0.16
16.17 239.70
256.03
30.05
179.33
33.25
16.70
0.17
16.70 300.99
317.86

ng'n2
TN Li"l-
a3'=2
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n'T�
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32'22
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0'00
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33.02
0
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0'00
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COMPOSITE STAGE DISCHARGE
gm
N
�j 20.00
W
Gl<Ql=
30.05 32.05 34.05 36.05 38.05
STAGE
f R(M -*- R(0) -t BARREL -0-1" ORIFICE --*-- Ew

K_ixliol
N 20.00
W
i 14
NET STAGE DISCHARGE
30.05 32.05 34.05 36.05 38.05
STAGE

9i3/94
CHAINSAW ROUTING
Input data:
Northchase Apartments
Qp- 22.68 RESULTS:
Tp- 17.9 OUTFLOW PEAK- 6.04
MAX STAGE- 34.51
dT- 1.8
Ks-
4748
b-
1.15
7.5
Etop -
34.06
Top of riser
Dr -
3.516
Area of grate openings
Db-
1.25
8inv-
30.05
N-
1
No. of orif.
Cd-
0.6
Orifice coeff.
D-
1.5
Dia. of orifice
Zi-
30.05
Inv. elevation
Cw- 3 Weir Coefficient
L- 15 Length of overflow weir
Zcr- 34.5 Elev. of overflow weir

1
2
3
4
5
6
7
8
TIME
INFLOW
STORAGE
STAGE
OUTFLOWORIFICE
WEIR
RISER/
[min]
[cfs]
[cu ft]
[ft]
[cfs]
[cfs]
[cfs]
BARREL
0
O.au
a
30.05
0.0a
0.000
0.00
0.09
1.6
0.56
0
30.05
0.00
0.000
0.00
0.00
3.6
2.19
61
30.07
0.00
0.000
0.00
0.00
5.4
4.72
297
30.14
0.00
0.000
0.00
0.00
7.2
7.91
807
30.26
0.02
0.023
0.00
0.00
9
11.44
1659
30.45
0.03
0.034
0.00
0.00
10.8
14.96
2891
30.70
0.05
0.045
0.00
0.00
12.6
18.12
4501
31.00
0.06
0.056
0.00
0.00
14.4
20.61
6452
31.36
0.07
0.066
0.00
0.00
16.2
22.18
8671
31.74
0.00
0.075
0.00
0.00
1B
22.68
1105B
32.14
0.08
0.084
0.90
0.00
19.8
22.06
13498
32.54
0.09
0.092
0.00
0.00
21.6
20.37
15070
32.91
0.10
0.099
0.00
0.00
23.4
17.99
10059
33.26
0.10
0.105
0.00
0.00
25.2
15.79
19991
33.55
0.11
0.110
0.00
0.00
27
13.05
21604
33.81
0.11
0.114
0.00
0.00
28.8
12.15
23168
34.03
0.12
0.117
0.00
0.00
30.6
10.67
24460
34.23
1.66
0.120
0.00
1.54
32.4
9.36
25441
34.37
4.04
0.122
0.00
3.91
34.2
8.21
26016
34.46
5.74
0.123
0.00
5.62
36
7.21
26283
34.50
6.60
0.124
0.00
6.48
37.8
6.32
26348
34.51
6.84
0.124
0.02
6.69
39.6
5.55
26293
34.50
6.63
0.124
0.00
6.51
41.4
4.B7
26175
34.40
6.25
0.123
0.00
6.13
43.2
4.27
26026
34.46
5.77
0.123
0.00
5.65
45
3.75
25864
34.43
5.27
0.123
0.00
5.15
46.8
3.29
25699
34.41
4.78
0.122
0.00
4.65
48.6
2.89
25539
34.39
4.31
0.122
0.00
4.19
50.4
2.53
25365
34.36
3.88
0.122
0.00
3.76
52.2
2.22
25239
34.34
3.48
0.121
0.00
3.36 .
54
1.95
25103
34.32
3.13
0.121
0.00
3.01
57
1.57
24891
34.29
2.60
0.121
0.00
2.48
60
1.26
24705
34.26
2.17
0.120
0.00
2.05
63
1.01
24541
34.24
1.B1
0.120
0.00
1.69
66
0.82
24398
34.22
1.52
0.120
0.00
1.40
69
0.66
24272
34.20
1.27
0.119
0.00
1.15
72
0.53
24161
34.18
1.07
0.119
0.00
0.95
75
0.42
24063
34.17
0.90
0.119
0.00
0.79
80
0.30
23919
34.15
0.68
0.119
0.00
0.56
85
0.21
23804
34.13
0.52
0.116
0.00
0.40
90
0.14
23710
34.11
0.40
0.118
0.00
0.28
95
0.10
23633
34.10
0.32
0.118
0.00
0.20
100
0.07
23568
34.09
0.25
0.110
0.00
0.13
105
0.05
23513
34.00
0.20
0.118
0.00
0.09
110
0.03
23466
34.08
0.17
0.11E
0.00
0.05
115
0.02
23425
34.07
0.15
0.110
0.00
0.03
120
0.02
23389
34.07
0.13
0.117
0.00
0.01
125
0.01
23355
34.06
0.12
0.117
0.00
0.00
130
0.01
23323
34.06
9.12
0.117
0.00
0.00
135
0.01
23290
34.05
0.12
0.117
0.00
0.00
140
0.00
23257
34.05
0.12
0.117
0.00
0.00
145
0.00
23223
34.04
0.12
0.117
0.00
0.00
150
0.00
23188
34.04
0.12
0.117
0.00
0.00

1
2
3
4
5
6
7
8
TIME
INFLOW
STORAGE
STAGE
OUTFLOWORIFICE
WEIR
RISER/
[min]
[cfs]
[cu ft]
[ft]
[cfs]
[cfs]
[cfs]
BARREL
155
0.00
23154
34.03
0.12
0.117
0.00
0.00
160
0.00
23119
34.03
0.12
0.117
0.00
0.00
165
0.00
23004
34.02
0.12
0.117
0.00
0.00
170
0.00
23049
34.02
0.12
0.117
0.00
0.00
175
0.00
23015
34.01
0.12
0.117
0.00
0.00
180
0.00
22900
34.00
0.12
0.117
0.00
0.00
185
0.00
22945
34.00
0.12
0.116
0.00
0.00
190
0.00
22910
33.99
0.12
0.116
0.00
0.09
195
0.00
22875
33.99
0.12
0.116
0.00
0.00
200
0.00
22840
33.90
0.12
0.116
0.00
0.00
205
0.00
22805
33.90
0.12
0.116
0.00
0.00
210
0.00
22771
33.97
0.12
0.116
0.00
0.00
215
0.00
22736
33.97
0.12
0.116
0.00
0.00
220
0.00
22701
33.96
0.12
0.116
0.00
0.00 .
225
0.00
22666
33.96
0.12
0.116
0.00
0.00
230
0.00
22631
33.95
0.12
0.116
0.00
0.00
235
0.00
22597
33.95
0.12
0.116
0.00
0.00
240
0.00
22562
33.94
0.12
0.116
0.00
0.00
245
9.00
22527
33.94
0.12
0.115
0.00
0.00
250
0.00
22493
33.93
0.12
0.115
0.00
0.00
255
0.00
2245E
33.93
0.12
0.115
0.00
0.00
260
0.00
22423
33.92
0.12
0.115
0.00
0.00
265
0.00
22309
33.92
0.12
0.115
0.09
0.00
270
0.00
22354
33.91
0.12
0.115
0.00
0.00
275
0.00
22320
33.91
0.12
0.115
0.00
0.00
280
0.00
22285
33.90
0.11
0.115
0.00
0.00
285
0.00
22251
33.90
0.11
0.115
0.00
0.00
315
0.00
22044
33.86
0.11
0.114
0.00
0.00
345
0.00
2183B
33.83
0.11
0.114
0.00
0.00
375
0.00
21633
33.00
0.11
0.113
0.00
0.00
405
0.00
21429
33.77
0.11
0.113
0.00
0.00
435
0.00
21226
33.74
0.11
0.112
0.00
0.00
465
0.00
21023
33.71
0.11
0.112
0.00
0.00
495
0.00
20822
33.68
0.11
0.112
0.00
0.00
525
0.00
20621
33.65
0.11
0.111
0.00
0.00
555
0.00
20421
33.62
0.11
0.111
0.00
0.00
585
0.00
20222
33.59
0.11
0.110
0.00
0.00
615
0.00
20024
33.56
0.11
0.110
0.00
0.00
645
0.00
19826
33.53
0.11
0.109
0.00
0.00
675
0.00
19630
33.50
0.11
0.109
0.00
0.00
705
0.00
19434
33.47
0.11
0.108
0.00
0.00
765
0.00
19045
33.41
0.11
0.107
0.00
0.00
825
0.00
18659
33.35
0.11
0.106
0.00
0.00
085
0.00
18277
33.29
0.11
0.105
0.00
0.00
945
0.00
17B9B
33.23
0.10
0.104
0.n0
0.00
1005
0.00
17522
33.17
0.10
0.103
0.00
0.00
1065
0.00
17150
33.11
0.10
0.102
0.00
0.00
1125
0.00
16762
33.06
0.10
0.101
0.00
0.00
1185
0.00
16417
33.00
0.10
0.100
0.00
0.00
1245
0.00
16056
32.94
0.10
0.099
0.00
0.00
1305
0.00
15698
32.09
0.10
0.098
0.00
0.00
1365
0.00
15344
32.83
0.10
0.097
0.00
0.00
1425
0.00
14994
32.7E
0.10
0.096
0.00
0.00

1
2
3
4
5
6
7
8
TIME
INFLOW
STORAGE
STAGE
OUTFLOWORIFICE
WEIR
RISER/
[min]
[cfs]
[cu ft]
[ft]
[cfs]
[cfs]
[cfs]
BARREL
1485
0.00
14647
32.72
U.lo
0.095
0.00
0.00
1545
0.00
14303
32.67
0.09
0.094
0.00
0.00
1605
0.00
13964
32.61
0.09
0.093
0.00
0.00
1665
0.00
13627
32.56
0.09
0.092
0.00
0.00
1725
0.00
13295
32.50
0.09
0.091
0.00
0.00
1785
0.00
12966
32.45
0.09
0.090
0.00
0.00
1845
0.00
12641
32.40
0.09
0.089
0.00
0.00
1905
0.00
12320
32.35
0.09
0.088
0.00
0.00
1965
0.00
12002
32.29
0.09
0.087
0.00
0.00
2025
0.00
11688
32.24
0.09
0.086
0.00
0.00
2085
0.90
11377
32.19
0.09
0.085
0.00
0.00
2145
0.00
11071
32.14
0.08
0.084
0.00
0.00
2205
0.00
10768
32.09
0.08
0.083
0.00
0.00
2265
0.00
10469
32.04
DAB
0.082
0.00
0.00
2325
0.00
10173
31.99
0.08
0.081
0.00
0.00
2385
0.00
9882
31.94
0.00
0.000
0.00
0.00
2865
0.00
7579
31.55
0.07
0.071
0.00
0.00
3345
0.00
5537
31.19
0.06
0.061
0.00
0.00

N 20.00
b
W
Q
p 10.00
m
CHAINSAW ROUTING
0 7.2 14 22 29 36 43 50 60 72 90
l7ME (MINS)
-M-INFLOW :;:OUTFLOW

PIPE SIZING CHART
NELPM
MEN
IN
INE
11M,
INIMMEM
MEN
mill
Sol
MEMO
OEM
MME
MINN
INIMME
IMOMMIN
MEN
����C��
ECC�
MEN
ME
NOMMIN
IME
IME
ONE
INS INS
ECCMINEM
Page 1