19991241 Ver 1_Stormwater Plans_20000724

BASS, NIXON & KENNEDY, INC., CONSULTING ENGINEERS
10405-E LIGON MILL ROAD, WAKE FOREST, NC 27587
919/570-1360 FAX [phone] BNK(o)-BNKinc.com
February 11, 2002
Mr. Todd St. John
NCDEHNR
Division of Water Quality
Non-Discharge Branch
1621 Mail Service Center
Raleigh, N. C. 27699 -1621
Re: - Heritage Station Shopping Center
Water Quality Basin Amendment
Dear Mr. St. John:
Please find attached herewith the stormwater design approval letter and revised plans and
calculations for the above-referenced project. While the subject detention pond remains in
the same general vicinity as originally permitted, it is hereby proposed to be relocated just
downstream of its previously approved position. This is due to existing site physical
constraints and proposed changes in the future development layout. The new wet pond's
capacity has been increased to accommodate an approximate 4.3 acre increase of
watershed area and its design remains in full compliance with requirements as set forth in
NCDEHNR's Stormwater BMP Manual, April, 1999 edition.
Please do not hesitate to contact me should any questions arise from your review of this
material. Your assistance regarding the approval of this amendment is greatly appreciated.
Respectfully submitted,
Bass, Nixon & Kennedy, Inc.
Keith A. Tew, PE
KAT/cd

5D
-Given:
BASS, NIXON & KENNEDY, INC., CONSULTING
7416 CHAPEL HILL ROAD, RALEIGH, NC 27607
919/851-4422 ¦ FAX [phone]
°I
Design Calculations for Stormwater Quality Measures
For`Proposed Heritage Station Shopping Center (Wet Detention Ba
00
Drainage area tributary to proposed basin = 1,240,670 Square Feet (28.5 Acres)
Estimated Impervious Area = 48% (based on existing residential area @ 25%,
Shopping Center @ 85% and Rights-of-Way at 35% impervious)
Design will be sized for at least 85% removal of total suspended solids (TSS). The
runoff volume required to be detained is based on runoff from the first 1 inch of rainfall of
any given storm event.
The basin was located on the available area northwest of the proposed realignment of
Forestville Road (SR 2049) between the existing alignment of Forestville Road and the
realignment of Rogers Road (SR 2052) and graded with 3:1 side slopes and an 8-foot
wide crest on the dike. The grading for the basin gives a surface area of 27,059 square
feet at the Normal Pool Elevation of 250.25 with an average depth of 3.07 feet. This
surface area to drainage area ratio is 2.18%. Interpolating values from Stonnwater Best
Management Practices, NC DEHNR (1995), (BMP Manual) Table IA, the required_
surface area to drainage area ratio for 50% impervious cover and: an average: depth of.-
3.07 feet is 1.98%, or 24,565 square feet. Therefor, the basin as shown meets the
minimum surface area to drainage area ratio.
The basin is required to store runoff from the first 1 inch of rain, and to release that
volume of water over a period of 2 to 5 days. This .storage is to be above .the. normal
pool elevation of 250.25. The method of estimating runoff volume is from the BMP
Manual as shown below.
Rv = 0.05 + 0.009(1)
Where: Rv = inches of runoff volume per inch of rainfall
= percent impervious area = 48% (say 50%)
= 0.05 + 0.009(50) = 0.50 in/in
Runoff Volume = drainage area (sq. ft.) x Rv (in./in.) x.083333 ft/in.
= 1,240,670 sq. ft. x 0.50 in./in. x 0.83333 ft./in.
= 51,695 cubic feet
The volume of the proposed basin between elevation 250.25 and 252.25 is 58,666
cubic feet, which is greater than the required 51,695 cubic feet. The top of the outlet
structure will be set at elevation 252.25, which will be considered the 1" storage
elevation.

The time required to release the stored water is between 48 and 120 hours. The
drawdown time is estimated using the following formula:
As?
AO - 60(t)
Where: A.= orifice area in square inches
AS = surface area of pool at 1" storage elevation
H = drawdown head in feet
t = time in hours
The surface area at the 1" storage elevation of 252.25 (AS) is 31,725 square feet.
The drawdown head (H) is 252.25 - 250.25 = 2.00'
AO _ 31,725sq.ft. 2.00 ft
60(120hr)
Ao = 6.23 sq.in.
The diameter of a circular opening with 6.23 sq. in. area is 2.81 inches. Rounding up to
the nearest nominal pipe size gives an opening diameter of 3.0 inches and an area of
7.06 sq. in. Solving the above equation for drawdown time for a 3-inch diameter opening
is as follows:
t._. q
60(Ao) :...;
t= 31,725sq.% 2.00 ft
60(7.06 sq.in.)
I =105.8 hr
24hr <_ 105.8 hr _< 120hr (OK)
Solving the above equation for drawdown time for a 4-inch diameter opening (Ao =
12.57 sq. in.) is as follows:
As- H--
t 60(Aa)
t= 31,725sq.ft. 2.00 ft
60(12.57 sq.in.)
t=71.4 hr
24hr <_ 71.4 hr <_ 120hr (OK)
2
The 4" draw down pipe shall be installed with an invert of 250.25.
The basin shall be equipped with a drain valve in the outlet structure to allow the basin
to be drained for cleaning and maintenance. The drawdown time from normal pool to
empty should be no more than 24 hours. An 8 inch gate valve was chosen for the drain
valve and the estimated drawdown time is as follows:
_ Ash
t 60(Ao)
t _ 27059 sq.ft. 4.25ft
60(50.27sq.in.)
t=18.5 hr
18.5 hr _< 24hr (OK)
The outlet structure for the basin was designed to safely pass the 25 year storm event,
with an emergency spillway designed to carry additional flow up to and exceeding the
100 year storm event. The standpipe is designed as a 72" diameter concrete riser (i.d.)
with the top weir elevation set at the 1" storage elevation of 252.25'. A 4" diameter
drawdown pipe assembly will be installed in the riser.at the water quality (normal pool)
elevation of 250.25'. The flow into this standpipe will be directed into the existing stream
channel through a 48" diameter concrete culvert. The design storms for the detention
basin outlet structure are the 2 year, 10 year, 25 year and 100 year; 24 hour events ;
using SCS Type III distribution. The watershed was modeled,. and the detention basin .....
routing calculations were done using Haestad Methods -PondPack watershed modeling
software. The design calculations, including stage.storage and discharges and rating
curves for the outlet structure are attached. The results from the model are summarized
as follows:
Storm Peak Inflow Peak Outflow Peak Elevation
2 year, 24 hour storm 67.7 CFS 14.8 CFS 252.64'
10 year, 24 hour storm 131.1 CFS 88.3 CFS 253.59'
25 year, 24 hour storm 169.3 CFS 149.1 CFS 253.93'
100 year, 24 hour storm 228.9 CFS 190.6 CFS 254.38'
The wet detention basin, as designed, exceeds the minimum requirements for water
quality measures as outlined in the Stormwater Best Management Practices, NC
DEHNR (1995), (BMP Manual) for the project as shown on the plans.
3
Job File: R:\1999JOBS\99251000\99251000.PPW
Rain Dir: C:\HAESTAD\PPKW\RAINFALL\
JOB TITLE
--------------------------
Water Quality Detention Basin for proposed Heritage Station
Shopping Center
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Table of Contents
Table of Contents
i
******************** NETWORK SUMMARIES *********************
Watershed....... 100yr
Executive Summary (Nodes) .......... 1.01
Watershed....... 10yr
Executive Summary (Nodes) .......... 1.02
Watershed....... 25yr
Executive Summary (Nodes) .......... 1.03
Executive Summary (Links) .......... 1.04
Watershed....... 2yr
Executive Summary (Nodes) .......... 1.05
Network Calcs Sequence ............. 1.06
****************** DESIGN STORMS SUMMARY *******************
storms.......... Design Storms ...................... 2.01
********************** CN CALCULATIONS *********************
SCS UH 2O..
SCS U.H. 20.......
SCS UH 2O......
Runoff CN-Area
**** RUNOFF HYDROGRAPHS ***'**********
SCS Unit Hyd. Equations ............
100yr
SCS Unit Hyd. Summary ..............
10yr
SCS Unit Hyd. Summary ..............
3.01
4.01
4.03
4.04
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Table of Contents ii
Table of Contents (continued)
SCS UH 2O...... 25yr
SCS Unit Hyd. Summary .............. 4.05
SCS UH 2O...... 2yr
SCS Unit Hyd. Summary .............. 4.06
********************* CHANNEL ANALYSES *********************
PR 10.......... Chn-Trapz . ......................... 5.01
Channel Equations .................. 5.03
*********************** POND VOLUMES ***********************
P 10........... Vol: Elev-Area ..................... 6.01
******************** OUTLET STRUCTURES *********************
PR 10.......... Outlet Input Data .................. 7.01
Composite Rating Curve ............. 7.06
*********************** POND ROUTING ***********************
P 10........... Pond E-V-Q Table 8.01
P 10 OUT l0yr
Pond Routing.Summary ........ ....... 8.03.
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
' Type.... Executive Summary (Nodes) Page 1.01
Name.... Watershed Event: 100 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 100yr
NETWORK SUMMARY -- NODES
(Trun.= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left & Rt)
DEFAULT Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 100yr
-
---------------------------------
-----
Data Type, File, ID = Synthetic Storm -------------
SCSTYPES.RNF ----------------
TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
HYG Vol Qpeak Qpeak Max WSEL
Node ID Type cu.ft Trun. hrs cfs ft
----------------- ---- ---------- -
Outfall OUT 10 JCT 556948 - ---------
12.0060 -------- ---------
201.28
P 10 IN POND 557150 11.9393 228.92
P 10 OUT POND 556948 12.0060 201.28 254.33
SCS UH 20 AREA 557150 11.9393 228.92
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Executive Summary (Nodes) Page 1.02
Name.... Watershed Event: 10 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 10yr
NETWORK SUMMARY -- NODES
(Trun.= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left & Rt)
DEFAULT Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 10yr
---------------------------------------
Data Type, File, ID = Synthetic Storm --------------
SCSTYPES.RNF ---------------
TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.3800 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
HYG Vol Qpeak Qpeak Max WSEL
Node ID Type cu.ft Tr
- un. hrs cfs ft
----------------- --
- ---------- -
Outfall OUT 10 JCT 313677 - ---------
12.0727 -------- ---------
88.35
P 10 IN POND 313877 11.9393 131.07
P 10 OUT POND 313677 12.0727 88.35 253.59
SCS UH 20 AREA 313877 11.9393 131.07
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Executive Summary (Nodes) Page 1.03
Name.... Watershed Event: 25 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 25yr
NETWORK SUMMARY -- NODES
(Trun.= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left & Rt)
DEFAULT Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 25yr
---------------------------------------
Data Type, File, ID = Synthetic Storm --------------
SCSTYPES.RNF ---------------
TypeII 24hr
Storm Frequency = 25 yr
Total Rainfall Depth= 6.4100 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
HYG Vol Qpeak Qpeak Max WSEL
Node ID Type cu.ft Trun. hrs cfs fit
----------------- ---- ---------- -
Outfall OUT 10 JCT 407331 - ---------
12.0060 -------- ---------
130.97
P 10 IN POND 407531 11.9393 169.25
P 10 OUT POND 407331 12.0060 130.97 253.99
5CS UH 20 AREA 407531 11.9393 169.25
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Executive Summary (Links) Page 1.04
Name.... Watershed Event: 25 yr
• File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 25yr
NETWORK SUMMARY -- LINKS
(UN=Upstream Node; DL=DNstream End of Link; DN=DNstream Node)
(Trun.= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left & Rt)
DEFAULT Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 25yr
Data Type, File, ID =
Storm Frequency =
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Synthetic Storm SCSTYPES.RNF TypeII 24hr
25 yr
6.4100 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
HYG Vol Peak Time Peak Q
Link ID Type
- cu.ft Trun. hrs cfs End Points
------------
A 40 ---- ----
ADD UN ---------- ---
407531 ------- -
11.9393 -------
169.25 ---
SCS -------------
UH 20
DL 407531 11.9393 169.25
ON 407531 11.9393 169.25 P 10 IN
PR 10 PONDrt UN 407531 11.9393 169.25 P 10 IN
PR 10 407331 12.0060 130.97 P 10 - OUT
DL 407331 12.0060 130.97
DN 407331 12.0060 130.97 OUT 10
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Executive Summary (Nodes) Page 1.05
Name.... Watershed Event: 2 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 2yr
NETWORK SUMMARY -- NODES
(Trun.= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left & Rt)
DEFAULT Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 2yr
Data Type, File, ID = Synthetic Storm SCSTYPES.RNF TypeII 24hr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Node ID Type
Outfall OUT 10 JCT
P 10 IN POND
P 10 OUT POND
SCS UH 20 AREA
HYG Vol Qpeak Qpeak Max WSEL
cu.ft Trun. hrs cfs ft
----------
162439 -- ---------
12.1394 -------- ---------
14.77
162640 11.9393 67.70
162439 12.1394 14.77 252.64
162640 11.9393 67.70
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Network Calcs Sequence Page 1.06
Name.... Watershed Event: 2 yr
• File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 2yr
NETWORK RUNOFF NODE SEQUENCE
Runoff
--------
-------- Data
--------------
-------------- Apply to
------------
------------ Node
---------------
-------------- Receiving Link
--------------------------
-
------
-----------------
SCS UH SCS UH 20 Subarea SCS UH 20 --
-
Add Hyd SCS UH 20
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Network Calcs Sequence Page 1.07
Name.... Watershed Event: 2 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 2yr
NETWORK ROUTING SEQUENCE
Link Operation UPstream Node DNstream Node
Add Hyd A 40 Subarea SCS UH 20 Pond P 10 IN
POND ROUTE TOTAL OUTFLOW...
Total Pond Outflow Pond P 10 IN Outflow P 10 OUT
SET POND ROUTING LINK TO TOTAL POND OUTFLOW...
Outlet PR 10 Outflow P 10 OUT Jct OUT 10
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Design Storms
Name.... storms
File.... C:\HAESTAD\PPKW\RAINFALL\WAKE.RNQ
Title... Water Quality Detention Basin for proposed Heritage
Station Shopping Center
DESIGN STORMS SUMMARY
Design Storm File,ID = WAKE.RNQ storms
Storm Tag Name = 100yr
Data Type, File, ID =
Storm Frequency =
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Page 2.01
Synthetic Storm SCSTYPES.RNF TypeII 24hr
100 yr
8.0000 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = 25yr
Data Type, File, ID = Synthetic Storm SCSTYPES.RNF TypeII 24hr
Storm Frequency = 25 yr
Total Rainfall Depth= 6.4100 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs -
Storm Tag Name = 10yr
Data Type, File, ID = Synthetic Storm SCSTYPES.RNF TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.3800 in
Duration Multipl-ier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = 2yr
Data Type, File, ID =
Storm Frequency =
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Synthetic Storm SCSTYPES.RNF TypeII 24hr
2 yr
3.6000 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Runoff CN-Area Page 3.01
Name.... SCS UH 20
File.... R:\1999JOBS\99251000\99251000.PPW
Title... Mostly Group B soils
RUNOFF CURVE NUMBER DATA
..........................................................................
Mostly Group B soils
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
--------------------------------
Residential (assume 1/2 ac. lots) ----
70 ---------
11.270 ----- ----- ------
70.00
Shopping Center (assume 85% Imp) 92 10.740 92.00
Rights-of-Way 74 4.790 74.00
Pond Area 61 1.670 61.00
COMPOSITE AREA & WEIGHTED CN --->
..................................
..................................
......
...... 28.470
..........
.......... 78.44 (78)
.........................
.........................
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... SCS Unit Hyd. Equations Page 4.01
Name....
File.... R:\1999JOBS\99251000\99251000.PPW
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
DEFINITION OF TERMS: ------------------------------------------------
At = Total area (acres): At = Ai+Ap
Ai = Impervious area (acres)
Ap = Pervious area (acres)
CNi = Runoff curve number for impervious area
CNp = Runoff curve number for pervious area
fLoss = f loss constant infiltration (depth/time)
dt = Computational increment (duration of unit excess rainfall)
Default dt is smallest value of 0.1333Tc, rtm, and th
(Smallest dt is then adjusted to match up with Tp)
UDdt = User specified override computational main time increment
(only used if UDdt is => .1333Tc)
D(t) = Point on distribution curve (fraction of P) for time step t
K = 2 / (1 + (Tr/Tp)): default K = 0.75: (for Tr/Tp = 1.67)
Ks = Hydrograph shape factor
= Unit Conversions * K:
= ((lhr/3600sec) * (1ft/12in) * ((5280ft)**2/sq.mi)) * K
Default Ks = 645.333 * 0.75 = 484
Lag = Lag time from center of excess runoff. (dt) to Tp: Lag = 0.6Tc
P = Total precipitation depth, inches
Pa(t) = Accumulated rainfall at time step t
Pi(t) = Incremental rainfall at time step t
qp = Peak discharge (cfs) for lin. runoff, for lhr, for 1 .sq.mi.
= (Ks * A * Q) / Tp (where Q = lin. runoff, A=sq.mi.)
Qu(t) = Unit hydrograph ordinate (cfs) at time step t
Q(t) = Final hydrograph ordinate (cfs) at time step t
Rai(t)= Accumulated runoff (inches) at time step t 'for impervious area
Rap(t)= Accumulated runoff (inches) at time step t for pervious area
Rii(t)= Incremental runoff (inches) at time step t for impervious area
Rip(t)= Incremental runoff (inches) at time step t for pervious area
R(t) = Incremental weighted total runoff (inches)
Rtm = Time increment for rainfall table (.RNF file)
Si = S for impervious area: Si = (1000/CNi) - 10
Sp = S for pervious area: Sp = (1000/CNp) - 10
t = Time step (row) number
Tc = Time of concentration
Tb = Time (hrs) of entire unit hydrograph: Tb = Tp + Tr
Tp = Time (hrs) to peak of a unit hydrograph: Tp = (dt/2) + Lag
Tr = Time (hrs) of receding limb of unit hydrograph: Tr = ratio of Tp
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... SCS Unit Hyd. Equations Page 4.02
Name....
File.... R:\1999JOBS\99251000\99251000.PPW
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
PRECIPITATION: -----------------------------------------------------------
Column (1): Time for time step t
Column (2): D(t) = Point on distribution curve for time step t
Column (3): Pi(t) = Pa(t) - Pa(t-1): Col.(4) - Preceding Col.(4)
Column (4): Pa(t) = D(t) x P: Col.(2) x P
PERVIOUS AREA RUNOFF (using SCS Runoff CN Method) ------------------------
Column (5): Rap(t) = Accumulated pervious runoff for time step t
If (Pa(t) is <= 0.2Sp) then use: Rap(t) = 0.0
If (Pa(t) is > 0.25p) then use:
Rap(t) = (Col.(4)-0.2Sp)**2 / (Col.(4)+0.8Sp)
Column (6): Rip(t) = Incremental pervious runoff for time step t
Rip(t) = Rap(t) - Rap(t-1)
Rip(t) = Col.(5) for current row - Col.(5) for preceding row.
IMPERVIOUS AREA RUNOFF ---------------------------------------------------
Column (7 & 8)... Did not specify to use impervious areas.
INCREMENTAL WEIGHTED RUNOFF: ---------------------------------------------
Column (9): R(t) = (Ap/At) x Rip(t) + (Ai/At) x Rii(t)
R(t) = (Ap/At) x Col.(6) + (Ai/At) x Col.(8)
SCS UNIT HYDROGRAPH METHOD: ----------------------------------------------
Column (10): Q(t) is computed with the SCS unit hydrograph method
using R o and Quo.
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... SCS Unit Hyd. Summary
Name.... SCS UH 20 Tag: 100yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 100yr
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Page 4.03
Event: 100 yr
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = C:\HAESTAD\PPKW\RAINFALL\
Rain File -ID = SCSTYPES.RNF - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = R:\1999JOBS\99251000\
HYG File - ID = WQBASIN.HYG - SCS UH 20 100yr
Tc = .1000 hrs
Drainage Area = 28.470 acres Runoff CN= 78
Computational Time Increment = .01333 hrs
Computed Peak Time = 11.9333 hrs
Computed Peak Flow = 230.57 cfs
Time Increment for HYG File = .0667 hrs
Peak Time, Interpolated Output = 11.9393 hrs
Peak Flow, Interpolated Output = 228.92 cfs
DRAINAGE AREA
ID:SCS UH 20
CN = 78
Area = 28.470 acres
S = 2.8205 in
0.25 = .5641 in
Cumulative Runoff
-------------------
5.3910 in
557141 cu.ft
HYG Volume... 557150 cu.ft (area under HYG curve)
***** UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .10000 hrs (ID: None Selected)
Computational Incr, Tm = .01333 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 322.58 cfs
Unit peak time Tp = .06667 hrs
Unit receding limb, Tr = .26667 hrs
Total unit time, Tb = .33333 hrs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
' Type.... SCS Unit Hyd. Summary
Name.... SCS UH 20 Tag: 10yr
• File.... R:\1999J OBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 10yr
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Page 4.04
Event: 10 yr
Duration = 24.0000 hrs Rain Depth = 5.3800 in
Rain Dir = C:\HAESTAD\PPKW\RAINFALL\
Rain File -ID = SCSTYPES.RNF - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = R:\1999JOBS\99251000\
HYG File - ID = WQBASIN.HYG - SCS UH 20 10yr
Tc = .1000 hrs
Drainage Area = 28.470 acres Runoff CN= 78
--------------------------------------------
--------------------------------------------
Computational Time Increment = .01333 hrs
Computed Peak Time = 11.9333 hrs
Computed Peak Flow = 131.72 cfs
Time Increment for HYG File = .0667 hrs
Peak Time, Interpolated Output = 11.9393 hrs
Peak Flow, Interpolated Output = 131.07 cfs
--------------------------------------------
--------------------------------------------
DRAINAGE AREA
ID:SCS UH 20
CN = 78
Area = 28.470 acres
S = 2.8205 in
0.2S = .5641 in
Cumulative Runoff
-------------------
3.0371 in
313877 cu.ft
HYG Volume... 313877 cu.ft (area under HYG curve)
***** UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .10000 hrs (ID: None Selected)
Computational Incr, Tm = .01333 hrs = 0. 20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 322.58 cfs
Unit peak time Tp = .06667 hrs
Unit receding limb, Tr = .26667 hrs
Total unit time, Tb = .33333 hrs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... SCS Unit Hyd. Summary Page 4.05
Name.... SCS UH 20 Tag: 25yr Event: 25 yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 25yr
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 25 year storm
Duration = 24.0000 hrs Rain Depth = 6.4100 in
Rain Dir = C:\HAESTAD\PPKW\RAINFALL\
Rain File -ID = SCSTYPES.RNF - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = R:\1999JOBS\99251000\
HYG File - ID = WQBASIN.HYG - SCS UH 20 25yr
Tc = .1000 hrs
Drainage Area = 28.470 acres Runoff CN= 78
--------------------------------------------
--------------------------------------------
Computational Time Increment = .01333 hrs
Computed Peak Time = 11.9333 hrs
Computed Peak Flow = 170.28 cfs
Time Increment for HYG File = .0667 hrs
Peak Time, Interpolated Output = 11.9393 hrs
Peak Flow, Interpolated Output = 169.25 cfs
--------------------------------------------
--------------------------------------------
DRAINAGE AREA
ID:SCS UH 20
CN = 78
Area = 28.470 acres
S = 2.8205 in
0.2S = .5641 in
Cumulative Runoff
-------------------
3.9433 in
407528 cu.ft
HYG Volume... 407531 cu.ft (area under HYG curve)
***** UNIT HYDROGRAPH PARAMETERS ***** "
Time Concentration, Tc = .10000 hrs (ID: None Selected)
Computational Incr, Tm = .01333 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 322.58 cfs
Unit peak time Tp = .06667 hrs
Unit receding limb, Tr = .26667 hrs
Total unit time, Tb = .33333 hrs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... SCS Unit Hyd.
Name.... SCS UH 20
File.... R:\1999JOBS\9'
Storm... TypeII 24hr
SCS UNIT
Summary Page 4.06
Tag: 2yr Event: 2 yr
3251000\99251000.PPW
Tag: 2yr
HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration = 24.0000 hrs Rain Depth = 3.6000 in
Rain Dir = C:\HAESTAD\PPKW\RAINFALL\
Rain File -ID = SCSTYPES.RNF - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = R:\1999JOBS\99251000\
HYG File - ID = WQBASIN.HYG - SCS UH 20 2yr
Tc = .1000 hrs
Drainage Area = 28.470 acres Runoff CN= 78
--------------------------------------------
--------------------------------------------
Computational Time Increment = .01333 hrs
Computed Peak Time = 11.9333 hrs
Computed Peak Flow = 67.80 cfs
Time Increment for HYG File = .0667 hrs
Peak Time, Interpolated Output = 11.9393 hrs
Peak Flow, Interpolated Output = 67.70 cfs
--------------------------------------------
--------------------------------------------
DRAINAGE AREA
-------------------
ID:SCS UH 20
CN = 78
Area = 28.470 acres
S = 2.8205 in
0.2S = .5641 in
Cumulative Runoff
--------------------
1.5738 in
162644 cu.ft
HYG Volume... 162640 cu.ft (area under HYG curve)
*****. UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .10000 hrs (ID: None Selected)
Computational Incr, Tm = .01333 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Reced ing/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 322.58 cfs
Unit peak time Tp = .06667 hrs
Unit receding limb, Tr = .26667 hrs
Total unit time, Tb = .33333 hrs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Chn-Trapz.
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... existing channel, assumed unmaintained
Solution to Mannings Open Channel Flow Equation
(Computed values are based on normal depth.)
TRAPEZOIDAL CROSS SECTION
Page 5.01
Slope = .037000 ft/fit
Mannings n = 0.08 000
Invert E lev. = 244.00 ft
Top of C hannel = 248.50 ft
Base wid th = 4.00 ft
Rt Side slope = 3.000 ho rizontal :1 ve rt.
Lt Side slope = 3.000 ho rizontal :1 ve rt.
Elev. Depth Flow Vel. Area Top W. Wet.P. Hd Froude
(ft) (ft)
--- (cfs)
------ (ft/sec
------- ) (sq.ft)
------- (ft)
------ (ft)
------ (ft)
----- No.
------
--------
244.000 ----
.00 .00 .00 .0000 .00 .00 .00 0.00
244.010 .01 .01 .16 .0403 4.06 4.06 .01 0.29
244.090 .09 .26 .69 .3843 4.54 4.57 .08 0.42
244.180 .18 .86 1.05 .8172 5.08 5.14 .16 0.46
244.270 .27 1.73 1.33 1.2987 5.62 5.71 .23 0.49
244.360 .36 2.87 1.57 1.8288 6.16 6.28 .30 0.51
244.450 .45 4.29 1.78 2.4075 6.70 6.85 .36 0.52
244.540 .54 5.98 1.97 3.0348 7.24 - 7.42 .42 0.54
244.630 .63 7.95 2.14 3.7107 7.78 7.98 .48 0.55
244.720 .72 10.23 2.31 4.4352 8.32 8.55 .53 0.56
244.810 .81 12.81 2.46 5.2083 8.86 9.12 .59 0.57
244.900 .90 15.70 2.60 6.0299 9.40 9.69 .64 0.57
244.990 .99 18.92 2.74 6.9004 9.94 10.26 ..69 0.58
245.080 1.08 22.48 2.88 7.8192 10.48 10.83 .751 0.59
245.170 1.17 26.39 3.00 8.7867 11.02 11.40 .80 0.59
245.260 1.26 30.66 3.13 9.8027 11.56 11.97 .85 0.60
245.350 1.35 35.30 3.25 10.8676 12.10 12.5.4 ..90 0.60
245.440 1.44 40.32 3.37 11.9808 12.64 13.1.1 .95 0.61
245.530 1.53 45.73 3.48 13.1427 13.18 13.68 1:00 0.61
245.620 1.62 51.54 3.59 14.3531 13.72 14.25 1.05 0.62
245.710 131 57.76 3.70 15.6124 14'.'26 14.82 1.09 0.62
245.800 1.80 64.41 3.81 16.9201 14.80 15.38 1.14 0.63
245.890 1.89 71.49 3.91 18.2763 15.34 15.95 1.19 0.63
245.980 1.98 79.01 4.01 19.6811 15.88 16.52 1.24 0.64
246.070 2.07 86.99 4.12 21.1348 16.42 17.09 1.29 0.64
246.160 2.16 95.43 4.22 22.6369 16.96 17.66 1.33 0.64
246.250 2.25 104.34 4.31 24.1875 17.50 18.23 1.38 0.65
246.340 2.34 113.74 4.41 25.7867 18.04 18.80 1.43 0.65
246.430 2.43 123.62 4.51 27.4346 18.58 19.37 1.48 0.65
246.520 2.52 134.01 4.60 29.1313 19.12 19.94 1.52 0.66
246.610 2.61 144.91 4.69 30.8763 19.66 20.51 1.57 0.66
246.700 2.70 156.34 4.79 32.6699 20.20 21.08 1.62 0.66
246.790 2.79 168.29 4.88 34.5122 20.74 21.65 1.66 0.67
246.880 2.88 180.78 4.97 36.4033 21.28 22.21 1.71 0.67
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Chn-Trapz.
Name.... PR 10
I
File.... R:\1999JOBS\99251000\99251000.PPW
Title... existing channel., assumed unmaintained
Solution to Mannings Open Channel Flow Equation
(Computed values are based on normal depth.)
TRAPEZOIDAL CROSS SECTION
Page 5.02
Slope = .037000 ft/ft
Mannings n = 0.08 000
Invert E lev. = 244.00 ft
Top of C hannel = 248.50 ft
Base wid th = 4.00 ft
Rt Side slope = 3.000 horizontal :1 ve rt.
Lt Side slope = 3.000 horizontal :1 ve rt.
Elev. Depth Flow Vet. Area Top W. Wet.P. Hd Froude
(ft) (ft)
---- (cfs)
------ (ft/sec
------- ) (sq.ft)
------- (ft)
------ (ft)
------ - (ft)
---- No.
------
--------
246.970 ---
2.97 193.82 5.05 38.3427 21.82 22.78 1.76 0.67
247.060 3.06 207.41 5.14 40.3308 22.36 23.35 1.80 0.68
247.150 3.15 221.58 5.23 42.3674 22.90 23.92 1.85 0.68
247.240 3.24 236.32 5.32 44.4529 23.44 24.49 1.90 0.68
247.330 3.33 251.64 5.40 46.5867 23.98 25.06 1.94 0.68
247.420 3.42 267.56 5.49 48.7692 24.52 25.63 1.99 0.69
247.510 3.51 284.08 5.57 51.0002 25.06 26.20 2.04 0.69
247.600 3.60 301.21 5.65 53.2802 25.60 -26.77 2.08 0.69
247.690 3.69 318.96 5.74 55.6084 26.14 27.34 2.13 0.69
247.780 3.78 337.33 5.82 57.9852 26.68 27.91 2.17 0.70
247.870 3.87 356.35 5.90 60.4106 27.22 28.48 2.22 0.70
247.960 3.96 376.01 5.98 62.8850 27.76 29.05 2.27 0.70
248.050 4.05 396.32 6.06 65.4076 28.30 29.61 2.31 0.70
248.14.0 4.14 .41.7.30 6.14 67.9788 ._-28.8.4 30.18 2.36. 0.70 .
248.230 4.23 438.94 6.22 70.5986 29.38 30.75 2:40 0.71
248.320 4.32 461.27 6.30 73.2674 29.92 31.32 2.45 0.71
248.410 4.41 48.4.28 6.37 75.9844 30..4.6 31.89 2.49 0.71
248.500 4.50.. 507.99 6.45 78.7500 _ 31.00 32.46 2.54; 0.71
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Channel Equations
Name.... PR 10
• File.... R:\1999JOBS\99251000\99251000.PPW
Title... existing channel, assumed unmaintained
SOLUTION TO MANNINGS OPEN CHANNEL FLOW EQUATION
(Computed values are based on normal depth.)
Q = (k/n) * A * (R**2/3) * (S**1/2)
Page 5.03
where: English Units SI units

Q =
Channel flow -------------
cfs ---------
cros
k = Mannings constant 1.485919 1.0
n = Mannings n no units no units
R = Hydraulic radius, A/WP ft m
A = X-section flow area sq.ft. sq.m.
WP = Wetted perimeter ft m
S = Slope ft/ft m/m
ADDITIONAL OUTPUT VARIABLES:
Vet= .Q/A
Hd = A/TpW
F Vet / ('g * Hd)**1/2
where: English Units, SI units

Vel=
Velocity -------------
ft/sec ---------
m/sec
Q = Channel flow cfs cros
A = X-section flow area sq.ft. sq.m.
Hd = Hydraulic depth ft m
TpW= Top width for flow area ft m
g = Acceleration of gravity ft/sec**2 m/sec**2
F = Froude No. no units no units
(Subcritical: F < 1; Critical: F = 1; Super critical: F > 1)
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000

Type.... Vol: Elev-Area
Name.... P 10
File.... R:\1999JOBS\99251000\99251000.PPW
Page 6.01
Elevation Planimeter Area Al+A2+sgr(A1*A2) Volume Volume Sum
(ft)
----------- (sq.in) (sq.ft)
---------------------- (sq.ft)
---------------- (cu.ft)
-
-
--- (cu.ft)
--------
-
--
246.00 ----- 0 -
0 ---
-
0 -
-
0
247.00 ----- 20256 20256 6752 6752
248.00 ----- 22213 63681 21227 27979
249.00 ----- 24227 69638 23213 51192
250.00 ----- 26297 75765 25255 76447
251.00 ----- 28673 82429 27476 103923
252.00 ----- 31161 89725 29908 133831
253.00 ----- 33762 97358 32453 166284
254.00 ----- 36481 105338 35113 201397
255.00 ----- 39319 113673 37891 239288
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-EL1) * (Areal + Areal + sq.rt.(Areal*Area2))
where: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for EL1, EL2, respectively
Volume = Incremental volume between EL1 and EL2
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000

Type.... Outlet Input Data
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 250.25 ft
Increment .25 ft
Max. Elev.= 255.00 ft
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (Upstream to DnStream)
<--- Reverse Flow Only (DnStream to Upstream)
< --- > Forward and Reverse Both Allowed
Structure
Stand Pipe
Orifice-Circular
Culvert-Circular
Weir-Rectangular
TW SETUP, DS Channel
Page 7.01
No. Outfall E1, ft E2, ft
----
sp -------
---> cv ---------
252.250 ---------
255.000
or ---> cv 250.250 255.000
cv ---> TW 245.000 255.000
es ---> TW 254.000 255.000
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000

Type.... Outlet Input Data
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
OUTLET STRUCTURE INPUT DATA
Page 7.02
Structure ID = sp
Structure Type
----------------- = Stand Pipe
-------------
------
# of Openings = 1
Invert Elev. = 252.25 ft
Diameter = 6.0000 ft
Orifice Area = 28.2743 sq.ft
Orifice Coeff. _ .600
Weir Length = 18.85 ft
Weir Coeff. = 3.000
K. Submerged = .000
K, Reverse = 1.000
Kb,Barrel = .000000 (per ft of full flow)
Barrel Length = .00 ft
Mannings n = .0000
Structure ID = or
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 250.25 ft
Diameter = .3333 ft
Orifice Coeff. _ .600
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000

Type.... Outlet Input Data
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
OUTLET STRUCTURE INPUT DATA
Structure ID = cv
Structure Type = Culvert-Circular
------------------
No. Barrels ------------
= 1 ------
Barrel Diameter = 4.0000 ft
Upstream Invert = 245.00 ft
Dnstream Invert = 244.00 ft
Horiz. Length = 64.00 ft
Barrel Length = 64.01 ft
Barrel Slope = .01563 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000
Kb = .004925
Kr = .5000
HW Convergence = .001
Page 7.03
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0078
Inlet Control M = 2.0000
Inlet Control c = .02920
Inlet Control Y = .7400
T1 ratio (HW/D) = 1.128
T2 ratio (HW/D) = 1.199
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 249.51 ft ---> Flow = 87.96 cfs
At T2 Elev = 249.80 ft ---> Flow = 100.53 cfs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Outlet Input Data
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
OUTLET STRUCTURE INPUT DATA
Structure ID
Structure Type
--------------
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
es
Weir-Rectangular
----------------
1
254.00 ft
25.00 ft
3.000000
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
USE DOWNSTREAM CHANNEL NORMAL DEPTH FOR TW...
Channel Type: Chn-Trapz.
Channel ID: PR 10
Page 7.04
CONVERGENCE TOLERANCES ...
Maximum Iterations= 30
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .10 cfs
Max. Q tolerance = .10 cfs
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000

Type.... Outlet Input Data
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
USE DOWNSTREAM CHANNEL NORMAL DEPTH FOR TW...
Channel Type: Chn-Trapz.
Channel ID: PR 10
Solution to Mannings Open Channel Flow Equation
(Computed values are based on normal depth.)
TRAPEZOIDAL CROSS SECTION
Page 7.05
Slope = .037000 ft/ft
Mannings n = 0.08000
Invert Elev. = 244.00 ft
Top of Channel = 248.50 ft
Base width = 4.00 ft
Rt Side slope = 3.000 horizontal :1 vert.
Lt Side slope = 3.000 horizontal :1 vert.
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
1
Type.... Composite Rating Curve
Name.... PR 10
File.... R:\1999JOBS\99251000\99251000.PPW
Title... riser/barrel assy
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .005 (+/- ft)
FLOW PATH: Elev= 254; Branch: or-cv-TW
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
-------- -------- -------- Converge ------------- ------------
Elev. Q TW Elev Error
ft cfs ft
-- +/-ft
--- Contributing Structures
--------
250.25 -------
.00 ------
244.00 --
.000 --------------
(no Q: sp,or ------------
,cv,es)
250.50 .10 244.08 .000 or,cv (no Q: sp,es)
250.75 .24 244.08 .000 or,cv (no Q: sp,es)
251.00 .32 244.11 .000 or,cv (no Q: sp,es)
251.25 .38 244.11 .000 or,cv (no Q: sp,es)
251.50 .44 244.11 .000 or,cv (no Q: sp,es)
251.75 .49 244.11 .000 or,cv (no Q: sp,es)
252.00 .53 244.13 .000 or,cv (no Q: sp,es)
252.25 .57 244.15 .000 or,cv (no Q: sp,es)
252.50 7.68 244.62 .000 sp,or,cv (no Q:-es)
252.75 20.63 245.03 .000 sp,or,cv (no Q: es)
253.00 37.40 245.39 .000 sp,or,cv (no Q: es)
253.25 57.25 245.70 .000 sp,or,cv (no Q: es)
253.50 79.76 245.99 .000 sp,or,cv (no Q: es)
253.75 104.65 246.25 .000 sp,or,cv (no Q: es)
254.00 131.56 246.50 .005 sp,or,c.v (no Q: e.s)
254.25 194.27 246.97 .000 sp,cv,es (no Q: or)
254.50 215.03 247.11 .000 sp,cv,es (no Q: or)
254.75 240.78 247.27 .000 sp,cv,es (no Q: or)
255.00 270.55 247.44 .000 sp,cv,es (no Q: or)
Page 7.06
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Pond E-V-Q Table Page 8.01
Name.... P 10
File.... R:\1999JOBS\99251000\99251000.PPW
LEVEL POOL ROUTING DATA
HYG Dir = R:\1999JOBS\99251000\
Inflow HYG file = WQBASIN.HYG - P 10 IN 100yr
Outflow HYG file = WQBASIN.HYG - P 10 OUT 100yr
Pond Node Data = P 10
Pond Volume Data = P 10
Pond Outlet Data = PR 10
No Infiltration
INITIAL CONDITIONS
Starting WS Elev = 250.25 ft
Starting Volume = 83094 cu. ft
Starting Outflow = .00 cfs
Starting Infiltr. _ .00 cfs
Starting Total Qout= .00 cfs
Time Increment = .0667 hrs
Elevation Outflow Storage Area Infilt. Q Total 2S/t + 0
ft cfs cu.ft sq.ft cfs cfs cfs
-
-
-------------
246.00 -----------
.00 ----------
0 --- --------
0 -----------
.00 ------------
.00 ---
----
-
.00
247.00 .00 6752 20256 .00 .00 56.24
248.00 .00 27979 22213 .00 .00 233.04
249.00 .00 51192 24227 .00 .00 426.38
250.00 .00 76447 26297 .00 .00 636.74
250.25 .00 83094 26881 .00 .00 692.10
250.50 .10 89888 27472 .00 .10 748.79
250.75 .24 96830 28069 -.00 .24 .806.76
251.00 .32 103923 28673 .00 .32 865.91
251.25 .38 111168 29285 .00 .38 926.32
251.50 .44 118566 29904 .00 .44 988.00
251.75 .49 126120 30529 .00 .49 1050.96
252.00 .53 133831 31161 .00 .53 1115.23
252.25 .57 141702 31801 .00 .57 1180.83
252.50 7.68 149733 32448 .00 7.68 1254.83
252.75 20.63 157926 33102 .00 20.63 1336.03
253.00 37.40 166284 33762 .00 37.40 1422.41
253.25 57.25 174808 34432 .00 57.25 1513.26
253.50 79.76 183501 35108 .00 79.76 1608.17
253.75 104.65 192363 35791 .00 104.65 1706.87
254.00 131.56 201397 36481 .00 131.56 1809.03
254.25 194.27 210605 37181 .00 194.27 1948.43
254.50 215.03 219988 37887 .00 215.03 2047.35
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Pond E-V-Q Table
Name.... P 10
1 File.... R:\1999JOBS\99251000\99251000.PPW
LEVEL POOL ROUTING DATA
HYG Dir = R:\1999JOBS\99251000\
Inflow HYG file = WQBASIN.HYG - P 10
Outflow HYG file = WQBASIN.HYG - P 10
Pond Node Data = P 10
Pond Volume Data = P 10
Pond Outlet Data = PR 10
No Infiltration
INITIAL CONDITIONS
IN 100yr
OUT 100yr
Page 8.02
Starting WS Elev = 250.25 ft
Starting Volume = 83094 cu.ft
Starting Outflow = .00 cfs
Starting Infiltr. _ .00 cfs
Starting Total Qout= .00 cfs
Time Increment = .0667 hrs
Elevation Outflow Storage Area Infilt. Q Total 2S/t + 0
ft cfs cu.ft sq.ft cfs cfs cfs
-------------
254.75 ------------
240.78 ---------
229548 -----------
38600 -----------
.00 ------------
240.78 ----------
2152.73
255.00 270.55 239288 39319 .00 270.55 2263.62
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Type.... Pond Routing Summary
Name.... P 10 OUT Tag: 10yr
File.... R:\1999JOBS\99251000\99251000.PPW
Storm... TypeII 24hr Tag: 10yr
LEVEL POOL ROUTING SUMMARY
HYG Dir = R:\1999JOBS\99251000\
Inflow HYG file = WQBASIN.HYG - P 10
Outflow HYG file = WQBASIN.HYG - P 10
Pond Node Data = P 10
Pond Volume Data = P 10
Pond Outlet Data = PR 10
No Infiltration
INITIAL CONDITIONS
Starting WS Elev = 250.25 ft
Starting Volume = 83094 cu.ft
Starting Outflow = .00 cfs
Starting Infiltr. _ .00 cfs
Starting Total Qout= .00 cfs
Time Increment = .0667 hrs
INFLOW/OUTFLOW HYDROGRAPH SUMMARY
IN l0yr
OUT l0yr
Peak Inflow = 131.07 cfs at 11.9393 hrs
Peak Outflow = 88.35 cfs at 12.0727 hrs
-----
Peak --------------
Elevation = -----------
253.59 -----------------------
ft
Peak Storage = 186539 cu.ft
MASS BALANCE (cu.ft)
-------------
+ Initial Vol -------------
= 83094
+ HYG Vol IN = 313877
- Infiltration = 0
- HYG Vol OUT = 313677
- Retained Vol = 83292
Unrouted Vol = -2 cu.ft
(.001% of Inflow Volume)
Page 8.03
Event: 10 yr
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
Appendix A
Index of Starting Page Numbers for ID Names
----- P -----
P 10... 6.01, 8.01, 8.03
PR 10... 5.01, 5.03, 7.01, 7.06
----- S -----
SCS UH 2O... 3.01, 4.03, 4.04,
4.05, 4.06
storms... 2.01
----- W -----
Watershed 100yr... 1.01, 1.02, 1.03,
1.04, 1.05, 1.06
A-1
S/N: 021002906a82 Bass, Nixon and Kennedy, Inc.
PondPack Ver: 7.0 (312) Compute Time: 14:35:04 Date: 06-29-2000
106/29/00 STORM SEWER DETAILED REPORT PAGE 1 OF 5
Data File : 9251base.stm Return Period: 25 Yrs
Rainfall file: r:\1999jobs\99251000\\9251base.RND I = 135.520/ ( Tc + 18.750)
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LINE 1 STORM SEWER HYDRAULIC REPORT
1-2 (NCDOT) Downstream Line # = OUTFALL
Diameter (in) = 48
Plan Length (ft) _
INVERT
(ft)
UPSTREAM 252.00
DNSTREAM 250.00
SLOPE(%) 1.695
CATCHMENT CUMULATIVE
Area (ac) = 3.7 25.8
Drainage Time (min) = 5.00 5.50
Intensity (in/h) = 8.08 7.94 TOTAL UNIFORM
Runoff Coefficient = 0.80 0.66 FLOW CAPACITY
Rational Flow (cfs) = 23.93 136.28 (cfs) (cfs)
Known Flow (cfs) = 0.00 0.00 136.28 186.92
Note: Supercritical flow detected - Normal depth assumed
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STORM SEWER INLET REPORT
Flow Results (cfs) Ponding Width (ft) = 0.00
Flow from Catchment = 23.93 Depth at Curb (ft) = 0.00
Carryover from previous inlet = 0.00 Efficiency (o)
Total flow to current inlet = 23.93 Curb =
Intercepted by current inlet = 23.93 Grate = * Total = 100.00
Bypassed by current inlet = 0.00 Slot =
INPUT PARAMETERS:
Inlet Type = NONE IN SAG Longitudinal Slope (ft/ft) = 0.000
Gutter Width (ft) = 0.000 Pavement Cross Slope (ft/ft) = 0.020
Inlet n-value = 0.016 Gutter Cross Slope (ft/ft) = 0.020
Downstream Inlet Number = 0 Gutter depression .(in) 0.00
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L19.99
DEPTH
(in)
30.40
30.40
N =
Pipe Len
HGL
(f t)
254.53
252.53
1.667
0.013 Critical Dep
gth (ft) = 118.01
EGL CROWN NAT GND
(ft) (ft) (ft)
258.63 256.00 263.00
256.63 254.00 250.00
1.667 10.834
:h (in) = 41.71
Kj (JLC) = 1.0
AREA VEL
(ft») (ft/s)
8.39 16.24
8.39 16.24
A
06/29/00 STORM SEWER DETAILED REPORT (continued) PAGE 2 OF 5
Data File : 9251base.stm Return Period: 25 Yrs
Rainfall file: r:\1999jobs\99251000\\9251base.RND I = 135.520/ ( Tc + 18.750)
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LINE 2 STORM SEWER HYDRAULIC REPORT
2-3 Downstream Line # = 1
Diameter (in) = 42
Plan Length (ft) _
INVERT
(ft)
UPSTREAM 258.00
DNSTREAM 252.00
SLOPE() 6.019
N =
L03.51 Pipe Len
DEPTH HGL
(in) (ft)
38.34 261.19
42.00 258.63
2.474
0.013
3th (f t)
EGL
(f t)
263.53
260.77
2.662
Critical Dep
99.69
CROWN NAT GND
(ft) (ft)
261.50 265.00
255.50 263.00
1.932
th (in)
Kj (J]
AREA
(f t» )
9.21
9.62
= 38.34
x) = 1.0
VEL
(ft/s)
12.25
11.73
CATCHMENT CUMULATIVE
Area (ac) = 4.2 22.1
Drainage Time (min) = 5.00 5.48
Intensity (in/h) = 8.08 7.94 TOTAL UNIFORM
Runoff Coefficient = 0.80 0.64 FLOW CAPACITY
Rational Flow (cfs) = 27.20 112.83 (cfs) (cfs)
Known Flow (cfs) = 0.00 0.00 112.83 246.72
Note: Transitional flow exists in this line
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
STORM SEWER INLET REPORT
Flow Results (cfs) Ponding Width (ft) = 0.00
Flow from Catchment = 27.20 Depth at Curb (ft) = 0.00
Carryover from previous inlet = 0.00 Efficiency M
Total flow to current inlet = 27.20 Curb =
Intercepted by current inlet = 27.20 Grate = * Total 100.00
Bypassed by current inlet = 0.00 Slot
INPUT PARAMETERS:
Inlet Type = NONE IN SAG Longitudinal Slope (ft/ft) = 0.000
Gutter,Width (ft) = 0.000 Pavement Cross. Slope (ft/ft) = 0.020
Inlet n-value = 0.016 Gutter..Cro.ss.Slope (ft/ft) = 0.020.
Downstream Inlet Number = 1 .Gutter.,depression.(in). = 0.00
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06/29/00 STORM SEWER DETAILED REPORT (continued) PAGE 3 OF 5
Data File : 9251base.stm Return Period: 25 Yrs
Rainfall file: r:\1999jobs\99251000\\9251base.RND I = 135.520/ ( Tc + 18.750)
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LINE 3 STORM SEWER HYDRAULIC REPORT
3-4 Downstream Line # = 2
Diameter (in) = 36 N = 0.013 Critical Depth (in) = 33.97
Plan Length (ft) = 326.43 Pipe Length (ft) = 322.49 Kj (JLC) = 1.0
INVERT DEPTH HGL EGL CROWN NAT GND AREA VEL
(ft) (in) (ft) (ft) (ft) (ft) (ft» ) (ft/s)
UPSTREAM 264.00 36.00 269.08 271.46 267.00 271.00 7.07 12.38
DNSTREAM 258.00 36.00 263.53 265.91 261.00 265.00 7.07 12.38
SLOPE() 1.861 1.701 1.701 1.838
CATCHMENT CUMULATIVE
Area (ac) = 2.0 18.0
Drainage Time (min) = 5.00 5.05
Intensity (in/h) = 8.08 8.07 TOTAL UNIFORM
Runoff Coefficient = 0.80 0.60 FLOW CAPACITY
Rational Flow (cfs) = 13.30 87.52 (cfs) (cfs)
Known Flow (cfs) = 0.00 0.00 87.52 90.94
Note: Upstream surcharge (ft) = 2.08
eeeeeee@eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
STORM SEWER INLET REPORT
Flow Results (cfs) Ponding Width (ft) = 0.00
Flow from Catchment = 13.30 Depth at Curb (ft) = 0.00
Carryover from previous inlet = 0.00 Efficiency (%)
Total flow to current inlet = 13.30 Curb =
Intercepted by current inlet = 13.30 Grate = * Total = 100.00
Bypassed by current inlet = 0.00 Slot .
INPUT PARAMETERS:
Inlet Type = NONE IN SAG Longitudinal Slope (ft/ft) = 0.000
Gutter Width (ft) = 0.000 Pavement Cross Slope (ft/ft) = 0.020
Inlet n-value = 0.016. Gutter Cross Slope (ft/ft) = 0.020
Downstream Inlet Number. = 1 Gutter.depression.(in) = 0.00
eeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeee •-
06/29/00, STORM SEWER DETAILED REPORT (continued) PAGE 4 OF 5
Data F''ile : 9251base.stm Return Period: 25 Yrs
Rainfall file: r:\1999jobs\99251000\\9251base.RND I = 135.520/ ( Tc + 18.750)
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LINE 4 STORM SEWER HYDRAULIC REPORT
4-5 Downstream Line # = 3
Diameter (in) = 36 N = 0.013 Critical Depth (in) = 32.54
Plan Length (ft) = 237.44 Pipe Length (ft) = 233.57 Kj (JLC) = 1.0
INVERT DEPTH HGL EGL CROWN NAT GND AREA VEL
(ft) (in) (ft) (ft) (ft) (ft) (ft» ) (ft/s)
UPSTREAM 272.00 32.54 274.71 276.61 275.00 279.00 6.72 11.06
DNSTREAM 264.00 36.00 271.46 273.18 267.00 271.00 7.07 10.52
SLOPE(`•-) 3.425 1.368 1.444 3.369
CATCHMENT CUMULATIVE
Area (ac) = 3.9 15.9
Drainage Time (min) = 5.00 5.01
Intensity (in/h) = 8.08 8.08 TOTAL UNIFORM
Runoff Coefficient = 0.80 0.57 FLOW CAPACITY
Rational Flow (cfs) = 25.30 74.35 (cfs) (cfs)
Known Flow (cfs) = 0.00 0.00 74.35 123.38
Note: Transitional flow exists in this line
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
STORM SEWER INLET REPORT
Flow Results (cfs) Ponding Width (ft) = 0.00
Flow from Catchment = 25.30 Depth at Curb (ft) = 0.00
Carryover from previous inlet = 0.00 Efficiency (o)
Total flow to current inlet = 25.30 Curb =
Intercepted by current inlet = 25.30 Grate = * Total = 100.00
Bypassed by current inlet = 0.00 Slot
INPUT PARAMETERS:
Inlet Type = NONE IN SAG Longitudinal Slope (ft/ft) = 0.000
Gutter Width (ft) = 0.000 Pavement Cross Slope (ft/ft) = 0.020
Inlet n-value = 0.016 Gutter Cross Slope (ft/ft) = 0.020
Downstream Inlet Number. = 3 Gutter. depression..(in) = 0.00
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06/29/00 STORM SEWER DETAILED REPORT (continued) PAGE 5 OF 5
Data File 9251base.stm Return Period: 25 Yrs
Rainfall file: r:\1999jobs\99251000\\9251base.RND I = 135.520/ ( Tc + 18.750)
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LINE 5 STORM SEWER HYDRAULIC REPORT
5-6 Downstream Line # = 4
Diameter (ij
Plan Length
UPSTREAM
DNSTREAM
SLOPE()
Z) = 36 N =
(ft) = 60.23 Pipe Len
INVERT DEPTH HGL
(ft) (in) (ft)
274.00 27.37 277.41
271.00 36.00 276.10
5.332 2.175
0.013
ath (f t)
EGL
(f t)
278.53
276.85
2.800
Critical Dep
56.27
CROWN NAT GND
(ft) (ft)
277.00 279.00
274.00 279.00
0.000
:h (in)
Kj (J]
AREA
(f t>>)
5.77
7.07
= 27.37
?C) = 1.C
VEL
(ft/s)
8.51
6.94
CATCHMENT CUMULATIVE
Area (ac) = 12.0 12.0
Drainage Time (min) = 5.00 5.00
Intensity (in/h) = 8.08 8.08 TOTAL UNIFORM
Runoff Coefficient = 0.50 0.50 FLOW CAPACITY
Rational Flow (cfs) = 49.08 49.08 (cfs) (cfs)
Known Flow (cfs) = 0.00 0.00 49.08 153.94
Note: Upstream surcharge (ft) = 0.41
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee?eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
STORM SEWER INLET REPORT
Flow Results (cfs) Ponding Width (ft) = 0.00
Flow from Catchment = 49.08 Depth at Curb (ft) = 0.00
Carryover from previous inlet = 0.00 Efficiency (o)
Total flow to current inlet = 49.08 Curb =
Intercepted by current inlet = 49.08 Grate = * Total = 100.00
Bypassed by current inlet = 0.00 Slot.
INPUT PARAMETERS:
Inlet Type- = NONE IN SAG Longitudinal`Slope (ft/ft) = 0.000
Gutter Width (ft) = 0.000 Pavement Cross Slope (ft/ft) = 0.020
Inlet n-value = 0.016 Gutter.,. Cross Slope (ft/ft) = 0. 02.0 ,..:.
?...___
Downstream Inlet Number = 4 Gutter, depression ..-(.in),. = 0.00
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