HomeMy WebLinkAboutWPO202200033 Calculations 2022-07-22SHIMP ENGINEERING, P.C.
Design Focused Engineering
Stormwater Management Plan
Calculation Packet
Project Name:
LOT A 13 BUNDORAN FARM.
Prepared by: Shimp Engineering P.C.
Date: July OS, 2021 'L."" � 0
FL
'1���22 ��`��
FIONAL C
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Table of Contents
Cover Page
Table of Contents
Project Narrative
Project Description
SWM Quantity
SWM Quality
Stormwater Quality Calculations:
Post -Development VRRM Map
Post -Development VRRM Spreadsheet.
Level spreader Analysis:
Post -Development Stormwater Level Spreader Drainage Area Map
Time of Concentration Calculation
Time of Concentration Nomographs Post DA _Ex Culvert and New
Stormwater inlets and Pipes Analysis:
VDOT Appendix C8-2
Post -Development Stormwater Culverts Drainage Area Map
Stormwater Culvert Drainage area Summary
Time of Concentration Calculation Ex Culvert and New
Time of Concentration Nomographs Post DA _Ex Culvert and New
HY-8 Culvert Analysis
VDOT LD-229
Post -Development Conveyance Channel Drainage Area Map
Conveyance Channel Drainage area Summary
VDOT LD-268
Independent Reports:
NRCS Soils Report
NOAA Precipitation Report
Appendix A:
Rip -Rap Calculation
SHIMP ENGINEERING, P.C.
Design Focused Engineering
July 08, 2022
Albemarle County
Regarding: LOT A 13 BUNDORAN FARM
Stormwater Management Plan
Proiect Descrtokon
The purpose of this project at Lot A 13 Bundoran Farm is to build a single-family residential house. All SWM
calculations required are contained within the following report. The development property has an area of 52.74 acres
and the development will disturb a total area of 2.86 acres. The proposed stormwater design meets water quantity
requirements set forth in 9VAC25-870-66-D (3) and 9VAC25-870-66-C.
SWM Ounntity
The requirements for stormwater quantity are satisfied by the proposed stormwater design meets water quantity
requirements set forth 9VAC25-870-66-D. Stormwater quantity is managed on site through the utilization of
sheetflow where possible & by providing (3) three level spreaders which will convert concentrated flow to sheetflow,
conditions.
SWM Quality
The stormwater management strategy for this site is governed by the VRRM development spreadsheet.
1. Water quality will be addressed by the dedication of 3.73 acres land into a swm forest/open space easement.
2. Per the VRRM spreadsheet, no further total phosphorous treatment is required.
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Stormwater Quality Calculations:
Post -Development VRRM Map
Post -Development VRRM Spreadsheet.
Land Cover (acres)
A Soils
BSoils
CSoils
DSoils
Totals
Forest/Open Space (acres) -- undisturbed,
mteded fores o ens ace or reforested
3.721
0.00
3.73
( Managed Turf (acres) -- disturbed, graded
far arils or otherturfto be
0.16
1.94
2.10
Impervious Cover(aaes)
OA6
0.67
0.73
• Foreslopen Space areas must he Protected In accordance with de Virginia lWnoff Reduction Method
6.56
51
O
3.73 Acrea
Open Space
I! I I I( 1 .1
150 0 150 300 450
Scale: 1 "=150'
SHIMPENGINEM%9.. P.C.
BV6INEH9N6-L4NDPL4NYIN0 -PROJECT MANAGEMENT
u •t:
\\\\\\\\\\\
Tlffl\\ilw
Legend VRRM DA
ImIMPERVIOUS E Open Space
El WOODS rv.7TURF
�— LOD
Lot A 13 Bundoran Farm
Submission Date: 07-08-2022
Mo Wryinia Run »Reduction Method New Development Complganm Spreadsheet - Version 3.0
C 2011 BMP Standards and Specifications D 2013 Draft BMP Standards and Specifications
Project Name: LOT A-13 BUNDORAN FARM
Date: 7/1/2022
BFdp Design Spedlicamons Usr 2013 Draft St is & Specs
Site Information
Post -Development Project (Treatment Volume and Loads)
land cover (acres)
Asoils
Bsons
CSoaa
DSolls
T.I.
Forest/Dpen space lane.)- undisturbed.
burbeend fortiori, en reforested bnd
3.]3
Dw
3 J3
Managed Tud(.tires) fdistumed, raced for
,yards or other turf [a be mowed/mane d
0.16
1.90
2.10
Inab o.Fnvclraes)
0.06
0.6J
0.J3
•Foresr/Open spode oreos mustbe werseelsom scox nre win
the Yryinio esuaXRedislion MCNod
6.56
lConstantg
Annual Rural (inches)
03
Target Rainfall Fvent(inohes)
LW
Total Phosphorus lFP) Doc orWO
1 0.26
Total wtrogen(Tnl RIC(mi
1.e6
Target TP mad(ro/anent)
0.41
P unidess correction (attar(
ago
ennnN rnaffi cidol
ASoils
Bsoils
Csolls
Osolls
FaresVOpen Space
0.02
0.03
O.M
0.05
Manag HTurt
0.15
0.20
0.22
0.25
lmperbous Cover
095
a.95
0.95
0.95
ForediDpen Space Cover(aeres)
3.73
Trert'aCMholume 0.0983
eei
Treatment Volume (cubic feed) 4,2M
TP bad(lb/yr) 2.69
TN Loatl(IbyQ 19.25
IMarmrtianal Pu me.Onl
Weighted RV(fored)
0.02
%Finad
5179c
Managed Turf Cmer(ai
2.10
Weighted Rv (curt(
0.20
%Managed Turf
32%
Impervious Crner(acres)
0.73
Rv(impervious)
0.95
%Impervious
11%
Site Area(acres)
6.56
Site RV
0.18
data inpm cells
nstant values
calculation cells
Virginia Runoff Reduction Method Mrksheet
DEQ Virginia Runoff Reduction Method New Development Compliance Spreadsheet - Version 3.0
BMP Design Specifications List 2013 Draft Stds & Specs
Site Summary Project Title: LOTA-13 BUNDORAN FARM
Date: 44749
Total Rainfall= 431nches
Site Land Cover Summary
A soils
BSoils
CSoils
DSoils
Totals
%of Total
Forest/Open (acres)
3.73
0.00
0.00
0.00
3.73
57
Managed Turf (acres)
0.16
1.94
0.00
0.00
2.10
32
Impervious Cover (acres)
0.06
0.67
0.00
0.00
0.73
11
6.56
100
Site Tv and Land Cover Nutrient Loads
Site Rv
0.18
Treatment Volume fts
4 284
TP Load (lb/yr)
2.69
TN Load (lb/yr)
19.25
Total TP Load Reduction Required (lb/yr) 0.00 '" TP LOAD REDUCTION NOT REQUIRED
Site Compliance Summary
Total Runoff Volume Reduction (fta)
0
Total TP Load Reduction Achieved (lb/yr)
0.00
Total TN Load Reduction Achieved (Ib/yr)
0.00
Remaining Post Development TP Load
2.69
(lb/yr)
Remaining TP Load Reduction (lb/yr)
0.00
Required
.'No further TP load reduction required (Required - Achieved <0.005 lb/yr)
Summary Print
Virginia Runoff Reduction Method Workeheet
Drainage Area Summary
D.A. A
D.A. B
DA. C
D.A. D
D.A. E
Total
Forest/Open (acres(
0.00
0.00
0.00
0.00
0.00
0.00
Managed Turf (acres)
0.00
0.00
0.00
0.00
0.00
0.00
Impervious Cover (acres)
0.00
0.00
0.00
0.00
0.00
0.00
Total Area (acres)
0.00
0.00
0.00
0.00
0.00
0.00
Drainage Area Compliance Summary
DA. A
D.A. B
DA. C
D.A. D
D.A. E
Total
TP Load Reduced (lb/yr)
1 0.00
0.00
1 0.00
1 0.00
0.00
Om
TN Load Reduced (Ib/yr)
1 0.00
0.00
1 0.00
1 0.00
0.00
0.00
Summary Print
Virginia Runoff Reduction Method Workeheet
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Runoff Volume and CN Calculations
1-yearstorm 2-yearstorm 10-yearstorm
Target Rainfall Event (in) 1 0.00 0.00 0.00
Drainage Areas
RV & CN
Drainage Area A
Drainage Area B
Drainage Area C
Drainage Area D
Drainage Area E
CN
0
0
0
0
0
RR (fta)
0
0
0
0
0
I -year return period
RV wa RR (. -in)
0.00
0.00
0.00
0.00
0.00
RV w Re (w,-in)
0.00
0.00
0.00
0.00
0.00
ON adju:retl
0
0
0
0
0
2-year return period
RV wo RR(ws-in)
0.00
0.00
0.00
0.00
0.00
RV w RR (ws-in)
0.00
0.00
0.00
0.00
0.00
ON adjusted
0
0
0
0
00
10-year return period
RV wa R0. (ws-in)
0.00
0.00
0.00
0.00
0.0
RV w RR (wsin)
0.00
0.00
0.00
0.00
0.00
CN adju:tea
0
0
0
0
0
Summary print
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Level spreader Analysis:
Post -Development Stormwater Level Spreader Drainage Area Map
Time of Concentration Calculation
Time of Concentration Nomographs Post DA _Ex Culvert and New
SHIMPENGINEERING, P.C.
ENCGYEERGYGLANOPLANNINC -PROJECT MANAGEMENT
FEW all
�"AW
•
••
!1111t(( lir,,//� ,
•� � � i sI I�t/ARA.�� � I I '
II it II II I II=1
!�— �j/� ♦ �' 1 II II II II II II II IL 'L
���//��j III II II II II II II III II II II II II Till ll➢
�jj� � 11 II I II II 11=
nII uIIn11 nnunnnn .
nnn—
�-
4 ♦T a Il n n u n n n n n n= �- - � � y�i,—�� � I� Il1111111411111f11111111p 111111 �11�p
`\ ♦ ��� l� II II II II II P n�-1ti
I
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations
POST DEV TOC
100 ft Overland Flow 3.00% slope 0.25 C-value 13.10 min Seelye Chart
1214.75 ft S.C. Flow 28.6% slope 1.3 fps velocity 15.6 min. NEH Figure 15-4
3270.0 ft Channel 84.0 ft height 16.2 min. Kirpich Chart
min.
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations
POST DEV TOC A
100 ft Overland Flow 10.0% slope 0.25 C-value 10.0 min Seelye Chart
612.0 ft S.C. Flow 15.0% slope 2.75 fps velocity 3.7 min. NEH Figure 15-4
360.0ft Channel 22.Oft height 0.4 min. Kirpich Chart
TOC= 14.11 min.
FOREST- Seelye Chart (Nomographs) 0.25
For paved channels, multiply by: 0.2
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations
POST DEV TOC B
100 ft Overland Flow 6.5% slope 0.35 C-value 8.5 min Seelye Chart
540.0ft S.C. Flow 10.4% slope 2.20 fps velocity 4.1 min. NEH Figure 15-4
467.0 ft Channel 18.2 ft height 0.6 min. Kirpich Chart
min.
NOTE: For
0.2
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations
POST DEV TOC C
100 ft Overland Flow 0.8% slope 0.35 C-value F12.8 min Seelye Chart
247.0 ft S.C. Flow 13.4% slope 2.40 fps velocity 1.7 min. NEH Figure 15-4
232.0 ft Channel 26.0 ft height 0.3 min. Kirpich Chart
TOC= 14.77 min.
NOTE: For paved channels, multiply by: 1 0.2
Appendix 6D-1
Overland Flow Tlme - Seelye
0" o.19 -t.o
To = 0.225 S C
Ty= O'..Ilntl F. TM.. mnuls
1. -4,gIh o14bI0M1
35
S -94v., b.1/bel
G =!,Vane) `C VQIM b GMUN 0,v Ow
600
30
500
Paved
0.0
<00
0.8
25
0.7
300
O's
Soil
us
10
r
200
\�
Poor
04 T,
13.10 mi
UU
rase
9Q 01
r 06
TOC—PRE
a
Avo
Grasses
0.3 a 10
"'
z
_
0
e o
20
w
F
OIa s
\N
P
70
5.0
0.2
U 12.8 min
so
�\ —
TOC—POST
o
F
�i'"�O
u
(g'1
50
20
Q
I-
w
0
u
u
Cz
30
0
1
O
2
8 8.50 min
20
TOC—POST
1C. Valw .v LI.C.W d.,um c.vac...
T
ocr Grow Surtow 0.40
ea. sort
5
10
0.m
Pond 0.90
OVERLAND FLOW TIME
REPRINTED
WITH PERMISSION
FROM "DATA BOOK FOR CIVIL ENGINEERS" VOL. I
- DESIGN
2nd EDITIM 11951) BY E. E. SEELYE
LOT A 13 BUNDORAN FARM
PRE & POST DEV TOC NOMOGRAPHS
LEVEL SPREADERS
11
- II.
i
II
0.050
Nearly hran, andumilled (merand flow); wd allurvial fare In western mmmmm 0.2 0,051 V-9.965(s)-n
Forest oath hearq ground 1mr md Imy meadows 0.2 0.1102 V=2.516(er�
I
I
I
C��..IIIIII
C■_=_=C.I.I�i
■■�■■11111111111
I/
I
I
■III%��illlillfl�■
IIIAIAII�■
�■���111111111�1�
-IINN
d�GG7.r
II
F � �
�
�
i
-,1�1111111111111�■
�Y11111111111111■_■
IIiP:�lllll�■
■■���aa���l��
C��������
-
I�a.11111111
I���11111111
___
��
���
��a11111111�
�1�1�11111111�■
�■
���IIIIIIIIII�■
�■
�■
,illn■mml�■
■
s��oiiiiiiiiii��
■
����.oenum��
1992
TRAVEL TIME FOR CHANNEL FLOW
(Kirpich Chart)
H (feet)
500 Tt (min.)
200
100
100 L (feet)
10000
f fxW�iW
50
« 50 SOOD `c
.
4
Note: o c 5.20 min
- �- (1) For Ise .ith Lev,) ounhet K; m � TOC—PRE
R 10 (2) ory�ved ohemels, =it PlY psp 1000 10
T 5
E �i
5 \ 500 5
3.0 min
\ OC—POs
IJ m,n
\ C—POS
100
1
1
1 .25 min
TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS OC—POS
Source: VDOT Plate 5-3
V-13
TOC—Pre
lj OC F,
— — TOC Post—DA e SHIMP. 6INEERIN6, PC.
ENGINEERING-I.S ND FMNNING-PROJECT MANAGEMENT
TOC Post—DA C
e, N. N eRT_e,w
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Stormwater inlets and Pipes Analysis:
VDOT Appendix C8-2 Culverts
Post -Development Stormwater Culverts Drainage Area Map
Stormwater Culvert Drainage area Summary
Time of Concentration Calculation Ex Culvert and New
Time of Concentration Nomographs Post DA _Ex Culvert and New
HY-8 Culvert Analysis
VDOT LD-229
Post -Development Conveyance Channel Drainage Area Map
Conveyance Channel Drainage area Summary
VDOT LD-268
NEW HDPE CULVERT Al-A2
RUNOFF CALCULATIONS
A= 2.95 AC
C= (AIMP* 0- 9+ATURF*0.3,)/ATOTAL
C=0.32
TOC=13.71 MINUTES
alo=161.60 (Regression Constants)
bIo=18.73 (Regression Constants)
I=al o/(TOC+bl o)
1=4.98 IN/HR
Q=C*I*A
010=4.64 CFS
HW/D=0.8
DPIPE=181 N=1.5FT
HW=HW/D *DPIPE
HW= 1.17
NEW HDPE CULVERT E11-132
RUNOFF CALCULATIONS
2.36 AC
FOC=10.31 MINUTES
)10=161.60 (Regression Constants)
> D=18.73 (Regression Constants)
=01 o/(TOC+bl o)
=5.56 IN/HR
=C*I*A
A0=4.92 CFS
iW/D=4.8
)PIPE=181 N=1.5FT
IW=HWW/D *DPIPE
iW= 1.23
EX. 48" HDPE CULVERT
CALCULATIONS
A= 262.60 AC
C= (AIMP* 0.9+ATURF*O.3) /ATOTAL
C=0.31
TOC=44.90 MINUTES
a10=160.23 (Regression Constants)
blo=18.36 (Regression Constants)
I =al o/(TOC+bl o)
1=2.54 IN/HR
Q=C*I*A
Q10=209.15 CFS (HYDROCAD 10yr)
HW/D=5.6
DPIPE=361N=3.OFT
HW=HW/D *DPIPE
LOT A 13 BUNDORAN FARM
CULVERTS CALCULATIONS
APPENDIX 8C-2
Chapter 8 - Culverts
Appendix 8C-1
Inlet Control, Circular Concrete
CHART
10
Igo
10,000
Is$
111,000
EXAMPLE
136
6 000
0.42 Iee3r113.5 f«11
6.
194
5,000
0•efe
120
3.
132
4,000
q B Rr
nM
8•
3.
3'0
UI 2.0 0.0
3.
74.
q,
Ito
2 000
N) 2.I ].•
4'
106
3.
'p I. r-1
3•
96
1.000
3.
HWW�=2.8
goo
84
600
_
2•
Y-
Soo
//
TY
400
a 2.
Bill
/
=
1.5
1.8
2
B3
V1
=
80
LL
200
r 1.3
g
S4
a
/
EX. 48" HDPE CULVEI'ial'f
010=209.15 CFSo
ae
o0
/
e
00
-
O
42
V
80
W
I.0
1.0
c
50 HW SCALE ENTRANCE
I.0
40
ID TYPEIK
1-
W
36
30
W se+•w we• wro
.9
i
33
30
20
42) Oren ad RIM
n••awu
W
A HWW�=0.82
(3) B..... •ne
YT
10
rreNel
HW/p=0.78
24
A
T
T
T
6
e u•• eeeb 1!) er p) pnpel
21
1lerleanfa031. w010 II),1M.
4
1e 11r•I3M Inelln•IIn1
up
and .. 0 1e•1.1, a ....... •1
.6
3
Ill+nrebB,
6
.8
s
t
ly
CULVERT
Q10=4.64 CFS
3
.3
3
ro
12
HEADWATER
DEPTH
FOR
CONCRETE PIPE
CULVERTS
HEADWATER SCALES 253
REVISED MAY 1964 WITH
INLET
CONTROL
BUREAU OF W2uc ))OAPs JAM. I943
Source:
HDS -5
1 of 1
VDOT Drainage Manual
DATE: 8 JULY 2022
SHIMPPNGINEERIM P. C.
TNGINTTRING-L4AVPLANNING-PRGIPCT MANAGEMENT
u=+ :
LOT A -13 BUNDORAN FARM
Conveyence Channels & Culverts Drainage Area Summary
Impervious C
Pervious C
10.9
10.3
Str. Type
Str. No.
Total Area (ft)
Imp. (ft)
Turf (ft)
C
Arca (ac)
Culvert A2 - Al
1
128,300
3,436
124,864
0.32
2.95
Culvert B2 - B1
2
103,010
12,689
90,321
0.37
2.36
EX Culvert 48" HDPE PIPE
3
11,438,677
256,991
11,181,687
0.31
262.60
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations - EX. 48" HDPE CULVERT
POST DEV TOC
100 ft Overland Flow 3.00% slope 0 C-value 13.10 min Seelye Chart
1214.75 ft S.C. Flow 28.6% slope 1.3 fps velocity 15.6 min. NEH Figure 15-4
3270.0 ft Channel 84.0 ft height 16.2 min. Kirpich Chart
TOC= 44.87 min.
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations - Culvert Al-A2
POST DEV TOC
100 ft Overland Flow 10.0% slope 0.25 C-value 10.0 min Seelye Chart
612.0 ft S.C. Flow 15.0% slope 2.75 fps velocity 3.7 min. NEH Figure 15-4
0.0 ft Channel 0.0 ft height 0.0 min. Kirpich Chart
min.
FOREST - Seelye Chart (Nomography) 1 0.25
LOT A -13 BUNDORAN FARM
Time of Concentration Calculations - Culvert B1-B2
POST-DEV TOC
100 ft Overland Flow 10.0% slope 0.35 C-value 7.7 min Seelye Chart
349.0 ft S.C. Flow 12.9% slope 2.45 fps velocity 2.4 min. NEH Figure 15-4
162.0 ft Channel 5.2 ft height 0.2 min. Kirpich Chart
TOC= 10.31 min.
For
l:A
Appendix 6D-1
Overland Flow Tlme - Seelye
To=0.2250" So.1B C
Ty= 0-1-od F. TM.. mnuls
35
1. zLimn, a AMP MI
S
C=Rinan- VaIMbGmuNCTva[M
600
30
500
Pie ed
0.9
4C0
0.8
25
0.7
300
0.8
a Soil
0.5
20
to
200
z
N
Poor
0.4 /
2
13.10 mi
g
s.rRns -
F\
TOC-PRE
Z
a
A Grrass�
0.5
0.3 � 1-0
o 15
0
90
2.0
80
Dross
\
70
5.0
0.2
w
50
i'�0
50
20
u
to
40
10.0 min
30
c
<
9
OC-POST
F
qd
8
7.70 min
20 1C.
an lvq, V.I...,,, S.I.C3Ad o.,u. cnmxr..
OC-POST
7
.m 0.3
ocr Grow 3ur•ow 0.36
10
ear. 0 sP90 l� .
Pgrsd .90
OVERLAND FLOW TIME
REPRINTED
WITH PERMISSION
FROM "DATA BOOK FOR CIVIL ENGINEERS" VOL. I
- DESIGN
2nd EDITION 11 951 ) BY E. E. SEELVE
TOC Post -Culvert A
TOC Post -Culvert B
LOT A 13 BUNDORAN FARM
POST DEV TOC NOMOGRAPHS
CULVERT
(lapter lS 9tmrof C,0ne0ntrad0n Part 6Y1
Nruinnal Englneering Hon&w*
Fignrel6-4
Velocity
versusslope for slwllow rvncentautedflow
l.00.
0.90
ow
n.7o
o.eo
MMMMENE
0W
IN
0.40
o.,
0.20
U.1U
o.00
o.0a
o.m
e 0.06
0.09
0.03
n.m
OX
o.<xM
Ve.IOeity (ttA)
1.3 fsp 2.75 fsp 2.45 fsp
TOC-PRE OC-POST OC-POST
7hhle 15-.t EgnariorM rmd aswnnprions dev loll from fl wre 1i 1
Plow tyye Dep*h Meeei„g§x Veloelty egllaUw
(R) (frh)
Pavement mid umall uphmd gn0lee 02 OX25 V 20.388(a)"'
Graysed waterway, DA 0.050 V=15.I35(a)".1
Nearly ham andunNlled(overland flow); and alluelnl fans in western mountain 0.2 0,051 V=0.965(s)""
rrilal
Oninnated sRolght row crops 0.2 DOGS V=8.76'L(spb
short-grasspasturc 0.2 0.073 V=6.962(s)""
Minimumtillage mItivation. connour or striperopped and woodlands 0.2 0,101 V=5.(Nzep'
Fobs[ with heavy ground Nair and hav meadows 0.2 0.`L02 V'=2.516(eri
lu8 i210.YI-hEH, May 2010)
■
I■■
•ee: le1e�
:• a !== :. � ililele
in i i m nnmla>•a>•
RIII - '/ ���■11111111��
. �■� ( ��■1111111111��
IIII � ,�1111111111111��
�����I�IIIIII�I■■
Cam:=C:..CCi
■■Giiiiiiiiiiiii'iii
����ll
a>•a>.��o
��■■■
��■■
��■
■_
1992
TRAVEL TIME FOR CHANNEL FLOW
(Kirpich Chart)
H (feet)
500
TO (min.)
2DO
100
100
L (feet)
]0000
Exe4NIW
50
�
�
so
Soon
u
1
4
xote:
r
o
6.20 min
a'
(1) For IAA wth letnr.t chi iti,L,
r:
C
TOC-PRE
(2) For paved channels, mttiply
r'
10
10
T b7 0.2
1000
£
5
s 500
5
�.
t
1
1 .20 min
TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS
TOC-POS
Source:
VDOT
Plate 5-3
V-13
SHIMPENGINEERING, P.C.'
ENCINEP.RING-L40FLANNING -PROJECT MANAGEMENT
a: <. ,o z
7
7
7
7
7
17
c
0
�7
m
w
7
7
7
7
7
7
Crossing - EX. 48 Inches HDPE PIPE, Design Discharge - 182.0 cfs
Culvert - Culvert 1, Culvert Discharge - 182.0 cfs
-10 -5 0 5 10 15 20 25 30 35 40 45 50 55
Station (ft)
Crossing Data -EX 48Inches HDPE PIPE
Crossing Properties
Name:
A DISOYIRGE DATA
Discharge Method
0.000
181.960
181.960
Minimum Flow
Design Flow
Maximum Flom
TAILWATER DATA
Channel Type
Trapezoi
Bottom Width
3.700
Side Slope (H:V)
2.000
Channel Slope
0.0115
0.040
Manning's n (charnel)
Channel Invert Elevation
705.100
Rating Curve
ROADWAY DATA
Constan
0.000
Roadway Profile Shape
First Roadway Station
Crest Length
50.000
Crest Elevation
711.000
Roadway Surface
Gravel
Top Width
22.300
Channel
Roadway Elevation
0 X
Culvert Properties
Add Culvert
,. Dupiete Culvert
Delete Culvert
cfs
cfs
CULVERT DATA
cfs
Name
Circular J
Smooth HDPE
Shape
0 Material
ft
4.000 ft
Diameter
-' 1
ft/ft
0.000 in
0.012
C) Embedment Depth
Manning's n
Straight J
ill Culvert Type
ft
Beveled Edge (1. 5: 1) (Ke=0. 2)
No
(� Inlet Configuration
Inlet Depression?
Calvert Invert Data
SIZE DATA
Site Data Input Option
ft
0.000 ft
Inlet Station
ft
705.800 ft
Inlet Elevation
ft
42,000 ft
705.100 ft
Cutlet Station
Outlet Elevation
ft
2
Number of Barrels
0.016667 ft/ft
Computed Culvert Slope
Help Click on any 4 icon for help on a speufic topic Long Flom AOP Energy Dissipation Analyze Crossing OK Cancel
HY-8 Ex 48" Culvert Analysis
' Summary of Flows at Crossing - EX. 48Inches HDPE PIPE — ❑ X
Display
*crossing Summary Table
0 Culvert Summary Table Cul:rert 1
Q Water Surface Profiles
Q Tapered Inlet Table
0 Customized Table Options...
Flow Types... Eclit Input Data.
Geometry
Plot
In -.. soon:
705.80 ft
Crossing Ratirg Gyve
Outlet Elevation:
705.10 ft
Culvert Length:
42.01 ft
Culvert Performance Cure•
Culvert Slope:
0.0167
Selected Water Pru4 —
Culvert Rise:
4.00 ft
Water Surface Profile C
Culvert Span:
4.00 ft
Outlet Control: Profiles
Energy Dissipation... AOP... '', Low Flow... Effort Report MS Word (`.door) � Close
LD-229 Storm Drain Design Computations
LOT A -13 BUNDORAN FARM
LD-229 STORM DRAIN DESIGN COMPUTATIONS
From
To
Catch.
Runoff
Inc
Accum
ToC
Total
Total
Up
Do
Pi e
Inv
Pie
Pie
Velocity
Flow time
Point
Point
Area
Coef
AC
AC
Intensity
Flow (cfs)
invert
Invert
Length
Slope
Diameter
Capacity
Inc
ac
(min)
(in/hr)
El
El
ft
%
in)
(cfs)
(ft/S)
(min
1
2
3
4
6
7
8
9*
10
11
12
13
14
15
16
17
*A2
Al
-
-
-
-
-
4.64
746.60
741.80
58.6
8.19%
18
32.57
13.06
0.02
*132
BI
4.92
733.30
732.20
32.2
3.42%
18
21.05
9.72
0.03
Total flow from Appendic 8C-2 Table calculation Q10-Yr 24-Hr Storm
M
DITCH #3
ece
DITCH #4
mx'�����,,R4gy ��/ � ■ i■i i i �
DITCH
150
MM
h\\.
`
SHIMP ENGINEERING, P.C.
ENGJNEERNG-LANDPLANMNO -PROJECT MANAGEMENT
D
,
Legend Ditch DA
POS
l POST DEV DA- IMPERV El POST DEV DA- WOODS
Ditch 1 DA ® POST DEV DA -TURF
— Ditch 2 DA ® POST DEV DA -TURF
----. Ditch 3 DA POST DEV DA -TURF
—. Ditch 4 DA ■ POST DEV DA -TURF
Ditch 5 DA POST DEV DA- TURF
50
Lot A 13 Bundoran Farm
4
Submission Dale: 07-08-2022
LOT A -13 BUNDORAN FARM
Conve ence Channels & Culverts Drain a e Area Summary
Impervious C 10.9
Pervious C 10.3
Str. Type
Str. No.
Total Area (ft)
Imp. (ft) Turf (ft)
C
Area (ac)
6' Conveyance Channel 1
1
128,300
3,436
124,864
0.32
2.95
6' Conveyance Channel 2
2
103,010
12,689
90,321
0.37
2.36
6' Conveyance Channel 3
3
1,203
76
1,127
0.34
0.03
6' Conveyance Channel 4
4
324,000
5,398
318,602
0.31
7.44
4' Conveyance Channel 5
5
77,860
9,835
68,026
0.38
1.79
LOT A -13 BUNDORAN FARM
Modified LD-268 Roadside and Median Ditch Design Form
Desing
Storm
Side Slope
Min.
Max
n=
0.04
Ditch
C
A
CA
Toc
I - lin
12
It0
Q - tin
Q2
Q10
:1 L
:1 R
Slope
Slope
Allowable
Velocity
2-yr
10-yr
Matting
Type
Freeboard
channel Designed Depth
SF
AC
INCR
ACC
FUFt
FUFt
'Velocity
"Depth
`Velocity
"Depth
1
0.32
128300.00
1 2.95
0.93
0.93
5.0
1.0
5.17
6.81
0.93
4.81
6.34
3
3
0.01
0.14
7.0
4.72
0.58
1.88
1.06
EC-3
TYPE 1
0.44
1.50
2
0.37
103010.00
1 2.36
0.88
1.82
5.0
1.0
5.17
6.81
1.82
9.38
12.36
3
3
0.03
0.09
7.0
4.73
0.81
3.35
1.11
EC-3
TYPE 1
0.39
1.50
3 0.34 1203.00 0.03 0.01
1.82
5.0
1.0
5.17
6.81
1.82 9.43 12.42 3 3 0.05
0.13
7.0
5.43
0.76
4.07
1.01
EC-3
TYPE 1
0.49
1.50
4 0.31 324000.00 7.44 2.31
2.31
13.19
1.0
3.69
5.06
2.31 8.52 11.67 3 3 0.02
0.07
7.0
4.20
0.82
2.84
1.17
EC-3
TYPE 1
0.33
1.50
5 0.38 77860.00 1.79 0.67
0.67
14.77
1.0
3.50
4.82
0.67 2.35 3.24 2 2 0.10
0.16
4.0
3.37
0.51
4.83
0.58
EC-2
TYPE 1
0.42
1.00
`Velocity calculations performed using maximum slope for this application
"Depth calculations performed using minimum slope for this application
"` Conveyance Channel 2 inclueds area from culvert 1
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Independent Reports:
NRCS Soils Report
NOAA Precipitation Report
USDA United States
Department of
Agriculture
N RCS
Natural
Resources
Conservation
Service
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Albemarle
County, Virginia
June 15, 2022
Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Hydrologic Soil Group
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Custom Soil Resource Report
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Vj
55D
.r
66E 4E
25C
14D
�M4-EE 26C3 14B
1 irm-MU � 14C. 7B
38D A4E '
20C3
19D
19 19B
668 19C
19B
16 36C
36D
20C3
25C 25B20D
7C J
36C 14E
36D
19D
19C _
`, 38DI
D3
I
20D3.81 B
19B� <¢`
36C
19C
25B
B
B
�',9�,
If +
MAPLEGEND
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
0 A
0 AID
O B
Q B/D
o C
0 CID
0 D
0 Not rated or not available
Soil Rating Lines
~ A
N AID
Custom Soil Resource Report
❑ C
p CID
p D
13 Not rated or not available
Water Features
Streams and Canals
Transportation
�-1-t Rails
ti Interstate Highways
N US Routes
Major Roads
Local Roads
Background
. Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Albemarle County, Virginia
Survey Area Data: Version 15, Sep 13, 2021
N
B
Soil map units are labeled (as space allows) for map scales
BID
1:50,000 or larger.
C
CID
Date(s) aerial images were photographed: Oct14, 2019—Sep
N
23, 2020
N
D
M 0
Not rated or not available
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
Soil Rating Points
imagery displayed on these maps. As a result, some minor
■
A
shifting of map unit boundaries may be evident.
■
AID
■
B
■
B/D
11
Custom Soil Resource Report
Table -Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
4B
Ashe loam, 2 to 7
B
2.1
0.3%
percent slopes
4D
Ashe loam, 15 to 25
B
37.3
5.2%
percent slopes
4E
Ashe loam, 25 to 45
B
57.2
8.0%
percent slopes
7B
Braddock loam, 2 to 7
B
7.4
1.0%
percent slopes
7C
Braddock loam, 7 to 15
B
3.2
0.4%
percent slopes
14B
Chester loam, 2 to 7
B
5.5
0.8%
percent slopes
14C
Chester loam, 7 to 15
B
11.2
1.6%
percent slopes
14D
Chester loam, 15 to 25
B
4.2
0.6%
percent slopes
14E
Chester loam, 25 to 45
B
6.5
0.9%
percent slopes
15C
Chester very stony loam,
B
0.4
0.1 %
7 to 15 percent slopes
15D
Chester very stony loam,
B
0.5
0.1%
15 to 25 percent
slopes
16
Codorus silt loam, 0 to 2
BID
3.5
0.5%
percent slopes,
occasionally flooded
19B
Minnieville loam, 2 to 7
B
30.5
4.3%
percent slopes
19C
Minnieville loam, 7 to 15
B
78.6
11.0%
percent slopes
19D
Minnieville loam, 15 to
B
37.6
5.2%
25 percent slopes
20C3
Minnieville clay loam, 7
B
18.8
2.6%
to 15 percent slopes,
severely eroded
20D3
Minnieville clay loam, 15
B
18.8
2.6%
to 25 percent slopes,
severely eroded
25B
Dyke silt loam, 2 to 7
B
108.9
15.2%
percent slopes
25C
Dyke silt loam, 7 to 15
B
75.2
10.5%
percent slopes
26C3
Dyke clay loam, 7 to 15
B
12.4
1.7%
percent slopes,
severely eroded
W
Custom Soil Resource Report
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
26D3
Dyke Gay loam, 15 to 25
B
13.5
1.9%
percent slopes,
severely eroded
36B
Hayesville loam, 2 to 7
B
1.7
0.2%
percent slopes
36C
Hayesville loam, 7 to 15
B
26.3
3.7%
percent slopes
36D
Hayesville loam, 15 to 25
B
11.4
1.6%
percent slopes
36E
Hayesville loam, 25 to 45
B
0.2
0.0%
percent slopes
37D3
Hayesville Gay loam, 15
B
6.5
0.9%
to 25 percent slopes,
severely eroded
37E3
Hayesville day loam, 25
B
4.5
0.6%
to 45 percent slopes,
severely eroded
38D
Hayesville loam, 15 to 25
B
6.4
0.9%
percent slopes, very
stony
55B
Danripple loam, 2 to 7
C
2.2
0.3%
percent slopes, rarely
flooded
56B
Meadomille loam, 2 to 7
A
43.7
6.1%
percent slopes
66E
Parker very stony loam,
A
25.1
3.5%
25 to 45 percent
slopes
76
Dan River loam, 0 to 2
B
17.2
2.4%
percent slopes,
occasionally flooded
77
Dan River-Codorus
B
6.8
0.9%
complex, 0 to 2
percent slopes,
occasionally flooded
79B
Meadomille silt loam, 2
B
2.1
0.3%
to 7 percent slopes
81 B
Thurmont loam, 2 to 7
B
1.9
0.3%
percent slopes
89B
Unison silt loam, 2 to 7
B
12.9
1.8%
percent slopes
89C
Unison silt loam, 7 to 15
B
7.0
1.0%
percent slopes
W
Water
8.6
1.2%
Totals for Area of Interest
717.9
100.0%
Rating Options -Hydrologic Soil Group
Aggregation Method., Dominant Condition
13
6/21/22, 12:55 PM Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: North Garden, Virginia, USA*
Latitude: 37, Longitude:-78.6677° €
Elevation: 747.38 ft"
source: ESRI Maps•
"source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonin, D. Martin, B. Lin, T. Parrybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average
recurrence interval (years)
Duration
1
2
5
10
25
50
1 100
00
200
500
1000
5-min
(0.309-0 379)
(0.3690 452)
(04340.530)
(0.488-0 598)
(0.5480.673)
(0.594 0..733)
(0.635-0..790)
(0.672 .844)
(0.71140 912)
(07 47--0.969)
2
3
10.min
(0.4940606)
(0.5910.722)
(0.695-0.849)
(0.781-0956)
(0.874107)
(0.945-11.17)
(1.01125)
(1.07-L34)
(113--1.a4)
1 (118-1.53)
1.63
1.
1.72
15-min
(0.6117--0..757)
(0.7430908)
(0.879-1.07)
(0.988-11.21)
(1. 1-1.36)
(1.20-314.48)
(1.28-11..59)
(1.341.69)
(1. 2-11..82)1
(1.48-1.92)
0.937
1.13
1.38
1.59
1.83
2.02
2:20
2.38
2.60
2.78
30.min
(0.846-1.04)
1 (1.03-1.25)
1 (1.251.53)
1 (1.43-1.75)
1 (1.64-2.02)
(1.80-2.23)
(1.952.43)
(2.09-2.63)
(2.26-2.89)
(2.39-3.10)
1.17
2.07
2.74
4.06
60.min
(1.M1.29)
(1.29-L57)
(1.60-�96)
(1.852.28)
(2.19�68)
(2.443.02)
(269-3..35)
(2.943.69)
(3.2a�414)
(3.494.53)
2.50
4.23
2-hr
(1.24i58)
(1.511091
(1.892?39)
(22 3-2.81)
(2. 333.34)
(2.973980)
(3.31-426)
(36 5-4.74)
(4.11542)
(4.48-6.01)
3-hr
(1.36-11..74)
(1.652.11)
(2.06 2.64)
(2.a23.09)
(2.87-3.69)
(3.243.71
4-4.18)
(3.62-4.71)
(3. 965.25)
(4.5" 02)
(4.92 673)
4.95
6-hr
618)
(17 8-2.24)
(2.14-271
(2.65-38.0)
(3.111-3?96)
(3.41�75)
(422 44)
(47
(52 96.99)
(6.058.15)
(669-9.19)
2.53
3.05
3.80
4.50
5A7
6.35
7.29
8.34
9.88
11.3
12-hr
(2.25-2.88)
(2.71-3.47)
(3.36-4.32)
(3.97-5.11)
(4.786.21)
(5.49-7.19)
(6.3-8.27)
(7.00-9.46)
(8.12-11.2)
(9.11-12.9)
24-hr
(27 53.43)
(3. 34.15)
(42 3-5.0)
(4.976.24)
(6.05674.63)
(6.978.82)
(7.94- 0.1)
(8.96- 1-6)
(10-5- 3.7)
(11.715.6)
5.4
2-dey
(3244.03)
(3. 34788)
(4986.19)
(5.83-76)
(7.03-8.81)
(8.01-610.1)
(9.06-11.5)
(102- 3.1)
(11.8- 5.4)
(13.11--17.3)
3-day
(3.484.6)
(4.215516)
(5. 366.55)
(6.24-7.67)
(7. 0)
(8.58--610.7)
(9.69- 2.1)
(10.9-13.7)
(12.6- 6.1)
(14.0. 8.1)
4-day
(3.714750)
(449-5.45)
(5. 96.90)
(6.658.08)
(8.02 9879)
1 (9.15-121.2)
(10.3- 2.8)
(11.6-14A)
(13A 16.9)
(14.8-19.0)
7.
7-day
(43 35.17)
(5.216.22)
(6. 0 7077)
(7.54-9.03)
(990-10.8)
(102- 2.3)
(11 4213.9)
(125.6)
(14•b- 8.1)
(16.0. 0.2)
10-day
(4.93-5.82)
(5.926.98)
(7.298360)
(8.38-9.90)
(9.88-8.7)
(11.112 3.2)
(12.3-14.8)
(13.6-16.4)
(15.3-18.8)
(1677- 0.8)
20-day
(6.56-356)
(7.829.01)
(9A2-10.9)
(107- 2.3)
(12.3-14.3)
(13.6- 5.8)
(14.9-127.4)
(162- 9.1)
(179- 1.3)
(19.3- 3.1)
30-day
(8.09-9.22)
(9.59-10.9)
(11.3-12.9)
(12.6-14.4)
(14.3-16.4)
(15.6-17.9)
(16.8-19.3)
(18.0. 0.8)
(19.5 22.8)
(20.6-24.2)
45-day
(102-8.5)
1 (12.0. 3.5)
1 (14.0- 5.8)
1 (15.57.4)
1 (173 9.6)
1 (1821.2)
1 (20.0.22.8)
(212?24.3)
(22846.3)
(23.9-27.8)
60 day
15.7)
P2
(12k 3.4)
(141
(16.1 18.1)
(178- 9.9)
(19722.1)
(21 3.8)
(2265 5.4)
(232
8- 6.9)
(254? 8.8)
(26.5 0.3)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
iven duration and average recurrence interval) vnll be greater than the upper bound (or less than the lovrer bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
hfps://hdsc.rws.noaa.govlhdsc/pfds/pfds_Printpage.html?lat=37.9882&Ion=-78.6677&data=depth&units=english&series=pds 1/4
Design Focused Engineering
Appendix A:
Rip -Rap Calculation
LOT A-13 BUNDORAN FARM
DESIGN OF OUTLET PROTECTION FROM A ROUND PIPE FLOWING FULL
MINIMUM TAILWATER CONDITION (TM � 0.5 DIAMETER)
.1
�r
I�
:1
Nppnh
•�i:.A1
• .
1
. 1
I
I
01�
1 11� 1111 I111II�p� II'1I1�� 1
1 /
I�f/111111lI�IMII�IM
�
..
��
1 11111
p
it
,
I,-,
' •
A�p�1p1111/XIX'Il
1
�I�:�
wit
Y'
I II111 { 1 !!
�! 1 INN
III
�r
1
11111111III111111
HIM
1111
111
I
Y
...,A..Ji
IIII
.i�
11'111�1p�®II1{11X1X'U1I
II
�~
•~I!I
1 I
1
1111111,
IIIlIlI�II
il11.1!.1{.1{!11-�
11„':�J11pPi!l;nll�'/i�1�Nlll,
{{!{{I1{Illllli-r
�p°,r`r
Ott-
1���1lpnp11,
1,��1j1
II
II
l
1111111111IIIIII11111
�/
A�gq
��1INN1`IIIMMMMI{
XIIII
IIIWNII,At'�X,L
NNNpp�I�NIIIIIfI
unNNn
IIIIIIIIII
IIIIIIIIf.I
1{III
III
'IpplI
•.
!'
,Illi
1111111111111111(
11111111111111111111IIIIN111I
1111111111111111111
�{
1 1
{III
1
I�
1
1
f
11
�
�
•1
'.�
dl
. �.K
MIL
1
1
I! ,•
11
I
I
� • �
111
I
III
IIXl1
III
{III
t
IX'
��r
-
...:1
�
�
toIIIi!—
•
No
M
. .�
1 1
1
11 11 11
111
Qd50=6" Discharge. ft./sec.
RIP -RAP A AP B
Qio=4.64 CFS =4.92 CFS
18" OUTLET PIPE. 8" OUTLET PIPE.