HomeMy WebLinkAboutWPO202000010 Calculations 2020-05-15SHIM P ENGINEERING, P.C.
Design Focused Engineering
Stormwater Management Plan
Calculation Packet
Stoudt Property
May 7, 2020
Revised: May 12, 2020
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Emily Cox
Albemarle County
Po. Box 160
Louisa, VA 23093
Regarding: WPO202000010 Stoudt Property
Stormwater Management Plan
Dear Ms.Cox,
Enclosed is the stormwater management calculations for the Stoudt Property Project. This project will
disturbed an area of 0.99 acres.
This project complies with the water quantity requirements of 9VAC25-870-66.D because the runoff from
the entire site will be sheet flow. The proposed grading does not concentrate but rather disperse runoff,
thus post -developed runoff is sheet flow. All runoff from the new impervious areas will be routed to a
Vegetated Filter Strip. The Vegetated Filter Strip will include a Gravel Diaphragm at the top and a
Permeable Berm at the toe. This will reduce the velocity and volume of the sheetflow runoff and will
effectively protect downstream properties from erosion. Since the increased volume of sheetflow runoff will
not cause adverse impacts downstream, this project satisfies water quantity requirements of 9VAC25-870-
66.D.
This site complies with the water quality requirements of 9VAC25-870-65. Per the VRRM spreadsheet, the
required Total TP Load Reduction Required is 0.25 Iblyr. Through the use of the Vegetated Filter Strip, the
Total TP Load Reduction Achieved is 0.25 lb/yr. Therefore the site complies with the water quality
requirements.
If you have any questions please feel free to contact me via e-mail at michael@shimp-engineering.com or
Justin Shimp at justin@shimp-engineering.com or by telephone at 434-227-5140.
Sincerely,
Justin Shimp
Shimp Engineering, P.C.
Contents:
Stormwater Quality Calculations:
Pre -Development VRRM Map
Post -Development VRRM Map
Vegetated Filter Strip Drainage Map.
VRRM Spreadsheet
Independent Reports:
Excerpt from NRCS Soils Report
NOAA Precipitation Report
Stormwater Quality Calculations:
Pre -Development VRRM Map
Post -Development VRRM Map
Vegetated Filter Strip Drainage Map.
VRRM Spreadsheet
SIIII7PPNGA RA6. P. C.
HSG ENGINEERING IANDPLANNING PROJECT MANAGEMENT
912 E HIGH ST PHONE: (434) 227-5140
CHARLOTTESVILLE, VA 22902 JUSTIN®SHIMP-ENGINEERING.COM
LEGEND
TURF MANAGED AREA
LIMITS OF DISTURBANCE
If
'4g0 SOI LS (TYF)
HSGB \�
I 1 EXISTING
/ AME BAN '- ---1 ____--- ------ `
'-49� �_4 8, \
8
--489,
1
`490�
00
1
00
/
/ MANAGED TURF LI M ITS OF ^49 4 4--`,\\ \
DISTURBANCE _,---- 496,
l i `4g7 \--- � �\
0.99 AC EXISTING �\ \� /'' ,_�� �G' \\ \ \\
1.5
//_a4�71 R,/ � AG \\
-,lFFE=498.0
8 \ \ I P
L
HSG B
F4X. 2 STORY FR E
HOUSE W/ BASE T
FEE=
/ I /
499 i i l
/ ! /
el
1CID Lithic Stoudt Handy
IHSGB / ,l I�Agj I HSGB \__V �I
\ ¢9''�'�-------- Pre -Development VKKM Map
REVISED: 05- 1 2-2020
-----_-494---'
• 1 • • i• _•
SCALE: 1 •
Pre -Re Development Land Cover (acres)
A Soils
B Soils
C Soils
D Soils
Totals
Forest/Open Space (acres) -- undisturbed
forest o ens ace
0.00
(Managed Turf ( acres) -- disturbed, graded
for yards or otherturf to be
0.99
0.99
Impervious Cover (acres)
000
0.00
0.99
SIIIMPEYNY PRING, P. C.
_ _ ENGINEERING-L 4YDPL4WNG -PROJECT MANAGEMENT
HSGP'/�_-- 912 E HIGH ST PHONE: (434) 227-5140
CHARLOTTESVILLE. VA 22902 JUSTIN®SHIMP-ENGINEERING.COM
LEGEND
TURF MANAGED AREA
LIMITS OF DISTURBANCE
/f, / ) i ¢` �,' �, �\ �\ \ -- 9$3 �- ■ IMPERVIOUS AREA
�-
��'`� , \� SOI LS (TYP)
AME BA EXISTING ` � �.\ ��\-----''�- ` �
I I _ \ \� _- - ___--- -----•
�j
IHSG
—
/ egg
I �
-490� -_
OFF
u
LIMITS OF
o DISTURBANCE
-495
EXISTING
__ _ '' IMPERVI'OUS 1.5 ST
`-1 j i i c4g6J//, _ 4 71 RgME/XRAG �\ �---
FFE=498.0 `\ ,,'--Agj/F� \ 1
rl
_480-
HSG
SWIMMING POOL DOESto
I I
I �
t Ln to F4K. 2 STORY FR E
NOT OUTLET Off51TE. ----yousE w/ BASE T ,' ,-` ,
NOT CONSIDERED . '' � -��w' I � FEE= J � �198�
CD
M ERV OUS IN VRRM
SPREADSHEET •� �, 49g11 Lithic Stoudt Handy
HSGB ''�;� �'``- "-'',, ", ;I Post -Development VKKM Map
HSGB / )�¢9j j HSGB �_ t
',�' � �\ �9) REVISED: 05- 12-2020
IF If , ) i
50 100 A 150
Post -Development Land Cover (acres)
ASoils
BSoils
CSoils
DSoils
Totals
Forest/Ope n Space (acres) -- and isturbe d,
rotectedforest/o ens ace or reforested
0.00
Managed Turf ( acres) -- di stu rbe d, graded
for yards or other turf to be
0.87
D.87
Impervious Cover (acres)
0.12
0.12
Area Check
OK.
OK.
OK.
OK.
0.99
/ SIIIVIPPNUNPPRIN6 PC
j6�
ENGINEERING -L 4NDFLANNIN6 -PROJECT MANAGEMENT
912 E HIGH ST PHONE: (434) 227-5140
VEGETATED L. O D CHARLOTTESVILLE, VA 22902 JUSTIN®SHIMP-ENGINEERING.COM
FI LTEK 5TKI P �' /.'' '/\\ \ \\\\ \ �\\4,8�__`V__� _ / �' /,.� LEGEND
— — /
IMPERVIOUS AREA
\
/r` `' ' \/ / �+ / •• '/ // �' \ \ \ \ '' � TURF AREA IN L.O.D
DRAINAGE AREA IN L.O.D. \ - ___ 3 - -' � ®
TO BUI=I=EK= O.G7 AC AREA NOT TABULATED (VRRM)
- 48 - o0
x ,-' -----
/ ./''•�; / / ` �_�'--� - ice- LIMITS OF DISTURBANCE (L.O.D)
�i •f�• / (0.5 G AC TU RI= AND `� ¢8s,, ����' _ _
�` � �,,----,,-- ��--- DRAINAGE AREA TO BUFFER
��k ��- • / 0. 1 I AC IMP)
I /
-1L to
/ •' �• / +C° � �+ �. TOTAL DRAINAGE AREA
+k�++ A+Ar � + + :� TO BUI=I=EK= 1.24 AC
++�+ } (DRAINAGE AREA A)
+ + — — — —
+ +, v \
+ v � v qv v--- AREA NOT TABULATED \\ \
■ / �+ ++ + /++ {o�vv00000FOR VRRM NUTRIENT \ \
' \
+ + I+ v v v v v v v ----_- \ \
�� + , ++ + + + ++: a o v v q v v REDUCTION -' '
�' 1 +AN + + 4 7/v v, v d'v v v v ri v v ' EXISTING
i LL _
+ + + 1 17 vl v V, v v v v/f7 v vt 1.5 ST �jj -Y
A- v �7 7 v v zbv/v v v /��f4971 R9ME ' AG
/ + ++ + + + ++ I+� + i .jv vl vl v v 1V<ZZ v v v v (/ I �,� FFE=498.0
+ + '+ + + +./+1C7v��Zvvv�\Vvvvv /'
+� + ++++ ++ ++++i '
Ar
—480- % + ++ + + ++ +/ + + ++ + + o v v\ v d° v b v v /'7 v v v
+ + /++ + �+ dvv�v�v47v�vvvv
+ #v + + +%'� . v v v v v �vv v EIS 2 STORY FR E
BLANK AREA NOT �+ ,+ + ••+' ouSE w BASE T ''--
NCLUDED IN BUFFER / % ; + + �� °'�° ° ° ° ° ° ° °Jiff
P° FEE=
+� �1v j/E7vvvvv °°vLithic 5toudt Handy
DRAINAGE AR. % ��'�°�6v°°°°°d°°°'b\
• i°° ° ° ° ° ° ° ° ° °'� Ve etated Filter Strip Draina e Ma
(POOL DOES NOT :/ ,�f' �vvvv vvvvo'vv'G�v�vv�vvvo' 499 j p
v v v v v v v v�,7 V V N, v.,V. V V \ v v v s�� / REVI5ED: 05- 1 2-2020
vvvvva'vvv vvlv19vvv vvv
OUTLET TO BUFFER) I I I
• ^�vvs7-5vvvv,vvv�bvivvvvwva� `.� \ �
�rf v v v v v v,/v v v v v \i p ° ° cb QI \ 00 Drainage Area A Land Cover (acres)
7�/vvvvvv,bv�
'-- - - -\/ 496'�\----------- 496-- �o,`�-
-494 -
A Soils
B Soils
C Soils
D Soils
Totals
Land Cover Rv
Forest/Open Space (acres)
0.00
0.00
Managed Turf(acres)
0.56
0.56
0.20
Impervious Cover (acres)
0.11
0.11
0.95
Total
0.67
Filter/Open9. Sheetf low to
9.a. Sheetflow to Conservation Area, A/B Soils
75
(Spec #2)
9.b. Sheetflow to Conservation Area, C/o Soils
(Spec #2)
50
9.c. Sheetflow to Vegetated Filter Strip, A Soils
or Compost Amended B/C/D Soils
50
0.56
0.11
(Spec #2 & #4)
DEQ Virginia RuroffReduction Method Re-DevelopmentC—pliance Spreadsheet -Version 3.0
StaudtLittle CLEAR ALL —_—_.
Linear Development Project? N
Site Information------- linalr Wts ---■
1
Post -Development Project (Treatment Volume and Loads)
Enter Total Disturbed
Area (acres)
�—
_--.
The site's net increase
Post -Development
Maximum
in impervious
TP Load Reduction)or5ite(Ib/y):
reduction required: 10%
cover (acres) is 0.12
0.25
t■■__Mw
Mr
_0
■�
��■
Runoff Coefficients
(Rv)
LAND COVER SUMMARY-- PRE
-REDEVELOPMENT
LAND
COVER
SUMMARY-- POST
DEVELOPMENT
.. .... ..
.. .......
...... -.. _
��—■111111110.�.
Treatment Volume and
Nutrien
■
Post -Development Requirement for
TP Load Reduction Required (lb/yr)
Nitrogen Loads (informational Purposes
Site Area
Only)
OMNI
-_■
VRRM_R.Dev_Compliance_ Spreadsheet_v3_082017 (5)
D.F. A
Drainage Area A
Drainaee Area A Land Cover (acres)
A Soils
BSoils
CSoils
DSoiIs
Totals
Land Cover Rv
Forest/Open Space (acres)
0.00
0.00
Managed Turf (acres)
0.56
0.56
0.20
Impervious Cover (acres)
0.11
0.11
0.95
Total
0.67
Stormwater Best Manaeement Practices (RR = Runoff Reduction)
Total Phosphorus Available for Removal in D.A. A (lb/yr) 0.49
Post Development Treatment Volume in D.A. A (ft3) 786
Runoff
Managed
Impervious
Volume from
Remaining
Total BMP
Phosphorus
Phosphorus Load Untreated
Phosphorus
Remaining
Practice
Reduction
Turf Credit
Cover Credit
Runoff
Upstream s
Runoff Volume
Treatment
Removal
from Upstream Phosphorus Load
Removed By
Phosphorus Load
Credit %
( 1
Area acres
(acres)
Area acres
(acres)
Practice ft Reduction (ft)
(')
a
(ft)
( a)
Volume ft
Efficient %
y ( )
Practices (lb) to Practice (lb)
( ) ( )
Practice (lb)
( )
Ib
( )
1. Vegetated Roof (FIR)
Roof #1 (Spec #5)
45
®,®'sa®®®®®®®®®®
r94 a0®®®®®®®®
:a�a`®®®®®®®'s'o•'of 0
.o0ay,®®®®4`4®4`
0
0
0
fob°®®®®®®®®®®%m'agf° 0.00
0.00
0.00
��aetated
I.b. Vegetated Roof #2 (Spec #5)
60
`�,}4�'{,�'}�}�{4
®®® 0
0
0
0
0.00
0.00
0.00
Rooftop2.a. Simple Disconnection to A/B Soils
50
0
0
0
0
0
0.00
0.00
0.00
0.00
(Spec#1)
®®®®®®®�
2.b. Simple Disconnection to C/D Soils
25®®
0
0
0
0
0
0.00
0.00
0.00
0.00
(Spec #1)
2.c. To Soil Amended Filter Path as per
�® ®®®®
specifications(existing C/D soils) (Spec #4)
50 ®®®®®
0
0
0
0
0
0.00
0.00
0.00
0.00
2.d. To Dry Well or French Drain #1,
®®®®®®
Micro-Infilration#1(Spec #8)
50 ®®®
0
0
0
0
25
0.00
0.00
0.00
0.00
2.e. To Dry Well or French Drain #2,
90 ®��®®®®®®®®
0
0
0
0
25
0.00
0.00
0.00
0.00
Micro -Infiltration #2(Spec #S)
�®
2.f. To Rain Garden #1,
®®®
40 ®®®®®®
0
0
0
0
25
0.00
0.00
0.00
0.00
Micro-Bioretention #1 (Spec #9)
0
0
0
0
50
0.00
0.00
0.00
0.00
Micro-Boretennon#2(Spec #9)
®®®®®®
2.h. To Rainwater Harvesting (Spec #6)
0 ®®®®®
0
0
0
0
0
0.00
0.00
0.00
0.00
2.1. To Stormwater Planter,
®®®®®®
40 ��®®®�®®
0
0
0
0
25
0.00
0.00
0.00
0.00
Urban Bioretention (Spec #9, Appendix A)
3. Permeable Pavement (RR)
4. Grass Channel (RR)
4.b. Grass Channel C/D Soils (Spec #3)
5. Dry Swale (RR)
16.
Bioretention (RR)
I7.
Infiltration (RR)
7.1h. Infiltration #2 (Spec#8)
8. Extended Detention Pond (RR)
19. Sheetflow to Filter/Open Space (RR)
or Compost Amended B/C/DSolls
TOTAL IMPERVIOUS COVER TREATED (ac) 0.11 AREA CHECK: OR.
TOTAL MANAGED TURF AREA TREATED (ac) 0.56 1 AREA CHECK: OK.
TOTAL RUNOFF REDUCTION IN D.A. A (ft') 393
TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (lb/yr) 0.49
TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) Cl!
TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 0.25
SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS
5l7/2020
1 of 1 3:30 PM
Site Results (Water Quality Compliance)
Area Checks
D.A. A
D.A. B
D.A. C
D.A. D
D.A. E
AREA CHECK
FOREST/OPEN SPACE (ac)
0.00
0.00
0.00
0.00
0.00
OK.
IMPERVIOUS COVER (ac)
0.11
0.00
0.00
0.00
0.00
L OK.
IMPERVIOUS COVER TREATED (ac)
0.11
0.00
0.00
0.00
0.00
OK.
MANAGED TURF AREA (ac)
0.56
0.00
0.00
0.00
0.00
OK.
MANAGED TURF AREA TREATED (ac)l
0.56
0.00
0.00
0.00
0.00
OK.
AREA CHECK
OK.
OK.
Site Treatment Volume (ft3)
1,oas
Runoff Reduction Volume and TP By Drainage Area
RUNOFF REDUCTION VOLUME ACHIEVED (ft)
393
0
0
0
0
393
TP LOAD AVAILABLE FOR REMOVAL (lb/yr)
0.49
0.00
0.00
0.00
0.00
0.49
TP LOAD REDUCTION ACHIEVED (lb/yr)
0.25
0.00
0.00
0.00
0.00
0.25
TP LOAD REMAINING (lb/yr)
0.25
0.00
0.00
0.00
0.00
0.25
NITROGEN LOAD REDUCTION ACHIEVED (lb/yr)
1.76
0.00
0.00
0.00
0.00
1.76
Total Phosphorus
FINAL POST -DEVELOPMENT TP LOAD (lb/yr)
0.66
TP LOAD REDUCTION REQUIRED (Ib/yr)
0.25
TP LOAD REDUCTION ACHIEVED (lb/yr)
0.25
TP LOAD REMAINING (lb/yr):
0.41
REMAINING TP LOAD REDUCTION REQUIRED (lb/yr):
**No further TP load reduction required (Required -Achieved < 0.005 Ib/yr)
Total Nitrogen (For Information Purposes)
POST -DEVELOPMENT LOAD (lb/yr)
4.70
NITROGEN LOAD REDUCTION ACHIEVED (lb/yr)
1.76
REMAINING POST -DEVELOPMENT NITROGEN LOAD (lb/yr)
2.93
Virginia Runoff Reduction Method Worksheet
DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0
BMP Design Specifications List: 2013 Draft Stcls & Specs
Site Summary
Project Title: Lithic Staudt Handy
Date: 43917 Total Rainfall (in): 43
Total Disturbed Acreage: 0.99
Site Land Cover Summary
Pre-ReDevelopment Land Cover (acres)
......... ......
A soils
B Soils
C Soils
D Soils
Totals
% of Total
Forest/Open (acres)
0.00
0.00
0.00
0.00
0.00
0
Managed Turf (acres)
0.00
0.99
0.00
0.00
0.99
100
Impervious Cover (acres)
0.00
0.00
0.00
0.00
0.00
0
0.99
100
Post-ReDevelopment Land Cover (acres)
. . . . . . . . . . . . . .......... .............. ....
A soils
B Soils
C Soils
D Soils
Totals
% of Total
Forest/Open (acres)
0.00
0.00
0.00
0.00
0.00
0
Managed Turf (acres)
0.00
0.87
0.00
0.00
0.87
88
Impervious Cover (acres)
0.00
0.12
0.00
0.00
0.12
12
0.99
100
Site Tv and Land Cover Nutrient Loads
Final Post -Development
®
(Post-ReDevelopment
1,,el.1111 & New Impervious)
Post-
ReDevelopment
Post-
Development
(New Impervious)
Adjusted Pre-
ReDevelopment
Site Rv 0.29
0.20
0.95
0.20
ITreatment Volume (ft3 1,045
632
414
632
ITP Load (lb/yr) 0.66
1 0.40
1 0.26
1 0.40 1
ITotal TP Load Reduction Required (lb/yr) 1 0.25 1 0.04 1 0.21
Final Post -Development Load
(Post-ReDevelopment & New Impervious)
Pre-
ReDevelopment
ITIM Load (lb/yr)
4.70
3.23
Pre-
ReDevelopment
Final Post -Development
Post-ReDevelopni
TP Load per acre
TP Load per acre
Load per acre
lb/acrer
(/y)
(lb/acre/yr)
(lb/acre/yr)
0.46
0.66
0.46
Summary Print
Virginia Runoff Reduction Method Worksheel
Site Compliance Summary
Maximum %Reduction Required Below 10%
Pre-ReDevelopment Load
Total Runoff Volume Reduction (ft')
393
Total TP Load Reduction Achieved (lb/yr)
0.25
Total TN Load Reduction Achieved (lb/yr)
1.76
Remaining Post Development TP Load
(Ib/yr)
0.41
Remaining TP Load Reduction (lb/yr)
Required
0.00
**No further TP load reduction required (Required - Achieved < 0.005 Ib/yr)
(Remaining TP load reduction <0.005)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Drainage Area Summary
®® ® ®®® ® ®®® ®®
D.A. A
D.A. B
D.A. C
D.A. D
D.A. E
Total
Forest/Open (acres)
om
0.00
0.00
0.00
0.00
0.00
Managed Turf (acres)
0.56
0.00
0.00
0.00
0.00
0.56
Impervious Cover (acres)
0.11
0.00
0.00
0.00
0.00
0.11
Total Area (acres)
0.67
0.00
0.00
0.00
0.00
0.67
Drainage Area Compliance Summary
D.A. A
I D.A. B
D.A. C
D.A. D
D.A. E
Total
TP Load Reduced (lb/yr)
0.25
0.00
1 0.00
1 0.00
0.00
1 0.25
TN Load Reduced (lb/yr)
1.76
0.00
1 0.00
1 0.00
0.00
1 1.76
Drainage Area A Summary
Land Cover Summary
®®®®® ®®®®® ®®®®®
ASoils
BSoils
CSoils
DSoils
Total
%of Total
Forest/Open (acres)
0.00
0.00
0.00
0.00
0.00
0
Managed Turf (acres)
0.00
0.56
0.00
0.00
0.56
84
Impervious Cover (acres)
0.00
0.11
0.00
0.00
0.11
16
0.67
BMP Selections
Managed Turf
Impervious Cover
BMP Treatment
TP Load from
Untreated TP Load
TP Removed
TP Remaining
Downstream Treatment
Practice
Credit Area
Credit Area
Volume (ft')
Upstream
to Practice (Ibs)
(Ib/yr)
(Ib/yr)
to be Employed
acres
acres
practices Ibs
9.c. Sheetflow to Vegetated Filter Strip, A
Soils or Compost Amended B/C/D Soils
0.56
0.11
785.90
0.00
0.49
0.25
0.25
(Spec #2 & #4)
Total Impervious Cover Treated (acres)
0.11
Total Turf Area Treated (acres)
0.56
Total TP Load Reduction Achieved in D.A.
Ib/ r
0.25
Total TN Load Reduction Achieved in D.A.
(lb/yr)
1.76
Summary Print
Virginia Runoff Reduction Method Worksheet
Runoff Volume and CN Calculations
1-year storm 2-year storm 10-year storm
ITarget 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
. . . . . . . . .
67
0
0
0
0
RR (ft')
393
0
0
0
0
1-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
CN adjusted
100
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
CN adjusted
100
0
0
0
0
10-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
CN adjusted
100
0
0
0
0
Summary Print
Independent Reports:
Excerpt from 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
January 21, 2020
3
711840
38' 10' 41" N
I
I
v
e
38° 10' 26" N
711840 711890 711940 711990 712040
3
Map Scale: 1:2,180 W printed on A portrait (8.5" x 11") sheet.
Meters
N 0 30 60 120 180
Feet
0 100 200 400 600
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
9
Custom Soil Resource Report
Soil Map
711890 711940 711990 712040
712090
712090
3
s
712140
38° 10' 41" N
38° 10' 26" N
712140
3
Custom Soil Resource Report
Albemarle County, Virginia
4D—Ashe loam, 15 to 25 percent slopes
Map Unit Setting
National map unit symbol: kbcl
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Ashe and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Ashe
Setting
Landform: Mountain slopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
H1 - 0 to 10 inches: loam
H2 - 10 to 19 inches: loam
H3 - 19 to 24 inches: sandy loam
H4 - 24 to 79 inches: bedrock
Properties and qualities
Slope: 15 to 25 percent
Depth to restrictive feature: 20 to 40 inches to lithic bedrock
Natural drainage class: Somewhat excessively drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 5.95 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Low (about 3.2 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Hydric soil rating: No
13
Custom Soil Resource Report
713-13raddock loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: kbfb
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Braddock and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Braddock
Setting
Landform: Fans
Landform position (three-dimensional): Tread
Down -slope shape: Convex
Across -slope shape: Linear
Parent material: Alluvium and colluvium derived from acid crystalline rocks
Typical profile
H1 - 0 to 8 inches: loam
H2 - 8 to 79 inches: clay
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
14
Custom Soil Resource Report
7C—Braddock loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: kbfc
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Braddock and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Braddock
Setting
Landform: Fans
Landform position (three-dimensional): Tread
Down -slope shape: Convex
Across -slope shape: Linear
Parent material: Alluvium and colluvium derived from acid crystalline rocks
Typical profile
H1 - 0 to 8 inches: loam
H2 - 8 to 79 inches: clay
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
15
Custom Soil Resource Report
1913—Minnieville loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: 2v7hq
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Minnieville and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Minnieville
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from acid and basic igneous rock
Typical profile
Ap - 0 to 8 inches: loam
Bt - 8 to 60 inches: clay
C - 60 to 67 inches: clay
Cr- 67 to 79 inches: bedrock
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: 60 to 120 inches to paralithic bedrock
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately
high (0.00 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 7.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
16
Custom Soil Resource Report
81 B—Thurmont loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: kbfh
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Thurmont and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Thurmont
Setting
Landform: I nterfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Colluvium derived from granite, granodiorite, and granite gneiss
Typical profile
H1 - 0 to 10 inches: loam
H2 - 10 to 46 inches: clay loam
H3 - 46 to 56 inches: loam
H4 - 56 to 79 inches: cobbly sandy loam
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: About 48 to 79 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 8.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
17
Custom Soil Resource Report
81 C—Thurmont loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: kbfj
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Thurmont and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Thurmont
Setting
Landform: I nterfluves
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Colluvium derived from granite, granodiorite, and granite gneiss
Typical profile
H1 - 0 to 10 inches: loam
H2 - 10 to 46 inches: clay loam
H3 - 46 to 56 inches: loam
H4 - 56 to 79 inches: cobbly sandy loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: About 48 to 79 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 8.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
18
2/12/2020 Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Free Union, Virginia, USA*
Latitude: 38.1751*, Longitude:-78.58*
Elevation: 607.32 ft**
source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, 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 50 100 200 500 1000
����������
0.338
0.405 IF
0.478
0.539
0.610
0.666 IF
0.719 IF
0.770
0.834 IF
0.887
5-min
(0.306-0.374)
(0.367-0.448)
(0.432-0.528)
(0.486-0.596)
(0.547-0.673)
(0.593-0.733)
(0.636-0.793)
(0.676-0.850)
(0.723-0.925)
(0.761-0.987)
0.540
0.647
0.765
0.861
0.971
1.06
1.14
1.22
1.32
1.39
10-min
(0.489-0.597)
(0.586-0.716)
(0.691-0.845)
(0.776-0.951)
(0.870-1.07)
(0.943-1.17 )
( 1.01-1.26 )
( 1.07-1.35 )
( 1.14-1.46 )
( 1.20-1.55 )
0.674
0.813
0.967
1.09
1.23
1.34
1.44
1.54
1.66
1.75
15-min
(0.611-0.746)
(0.736-0.900)
(0.874-1.07)
(0.981-1.20)
(1.10-1.36)
1 (1.19-1.48)
1 (1.27-1.59)
1 (1.35-1.70)
1 (1.44-1.84)
1 (1.50-1.95)
0.923
1.12
1.37 1.58 1.82
2.01
2.20
2.39
2.63
2.83
30-min
(0.836-1.02)
1 (1.01-1.24)
1 (1.24-1.52) 1 (1.42-1.74) 11 (1.63-2.00)
1 (1.79-2.22)
1 (1.95-2.43)
1 (2.10-2.64)
1 (2.28-2.92)
1 (2.42-3.14)
1.15
1.41
1.76 2.05 2.42
2.73
3.03
3.35
3.78
4.12
60-min
(1.04-1.27)
1 (1.27-1.56)
1 (1.59-1.94) 1 (1.85-2.27) 11 (2.17-2.67)
1 (2.43-3.01)
1 (2.69-3.34)
1 (2.94-3.70)
1 (3.27-4.18)
1 (3.54-4.59)
1.38
1.68
2.11 2.48 2.96
3.37
3.79
4.23
4.86
5.39
2-hr
(1.23-1.55)
1 (1.50-1.88)
1 (1.88-2.36) 1 (2.21-2.77) 1 (2.62-3.31)
2.30 2.70 3.23
1 (2.96-3.76)
1 (3.31-4.23)
1 (3.67-4.73)
1 (4.16-5.45)
1 (4.56-6.07)
1.51
1.83
3.68
4.14
4.64
5.34
5.94
3-hr
(1.35-1.71)
1 (1.63-2.07)
1 (2.04-2.60) (2.39-3.04) 1 (2.84-3.63)
1 (3.21-4.13)
1 (3.60-4.66)
1 (3.99-5.23)
1 (4.54-6.03)
1 (4.99-6.73)
1.94
2.34
2.91 3.42 4.12
4.73
5.38
6.08
7.10
7.99
6-hr
(1.73-2.18)
(2.09-2.64)
(2.59-3.28) (3.03-3.85) 11 (3.62-4.63)
(4.13-5.31)
(4.64-6.04)
(5.19-6.84)
(5.96-8.01)
(6.61-9.05)
2.44
2.95
3.67
4.33 7F
5.27
6.11
7.02
8.04
9.55
10.9
12-hr
(2.17-2.77)
(2.62-3.34)
(3.25-4.17)
(3.83-4.92)
(4.62-5.97)
(5.29-6.91)
(6.00-7.95)
(6.77-9.10)
(7.88-10.9)
(8.85-12.5)
3.01
3.65
4.65
5.49
6.73
7.78
8.95
10.2
12.2
13.8
24-hr
(2.71-3.37) 11
(3.29-4.08)
1 (4.18-5.19)
(4.91-6.12)
(5.98-7.49)
(6.87-8.65)
(7.83-9.93)
(8.86-11.3)
(10.3-13.5)
(11.6-15.3)
3.55
4.29
5.45
6.40
8.92
10.2
11.5
13.5
15.2
7.77
2-day
(3.20-3.95)
1 (3.88-4.78)
1 (4.92-6.06)
(5.75-7.11)
(6.93-8.62)
(7.90-9.88)
(8.93-11.3)
(10.0-12.8)
1 (11.6-15.1)
1 (12.9-16.9)
3.77
4.57
5.80 IF
6.80 IF
8.26 IF
9.47
10.8
12.2
14.3
16.0
3-day
(3.43-4.19)
4.00
(4.15-5.06)
4.85
(5.26-6.42)
(6.16-7.52)
(7.43-9.12)
(8.46-10.5)
(9.56-11.9)
(10.7-13.5)
(12.4-15.8)
(13.8-17.8)
6.15
7.21
8.75
10.0
11.4
12.9
15.1
16.9
4-day
(3.66-4.43)
(4.43-5.35)
(5.60-6.78)
(6.56-7.93)
(7.92-9.62)
9.78
(9.03-11.0)
(10.2-12.5)
(11.5-14.2)
(13.2-16.6)
(14.7-18.7)
4.66
5.61
7.01
8.15
11.1
12.6
14.1
16.4
18.2
7-day
(4.26-5.10)
(5.13-6.14)
(6.40-7.67)
(7.42-8.92)
(8.87-10.7)
(10.0-12.2)
(11.3-13.8)
(12.6-15.5)
(14.4-18.0)
(15.8-20.1)
5.29
6.35
7.83
9.02
10.7
12.0
13.5
15.0
17.1
18.9
10-day
(4 .86-5.75)
(5.84-6.89)
(7.19-8.50)
(8.27-9.79)
(9.76-11.6)
(10.9-13.1)
(12.2-14.6)
(13.4-16.3)
(15.2-18.6)
(16.6-20.6)
6.95
8.29
10.0
11.3
13.2
14.6
16.0 17.5
19.5
21.1
20-day
(6.49-7.48)
(7.74-8.90)
(9.33-10.7)
(10.612.2)
(12.2-14.1)
(13.5-15.7)
(14.8-17.2) (16.1-18.9)
17.9 19.2
(17.8-21.1)
(19.1-22.9)
8.53
10.1
11.9
13.3
15.2
16.5
21.0
22.3
30-day
(8.01-9.10)
(9.50-10.8)
(11.2-12.7)
(12.5-14.2)
(14.2-16.2)
(15.4-17.6)
(16.6-19.1) (17.8-20.5)
(19.3-22.5)
(20.4-23.9)
10.6
21.2 22.6
12.6
14.7
16.2
18.3
19.8
24.4
25.7
45-day
(10.0-11.3)
(11.8-13.4)
(13.8-15.6)
(15.3-17.2)
(17.1-19.4)
(18.5-21.0)
(19.8-22.5) (21.0-24.0)
(22.6-26.0)
(23.7-27.5)
12.5
14.7
16.9
18.6
20.7
22.2
23.7 25.1
26.9
28.2
60-day
(11.8-13.2)
(13.9-15.5)
(16.0-17.9)
(17.6-19.6)
(19.5-21.8)
(20.9-23.5)
(22.3-25.1) (23.5-26.6) ]LE
5.1-28.5)
(26.2-29.9)
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 given duration and average recurrence interval) will be greater than the upper bound (or less than the lower 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.
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