HomeMy WebLinkAboutWPO202000011 Calculations WPO VSMP 2020-02-20 TRUMP WINERY VSMP STORMWATER
MANAGEMENT CALCULATIONS PACKET
Date of Calculations
FEBRUARY 20, 2020
PREPARED BY:
(M, COLLINS ENGdOgE2RING
200 GARRETT STREET,SUITE K
CHARLOTTESVILLE,VA 22902
434.293.3719 PH
434.293.2813 FX
www.collins-engineering.com
SCS TR-55 Calculations
Soils Mapping (Source: NRCS Web Soil Survey Online Database)
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Soils Table (Source: NRCS Web Soil Survey Online Database)
Albemarle County, Virginia (VA003)
Map Unit Percent of
S rnbol Map Unit Name AOI
Y
23B Yadkin clay 98.2%
loam, 2 to 7
percent slopes
72D3 Rabun clay, 15 1.8%
to 25 percent
slopes, severely
eroded
Totals for Area of 100.0%
Interest
Note: The soils' properties witin this development are predominantly composed of hydrologic group
type B soils.
Precipitation Data
(Source: NOAA's National Weather Service, Hydrometerorological Design Studies Center, Atlas 14
Point Precipitation Frequency Estimates)
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POINT PRECIPITATION FREQUENCY(PF):ESTIMATES
WITH 90%CONFIDENCE INTERVALS AND SUPPLEMENTARYINFORMATION"'
NOAA Atlas 14,Volume 2,Version 3<`'
PDS-based precipitation frequency estimates with 90%confidence Intervals(in inches)1
L_____,_ Average recurrence Interval(years)
Duration I 1 �� 2--� II 5 II 10 II 25 II 50 II 100 II 200 II 500 II 1000 I
24-hr 2.99 3.62 4.62 5.47 6.73 T.80 8.99 10.3 12.3 14.0
(2.68-3.36) (3.25-4.07) (4.14 5.20) (4.88-6-13) (5-96 7.52) (6.87-8.70) (7.85-10.0) (8.90-11.5) (10.4-13.6) (11.7-15.5)
U.S.Department of Agriculture FL-ENG-21A
Natural Resources Conservation Service 06/04
TR 55 Worksheet 2:Runoff Curve Number and Runoff
Project: Trump Winery Designed By: FGM,PE Date: 2/20/2020
Location: Winery Lane Checked By: SRC,PE y Date: 2/20/2020
•
Check One: Present X Developed X �� 1,''ff
1.Runoff curve Number(CN) /
I
Cover description CN(weighted)=
Drainage Area Soil name and hydrologic Area P oduct of CN x Calculated'S'
Description group(Appendix A) (Cover type,treatment,and hydrologic condition;percent CN (Acres) Area total product/ Value
impervious;unconnected/connected impervious area ratio) total area
DA A Impervious Areas 98 0.11 / 11.0
(Pre-Dev.)
B Lawns in Good Condition 61 1.15 70.3 68 ,4.71
Gravel in Good Condition 85 0.28 23.4
DA A Impervious Areas 98 0.34 33.4
(Post-Dev.) B Lawns in Good Condition 61 0.641 39.3 78 /2.85/
Gravel in Good Condition 85 0.56 _ 47.2 ��
DA B Impervious Areas 98 0.18 18.0
B Lawns in Good Condition 61 0.04 U:1',5 2.4 91 0.96
(Not Modified) Gravel in Good Condition 85 0.01 0.6
2.Runoff
1-Year Storm 2-Year Storm 10-Year Storm Drainage Area Description
Frequency-years - 1 2 10 rn/a
Rainfall,P(24 hour)-inches 2.99 3.62 5.47 n/a
Runoff,Q-inches 0.62 0.97 2.22 DA A(Pre-Dev.)
Runoff,Q-inches 1.11 1.58 3.10 DA A(Post-Dev.)
Runoff,Q-inches 2.09 2.68 4.47 DA B(Not Modified)
U.S. Department of Agriculture FL-EN
Natural Resources Conservation Service
TR 55 Worksheet 3:Time of Concentration(Tc)or Travel Time(Ti)
Project: Trump Winery Designed By: FGM, PE Date: 2/20/2020
Location: Winery Lane Checked By: SRC, PE Date: 2/20/2020
Check One: Present X Developed X
Check One: Tc X Tt Through subarea n/a
DAA DAA DA B
Segment ID: (Pre-Dev.) (Post-Dev.) (Not Modified)
Sheet Flow: (Applicable to Tc only)
Dense Dense Dense
1 Surface description (Table 3-1) Grass Grass Grass
2 Manning's roughness coeff.,n (Table 3-1 0.24 0.24 0.24
3 Flow length, L(total L<100) (ft) 100 100 100
4 Two-year 24-hour rainfall, P2(in.) 3.62 3.62 3.62
5 Land slope,s(ft/ft) _ 0.07 0.07 0.10
6 Compute Tt=[0.007(n*L)o.8]/P2°3 s0.4 0.14 0.14 0.12
Shallow Concentrated Flow:
7 Surface description(paved or unpaved) Unpaved Unpaved Unpaved
8 Flow Length, L(ft) 375 350 45
9 Watercourse slope,s(ft/ft) 0.08 0.07 0.11
10 Average velocity,V(Figure 3-1) (ft/s) 4.6 4.3 5.4
11 Tt=L/3600*V 0.02 0.02 0.00
Channel Flow: ,----�
12 Cross sectional flow area,a(ft2) ,r'c\ti, '/ c •�
—
3
1 / o \\ LL °0
13 Wetted perimeter, Pv,(ft) LL -
m °;
14 Hydraulic radius, r=a/P,,,(ft) c u ° c b (L)c .,., CO c 2_
15 Channel Slope,s(ft/ft) al , c6 v 0_ /
16 Manning's Roughness Coeff, n U ; 1 o y
17V= [1.49r2/3s°°5]/n o \ \ Q
ED
18 Flow length, L(ft) 00 \r\�
19 Tt=L/3600*V \ 0;00 \�0.00
20 Watershed or subarea Tc or Tt
(Add Tt in steps 6, 11 and 19) 0.16 0.16 0.12
U.S. Department of Agriculture
Natural Resources Conservation Service
TR 55 Worksheet 4:Graphical Peak Discharge Method
Project: Trump Winery Designed By: FGM, PE Date: 2/20/2020
Location: Winery Lane Checked By: SRC, PE Date: 2/20/2020
Check One: Present X Developed X
1. Data Drainage Area Description Drainage Area Description Drainage Area Description
DAA DAA DA B
(Pre-Dev.) (Post-Dev.) (Not Modified)
Drainage Area (Am)in miles2= 0.0024 0.0024 0.0004
�
Runoff curve number CN= � -�(68) ( 787 91
Time of concentration(Tc)= / 0.16 0.16 0.12
Rainfall distribution type= / II II II 0
Pond and swamp areas spread f 0 0 0
throughout the watershed=
ti
y
1 "�
2. Frequency-years \ 1 2 10 1 2 10 1 2 10
3. Rainfall, P(24 hour)-inches 2.99 3.62 5.47 2.99 3.62 5.47 2.99 3.62 5.47 ,---1
4. Initial Abstraction, la-inches 0.94 0.94 0.94 0.57 0.57 0.57 0.19 0.19 0.19
5.Compute la/P \ 0.32 0.26 0.17 0.19 0.16 0.10 0.06 0.05 0.04 r" a
6. Unit peak discharge,Qu-csm/in 750 800 850 825 850 875 950 950 950 /i
7.Runoff,Q from Worksheet 2-inches 0.62 0.97 2.22 Z-1.11� 1.58 3.10 2.09 2.68 4.47
8. Pond and Swamp adjustment factor,Fp 1 1 1 1 1 1 1 1 1 x
9.Peak Discharge,Qp-cfs Routed Through The
where Qp=Qu Am Q Fp 1.12 1.87 4.54 Detention Basin 0.71 0.92 1.53 .-
c,
WATERSHED SUMMARY _ it
Area, 1-year Flow, 2-year Flow, 10-year Flow,
CN ( ,--...
ac. cfs cfs cfs
DAA(Pre-Dev.) 68 1.54 1.12 1.87 4.54 t�v
DAA(Post-Dev.) 78 1.54 0.48 0.55 2.70
C)
Channel and Flood Protection Calculations
9 VAC 25-870-66 (Subarea A)
Section B:Channel Protection
"Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet
the criteria in subdivision 1, 2 or 3 of this subsection..."
Section B.1: Manmade stormwater conveyance systems
"When stormwater from a development is discharged to a manmade stormwater conveyance system,
following the land-disturbing activity, either..." a. or b.shall be met:
Section B.1.b.
"The peak discharge requirements for concentrated stormwater flow to natural stormwater conveyance
systems in subdivision 3 of this subsection shall be met."
Section B.3
"...the maximum peak flow rate from the one-year 24-hour storm following the land-disturbing activity
shall be calculated either.." a. or b."
Section B.3.a.
In accordance with the following methodology:
Q Allowed<1.F. * (Q Pre-Developed * [RV Pre-Developed))/(RV Developed)
Q Allowed < 0.50 cfs
Where: Q Pre-Developed= 11.12 cfs (From Worksheet 4 Watershed Summary)
CN Pre-Developed= J 68 (From Worksheet 4 Watershed Summary)
S Pre-Developed= \4.71 (From SCS TR-55 eq. 2-4)
RV Pre-Developed= 'i 0.62 in. (From SCS TR-55 eq. 2-3)
CN Post-Developed= J 78 (From Worksheet 4 Watershed Summary)
I
S Post-Developed= �J2.85 (From SCS TR-55 eq. 2-4)
RV Post-Developed= 1.11 in. (From SCS TR-55 eq. 2-3)
I.F. = J 0.80 (Factor of Safety)
Q Developed = 0.48 cfs
Section B.4 Limits of Analysis
The analysis terminates at Subarea A since subsection B.3.a is met.
9 VAC 25-870-66 (Subarea A)
Section C: Flood Protection
"Concentrated stormwater flow shall be released into a stormwater conveyance system and
shall meet one of the following criteria as demonstrated by use of acceptable hydrologic and
hydraulic methodologies:"
Section C.2.b.:
The point of discharge, "releases a postdevelopment peak flow rate for the 10-year 24-hour
storm event that is less than the predevelopment peak flow rate from the 10-year 24-hour
storm event. Downstream stormwater conveyance systems do not require any additional
analysis to show compliance with flood protection criteria if this option is utilized."
10-Year, 24-Hour Pre-Development Subarea A Peak Flow Rate= 4.54 cfs
10-Year, 24-Hour Post-Development Subarea A Peak Flow Rate= 2.70 cfs
Section C.3 Limits of Analysis
The flood protection analysis terminates at Subarea A since subsection C.2.b is met.
Proposed Detention Basin Routings
SWM Facility A Routings
BasinFlow printout
INPUT:
Basin: SWM Facility A Routings
5 Contour Areas
Elevation(ft) Area(sf) Computed Vol. (cy)
678.75 5.00 0.0
679.00 570.00 1.9
680.00 1075.00 31.9
682.00 2316.00 154.6
684.00 3803.00 379.0
Start_Elevation(ft) 678.75 Vol. (cy) 0.00
4 Outlet Structures
Outlet structure 0
Orifice
name: Barrel
area (sf) 0.349
diameter or depth (in) 8.000
width for rect. (in)
coefficient 0.500
invert (ft) 678.250
multiple 1
discharge out of riser
Outlet structure 1
Orifice
name: Low-Flow Orifce
area (sf) 0.087
diameter or depth (in) 4.000
width for rect. (in) 0.000
coefficient 0.500
invert (ft)
multiple 1
discharge into riser
Page 1
SWM Facility A Routings
Outlet structure 2
Weir
name: Riser Top
diameter (in) 24.000
side angle 0.000
coefficient 3.300
invert (ft) 68QL
multiple 1
discharge into riser
transition at (ft) 0.608
orifice coef. 0.500
orifice area (sf) 3.142
Outlet structure 3
Weir
name: Emergency Spillway
length (ft) 25.000
side angle 0.000
coefficient 3.300
invert (ft) 682.750
multiple 1
discharge through dam
4 Inflow Hydrographs
Hydrograph 0
SCS
name: 1-yr 24-hr SCS Design Storm
Area (acres) 1.540 ,
CN 78.000
Type 2
rainfall, P (in) 2.990
time of conc. (hrs) 0.1600
time increment (hrs) . 0.0200
time limit (hrs) 30.000
fudge factor 1.00
routed true
peak flow (cfs) 1.984 -
peak time (hrs) 11.938
volume (cy) 232.019
Page 2
SWM Facility A Routings
Hydrograph 1
SCS
name: 2-yr 24-hr SCS Design Storm
Area (acres) 1.540
CN 78.000
Type 2
rainfall, P (in) 3.620
time of conc. (hrs) 0.1600
time increment (hrs) 0.0200
time limit (hrs) 30.000
fudge factor 1.00
routed true
peak flow (cfs) 2.811
peak time (hrs) 11.938
volume (cy) 328.710
Hydrograph 2
SCS
name: 10-yr 24-hr SCS Design Storm
Area (acres) 1.540
CN 78.000
Type 2
rainfall, P (in) 5.470
time of conc. (hrs) 0.1600
time increment (hrs) 0.0200
time limit (hrs) 30.000
fudge factor 1.00
routed true
peak flow (cfs) 5.511
peak time (hrs) 11.938
volume (cy) 644.310
Hydrograph 3
SCS
name: 100-yr 24-hr SCS Design Storm
Area (acres) 1.540
CN 78.000
Type 2
rainfall, P (in) 8.990
time of conc. (hrs) 0.1600
time increment (hrs) 0.0200
time limit (hrs) 30.000
fudge factor 1.00
routed true
peak flow (cfs) 11.168
peak time (hrs) 11.938
volume (cy) 1305.742
Page 3
SWM Facility A Routings
OUTPUT:
Routing Method: storage-indication 1
Hydrograph 0
Routing Summary of Peaks: 1-yr 2k-hr SCS Design Storm
inflow (cfs) g1_.984/at 11.94 (hrs)
discharge (cfs) _ �E 0 t 12.18 (hrs)
water level (ft) �680. at 12.18 (hrs)
storage (cy) 69.782
Hydrograph 1
Routing Summary of Peaks: 2-yr _24 hr SCS Design Storm
inflow (cfs) c 81O�,at 11.94 (hrs)
discharge (cfs) 0:550-at 12.20 (hrs)
water level (ft) 681.385 at 12.22 (hrs)
storage (cy) 106.853
Hydrograph 2 '
Routing Summary of Peaks: 10-yn, 4-hr SCS Design Storm
inflow (cfs) 508 at 11.94 (hrs)
discharge (cfs) �2 69t 12.10 (hrs)
water level (ft) 682.2D9 at 12.10 (hrs)
storage (cy) 181.313
Hydrograph 3
Routing Summary of Peaks: 100..-_y 24-hr SCS Design Storm
inflow (cfs) 41.163)at 11.94 (hrs)
discharge (cfs) 10:189 at 11.98 (hrs)
water level (ft) 682.960 at 11.98 (hrs)
storage (cy) 248.611
Thu Feb 20 13:23:41 EST 2020 \ O‘ nn _ gzE
Page 4
Detention Basin Outlet Protection Calculations
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Level Spreader Calculations
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Virginia Runoff Reduction Method Water Quality
Calculations
Water Quality Notes:
1. Compliance is met through the best management practice of releasing runoff in a sheet flow manner to a
conservation area with A/B soils.
2. The boundary for the ESC limits of disturbance is used to define the boundary for the VRRM water quality
calculations in the 'Site'tab of the spreadsheet.This is standard practice in Albemarle County.
3. The area (post-development subarea A) being treated via the sheet flow to a conserved area with A/B soils
//-e4(,4) is greater than the VRRM water quality boundary described above in#2.Applying the full subarea to the
FDA A'VRRM spreadsheet tab would yield inaccurate results since the drainage area would exceed the
g24, aCsite's land cover area.This would falsely show a higher phosphorous removal rate credit.This is because it
would incorrectly show the treatment of the upland, undisturbed area.As a result,this upland,
�Hac undisturbed area was omitted from the 'DA A'water quality analysis tab.This design approach is
Q appropriate since the development is required to treat the areas of proposed improvements/
disturbances.This design approach is also conservative because in actuality the phosphorous removed
from the sheet flow to conserved areas with A/B soils is greater than what is depicted in the calculations.
L.OD = ('37 p,c The applicant wanted to bring this information to the reviewer's attention for his/her benefit.
DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet-Version 3.0
D 2011 BMP Standards and Specifications 13 2013 Draft BMP Standards and Specifications
Project Name: Trump Winery data input cells
Date: 2/20/2020 constantvalues
Linear Development Project?I No I . calculation cells
Site Information final results
Post-Development Project(Treatment Volume and Loads)
Enter Total Disturbed Area(acres) 41 1.37 I Check:
BMP Design Specifications List: 2013 Draft Stds&Specs
Maximum seduction required: 20% Linear project? No
The site's net increase in impervious cover(acres)is: 0.51 Land cover areas entered correctly?
Post-Development TP Load Reduction for Site(Ib/yr): 0.99 Total disturbed area entered?
Pre-ReDevelopment Land Cover (acres)
ASoils BSoils CSoils DSoils Totals
Forest/Open Space(acres)—undisturbed,
protected forest/open space or reforested land 0.00
Managed Turf(acres)—disturbed,graded for 1.33
yards or other turf to be mowed/managed - 1.33
Impervious Cover(acres) 0.04 0.04
1.37 .
Post-Development Land Cover (acres)
-- -_-- - --_ ASoils BSolls CSoils DSoils Totals
Forest/Open Space(acres)—undisturbed,
protected forest/open space or reforested land 0.00
Managed Turf(acres)—disturbed,graded for
yards or other turf to be mowed/managed 0.82 0.82 —Impervious Cover(acres) 0.55 0.55
Area Check OK. OK. OK. OK. 1.37
Constants Runoff Coefficients(Rv)
Annual Rainfall(inches) "43 -- -- - - A Soils B Soils C Soils D Soils
Target Rainfall Event(inches) -• --1.00 Forest/Open Space - 0.02 - -0.03.>., -0.04 - _ 0.05
Total Phosphorus(TP)EMC(mg/L) 0.26'.- Managed Turf - 0.15 - - 0.20.- 0.22 • 0.25
Total Nitrogen(TN)EMC(mg/L) -'1.86 Impervious Cover - 0.95 ' , '0.95.- 0.95 ... .-_'0.95
Target TP Load(Ib/acre/yr) -
Pj(unitiess correction factor)
LAND COVER SUMMARY-- PRE-REDEVELOPMENT 11.1M1 LAND COVER SUMMARY--POST DEVELOPMENT
Land Cover Summary-Pre Land Coversummane-Post(Final) Land Cover Summary-Post Land Cover Summary-Post _
Pre-ReDevelopment I Listed Adjusted' Post ReDev.8 New Impervious Port-ReDevelopment Past-Development New Impervious
Forest/Open Space Cover Forest/Open Space %,a'-)`>:y_:x ,'%; `''t ','
Forest/Open Space Cover(acres) 0.00 0.00 0.00 0.00 ;`{,T,rry, ;-- -n a'�z'.'s','
(acres) Cover(acres) _... .__.__.. 's'`S`-`'''�fs'r';y'i«°•:v?,.'•,'.✓,hi
Weighted Rv(forest) 0.00 ' 0.00 Weighted Rv(forest) 0.00 Weighted Rvlforest) 0.00 ',''`'':'i +• vg^;: r`;',>s.;;'>
%Forest 0% 0% %Forest 0% %Forest 0% '''`'.�`<'t'x';+%",i,'i'`t'r.'i.'';v' -
rz"x x>r>y.
Managed Turf Cover(acres) 1.33 0.82 Managed Turf Cover 082 Managed Turf Cover 082 y7,y.�-,'r,z�s"y,>-„A�,.,�,11 ;�y' ,
- ".. (acres) (acres) s. :;<:5'0''':;'`-'i,''ga;'„`.�.'>,ry.,c
Weighted Rvltur0 0.20 0.20 Weighted Rv to 0.20 Weighted Rv to 0.20 2" h r�'s,,F>,''if '` `•,'.,
}..k,:".'K,:,4 - __.P 0 Jc`/,'�,F`<"•'
%Managed Turf 97% 95% %Managed Turf 60% %Managed Turf 95% r c' ��'•5'''':-y �'
ReDev.Impervious New Impervious Cover
Impervious Cover(acres) 0.04 0.04 Impervious Cover(acres) 0.55 0.51
Cover(aces) 0.04 (acre)
Rv(impervious) 0.95 0.95 Rv)lmpervious) 0.95 Rv(impervious) 0.95 Rv(impervious) I 0.95
%Impervious 3% 5% %Impervious 40% %Impervious 5%
Total ReDev.Ske Area > "i i.
TatalSke Area aces 3.37 0.86 anal Site Area aces 1.37 0.86 `
aces• � ':. -?; ^,',,
Site Rv 0.22 0.23 Final Post Dev Site Rv 0.50 ReDev Site M l----0.23 )Y ..r; . ./2,,}:,'
Treatment Volume and Nutrient Load , - _ - Treatment Volume and Nutrient Load
Pre-ReDevelopment Treatment Volume Final Post-Development - Post-ReDevelopment I Post-Development
(acre-k) 0.0253 0.0168 - Treatment Volume 0.0572 _ Treatment Volume 0.0168 ''.1 Treatment Volume 0.0404 i
(acre-ft) I (ace-k) i'!, (acre-ft) i
Pre-ReDevelopment Treatment Volume Final Post-Development , - _ '1 Pont-ReDevelopment t ' Post-Development
lcubkfee 1,104 733 Treatment Volume 2,492 . ; Treatment Volume 733. °Treatment Volume(cubic 1,759
(cubic feet) .- (cubic feet) feet)
Pre-ReDevel meat 7P Load Final Post- Post-ReDevelopment
ap `Post-Development TP Load
0.69 0.46 Development TP Load 1.57 - toad(TP) 0.46 .-- 1.11
(Ib/yr) _ -- (ib/yrl'
PrrReDeveioPment TP Load per Final Port-Development TP - Post-ReDevelopmentTP - - _-- _-
_
(lb/acre/at) 0.5acre1 0.54 Load per acre L14 _ Load per acre 0.54
pb/ane/yr) 0/ate/Td
Baseline TP Load(Ib/yr) Man.Reduction Required
(0.418as/ate/yr applied to pre-redevelopment areaevcluding pervious 0.35 (Below Pre- 20%
land proposed for new Impervious cover) ReDevelopment Load)
_- __
TP Load Reduction '
'Adjusted Land CoverSummaty: TP Load Reduction
Pre ReDevelopment land cover minus pervious land rover(forest/open space or managed Req III
uired for
Redeveloped Area 0.09 Required for New 0.90
tur/)oceage proposed for new impervious caves p Impervious Area(Ib/yr)
(Ib/yr)
Adjusted total acreage In consistent with Post-ReDevelopment acreage(minus acreage of -
new impervious cover).
Column 1 shows land reduction requriement for new impervious cover(based on new
development land limit.0.411bs/ace/year).
Post-Development Requirement for Site Area
TP Load Reduction Required(Ib/yr) 0.99
Nitrogen Loads(Informational Purposes Only)
r Final Post-Development TN Load - ,
Pre-ReDevelopment TN Load(lb/yr) 4.96 (Port-ReDevelopment&New Impervious) 11.20 ' -
(Ib/yr)
I i I '
Puss _Tmm
DAP
Drainage Area A
CLEAR RMP AREAS
Dea [e Area A land Cover(Moe)
PWM Inas [SON DSOs TvbN smMravmh •
emeaMpena0me lanes) ram 0.03
MvuPedTud Iran) 0.31 031 0.20
n CususAoe) 0.55 055 0.95 Total Phephow Mashie for Removal In DA Aim/M 133
Total 036 post DeveepmentTmatrmntVeblm In PAP(13.) 2333
Stormwater Best Management Practices(RR=Runoff Reduction) -select from dmpdown Nts-
Runan Managed Ted Imerebus Volume from PUMI Remaebg Total MVP Phosphor. Pbmphormlaad Untreated MmsphoMs RLmaulet Dowmbem Pnmk. ba rel0Oged Nsogen Load Untreated N.D. Rmbsloa
Practice Redaction Cnedltkm Cover Coedit Upstream Rm m c000oue 'Treatment Removal from Upstream eM lo
ad ad Renewed Ely Phosphoms mad Remael from Upstream Nitrogen Mad bad Removed By Mermen load
Ceemt all lame) Area(ales) Practice Redectim u.' vol.. roammyltll UmMem0bl toenmtwlel Mac.Eel Ml Em° Efficiency lxl Practice PM Macom lea) Macao Meal (Dal
1.Vegetated Roof(RRl 1.Vegetated gooffeol
�,�c.,y� .A •'ti::•� -'Y•' Cm am ram •a'i:
lave°emNamluDpmrsl �. -`���c'��a :;:•,: i{;:ti• o ° a ...,. ,...' J.,.{:h;•.;. . ... .�$:{�°.ii am ram ram
14 Vegetated aoM.lDpese) _, - x'.CiY<+(rpt .evZ:g1': 0 D 0 '•'•:i:•e•:•:i.: ram ram ram M';gal j am am am
I.emhap Disconnection ISM
0.eary.mmmtmlmmwsma 0 0 0
•,�hyJ-
00mM1 o ram am ram ram am - ram ram ram
10.sm,w.1sconn.nanmw5m1 . '••,,,,,,' - -
15npn1 a a o o am ram 0m ram ° am am am am
'' l•wwiwsnml""70 _ .- 0 0 a � m m a a ram am _ ... am am am
16TOmywecmrmrh era IL <RA•a,4n? 0 0 0 0 .. - am ram 0.m am 'I5
Lmowae.wnppmnl Mao ram am mo
.T mywea r afie":nn , el. �' 0 0 a 0 am am cm ram . . „ .. ram , Dm am am
Me Vim.TOw Gard.St •q
Isncel �p 4 0 0 a a . .... am am am ram ., 0m mo ram ram
rnwA nrwdena; m to
n UPm el t�.4.tt� o 0 0 .. am 0m ao° ram ...ram;"t ram am ram ram
L4 To Rammer MeresOnalSpecobl a a 0 0 0 OM ram am am ,+t,;:a:, am DLO 0m am
2Lamtmmamfamn• ""„F a - .'E" am ram ram m om
unm tbnlsnte.bm�alcal `. "' a a D - .... .. am 0m
3.Permeable Pavement IRRI �����` 1eable Pavement IRRI
3aMmaahm Pennant atlspma) 'x .'L ° ° 0 0. °m ram ram 111 ram ram Om
3.4 Perm....Mvmentar(Wean „ .s k�±ay''�na's+d-S •..•..••.•.J D a ° 13 v.-. •.d?..5:•:::L•: m am am Mil {:.••e 'tb ram ..11:111 am
.Grass Channel(RR) a.Gross Channel IRRI
...ma m 05 anelsam lsoman - ..a .. ¢m
ME
WIN am
.armw.awrmtape.m 0 0 0 0 - ram mooam am am 0 am
k .ayrmmmane,deeenm ram - am
Mal a Demme m.spmMl o 0 E. _ am am am OMram
Dry Swale INN S.Dry Swale Oft)
Sa°gaets 010m Dlal _ 0 - D a o ., 20.._.. am °m am ram am
aao OM
s.e.evs03enlbmna) ,,so 1. 0 ° n 0 OW am ram Om Mil um ram am
ndbn(OM don(Sal
nmree s.ameen
a.emeAenwnnmarleoamaewmram --m
° D 0 a ... "is....,: am ra m ram• am am ME °.m ram
eummnnl WM odem elm
ae.mmeAenam 13Pmnl Mp m mmnn ..., a a ° ° .. ram ram am ram ECIE ram ram .:111 ram
T.Infiltration OM) p.Infiltration WO
7...In/Stream eo0.ee) m „ a a ° o as OM am ram ram ® m mD am
ee.mnraaan al Upee sal m. 0 0 0 0 ram DM °m am ME ram am UM ram
.Extended DetentMn Pmd(Re) a.handed Detention Pond(OR)
a..mn)spm ale -. 0 0 0 a am 030 cm 0m Mtill am ram NM ram
an EOM(Wale) 1s - 0 I 0 1s am °a° am nao Elial ram Dm ram rave
'.Shearlow to Rhee/open spare 100 9.Sbeetflow to Filter/open sore MP)
9a Amman l�M. .• ... all esv 0 L103 Sm L131 - _ 003 L33 100 - 033 ME am 353 ® 33a
pa aaaw5m, _m l5pmm a D 0 ... ..- ram ram . Dos aaD Dos ram ram
y� mreg mw ma.smp.Asmtm'.....m
rmmpaamewed wos0m o 0 a 0 ram ram - am am SEI Dos
open a mq ... _
VRRY R.a._Y>_0.0
DAD
TOTAL IMPERVIOUS COVER TREATED(0) 055 AREA CHEQ:0L
TOTAL MANAGED TURF AREA TREATED lac) 031 AREA OECD OR.
TOTAL RUNOFF REDUCRON IN DA A)Nr) 1$91
TOTAL PHOSPHORUS AVMIABLF FOR REMOVAL IN DA A 00/y0 133
TOTAL PHOSPHORUS REMOVED WITHRUN0FF REDUCTION PRACTICES IN DA A(1T/wl 100 TOTAL RUNOFF REDUCTION IN DA A(N') 1.391
TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACITCES IN DA A(0/yr) 033 NITROGEN REMOVED WOH RUNOFF REDUCTION PRACTICES IN DA A OR/yr) MS
SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS SEE WATER QUALITY COMPLIANCE TAD FOR SITE CALCULATIONS(Oaf ama0On Only)
I
10.wetSW01e(n0 R.1 lo.wet 5w0le(Coastal Plal1)00 RR)
IDA we s.ata FL DewDewat) ...0 s. 0 0 0 0 .m am 0m am m0 ® 0m am WM Um
IAA Wet WaYRlsl.c all) 0 0 0 0 00 003 0m 000 0m Mill om 0m M. Om
l I.010On.Practices(m RR) t..(no Rltl
tt.Flnare♦Nm.s (Y.0 alalt) , 0 0 0 0 0 ... Om 000 000 000 WINai 0.m 0m Em 0
111.11rte00P/lab e3 New.) 0 0 0 0 - - 000 Om ow 000 ® Om Om m
M. 0
12.Construct.Wetland(no AR) 11 Construed Wetland(no RR)
u..mmmn.dwed.M n Ism n01 L 0 0 0 a 000 am 0m am Mil Om m0 WM DOD
02.100000:a weaandnlsomal3) I 0 0 0 0 am om Om am ® Om 0.00 nm
I3..Wet Ponds(n0 RR)
IDaWn NW nl3pcalq - 0 0 A .. OW0,03 o0f 0.000.00 OW 603 0.00
13A Wes Pond R(Cm.n NAM lSaaalal 0 0 0 0 - O.m Om Am Am Om 0.m OM 0.00
11c.w0Pore111100.•010 ., ,,- 0 0 A 0 Y09_ a 0.00 000 000 ,, ._ 0m 0.00 0.00
IA&Wet Pa2BOW 0. Plw)M...) D _ 0 0 0 0N O -- 003 mo am om om Om 0m Om
DI.
Manufactured WW.(no 3111
t4Mel.daea.aTn.umnurs M.
om om
Om am
M.
Ian Mn.dm.3nemv 0.1e0.0.1. ' 0 0 0 0 m 000 003 00, 003 om m 0m
1109el.ad.mo.dn..R.000.900eu. 0 0 0 0 20 .0am am . ICE 0m am om
TOTAL UMW.COVER SAEATFDIeA - OSS AREA01E00 OIL
TOTAL MANAGEDTUNF AREA TREATED(a0) 031 ARM CHECK:OR.
TOTAL PHOSPHORUS REMOVAL REQUIRED ON snub/Ill
TOTAL PH 05PH0RUSAVASABIE FOR REMOVAL IN DA A Phi _-0.33
TOTAL PHOSPHORUS REMOVEDWRHOOTRUNOEF REDUCTION PMCIICFSIN DA.A(W/yr) 0.00
TOTAL PHOSPHORUSREMOVED MN(WNW REDUCTION PRACTICES IN OA A(Ib/yr) 100
TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED INDA A0bM) 100
TOTAL PHOSPHORUS REMAINING AFTFRAPPLYTNG IMP LOAD REDUCTIONS IN DA.A(Ib/Yr) '0.33
SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS
NITROGEN REMOVEOWLIH RUNOFF REDUCTION PRACTICES IN DAABb/yr) 7.14
NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA A(W/yN MOO
TOTAL NITROGEN REMOVED IN DA.A(WAN) 7.14
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) 0.55 0.00 0.00 0.00 0.00 OK.
IMPERVIOUS COVER TREATED(ac) 0.55 0.00 0.00 0.00 0.00 OK.
MANAGED TURF AREA(ac) 0.31 0.00 0.00 0.00 0.00 OK. 1
MANAGED TURF AREA TREATED(ac) 0.31 0.00 0.00 0.00 0.00 OK.
AREA CHECK OK. OK. OK. OK. OK.
Site Treatment Volume(ft3) 2,492
Runoff Reduction Volume and TP By Drainage Area
D.A.A D.A.B D.A.C D.A.D _ D.A.E TOTAL
RUNOFF REDUCTION VOLUME ACHIEVED(ft3) 1,591 0 0 0 0 1,591
TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) 1.33 0.00 0.00 - 0.00 0.00 1.33
TP LOAD REDUCTION ACHIEVED (Ib/yr) 1.00 0.00 0.00 0.00 0.00 1.00
TP LOAD REMAINING (Ib/yr) 0.33 0.00 - 0.00 0.00 0.00 I 033 i
1I I I
NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 7.14 0.00 . 0.00 0.00 - . -. 0.00 l 7.14
Total Phosphorus
FINAL POST-DEVELOPMENT TP LOAD(Ib/yr) 1.57
TP LOAD REDUCTION REQUIRED(Ib/yr) 0.99
TP LOAD REDUCTION ACHIEVED (Ib/yr) 1.00
TP LOAD REMAINING(Ib/yr):L 0.57
REMAINING TP LOAD REDUCTION REQUIRED(Ib/yr): 0.00 **
**TARGET TP REDUCTION EXCEEDED BY 0.01 LB/YEAR**
Total Nitrogen(For Information Purposes)
POST-DEVELOPMENT LOAD(Ib/yr) 11.20
NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 7.14
REMAINING POST-DEVELOPMENT NITROGEN LOAD(Ib/yr) 4.06
Virginia Runoff Reduction Method Worksheet
DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet-Version 3.0
BMP Design Specifications List: 2013 Draft Stds&Specs
Site Summary
Total Rainfall(in): 43
Total Disturbed Acreage: 1.37
Site Land Cover Summary
Pre-ReDevelopment Land Cover (acres)
NiMi,'.M:0-7ENRiAAMM 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 1.33 0.00 0.00 1.33 97
Impervious Cover(acres) 0.00 0.04 0.00 0.00 0.04 3
1.37 100
Post-ReDevelopment Land Cover (acres)
"r 1':'^s i<iV M%`";:n::': 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 0.82 0.00 0.00 0.82 60
Impervious Cover(acres) 0.00 0.55 0.00 0.00 0.55 40
1.37 100
Site Tv and Land Cover Nutrient Loads
,nvy, ti:z:%< Pre-
<1.tr>;::is •>s"':ii• �'=:?bW:.;. Final Post-Development Post-ReDevelopmentTP
Eili ;je>., .;,.; . . ....,. .,r Final Post-Development Post- p
:aj <$j:'e:yC •,.�,:^j;;;;:.:',:;�r I;>;:-Z$i:.: Post- Adjusted Pre- ReDevelopment
:t: ; ;.:.;r -^ .r '; ;:. (Post-ReDevelopment Development TP Load per acre Load per acre
> ve.f;;.,+,,,..:•sr-,.;;,;, > ;;; ? ReDevelopment ReDevelopment TP Load per acre
r ..,.. :,....4,..>,....,,.,..5•. &New Impervious) (New Impervious) (Ib/acre/yr) (lb/acre/yr) (Ib/acre/yr)
Site Rv 0.50 0.23 0.95 0.23 0.54 1.14 0.54
Treatment Volume(ft3) 2,492 733 1,759 733
TP Load(lb/yr) 1.57 0.46 1.11 0.46
Total TP Load Reduction Required(Ib/yr) 0.99 0.09 0.90
.;. `• Kea:'f,g0M ;f,;. Final Post-Development Load Pre-
^' t ;''" (Post-ReDevelopment&New Impervious) ReDevelopment
TN Load(Ib/yr) 11.20 4.96
Summary Print
Virginia Runoff Reduction Method Worksheet
Site Compliance Summary
Maximum%Reduction Required Below 209'
Pre-ReDevelopment Load
Total Runoff Volume Reduction(ft3) 1,591
Total TP Load Reduction Achieved(Ib/yr) 1.00
Total TN Load Reduction Achieved(Ib/yr) 7.14
Remaining Post Development TP Load 0.57
(Ib/yr)
Remaining TP Load Reduction(Ib/yr) 0.00 **TARGET TP REDUCTION EXCEEDED BY 0.01 LB/YEAR**
Required
Summary Print
Virginia Runoff Reduction Method Worksheet
-- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Drainage Area Summary
<'ys'<: '% "'``"� ;< yL;>;`:£r,.;, D.A.A D.A.B D.A.C D.A.D D.A.E
. ,. ., .•.r:.�s^•'s<.. _... ........ ... . Total
Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Managed Turf(acres) 0.31 0.00 0.00 0.00 0.00 0.31
Impervious Cover(acres) 0.55 0.00 0.00 0.00 0.00 0.55
Total Area(acres) 0.86 0.00 0.00 0.00 0.00 0.86
Drainage Area Compliance Summary
'`? ......:?x^ >,agNiii ..........,.... D.A.A D.A.B D.A.C D.A.D D.A.E Total
TP Load Reduced(Ib/yr) 1.00 0.00 0.00 0.00 0.00 1.00
TN Load Reduced(Ib/yr) 7.14 0.00 0.00 0.00 0.00 7.14
Summary Print
Virginia Runoff Reduction Method Worksheet
Drainage Area A Summary •
Land Cover Summary
j:.y'; :,,,__,, .,y'?`:;g;r-;.,,,, .,,:;', :_IM. A Soils B Soils C Soils D Soils Total %of Total
Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0
Managed Turf(acres) 0.00 0.31 0.00 0.00 0.31 36
Impervious Cover(acres) 0.00 0.55 0.00 0.00 0.55 64
0.86
BMP Selections
Managed Turf Impervious TP Load from
BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment
Practice Credit Area Cover Credit s Upstream
Volume(ft) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed
____ (acres) Area(acres) Practices(Ibs)
9.a.Sheetflow to Conservation Area,A/B 0.31 0.55 2,121.74 0.00 1.33 1.00 0.33
Soils(Spec#2)
Total Impervious Cover Treated(acres) 0.55
Total Turf Area Treated(acres) 0.31
Total TP Load Reduction Achieved in D.A. 1.00
(Ib/yr)
Total TN Load Reduction Achieved in D.A. 7,14
(Ib/yr)
Summary Print
Virginia Runoff Reduction Method Worksheet
Runoff Volume and CN Calculations
.•?..Z:E'lif,M;M::',.ZZOMP"gaN 1-year storm 2-year storm 10-year storm
Target Rainfall Event(in) 2.99 3.62 5.47
Drainage Areas RV&CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E
CN Mitang 85 0 0 0 0
RR(ft3) ENMS: 1,591 0 0 0 0
RV wo RR(ws-In) 1.58 0.00 0.00 0.00 0.00
1-year-return period RV w RR(ws-In) 1.07 0.00 0.00 0.00 0.00
_i -•
i.., CN adjusted 77 0 0 0 0
- . RV wo RR(ws-in) 2.12 0.00 0.00 0.00 0.00
2-year return period -• RV w RR(ws-in) 1.61 0.00 0.00 0.00 0.00
, CN adjusted 78 . 0 0 0 0
RV wo RR(ws-In) 3.80 0.00 0.00 0.00 0.00
.._.., .
10-year return period RV w RR(ws-In) 3.30 0.00 0.00 0.00 0.00
CN adjusted 80 0 0 0 0
Summary Print