CC - Storm Drainage Calcs STORMWATER RUNOFF CALCULATIONS
for
TEAKWOOD PLACE SUBDIVISION
Meridian, Idaho
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4 17650
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LEAVITT & ASSOCIATES
ENGINEERS, INC.
ClVl4--�T[tIH:TUit�►l-SURVEYINQx.LANO D�IEt,OPl1lENT
1324 V Street South,Nampa Idaho 83651 —(208)463-7670—www.leavittnengineers.com
Revision# Prepared and Certified by I Reviewed by Project#
0 Nathan J. Porter, P.E. I Dan Lardie SD084.001
DESIGN CRITERIA:
ACHD—Stormwater Policy Manual
100-year Design Storm Frequency for Storage Facilities
25-year Design Storm Frequency for Primary Conveyance Systems
100-year Storm Frequency for Secondary Conveyance Systems
TABLE OF CONTENTS
RunoffArea Map---------------------------------------------------------------------------------------------- 1
Boise Area Intensity-Duration-Frequency Curve--------------------------------------------------------- 2
Subdivision Information-------------------------------------------------------------------------------------- 3
RationalMethod----------------------------------------------------------------------------------------------- 4
RunoffAreas--------------------------------------------------------------------------------------------------- S
Forebay Post Development Flow--------------------------------------------------------------------------- 6
Forebay Facility Sizing--------------------------------------------------------------------------------------- 7
Area 1 Post Development Flow----------------------------------------------------------------------------- 8
Pond 1 Facility Sizing -------------------------------------------------------------------------------------- 9
Inletsand Pipes-----------------------------------------------------------------------------------------------10
Sand& Grease Trap Design--------------------------------------------------------------------------------11
Conveyance ---------------------------------------------------------------------------------------------------12
CurbOpening Inlet-------------------------------------------------------------------------------------------13
JANUARY 20,2021
�-
DRAINAGE AREA 1
TOTAL: 233,217 SQFT.
PAVEMENT: 73,796 SOFT.
ROOF: 21,000 SQFT.
LANDSCAPE: 157,321 SQFT.
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LEAVITT&ASSOCIATES
DRAINAGE AREA MAP ENGINEERS, INC.
H STRUCTURAL*CIVIL
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2 HESSCOM CORP EAKWOOD SUBDIVISION SURVEYING
to
6700 N.LINDER ROAD r: ca e:
MERIDIAN,ID 83646 1"=150'
y (208)789-4064 Y: rawn y: ee,e Y 1324 FIRST STREET SOUTH, Wu1PA. IDAHO 63651
PHONE(20SX63—ow/ew-767o FAX (208)es3-9M
BOISE AREA INTENSITY-DURATION-FREQUENCY,WITH REVISED IDF CURVES
Intensity(inches per hour)
Design Storm 2 5 10 25 50 100
Tc
0.17 10 min 0.69 1.15 1.45 1.85 2.20 2.58
0.25 15 min 0.59 0.97 1.22 1.56 1.86 2.18
0.33 20 min 0.49 0.81 1.01 1.30 1.54 1.81
0.42 25 min 0.43 0.71 0.89 1.14 1.35 1.58
0.50 30 min 0.41 0.67 0.85 1.08 1.29 1.51
0.58 35 min 0.34 0.56 0.70 0.90 1.07 1.25
0.67 40 min 0.31 0.51 0.64 0.82 0.98 1.15
0.75 45 min 0.29 0.48 0.60 0.77 0.91 1.07
0.83 50 min 0.27 0.45 0.56 0.72 0.85 1.00
0.92 55 min 0.26 0.43 0.54 0.69 0.82 0.96
1.00 1 hour 0.26 0.43 0.54 0.69 0.82 0.96
2.00 2 hours 0.16 0.25 0.31 0.39 0.46 0.54
3.00 3 hours 0.13 0.19 0.23 0.29 0.34 0.40
6.00 6 hours 0.09 0.12 0.14 1 0.18 0.21 0.25
12.00 12 hours 0.06 0.08 0.10 0.12 0.14 0.16
24.00 24 hours 0.04 0.06 0.06 0.08 0.09 0.10
Boise Area
Intensity Duration Frequency (IDF)
3.00
-------2 year
2.50 -x-5 year
-x-10 year
1�2.00
y 6 25 year
L
c1.50 0 50 year
0 ` S 100 year
00
r
G
"-------------
0.50
0.00
10 min 15 min 30 min 1 hour 2 hours 3 hours 6 hours 12 hours 24 hours
Duration in minutes and hours
T:\SUBDIVISIONS\Hessing Victory Subdivision-5D084.001\Reports\Storm Drainage\ACHD_SD_CALCS_IWOIB0r29rp7:29 AM
Version 10.0, May 2018
Page 3
LEAVITT&ASSOCIATES ENGINEERS, INC. JOB: Teakwood Place
1324 1st Street South JOB NUMBER: 3D084.G01
Nampa,Idaho 83651 DATE: 1/20/2621
(208)463-0333 FILE:
Design Criteria
Subdivision Information
Total Area: 233217 sf= 5.35 acres
Type of Area: Urban Construction Type: Residential-Single Family
Average Slope: 1
Policy Manual:ACHD Policy Manual-Section 8000,Drainage-2010
Rainfall Intesity Area Classification: Zone A
Primary Conveyance Design Storm Frequency: 25 yr
Secondary Conveyance Design Storm Frequency: 100 yr
Minimum Depth of Freeboard: 6 in
Maximum Side Slope of Infiltration Swales 3:1
Minimum Depth of Bottom of Infiltration Facility to Groundwater: 3 ft
Minimum Depth of Bottom of Infiltration Facility to Bedrock: 3 It
Time of Infiltration Until No Visible Water Exists After Primary Storm: 48 him
Time of Infiltration Unfit No Visible Water Exists After Secondary Storm: 72 him
Predevelopment Flow
2 1 25 1 50 100
C= 0.13 0,h (in/hr) 0.40 0.78 0.90 1.10
16
Hixzxw�(in/hr) 1 0.04 0.07 0.08 1 0.08
Qu= CA Qu 60— (cfs) 0.28 0.54 0.63 1 0.77
Qu(v.)We) 0.03 0.05 0.05 1 0.06
Storm Conveyance Statement
The primary flow will be conveyed through gutters,sand&grease traps,catch basins,drop inlets&grates,
and pipes with minimum impact or inconvenience to the public.
The following items will be designed based on the primary flow:
-sand&grease traps -pipes
-catch basins -gutters(clear driving lane)
-drop inlets&grates
The secondary flow:
-gutters(depth of water does not exceed 12 in.)
Pa9a (y
s caV/TT S ASSOCIATES MISINEERSr ING lim iTeannaund Plana
1324 1st5timet SOYD1 JDBNWBM SDDB4.D91
Nampa,Idaho 83851 IDAM linclawl
2118463.0333 FILE: 1 0
STORM RUNOFF CALCULATIONS-RATIONAL METHOD
SUMMARY OF RATIONAL METHOD
FLOW CALCULATION Table l:Zone A Rental Intensityr, i nonfat
Ountlon 2 25 50 100
10 1.21 2.37 2.73 3.11
CV-RUNOFFFLOW,CPS=C'i'A 15 1.02 2.00 2.30 2.62
i=Rainnd Intensity-From Table 1:Zane Raltal Intensity 20 0.85 1.67 1.91 228
A=Runoff Area,Arms 25 0.74 1.441 1.115 2.W
C=Runoff Coefficient 30 0.71 1.39 1.59 1.82
35 0.59 1.14 1.31 1.%
Do=UNDEVELOPED RUNOFF,CFS(FROM PRE-DEVELOPMENT) 40 0.54 1.05 1.20 1.37
45 0.50 O.97 1.11 126
Of=INFILTRATATION,CFS 50 0.47 0.90 1.04 1.17
Ab=Area of Infiltration at Bottom of Pond,of(does not include area of sand mdoev) 55 0.45 0.0 1.01 1.15
Ib=Intimation Rate of Native Soil at Bottom of Pond,imM 60 0.45 0.88 1.01 1.15
Ac=Area of Infiltration of Trench,sf 120 D21 0.50 In SS 0.88
I.=Itdtatlon Rate of Native Sol at Bottom of Trench,Whr 18in 0.20 0.8] O. 0.48
Ab,=Area of Infttuation at Send Wndow,at 360 1 0.13 1 023 1 0.27 0.30
1,=Infiltration Rate of Native Soil at Bottom of Sand Willow,ithr 120 0.00 1 0.15 1 0.10 0.19
Ia,=Infinration Rate of Deeper Soil at Sand Wndow,ithr 1440 0.05 1 0.09 0.11 0.12
Of-E(A(sp'I pnmr)p(1 HRI380(I SEC)'(1 M12 IN)
VOLUME CALCULATION Table 2:Standard Soil Infiltration Rtas'
Soil Class Solt T ^Rate
Vmd=NET VOLUME REQUIRED FOR POND ANDIOR SUMP STORAGE.CF A-1 Medium Sand 8
A-2b Fine Sand Send 2
Vnc1= Cant-(60 sedmin)'Durefion(min) &1 Sandy Loam 1
&2 Loam Silt Loam 0.5
01 Sandy or Silly Clay,Loam D.2
Onel=NET DISCHARGE FLOW WHICH FILLS THE POND OR SUMP,CM G2 Clay Loam DAS
=Qd-QY-OI D CIe .OraNCMuck Dumpan.H&ahR Gayp C0.C9
Infdration rate determined by Ilamolafan teal may also as used
Add 16%For Sedimen r Minimum rate,soils whin lesser rates shall not be cons"dered as
candidates far li flbation hie lilies
Vreq= Vnetx 1.15
Vs=VOLUME OF SURFACE STORAGE.CIF d1n
Vs=VnN-Subsurface steua0e Capaoty l
TIME OF INFILTRATION CALCULATIONS
Time to Fin Subsuda x,Layer,sac=Volume of Subsurface Stauagel Qs r�2.-11T-J-------
where Qs=SAND INRLTRATATION,CF8
As=Area ofTrandi or Send Wndow Modified Triangular Hydrogmph
Is Infiltration Rate of ASTM C 3 Sand=B iNhr
Os=As(s0'Is(INIHR)-(1 HROSIX)SEC)'(1 M12 IN)
Time Until No Visible Water Exist,sac=Time to Fill Subsurface Layer+Volume Surface Stor 1pi
Total Time of Insinuation,sec=Tend Required VOlum&Qi
Page 5
LEAVITT&ASSOCIATES ENGINEERS, INC. JOB: ITeakwood Place
1324 1st Street South JOB NUMBER: SD084.001
Nampa,Idaho 83651 DATE: 1/20/2621
(208)463-0333 FILE: 0
Runoff Areas 8 Runoff Coefficients
Cd= Developed runoff coefficient = 0.50 (or use C...r value ifhigher)
Cma a= Roof Area(0.95)+Paved Area(0.90)+Landscaped Area(0.20)+Gravel Area(0.4)+Undeveloped Area(0.15)
Total Area
Tc= Time of Concentration,based on Kirpichs equation for flow an concrete or asphalt
L1.5
re=0.0078 x( h- )o.n
L=Length of roadway from furthest point to drainage facility(ft)
h=elevation change from furthest point to top of drainage facility(ft)
if Tc>1 hr,use 60 min
Area 1 ft2 acres
Total Area= 233,217 5.35
Total Hardsurface = 73.796 1.69
Roof Area 21,000 0.48
Total Landscape 138,421 3.18
Landscape Runoff 6 eo ota g2742 213
Landscape)=
Length of Drainage Path,L(ft)= 300
Elevation Change,h(ft)= 1.0
Effective Area=Har-surface+Roof+ 187538 4.31
67%Landscape
C, ffim= OA91 Use 0.50
Tc(min)= 6 mini Use 10
NOTE:
Rainfall on individual lots is the responsibility of the homeowner. However,the stormwater shall accommodate flows from the
driveways and half of the area of the homes and garages in the subdivision. As a conservative measure,67%of all landscaped
areas,which includes private properties and the remaining half of the roof area,has been considered to contribute to the public
stormwater system.
Page
LEAVITT S ASSOCIATES ENGINEERS,INC. JOB: Teakwood Place
1324 1st Street South JOB NUMBER: SD084.001
Nampa,Idaho 83651 1 DATE: 1/20/2021
2081463-0333 FILE: 1 0
STORM RUNOFF CALCULATIONS-RATIONAL METHOD
POST-DEVELOPMENT FLOW
Storm Runoff for Soil Profile Test Pit# 1
Area 1 Depth(ft) Classill if Infiltration
Rate I
0 to 4.0 G1 0.25
Effective Area 4.0 6.0 .2 0.50
4.305 acres 6.0 1 17.0 A-2a 10.60
Design Runnoff Coefficient,C
0.50 6.0 Hardpan
Time of Concentration,Tc 2o.0 No Groundwater enccuntere
10 min
Pondrrmnch Summary Areas De ft I in81r Axl
Infiltration at Pond Bottom 7350 1.5 0.3 0.00
Infiltration Area of Trench 0 0.0 NA 0.00
Sand Window or Trench Bottom 7350 10.0 0.6 4410.00
L(Axl)= 4410.00 sf x iNhr
Ou = Outflow to Main Pond= 3.700 cfs Assume Constant for all storm durations after to
Qi= 4410 sf x inlhr x lhd 3600 sec x 1ft/l2in= 0.000 cfs Assume Constant for all storm durations after tc
Os= 7350 sf x 8 in01r x 11hr/3600sec x 1ft/12ln= 1.36 ds Assume Constant for all storm durations after tc
SECONDARY RUNOFF EVENT FREQUENCY: 100 PRIMARY RUNOFF EVENT FREQUENCY: 25
Duration(Mtn) I(in./hr) QdIda) Vnet Duration Min i(in.nlr) Odids) Vnet(cf)
10 3.11 6.695 2398.8 10 2.37 5.102 1122.8
15 2.62 5.640 2330.8 15 2.00 4.305 727.2
20 2.28 4.908 1935.2 20 1.67 3.595 0.0
25 2.02 4.348 1298.3 25 1." 3.100 0.0
30 1.82 3.918 523.4 30 1.39 2.992 0.0
35 1.50 3.229 0.0 35 1.14 2.454 0.0
40 1.37 2.949 0.0 40 1.05 2.260 0.0
45 1.26 2.712 0.0 45 0.97 2.088 0.0
50 1.17 2.519 0.0 50 0.90 1.937 0.0
55 1.15 2A76 0.0 55 0.88 1.894 0.0
60 1.15 2.476 0.0 60 0.88 1.894 0.0
120 0.66 1.421 0.0 120 0.50 1.076 0.0
180 0.48 1.033 0.0 180 0.37 0.796 0.0
360 0.30 0.646 0.0 360 0.23 0.495 0.0
720 0.19 1 0.409 0.0 720 0.15 0.323 0.0
1440 0,12 1 0.258 0.0 1440 0.09 0.194 0.0
SECONDARY CONVEYANCE FLOW RATE,Q100= 6.69 cis(at To)
PRIMARY CONVEYANCE FLOW RATE,Q25= 5.10 cis(at Tel
REQUIRED STORAGE VOLUME (Add 15
%For Sediment)= 2759 cf
VOLUME OF SUBSURFACE STORAGE= 0 cf
REQUIRED ABOVE SURFACE STORAGE VOLUME= 2759 cf
TIME OF INFILTRIATION INTO SUBSURFACE LAYER= 0 sec 4.00
TIME UNTIL NO VISIBLE WATER EXISTS AFTER
PRIMARY STORM= 349 sec= 0.10 hrs<48hrs O.K.
TIME OF UNTIL NO VISIBLE WATER EXISTS AFTER
SECONDARY STORM= 746 sec= 0.21 hrs<72hrs O.K.
DEPTH FROM BOTTOM OF FACILITY TO GROUNDWATER= 10.00 it ok
DEPTH FROM BOTTOM OF FACILITY TO BEDROCK= 20.00 it ok
Page 7
LEAV/TT 8 ASSOCIATES ENGINEERS, INC. roe: Teakwood Place
1324 tat Street South Joe HuaeeR: SD084.001
Nampa,Idaho 83651 onre: 1/20/2021
208/463-0333 Fl. : 10
Pond&Trench Size
Area 1
Total Required Storage Volume=2,759 cf
Infiltration Pond 1
Total Pond Length= ft. Top of Water Area= 3400 sf
Total Pond Width = ft. Bottom of Pond Area= 2371 sf
Water Depth=1.00 ft.
Side Slope= 3:1
Freeboard=6 in.
Pond Storage Volume= (Top of Pond Area+Bottom of Pond Area)12 x Water Depth
2,886 cf
SUBSURFACE STORAGE:
Sand Window Storage 1
Sand Window Area=0 ftsq.
Sand Window Depth=8.5 ft.
Void =25%
Sand Window Storage Volume= (Area x Depth x Void)
cf
Infiltration Trench 1
Freeboard=1.00 ft.
Trench Width= ft. Perimeter=0 ft.
Trench Length= ft. Area= ftsq.
Gravel Depth=0 ft. Void of Gravel =40%
Sand Depth=0.0 ft. Void of Sand=25%
Trench Storage Volume= (I;Area x Depth x Void)
cf
Total Above Surface Storage Volume= 2,886 cf
Total Subsurface Storage Volume= cf
Total Storage Volume= 2,886 cf >Required Volume,Dimensions Good!
Required Storage Volume= 2,759 cf
Summary of Infiltration Areas
Depth from
Area(sf) Grade(ft) Notes
Infiltration at Bottom of Pond 0 1.5 Does not include area of sand window or trench
Sidewall Infiltration (Includes Sand) NA 10 Area=213(Wall Depth x Perimeter)
Sand Window or Trench Area 7231 18.5
page
LEAVITT A ASSOCIATES ENGINEERS,INC. JOB: Teakwood Place
1324 1st SVeel South IJOB NUMBER: SD084.001
Nampa,Idaho 83651 IDATE, 120/2021
2081463-0333 FILE: 0
STORM RUNOFF CALCULATIONS-RATIONAL METHOD
POST-DEVELOPMENT FLOW
Storm Runoff for Soil Profile Test Pit# 1
Area 1 Depth(it) Class ca Inflllretion
Rate 1
0 to 4.0 C-i 0.25
Effective Area 4.0 6.0 B-2 10.50
4.305 acres &0 17.0 A-2a 10.60
Design Runnoff Coefficient,C
0.50 6.0 Hardpan
Time of Concentration,Tc 20.0 No Groundwater encounters
10 min
Pondrrrench Summary Area Depth ft 1 iNhr A x I
Infiltration at Pond Bottom 7231 1.5 0.3 0.00
Infiltration Area of Trench 0 0.0 NA 0.00
Sand Window or Trench Bottom 7231 10.0 0.5 3832.43
£(Ax))= 3832.43 sf x iNhr
Qu = Discharge flow, if allowed,see prederalompem fl 0.000 cis Assume Constant for all storm durations after tc
QI= 3832 of x in/hr x 1 hr/360D sec x 1fl/121n= 0.089 ats Assume Constant for all stomr durations after to
Qs= 7231 sf x 8 in/hr x lhr/3600sec x ift/12in= 1.34 cis Assume Constant for all storm durations aftertc
SECONDARY RUNOFF EVENT FREQUENCY: 100 PRIMARY RUNOFF EVENT FREQUENCY: 25
Duration(Min) I(In./hr) Qd(del Vnet(cq Duration(Min 1(in.mr) Qd cfa Vne[
10 3.11 6.695 5291.4 10 2.37 6.102 4015.4
15 2.62 5.640 6669.8 15 2.00 4.305 5066.2
20 2.28 4.908 7720.5 20 1.67 3.595 5616.9
25 2.02 4.348 8529.9 25 1.44 3.100 6029.7
30 1.82 3.918 9201.3 30 1.39 2.992 6977.0
35 1.50 3.229 8803.7 35 1.14 2.454 6631.1
40 1.37 2.949 9164.7 40 1.05 2.260 6957.7
45 1.26 2.712 9456.8 45 0.97 2.088 7206.6
50 1.17 2.519 9731.7 50 0,90 1.937 7403.9
55 1.15 2.476 1051 . 1 55 0.88 1.894 7954.6
60 1.15 2.476 11471.1 60 0.88 1.894 8677.8
120 0.66 1.421 12803.5 120 0.50 1.076 9492.9
180 0.48 1.033 13618.6 180 0.37 0.796 10204.5
360 0.30 0.646 16063.9 360 0.23 OA95 11718.8
720 0.19 0.409 18471.7 720 0.15 0.323 13505.8
1440 0.12 0.258 19562.7 1440 0.09 0.194 12113.9
SECONDARY CONVEYANCE FLOW RATE,Q100= 6.69 cis(at To)
PRIMARY CONVEYANCE FLOW RATE,Q25= 5.10 cfs(at To)
REQUIRED STORAGE VOLUME (Add 15
%For Sediment)= 22497 of
VOLUME OF SUBSURFACE STORAGE= 0of
REQUIRED ABOVE SURFACE STORAGE VOLUME= 22497 of
TIME OF INFILTRIATION INTO SUBSURFACE LAYER= 0 sec 4.00
TIME UNTIL NO VISIBLE WATER EXISTS AFTER
PRIMARY STORM= 11599 sec= 3.22 hs<48hrs O.K.
TIME OF UNTIL NO VISIBLE WATER EXISTS AFTER
SECONDARY STORM= 253593 sec= 70.44 hm<72hrs O.K.
DEPTH FROM BOTTOM OF FACILITY TO GROUNDWATER= 10.00 /t ok
DEPTH FROM BOTTOM OF FACILITY TO BEDROCK= 20.00 In ok
Page Cf
LEAVITT&ASSOCIATES ENGINEERS,INC. Joe: Teakwood Place
1324 tat Street South JOB NUMBER: SDO84.001
Nampa,Idaho 83651 onTe: 1I20/2021
208/463-0333 FILE: 10
Pond&Trench Size
Area 1
Total Required Storage Volume=22,497 cf
Infiltration Pond 1
Total Pond Length= ft. Top of Water Area= 8746 at
Total Pond Width = ft. Bottom of Pond Area= 7231 at
Water Depth=1.00 ft.
Side Slope= 3: 1
Freeboard=6 in.
Pond Storage Volume= (Top of Pond Area+Bottom of Pond Area)/2 x Water Depth
= 7,989 cf
SUBSURFACE STORAGE:
Sand Window Storage 1
Sand Window Area=7,231 ftsq.
Sand Window Depth=8.5 ft.
Void =25%
Sand Window Storage Volume= (Area x Depth x Void)
15,366 cf
Infiltration Trench 1
Freeboard=1.00 ft.
Trench Width= ft. Perimeter=0 ft.
Trench Length= ft. Area= ftsq.
Gravel Depth=0 ft. Void of Gravel =40%
Sand Depth=0.0 ft. Void of Sand=25%
Trench Storage Volume= (EArea x Depth x Void)
= cf
Total Above Surface Storage Volume= 7,989 cf
Total Subsurface Storage Volume= 15,366 cf
Total Storage Volume= 23,354 cf >Required Volume,Dimensions Good!
Required Storage Volume= 22,497 cf
Summary of Infiltration Areas
Depth from
Area(so Grade(ft) Notes
Infiltration at Bottom of Pond 0 1.5 Does not include area of sand window or trench
Sidewall Infiltration (Includes Sand) NA 10 Area=2/3(Wall Depth x Perimeter)
Sand Window or Trench Area 7231 18.5
Page )jf
LEA VITT B ASSOCIATES ENGINEERS,INC. .ae: Teakwood Place
1324 1st Street South .roaauaeea: 5D084.001
Nampa,Idaho 83651 IMM 1/20/2021
2081463-0333 Fos: 10
Roe Smne
Pipe Flow Capacity
Velocity,v=1.486/n'R�'&10
n=Mannings coefficient for roughness=0.009 for PVC
R=Hydraulic radius=Cross-sectional Area/Wetted Perimeter
s=minimum slope
Mm.Flow=Qma =Velocity•Area
Pipe Size
(in) R(ft) s(%) V(ft/sec) Qm cfs
12 0.250 0.25 3.28 2.57
12 0.250 0.55 4.86 3.82
18 0.375 0.22 4.03 7.12
21 0.438 0.22 4.46 10.74
24 0.5 0.22 4.88 15.33
Summary of Pipe Flows
Q25 %or a Allowable Pipe
Area#Pi # (CIS) sl % flow Gs Size in
TO Foreba all 5.10 50% 2.55 12 0.25%Slope
TO Pantl all 3.70 100% 3.70 12 0.55%Slope
an
all
aft
ell
Page �)
LEA VITT&ASSOCIATES ENGINEERS, INC. JOB: ITeakwood Place
1324 1st Street South IJOBNUMBMISDO84.001
Nampa, Idaho 83651 DATE: 1/2 012 0 21
2081463-0333 FILE: 10
SAND&GREASE TRAP
SAND & GREASE TRAP DESIGN
NM
� H .
Sand & Grease Trap Capacity
z_ WT T
Design Criterion B�W' vro Wru-r
Maximum Throat Velocity,V..= 0.5 ft EL
/s acv a now
EV A �
�IC1
Equations '
NN°BVELBV C
Q,iim,.,d based on Velocity=Vma,*A,
Qmia„ad based on Residency Time=Vollt SECTION
NTY--
Dimensions of Amcor Product Q allowed
Baffle Based on Based on
AverageWi Height Throat Area,At Retention Vmax ACHD
Size allons Baffle Spacing in dth ft Lenth(ft) (ft) (ft) Times ofs (ds) Q max ds
1000 20 4.25 5.041 3.92 7.08 25.22 3.54 3.33 3.33
1500 21 5.25 4.041 4.92 9.19 25.15 4.59 4.15 4.15
025 S&G Trap %of Number of S&G Required
Area# (ds) Used(Y/N) flow O Traps Required Size(gallons) Qjw B ass
1 5.10 Y 50% 2.65 1 1000 6.69 Yes
"signifies Q2 was used for design
Pa#a /L
LEAVITT S ASSOCIATES ENGINEERS,INC. JOB: Teakwood PMpa
132a 1at5treel South JOBNumli SDOBs.001
Nampa,Idaho M51 DATE: 1GQ2021
201VB 0333 FlLE: Ism
FLOW IN GUTTER
L= D
D.dt
D=D•IT
REF:
laard,C.F. 'Tentative
Results an Capacity of Curb C= J-E - o IAOCFm VaRNING EQUATION
Opening Inlets,-Research _
report no.11.0 on surface ---- --- ---- -- -- —_-
Unit Conversion 0.560
Mannings Number,n= 0.016
Cross Slope,tiz= 0.020
Inseam Double:
Type of Street Loral Street
Min.Slope of Clunnel: OA%
Road Width(TEC): 65n
Flow Summary.Primary Systems
Cause Criteria
Number Clear Lanes Required:2
Vvdh of Clear Lane Required: O0
Mix Daplh M Ropmay Crown:2 in
Maximum Velocity 5fps
025M
L=(DOO Depth at Gutted Depth at Crown Velouly Clear Lane Wirth
Area• (es) (a) (In) on) (Ips) (6)
TO Fonts 5.10 Ise 3.70 0.00 2.05 33.5 okay
Flow Summary.Secondary Systems
Deafen Cross,
Max Depth at Gabor Flow Line:12 in
Max Depth at Roadway Crown:6 in
Maximum Velocity 8fps
TO F Q100 %niv L=(D/z Depthat Gutlu Dsphat Cravm Velog y
Area# (on) t num afood (it) (n) (,a) (fps)
probe 6.69 17.48 9.18 0.00 2.20 Okay
PAGE j
LEAVITT A ASSOCIATES ENGINEERS,INC. ljoe. Mossy Creek
1324 1st Street South lJOBNUMBIMISDO82.01
Nampa,Idaho 83651 JDAi 1/20/2021
2081463-0333 lFam [Mossy creek Stormwater.xls
Pipe SI9np
Weir Flow Capacity
Velocity,v=1.486/n•R' sla
n=Mannings coefficient for roughness=0.013 for wncrete
R=Hydraulic radius=Cross-sectional Area/Wetted Perimeter
s=minimum slope
Max.Flow=Q,,,,=Velocity•Area
Pipe Size V
(in) I WP I A R(R) I s(%) I(If/sec) s
1.5 2.625 0.8438 0.321 1.6 5.781P5.72
Summary of Weir Flows
25 yr %of Q Number
Area#pl # als flow crs Weirs
1 all 6.69 100% 6.69 2
all 100% 0.00 0
all 100% 0.00 0
all 100% 0.00 0
all 100% 0.00 a
all 100% 0.00 0