HomeMy WebLinkAbout013 Stormwater Management Design Report STORMWATER MANAGEMENT
DESIGN REPORT
FOR:
AUTUMN GROVE CONDOMINIUM
LOT 5 BLOCK 2
WEST WINDS SUBDIVSION PH 5
BOZEMAN, MT
Prepared By:
MADISON
ENGINEERING
Madison Engineering
895 Technology Drive, Suite 203
Bozeman, MT 59718
(406) 586-0262
DECEMBER 2021
STORMWATER MANAGEMENT
DESIGN REPORT
FOR:
AUTUMN GROVE CONDOMINIUM
LOT 5 BLOCK 2
WEST WINDS SUBDIVSION PH 5
BOZEMAN, MT
Madison Engineering
895 Technology Blvd Ste 203
Bozeman, MT 59718
(406) 586-0262
o .'•GHHIS G.•'•
' BL'GFSI�! •
No i0 25PE - w:
DECEMBER 2021 , ENS��• ��
AUTUMN GROVE CONDOMINIUM
LOT 5 BLOCK 2 WEST WINDS SUB PH 5
STORMWATER DESIGN REPORT
A. Introduction
This design report will give an overview of the proposed stormwater system for the proposed 5-
acre site plan for `Autumn Grove Condominium' located on Davis Lane and Autumn Grove
Street in Bozeman, Montana.
The proposed multi-unit, multi-story residential condominium development will be constructed
in multiple phases on R-3 (Residential Medium-Density District) zoned property and consists of
5 — Tri-Plexes and 8 — Four Plexes, with associated on-site drive aisles, driveways, pedestrian
walkways, parking, and landscaping. Open space will be provided by ground level private
outdoor space which will be adjacent and directly accessible to the subject unit.
The proposed storm water management system consists of overland sheet flow, curb & gutter
and piping that will direct stormwater to on site ADS Stormtech SC-740 retention/infiltration
basins to serve the site. Off-site discharge is not proposed. The infiltration basins will be
excavated to native gravels to permit maximum infiltration.
The following references were used in the preparation of this report:
a. COB Design Standards and Specifications Policy, 2004. Addendum#7
b. COB Modifications to Montana Public Works Standard Specifications (MPWSS)
The proposed drainage and grading plan and ADS Stormtech basin detail are included in
Appendix A of this report.
B. Runoff and Basin Calculation
A 10-year, 2-hour design rainfall frequency was used for calculating the basin sizing utilizing the
rational method in accordance with the COB design standards. A runoff coefficient C of 0.90
was used for impervious areas and a C value of 0.20 was used for landscaped areas. The tables
below illustrate the calculated runoff coefficients and areas for each as well as a summary of the
stormwater basin calculations.
Page 1 of 3
Table 1: Stormwater Basin Run-Off Area & Coefficient
Total Area Impervious Landscaped
Basin Weighted C (sf) Area (sf) Area (sf)
A 0.68 143,630 97,466 46,164
B 0.58 74,435 40,515 33,919
Table 2: Stormwater Basin Calculations
Basin Required Provided
Storage (cf) Storage (cf)
A 6,570 6,896
B 2,931 3,101
C. Native Soils and Groundwater Data
Soils on the subject property are typical for the area and are detailed in Appendix A — On-Site
Exploration Logs section of the Geotechnical Report prepared by Allied Engineering. Native
Sandy Gravels are 4'-6' in depth, overlain with native silty clays. The nearest off site Test Pit to
this site is Test Pit #23. Both ADS Stormtech SC-740 infiltration systems consisting of oversize
cobbles should be excavated to native gravels to permit maximum infiltration of stormwater.
Backfill above the ADS chambers to consist of clean, crushed angular stone and well-graded
aggregate mixtures.
Groundwater depths were observed and recorded during the peak high ground water in June and
July of 2021. Groundwater depths were measured in on site monitoring well #4 (Basin A)
ranged in depth between 3.48 — 5.0 feet below the existing ground surface (4729.74 — 4728.22).
Groundwater depths in on site monitoring well #1 (Basin B) ranged in depth between 5.72—7.55
feet below the existing ground surface (4731.89 — 4730.06). Elevation of bottom of basin
gravels in Basins A & B are 4730.0 and 4732.0 respectively. These test pits are located at or near
the proposed underground stormwater basins. Groundwater information is included in Appendix
B of this report.
D. Conveyance Capacity
The proposed private stormwater collection and retention/infiltration systems were designed to
convey the 25-year storm event per the City of Bozeman standards. The conveyance structures
include piping that directs stormwater run-off to the on-site infiltration basins. Twelve-inch
storm sewer and catch basins are proposed to collect and convey the stormwater run-off from
Basins A & B to the retention/infiltration basins. Stormwater piping calculations are included in
Appendix C of this report.
E. Stormwater Retention/Infiltration Basin
Page 2 of 3
All of the stormwater runoff from the site is proposed to be conveyed to on-site
retention/infiltration basins and ultimately infiltrate into native gravels. Subsurface ADS
infiltration chambers are proposed for this project. Stormwater calculations are included in
Appendix C of this report.
Table 3 below shows the finished grade elevations of each ADS infiltrator basin and the depth to
the bottom of gravel for each basin.
Table 3: Groundwater Depth vs. Proposed FG Elevations
Basin A Basin B
TP 4 TP1
Existing Ground Elevation: 4733.0 4736.5
Average Depth to Peak Groundwater: 4.3 6.5
Elevation of High Groundwater: 4729.74 4730.06
Proposed Finish Surface Grade: 4735.0 4736.25
Bottom of ADS Basin Gravel Elevation: 4730.0 4732.0
Bottom of Basin Gravel Above High Groundwater Yes Yes
As shown in Table 3 there is adequate separation between the bottom of the basin gravels and the
estimated seasonally high groundwater.
The retention storage volumes were sized based on the 10-year 2-hour design rainfall frequency
per the City Design Standards. The rational method was used to determine post-development
stormwater flows. The calculations for all stormwater storage facilities are included in Appendix
C of this report. The proposed stormwater facilities reduce the post-development runoff rate to
zero. All impervious surface runoff is conveyed to the infiltration retention systems and then
infiltrates into the ground.
F. Stormwater Facility Maintenance
The proposed storm drainage facilities will be privately operated and maintained by the property
owners association of the on-site development. Included in Appendix D is a proposed
maintenance program for the stormwater collection and infiltration systems as well as the O&M
Manual for the ADS StormTech system..
Appendices
A. Drawings and Details
B. Groundwater Monitoring Data
C. Stormwater Calculations and ADS Stormtech SC-740 Chamber Design
D. Stormwater Maintenance Plan
Page 3 of 3
Appendices
Appendix A — Drawings and Details
�ld � h �
STM, INLET 11C470
IE OUT 4728 7'(W
It IN 4728.6'(N) z
STM. INLET NG469 #
IE OUT 7,6' aS
IE IN 472727 5' (E)E)
1 > >
3 3 3 3 3 ; 3 V'• SCALE
SAN MH pG46B > >_ > > > 4r' 0
IE OUT 4723.T (N) _ 0 0 o re && " •
LOT 4 IE IN 4723.8• (E)
W W lo* - W. W W W W W - - W IY VY W W w W W 7 h.&- 30
OPEN I (2)REBAR WITH HKM PLASTIC I I - J 4155 EXTG'ADA _ +'
SPACE CAPS, 010' APART, ACCEPTED TBC- END CRIB 5 S 7L S S L�S AUTUMN GROVE s 5 S S 3 �-S -5
xx RAMPS
PUBLIC I 14E STERLY PIN BASED ON I t 4735.26 ji,♦ Jl q7]]� STRM �t �-
ACCESS POSITION TBC- END CRB _ S7111 I/gET,�G473
4735.13 IE OEfT g3G.5'(E)
UP
J4
473e. GRO BRK 7 1 -
- 1- 47J5.27 `• - - (- 47iq s
FINISH E e•CONC. t e•COW- 'L• \ 6'cow_ e•fONL
FLOOR 1{ oc SATs s7Trs STEPS STEPSmns t
-it
- ELEVATION I 4735.0 FIIVISH FLOOR FINISH FLOOR 02 FINISH FLOOR < yTrmo
'` 4736.SS f ELEVATION ELEVATION ELEVATION
47366 47360Tw 4735.S
o r
gB• C. .+ _ _
Tec - -
447735.92 . Y 73B 7J� 73+ 73` a►o' 7>s DRAWN BY:CGB
L: 135J8' ,
R: 1152 00' 4737.5 Jam_ (9 TBC ( REVIEWED BY:DAC
TBC-DRP CBS '� I PROJECT ENGINEER:COD
A 6*45'11" I 4736.0 7 733, BRPVC
7 -473J.9
CB: N 04'16'3B'E 738. 73B DRP CIja P B
CH: 1JSJ0' DESIGNED 6Y:CG
O��J 7 - 4•
\ "p' ]P. I _ 4736. 71i TBC 35. STEPS D 3
,4737. 73a.' \730. 473e•.OgTBC 35.26 ' E 4I
- -_ '-t- .� FINISH
47 .3 , 737 i s r 4734.8 .T ^ a TBC 35.26 35. P / ELEVATION SIN. INLET dG975
c IE CUT 47„0 9'(N)
�\ > \ C; FIIQISH FLOOR ` - FINIM FLOOR 1 \
\ , s}rEBPs srTps SiErs A T ELEVATION ELEVATION , 4737.1 3I E IN 4731 0(S)
473 T'-- 9.25 4737.43
r�
.7 STEPS FINMHFLOOR '. �1i 0�� \ - �ti UNONROTOGAS F
! _ CONDUwdRIT
&GAS
{ pQ ELEVATION _ - CON SUIT STUB ~.
1 �f 4740.25 7HC yI� 6 B STEPS
B B B stFps
4738.07; 11 I - \`\ TBC / `u51EP5 C 7aB�
a w 35.2r9C 3520 -I O
L. 74.✓ R: 30.00'\77
f TBC 1 N _ A 13*0610"
4739.E Tom• - - Y T3- " 35.34 �•' I vv CB: N)16-52'59•W
w CRe w - THC - w -w w -w w -w N w -r w O a
(J CH: 74.�3'
+ 7,}0. T3Y -TBC - 4737.E 7J7 7.14 , 73# TBC a� .j ,� TBC7 END CRB
it ,1,P 740. 3 47389 _ 5 5 5 0� 38.0 TBC 36.3 ! 1 I 4737.4 N
' OfleSRB _.CRB__-- � 1HC I
Q A
TBC o - a40. .�. ! -- _. P •jp.•- _1 'r` M30
3740,81 4741. WAY Fi)
1 FINISH FLOOR v FINISH FLOOR �^ FE M FLOOR FINISH FLOOR FINISH FLOOR I 1
`p f ELEVATION ` ELEVATION ELEVATION ELEVATION ELEVATION a TBC- END CRB-SAN MH NG476 11-�
y( X 4741.9 4741.0 `a , 4739.1 47383 14737.67 1�4
4738.0 PIPE DIRECTION IN
Q O I 3-5' -_` -- _�) - _`0 NOTES DON'T MATCH
y y. 7A N BOZEM AN G15,NEED TO
C ¢ TBC ! • VERIFY
Tric
61 CONC 8'CONC Y 0•CONC, B•CONC B'CONC - B'CONO- B'CDNC 36.9
STEPS SEEPS / SEEPS STEPS STEPS STEPS ;TIPS / �.1 :b
\ 1 o
- I o
5 IN
LET OG477
- IF
I I I I I I 1 I 1 I I
T 4733 9'(E)
1 1 I I 1 I
BENT AIT _-
AR LAID
- --_ _y _-___-9]3]-- _-_--- -T-----�-_-: 9EVTY-
VER
���� �. -4738
L: 73.25' R: 723.00',_4742 ��'- -PUBLIePARB--'--__-_-_-477e-_
_A 5,48,18" ---�
1 CB: S O4.20'25' W I -� -I _ \ 1' 1 1 0-4 (NcJ
REBAR
I TION eq
iRR %, CONTROL BOX
ROL BOX / { STM.INLET#G483 I1\ IRRIGaTICN � '' I�•I
IF IE OUT
� M
o
SAN MH 1Y ,W' 14 11 W-_--�-w W N 'N IN - w ��-W W - r FLOWIINE EL 0' V H N v
ays •�, - 'AN-�1H A w v w W W -w w w W w .w v a p
NSW)
T7 �UT
STM. INLET#Ga90 7 ( O
' s s\ s s Q -'s s s�^c�--is iE�rsszs(W) s s - s s z s s s Ch u
�TI % WINTER PARR STREET *-SAN M H 3 3
FLOWUNE
3 SAN. MH 3 3 34734.J N j> 3 SAN MN pG4Bl ¢ V, l4'BS
I` - FLOWL NE EL 3 STM INLET PI-,tgp S'4 MN �G46a
I G487 > &03 4732.9' IE IN +'34.� (Wj IE Ou1 4133-9'(E) i
o FLOWLINE Eh o 0 0 o It OUT 4734.4'(E) IE IN 47341•(W) u $HEEj'
SIN. MH ,yG4B4 1 4735.8 Q WATER PIPES COVERED W/ IF IN 4732 54(W) Y C1•2
IE IN 4732.8'(S) 2 AUTUMN GROVE
IE OUT 4732 5-(E)
GRADING PLAN
R PROJECT:21-104
DATE:DECEMBER 2021
STY- INLET#C47C
IF OUT 4728,7'(W)
IE IN 4728.6'(N)
STM INLET#G469 9
IE OUT 4727.6' (N)
IE IN 4727 5' (E)
3 3 3 < > }
3 2 vV SCAMSAN MH pG468 3 M
IF (E)our 4723.T (N) - ` o 0 0 0 0 LOT 4 I ,8'E IN 4723 8
o
w w �►f --w w ow w l-- w w w � w w w w -w w �w N -v�I�N 1�- w
OPEN ( (2)REBAR WITH HKM PLASTIC I 3
SPACE CAPS, 010'APART, ACCEPTED 5� S s S s 1. 5 -A -gj3 E%TG'ADA _
PUBLIC I WESTERLY PIN BASED ON I N / Q S S �- S -S RAMPS
ACCESS POSITION
STM- INLET,yG473
24" DIA AREA DRAIN I' IE OUTi730.5'(E)
III \ J ��ir1�}�• GRATE I 4735.4 •• - r -INV IN 4733.8.
® UP UP L' IJ lIP UP
ADS STORMTECH SC-740
CHAMBER-WEST
RETENTION/INFILTRATION BASIN. ADS STORMTECH
BOTTOM OF CHAMBER 4732,5 1 ---•a 1 c SC-740 CHAMBER
BOTTOM OF GRAVEL: 4732,5 FLOORFEqmH 1 ! ` �4
I ,I BASIN RETENTION/INFILTRATION- EAST
ELEVATION FIIVISH FLOOR FIIdISH FLOOR , \ ( to BOTTOMOF CHAMBER: 47B31.0
I- 47568$ ELEVATION ELEVATION PINISIIFioOR�" NYLOPLASF BOTTOM OF GRAVEL: 4730.0K
- I ELEVATION DRAIN BASIN 7 F} 4J r I '
\V NYLOPLAST F 4736.E 4736.0 �ttiti 1 473$.$ GRATE 47J3,6' f--k-f/II ()�
DRAIN BASIN -AREA DRAIN \ J IN1V IN 4737.9 \
GRATE 4736.2 GRATE 4134.9 •�
INV OUT 4733.9
1-- 12•ADS SD
INV IN 4733-4 � � ! \ I � - S=2.OS.
1 �. /^II •n •,, .�.- .. DRAWN BY:CGB
V 12'ADS SD l I - -8"ADS SD r'I 7
L: 1JSJB' S=0.46% S=1.OX z REVIEWED BY:DAD
R: 1152.0C' - '
A 6'45'11" 24" DIA AREA DRNN �- 16•WIDE CURB I, PROJECT ENGINEER:CGB
GRATE 473Z1 CUT G.C. 47J4.8. ti ° I ,IA �y\y
CB: N 04'16.38'•E 24"SO AREA DRAIN
CH: 135.70' INV THRU 4733.6E GRATE 4733.8 7 DESIGNED BY:CGB
INV OUT 4732 0
3
r12.5 05 SID46x I 1 f •�, 'V + . FLOOR�R 3I INLET NG475
NL EATION T 4730.9'(N)
47371ELEVATION ELEVATON r IE IN4731 D(S)
4737.45 UND�'.ROUND F f FIIV SH FLOOR 5- 111111���
J ELEVATION \ Y --- CCOONDUI TSIUB I"
474025 I - I .n_e O
10'
�I\€v CB:
1 �'W�_ - , b\ W W W W W W W W W W� W- W NI CH: 77'
W W W f
5 S ! S S S S --S- S --S I I P l 3 NW W W
•.1� l P - UP -' r 1J4 - .UP P UP 4' :11' - Ud-"�.II C' -'.IJ /
�_ WND WAY O
!I FIIQI9H FLOOR FINISH FLOOR \� FEVISH FLOOR r
s FDMH FLOOR FEVIHH FLIMR � l i 3
ELEVATION ELEVATION ELEVATION A EI.EVAnON ELEVATION _ r vv
4741.9 4741.0 47391 4738$ us SAN, IR CTION / A
_ 47�.0 _ I PIPE DIRECTION IN I�4 a �
NOTES DON'T MATCH 5
BOZEMAN GIS,NEED TO ("I
VERIFY Frrl
_ - S INLET IG477 F--1
BENT R AR IF T 4733.9'(E) 1��1
HEBAR LAID __ _ _ 24' WIDE GRAVEL 24"WIDE GRAVEL _4737-_ 24"WIDE GRAVEL
6\pR -INFILTRATION BASIN - INFILTRATION BASIN --�1 1 - I. -INFILTRATION_BASIN __---- -,---� SENT
723.00' -4742-'- y --__ �i ✓s ' �y v
_ \ �_PLTELW-PARK----_-- --4139---
L: 73.25'R:
` CB: S 04'20'25" W
N
\ / CCNI
RlrGOLO BOX // - } _STM INLET NG483 i/ FIRRIIA BOX
I � ~ ra Gr N
IE OUT 4735.6'(S) CCNTR (� T.
04A
SAN MH JG478 z O
-11 W ��:V W -w �- W \y y�r .. 1V W W LV W W W�K�w 1Y 1V - 1 A- -♦�,f0 FLOW'LINE EL 47320' n O v
S� s s 's\ s s bb-5 s 5 -si ;'s E_4735_25(1-STM. INLET 4)49D s S s s �,• S s s (NSW) y Q
r WIIVIER PARK SIRRBBCc IE UT i R {�
JAN. MH 3 JE T T IrA�'I F
3 3 Y �1
f Iv% FLOWLIIN El\ ! � iJ
> I #G48 MH 3 a j4734.5' v >'< 3 sAFLOWLINE EL ` ' vt p
3 STM INLET G490 STM, MH G480
> 47329' > -IE IN 4734,5'(W) IE OUT 4733.9'(E)
o FLOWL NE Eg a p ST ,, MH 'G4B43 o IE OUT 4734.4'(E) IE IN 4734.1'(W) gSHEffr
4735.8 ®Q PIPES COVERED W/ S;LV. MH #'G479 Cy.3
WATER IE N 47325'(W) Z 1
IE IN 4732:8'(S) AUTUMN GROVE
IF OUT 4732.5'(E)
DRAINAGE PLAN
tgj PROJECT•21-104
4 DATE:DECEMBER 2021
Appendix B — Soil Data and Groundwater
Monitoring Data
Soils Investigation Report
_ z
-
-
-
------- ------ lar,av Rr -- -
I I
►Jr tr.o � ,, n.0 I
�1 I TM I I ,e►.
,� I Tnze
�.sa n-zz- T►1 TP•u---TI-a) ' _— -— e„p.
vs,,.
ar
TM:1 pry LEGEND
K I el RT
" ' 7.9 TMfe TEST PIT LOCATION W/
f f f GROUNDWATER DEPTH(BGS)
(DURING TEST PIT EXCAVATION,
_ _ I AND SHALLOWEST MEASUREMENTS IN
I GROUNDWATER MONITORING WELLS)
NOTES:
1) TEST PITS#1-#8 WERE EXCAVATED ON FEBRUARY 12,2016
+ AND EACH CONTAIN GROUNDWATER MONITORING WELLS.
Rr :-- -_-. I- p'-- - 1K1 - 2) TEST PITS#9-#33 WERE EXCAVATED ON MARCH 23 AND
' J.R1 MARCH 24,2016 AND DO NOT CONTAIN MONITORING WELLS
--_`V. 3) TO DATE, THE SHALLOWEST MEASUREMENTS IN THE
j I GROUNDWATER MONITORING WELLS WERE RECORDED ON
I _ APRIL 8,2016.
r r 4) THE DEPTHS OF MW-1 AND MW-5 ARE 8.7'AND 9.6-BELOW
GROUND, RESPECTIVELY. GROUNDWATER HAS NOT YET
RISEN INTO THESE WELLS.THEREFORE, THE WELLS ARE
LISTED AS BEING DRY.
• —--� r -`ma's ----�'�, —- _— _�.�_ _I_ --r•;-'1'.;_..�-- .
5) TEST PITS#22-#33 WERE DUG TO A SHALLOW DEPTH AND
9� DID NOT ENCOUNTER GROUNDWATER-THEREFORE, THEY
ARE LISTED AS BEING DRY.
III
WEST WINDS DEVELOPMENT ,�a„ r„,• FTCLRF
soawu ur uin, I CIWI&rglncertng `.
GROUNDWATER DEPTH Geotec4n7cal Erylnowfng
ni A07.EMANr MONTANA Land Surveying
=�isw'erroovo 34 F- W TEST PIT DESIGNATION: TP-23 LOCATION: South Side of Pond
CivH F.ogmtering Z (Ll
Bozeman.MT 59718 `.1
q M. !- GeoteehviwEnginerring Phone,(40°)582.0221 3 z a 0. HORIZONTAL DISTANCE(FT): (See Figures 4,5,&6 for Approximate Location)
Lane Surveying Fa:(4a6)582-5770 o 2 4 6 8 10
1
DESCRIPTION OF MATERIALS Q A 4 A m Q A o Q
o. o. a. o. o. o. o_ � : .• o. •. o. • . o. o.
Q: Q•. Q: Q: Q: Q: . .
p Q' p Q 'p Q'' Q'� Q''� The random fill in TP-23 was
O{0.0'-0.2'}: Organic Fill �cia' �O.' ��a. �d ' Ada' a mixture of brown and black
Medium stiff,dark brown;organic AQ. Qp. Q4. Q. po Via•
clayey SILT w/abundant roots and Q' " Q o. Q: ..o. Q: .•o. Q: . Q: silt/clay w/scattered gravels •o
Q p 'Q •� Q•:p Q .� Q .� and some intermixed topsoil. 1 .
scattered gravels;moist. 2 F
Notes:
-Fill is comprised of poor topsoil. 3
O{0.2'-2.5'}: Random Fill - _ _ ,�_�
Med.stiff to stiff, brown and black; - - - -` -��"- "Target"foundation bearing in
sandy SILT to sandy lean CLAY w/ 4 - - - - - -� -� sandy GRAVEL below 4.5'depth.
scattered gravels and some inter- w �o - ° -. ° _. ° -
mixed topsoil;moist to very moist. ° ° ° 0 0 °o o e ° o ° G°o ° ° 0 ° °° o° ° D o C
Notes: O v ° D Q ° Oo D O ° v v D p ° v °
-Fill is comprised of silt/clay w/ �° ° °°° a o�° °� �° °°° p°o ° o` °
P y O ° ,
scattered gravels. It is a mixture 6 ° ° ° O 0 ° ° ° ° ° o 0 ° ° O
of brown and black.
-Fill is very moist.
O{2.5'-3.0'}: Native Topsoil
Stiff;black to dark brown; organic
clayey SILT w/abundant roots; 8
moist.
0{3.0'-4.5'}: Native Silt/Clay
Very stiff to stiff,dark brown to ;0
brown;sandy SILT to sandy lean a DESCRIPTION OF MATERIALS(cont.): t9
CLAY;moist. 4'
10 O 14.5'-6.0'}: Native Sandy Gravel
j Dense; brown;sandy GRAVEL w/
Notes: a
-Vuggy appearance(pin holes). abundant gravels&cobbles;moist.
-Stiff to very stiff throughout depth.
-Becomes little more moist w/depth. Notes;
c -"Clean"sandy gravel.
-Lower 1.0 contains some gravels. Z _"Target"bearing material. rn
-Unsuitable bearing material. 12 W
SURFACE ELEVATION: N/A BACKHOE TYPE: Cat 312 Excavator JOB NUMBER: 16-003
TOTAL DEPTH: 6.0' BACKHOE OPERATOR: Brynn Harris-Townsend Backhoe PROJECT: West Winds Dev.
GROUNDWATER: Dry (on 3/24/16) LOGGED BY. Lee S.Evans-AESI DATE: March 24,2016
Groundwater Monitoring Data
IS.
-- -- - i- j, - •
Paoli
gig
■-r rr t' .
- Yr'
S
tP
Googl Earth N
,; 300 t
Autumn Grove
Lot 5 Block 2 West Winds Subdivsion PH 5
Groundwater Monitoring Summary
Top of Grnd 6/23/2021 7/2/2021 7/9/2021 7/16/2021 7/22/2021
Monitoring Pipe Top of Casing Elevation I Depth of Depth of Depth of I Depth of I Depth of
Well Elevation to Ground(ft) @ Pi a Measured GW Grndwtr Measured GW Grndwtr Measured GW Grndwtr Measured GW Grndwtr Measured GW Grndwtr
1 4738.78 1.17 4737.61 8.65 4730.13 7.48 8.72 4730.06 7.55 6.98 4731.80 5.81 6.89 4731.89 5.72 6.92 4731.86 5.75
2 4741.92 0.92 4741.00 9.57 4732.35 8.65 9.80 4732.12 8.88 7.02 4734.90 6.10 7.00 4734.92 6.08 7.07 4734.85 6.15
3 4739.23 3.58 4735.65 7.77 4731.46 4.19 8.20 4731.03 4.62 7.96 4731.27 4.38 7.76 4731.47 4.18 7.59 4731.64 4.01
4 4736.22 3.00 4733.22 6.48 4729.74 3.48 6.82 4729.40 3.82 8.00 4728.22 5.00 7.70 4728.52 4.70 7.38 4728.84 4.38
5 4738.93 2.75 4736.18 9.23 4729.70 6.48 9.41 4729.52 6.66 1 8.62 1 4730.31 1 5.87 8.21 4730.72 5.46 8.27 4730.66 5.52
Appendix C — Stormwater Calculations
and ADS Storm Chamber Design
Pipe Capacity Calculations
Autumn Grove
25 year Storm Event
Stormwater Run-off Calculation
Design Rainfall Freq. 25 year
IDF coefficient a 0.78
IDF coefficient b
IDF coefficient n 0.64
Basin A
Post-development Calculations
- C
Areas (ft): Landscape 46,164 0.20
Impervious 97,466 0.90
Total: 143,630
total area: 3.30 acres
composite C: 0.68
Overland t,
average slope: 1.6 percent
travel distance: 230 feet
tc: 10 minutes
Total k: 10 minutes
intensity at tc(fig 23): 2.41 in/hr
pre-devel peak runoff: 5.36 cfs
Basin B
Post-development CaICUlationS
C
Areas(ft): Landscape 33,919 0.20
Impervious 40,515 0.90
Total: 74,434
total area: 1 71 acres
composite C: 0.58
Overland t,
average slope: 1.85 percent
travel distance: 230 feet
tc: 12 minutes
Total k: 12 minutes
intensity at t,(fig 23): 2.19 in/hr
pre-devel peak runoff: 2.17 cfs
Storm Runoff Calculation-25 year event.xls
12"PVC Appendix C
Checked at slope=0.46%
CIRCULAR CHANNEL
T
Manning's Eqn. Q= 1.486 A RV3 S1n
n
Diameter,do(in)= 12 4-Enter Value
Diameter,do(ft)= 1
THETA
Units= 1.486
n= 0.013
Slope,S(ft/ft) 0.0046
Wetted Hydraulic Hydraulic 58ctlOn Energy,IE
Area,A Perimeter,P Radius,R Top Width,T Depth,D Factor,Z Q(gpd-8 =V=/2g
Dep)h,y(it) Theta(red) (it') (it) (ft) (ft) (ft) (ft"*) Q(cfs) Q(gpm) hourday) V(ft/s) (ft)
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00
0.05 0.90 0.01 0.45 0.03 0.44 0.03 0.00 0.0 5.2 24997 0.8 0.01
0.10 1.29 0.04 0.64 0.06 0.60 0.07 0.01 0.1 22,6 108680 1.2 0.02
0.15 1.59 0.07 0.80 0.09 0.71 0.10 0.02 0.1 52,7 25303.7 1.6 0.04
0.20 1.85 0.11 0.93 0.12 0.80 0.14 0.04 0.2 95.0 45585.5 1.9 0.06
0.25 2.09 0.15 1.05 0.15 0.87 0.18 0.06 0.3 148.6 71306.3 2.2 0.07
0.30 2.32 0.20 1.16 0.17 0.92 0.22 0.09 0.6 212.4 101940.5 2.4 0.09
0.35 2.63 0.24 1.27 0.19 0.95 0.26 0.12 0.6 285.2 136874.1 2.6 0.10
0.40 2.74 0.29 1.37 0.21 0.98 0.30 0.16 0.8 365.5 175420.0 2.8 0.12
0.45 2.94 0.34 1.47 0.23 0.99 0.34 0.20 1.0 451.7 216825.6 2.9 0.13
0.50 3.14 0.39 1.57 0.25 1.00 0.39 0.25 1.2 542.2 260276.5 3.1 0.15
0.55 3.34 0.44 1.67 0.26 0.99 0.44 0.30 1 A 635.2 304893.6 3.2 0.16
0.60 3.64 0.49 1.77 0.28 0.98 0.50 0.35 1.8 728.6 349728.5 3.3 0.17
0.65 3.75 0.54 1.88 0.29 0.95 0.67 0.41 1.8 820.3 393750.7 3.4 0.18
0.70 3.96 0.59 1.98 0.30 0.92 0.64 0.47 2.0 908.0 435826.6 3.4 0.18
0.75 4.19 0.63 2.09 0.30 0.87 0.73 0.64 2.2 988-9 474680.7 3.5 0.19
0.80 4.43 0.67 2.21 0.30 0.80 0.84 0.62 2.4 1060.0 508823.4 3.5 0.19
0.85 4.69 0.71 2.35 0.30 0.71 1.00 0.71 2.5 1117.5 536398.9 3.5 0.19
0.90 5.00 0.74 2.50 0.30 0.60 1.24 0.83 2.6 1155.8 554804.1 3.5 0.19
0.95 5.38 0.77 2.69 0.29 0.44 1.77 1.02 2.8 1165.3 5593418 3.4 0.18
1.00 6.28 0.79 3.14 0.26 0.00 ?.4 1084.9 520729.1 3.1 0.15
40
35
3,0
25
20
i
-E(ft) /
15
10
0.5 /
0.0
0.00 0.20 0.40 0.60 0.80 1.00 1.20
Depth(ft)
12"PVC Appendix C
Checked at slope=2.0%
CIRCULAR CHANNEL
- T
Manning's Eqn. Q=1.486 A R as S112
n
Diameter,do(in)= 12 All-Enter Value
Diameter,do(ft)= 1
TFIETi,
Units= 1.486
n= 0.013
Slope,S(ft/ft) 0.02
Wetted Hydraulic Hydraulic Section Energy,
Area,A Perimeter,P Radius,R Top Width,T Depth,D Factor,Z Q(gpd-8 =VZ/29
Depth,y(ft) Theta(red) (ft) Ot) (ft) VQ (ft) (ftw) Q(cfs) Q(gpm) hour day) V(ft/s) (h)
0.00 0.00 0.00 000 0.00 0.00 0.00 000 0.0 0.0 00 0.0 0.00
0.05 0.90 0.01 0.45 0.03 0.44 0.03 0.00 0.0 109 5212.3 1.6 0.04
0.10 1.29 0.04 0.64 0.06 0.60 0.07 0.01 0.1 47.2 22661.4 2.6 0.10
0.15 1.59 0.07 0.80 0.09 0.71 0.10 0.02 0.2 109.9 527620 3.3 0.17
0.20 1.85 0.11 0.93 0.12 0.80 0.14 0.04 CIA 198.0 950524 3.9 0.24
0.25 2.09 0.15 1.05 0.15 0.87 0.18 0.06 0.7 309.8 1486839 4.6 0.31
0.30 2.32 0.20 1.16 0.17 0.92 0.22 0.09 1.0 442.8 2125607 5.0 0.38
0.35 2.53 0.24 1.27 0.19 0.95 0.26 0.12 1.3 594.6 2854023 5.4 0.45
0.40 2.74 0.29 1.37 0.21 0.98 0.30 0.16 1.7 762.0 365776.0 5.8 0.52
0.45 2.94 0.34 1.47 0.23 0.99 0.34 0.20 2.1 941.9 452113.0 6.1 0.58
0.50 3.14 0.39 1.57 0.25 1.00 0.39 0.25 2.5 1130.7 542714.1 6.4 0.64
0.55 3.34 0.44 1.67 0.26 0.99 0.44 0.30 3.0 1324.5 635747.1 6.7 0.69
0.60 3.54 0.49 1.77 0.28 0.98 0.50 0.35 3A 1519.2 7292343 6.9 0.73
0.65 3.75 0.54 1.88 0.29 0.95 0.57 0.41 3.8 1710.5 8210270 7.1 0.77
0.70 3.96 0.59 1.98 0.30 0.92 0.64 0.47 4.2 1893.3 9087614 7.2 0.80
0.75 4.19 0.63 2.09 0.30 0.87 0.73 0.64 4.6 2062.0 989777.7 7.3 0.82
0.80 4.43 0.67 2.21 0.30 0.80 0.84 0.62 4.9 2210.4 1060970.1 7.3 0.83
0.85 4.69 0.71 2.35 0.30 0.71 1.00 0.71 5.2 23301 1118469.1 7.3 0.83
0.90 5.00 0.74 2.50 0.30 0.60 1.24 0.83 6.4 2410.1 1156846.5 7.2 0.81
0.95 5.38 0.77 2.69 0.29 0.44 1.77 1.02 5 t 2429.8 1166308.4 7.0 0.77
1.00 6.28 0.79 3.14 0.25 0.00 SA 2262.1 10857952 6.4 0.64
8.0
7.0
60
5.0
i
----0(CFS)
-V(R/s) 4.0 / �I
-E(R) �
3.0 �
2.0
i�
1.0
i
00 ''-
0.00 0.20 0.40 0.60 0.80 1.00 1.20
Depth(ft)
Basin Calculations
I I `r `�� .'•« ` -.' -' - -' �� -AU,rU-M,AN GROVE STREET -.� -• -. r-.
III II I
BASIN B I
ADS -
Sx,
SiORMTECH SC
STOMRWATER BASIN - -- - F TY TTTY77
1 �r±y* iQEYAYfOlf FRommo R FINIEFLOOR FINMFI.00�
+
4736ffi I =M� ffiBVA PLUVATiON ++++++ +
4fll.S - I + +tttt
I
ollp
BASIN B
74,435 SF I �� I � ,;' Ml
' rC�7
473LIS 4777A5 a
FINISH FLOOR
� ELEVATION t
474025 BAST A I- --
1 ; - - - •� :,i _.�{ 143,630 SF `
I• a •.'...f �•� �` •-`-� .. f _ jai-w--.".�-'^--._ N_ ��-� I r• :" � -. n .�_,.—., �� - � -• -- 1 �i
i FINISH FLOOR - PINIBHFLOOR i� I t mm FLOOR FINIDHFLOI ' �, FIIil8HM.00lt s ` ;
ELEVATION ELEVATION El"AnON MZVATM EZMA77M
4741.9 4741.0 47M 47M � 47560
� , E
I ?
> o
PUBLIC
AUTUMN GROVE MADISON ENGINEERING EXHIBIT A
STORMWATER DRAINAGE "STIMENOLOCY BLVD.B=2M DRAWN BY: CGB
HOZEMAN,MT 59n8 DATE: 12/02/21
BASIN EXHIBIT PHONE(406)58"M
PROJECT#21-104
Autumn Grove 12/2/2021
Lot 5 Block 2 West Winds Subdivsion PH 5
Stormwater Detention/Retention Calculations
Basin A
Calculation of Required Volume for Storm Water Retention & Infitration System
Design Rainfall Freq. 10 year-2 Hour event
OF coefficient a 0.64
OF coefficient b
OF coefficient n 0.65
Post-development Calculations:
Total Basin Area: 143,341 sf
C
Areas(ft): Roof Area 49,300 0.90
Impervious 48.166 0.90 Sidewalk
Landscaped 46.164 0.20
Total: 143,630 0.68
Retention Basin Calculation:
Q=CIA
C= 0.68 (post-development)
I = 0.41 in/hr(10-yr,2-hr storm)
A= 3.30 acres
QpOsc= 0.91 cfs
Required retention storage(ft3) = 6,570 ft' (10-yr,2-hr storm)
Provided retention storage(ft3) = 6,896 ft'
,in-East.xls
Autumn Grove 12/2/2021
Lot 5 Block 2 West Winds Subdivsion PH 5
Stormwater Detention/Retention Calculations
Basin B
Calculation of Required Volume for Storm Water Retention & Infitration System
Design Rainfall Freq. 10 year-2 Hour event
OF coefficient a 0.64
OF coefficient b
OF coefficient n 0.65
Post-development Calculations:
Total Basin Area: 74,434 sf
C
Areas(ft): Roof Area 18,850 0.90
Impervious 21,665 0.90 Sidewalk
Landscaped 33.919 0.20
Total: 74,434 0.58
Retention Basin Calculation:
Q=CIA
C= 0.58 (post-development)
I = 0.41 in/hr(10-yr,2-hr storm)
A= 1.71 acres
QpOgt= 0.41 cfs
Required retention storage(ft3)= 2,931 ft3 (10-yr,2-hr storm)
Provided retention storage(ft3)= 3,101 ft3
ADS Basin-West.xls
ADS Storintech Basin Calculations
//ADS
User Inputs Results
Chamber Model: SC-740 Svstem Volume and Bed Size
Outlet Control Structure: No
Project Name: Autumn Grove- Installed Storage Volume: 6896.26 cubic ft.
Basin A(East)
Storage Volume Per Chamber: 45.90 cubic ft.
Engineer: Chris Budeski Number Of Chambers Required: 70
Project Location: Montana Number Of End Caps Required: 20
Measurement Type: Imperial Chamber Rows: 10
Required Storage Volume: 6570 cubic ft.
Maximum Length: 57.71 ft.
Stone Porosity: 40% Maximum Width: 49 ft.
Stone Foundation Depth: 12 in.
Approx.Bed Size Required: 2760.26 square ft.
Stone Above Chambers: 12 in.
Average Cover Over Chambers; 18 in. System Components
Design Constraint Dimensions: (70 ft.x 60 ft.)
Amount Of Stone Required: 341.04 cubic yards
Volume Of Excavation(Not Including 460.04 cubic yards
Fill):
Non-woven Geotextile Required(ex- 864.12 square yards
cluding Isolator Row):
Non-woven Geotextile Required(Iso- 54.84 square yards
lator Row):
Total Non-woven Geotextile Required:918.97 square yards
Woven Geotextile Required(excluding47.50 square yards
Isolator Row):
Woven Geotextile Required(Isolator 34.28 square yards
Row):
Total Woven Geotextile Required: 81.78 square yards
EMBEDMENT STONE SHALL BE A CLEAN,CRUSHED AND ANGULAR GRANULAR WELL-GRADED SOIUAGGREGATE MIXTURES,<35%
STONE WITH AN AASHTO M43 DESIGNATION BETWEEN•3 AND•57 FINES,COMPACT IN 6'(150 mm)MAX LIFTS TO 95%PROCTOR
CHAMBERS SHALL MEET THE REQUIREMENTS FOR DENSITY SEE THE TABLE OF ACCEPTABLE FILL MATERIALS
ASTM F241B POLYPROPLENE OPP)CHAMBERS
OR ASTM F922 POLYETHYLENE(PE)CHAMBERS CHAMBERS SHALL BE BE DESIGNED IN ACCORDANCE WITH ASTM F2787
\ "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC
ADS GEOSYTHETICS 601T NON-WOVEN CORRUGATED WALL STORMWATER COLLECTION CHAMBERS'
GEOTTXTILE ALL AROUND CLEAN,CRUSHED, PAVEMENT LAYER(DESIGNED
ANGULAR EMBEDMENT STONE BY SITE DESIGN ENGINEER)
(450
1 I f 1( 4
MAX
6'(150 mm1 MOJ
PERIMETER STONE'J _ \ (760 mm)
EXCAVATION WALL 1
(CAN BE SLOPED_ _. .. 1'1-.
OR VERTICAL)
_lIl � DEPTH OF STONE TO BE DETERMINED
12'(300 mm)MIN SG740
L
BY SITE DESIGN ENGINEER 6'(150 mm)MIN
ray
END CAP
SITE DESIGN ENGINEER IS RESPONSIBLE FOR 6' S1'(1295 mm) 7Y(300 mm)TYP
THE ENSURING THE REQUIRED BEARING - (150 mm)MIN
CAPACITY OF SUBGRADE SOILS
'MINIMUM COVER TO BOTTOM OF FLEXIBLE PAVEMENT.FOR UNPAVED INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR.INCREASE COVER TO 24"IWO mm)
Project: Autumn Grove - Basin A
StormTech-
Chamber Model - SC-740 oeWren•Rater -vare.a�mr
Units- Imperial(� Click Here for Metric A�ivisivn of MM
- - 11,13906
Number of chambers- 70
Voids in the stone (porosity)- 40 %
Base of Stone Elevation- 10000 ft
Amount of Stone Above Chambers- 12 in 0 Include Perimeter Stone In Calculations
Amount of Stone Below Chambers- 12 in
Area of system- 2761 Isf Min.Area- 2366 sf min. area
StormTech SC-740 Cumulative Storc-,c,
Height of Incremental Single Incremental Incremental Incremental Ch Cumulative
System Chamber Total Chamber Stone & St Chamber Elevation
(inches) (cubic feel) (cubic feet) (cubic feet) (cubic feet) cubic feet) (feet)
54 0.00 0.00 92.03 92.03 6899.74 104.50
53 0.00 0.00 92.03 92.03 6807.70 104.42
52 0.00 0.00 92.03 92.03 6715.67 104.33
51 0.00 0.00 92.03 92.03 6623.64 104.25
50 0.00 0.00 92.03 92.03 6531.60 104.17
49 0.00 0.00 92.03 92.03 6439.57 104.08
48 0.00 0.00 92.03 92.03 6347.54 104.00
47 0.00 0.00 92.03 92.03 6255.50 103.92
46 0.00 0.00 92.03 92.03 6163.47 103.83
45 0.00 0.00 92.03 92.03 6071.44 103.75
44 0.00 0.00 92.03 92.03 5979.40 103.67
43 0.00 0.00 92.03 92.03 5887.37 103.58
42 0.05 3.85 90.49 94.34 5795.34 103.50
41 0.16 11.40 87.47 98.88 5700.99 103.42
40 0.28 19.74 84.14 103.87 5602.12 103.33
39 0.60 42.28 75.12 117.40 5498.24 103.25
38 0.80 56.12 69.59 125.71 5380.84 103.17
37 0.95 66.55 65.41 131.96 5255.14 103.08
36 1.07 75.22 61.95 137.16 5123.17 103.00
35 1.18 82.63 58.98 141.61 4986.01 102.92
34 1.27 88.60 56.59 145.19 4844.40 102.83
33 1.36 94.85 54.09 148.94 4699.21 102.75
32 1.45 101.79 51.32 153.11 4550.26 102.67
31 1.52 106.73 49.34 156.07 4397.16 102.58
30 1.58 110.76 47.73 158.49 4241.09 102.50
29 1.64 114.96 46.05 161.01 4082.59 102.42
28 1.70 118.97 44.45 163.41 3921.59 102.33
27 1.75 122.70 42.95 165.66 3758.17 102.25
26 1.80 126.20 41.55 167.75 3592.52 102.17
25 1.85 129.85 40.09 169.94 3424.76 102.08
24 1.89 132.52 39.03 171.54 3254.82 102.00
23 1.93 135.38 37.88 173.26 3083.28 101.92
22 1.97 138.25 36.73 174.98 2910.02 101.83
21 2.01 140.69 35.76 176.45 2735.03 101.75
20 2.04 143.15 34.77 177.92 2558.58 101.67
19 2.07 145.25 33.93 179.18 2380.66 101.58
18 2.10 147.34 33.10 180.44 2201.48 101.50
17 2.13 149.23 32.34 181.57 2021.04 101.42
16 2.15 150.77 31.73 182.50 1839.47 101.33
///ADS-
User Inputs Results
Chamber Model: SC-740 System Volume and Bed Size
Outlet Control Structure: No
Project Name: Autumn Grove- Installed Storage Volume: 3101.15 cubic ft.
Basin B(West)
Storage Volume Per Chamber: 45.90 cubic ft.
Engineer: Chris Budeski Number Of Chambers Required: 36
Project Location: Montana Number Of End Caps Required: 12
Measurement Type: Imperial Chamber Rows: 6
Required Storage Volume: 2931 cubic ft.
Maximum Length: 50.23 ft.
Stone Porosity: 40°r6
Maximum Width: 30 ft.
Stone Foundation Depth: 6 in. Approx.Bed Size Required: 1506.94 square ft.
Stone Above Chambers: 6 in.
Average Cover Over Chambers: 18 in. System Components
Design Constraint Dimensions: (50 ft.x 54 ft.)
Amount Of Stone Required: 134.14 cubic yards
Volume Of Excavation(Not Including 195.34 cubic yards
Fill):
Non-woven Geotextile Required (ex- 476.73 square yards
cluding Isolator Row):
Non-woven Geotextile Required(Iso- 47.25 square yards
lator Row):
Total Non-woven Geotextile Required:523.99 square yards
Woven Geotextile Required(excluding39.58 square yards
Isolator Row):
Woven Geotextile Required(Isolator 29.53 square yards
Row):
Total Woven Geotextile Required: 69.12 square yards
EMBEDMENT STONE SHALL BE A CLEAN,CRUSHED AND ANGULAR GRANULAR WELL-GRADED SOIUAGGREGATE MIXTURES,�35%
STONE WITH AN AASHTO M43 DESIGNATION BETWEEN N3 AND#57 1 FINES,COMPACT IN 6-(150 mm)MAX LIFTS TO 95%PROCTOR
CHAMBERS SHALL MEET THE REQUIREMENTS FOR DENSITY SEE THE TABLE OF ACCEPTABLE FILL MATERIALS
ASTM F2418 POLYPROPLENE(PP)CHAMBERS
OR ASTM F922 POLYETHYLENE(PE)CHAMBERS CHAMBERS SHALL BE BE DESIGNED IN ACCORDANCE WITH ASTM F2787
` 'STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC
ADS GEOSYTHEIICS 6017 NON-WOVEN \ CORRUGATED WALL STORMWATER COLLECTION CHAMBERS'
FX GEOTTILE ALL AROUND CLEAN,CRUSHED, PAVEMENT LAYER(DESIGNED
\\\
ANGULAR EMBEDMENT STONE
BY SITE DESIGN ENGINEER)
(450 mm)MIN Rom)
6.Imam)MIN
PERIMETER STONE - (760 mm)
EXCAVATION WALL
(CAN BE SLOPED
OR VERTICAL)
DEPTH OF STONE TO BE DETERMINED
BY SITE DESIGN ENGINEER 6'(150 mm)MIN
12-(300mm)MIN--r� END
SITE DESIGN ENGINEER IS RESPONSIBLE FOR 6' S1'(1295 mm) 12'(300 mm)TYP
THE ENSURING THE REQUIRED BEARING (150 mm)MIN
CAPACITY OF SUBGRADE SOILS
'MINIMUM COVER TO BOTTOM OF FLEXIBLE PAVEMENT.FOR UNPAVED INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR.INCREASE COVER TO 24-(600 MM)
Project: Autumn Grove - Basin B
StormTech-
Chamber Model- SC-740 DBOOM-xWrum•water aA&W
Units- l Im eria
(� Click Here for_Metric A dnisinn of
Number of chambers- 36
Voids in the stone(porosity)- 40 %
Base of Stone Elevation- 10000 ft
Amount of Stone Above Chambers- 6 in Include Perimeter Stone in Calculations
Amount of Stone Below Chambers- - in
Area of system- sf Min.Area- 1217 sf min. area
StormTech SC-740 Cumulative Storage Volumes
Height of Incremental Single Incremental mental Incremental Ch Cumulative
System Chamber Total Chamber � Stone & St Chamber Elevation
(inches) cubic feel) (cubic feet) (cubic feel) (cubic feel) (cubic feel) (feet)
42 0.00 0.00 50.23 50.23 3102.34 103.50
41 0.00 0.00 50.23 50.23 3052.10 103.42
40 0.00 0.00 50.23 50.23 3001.87 103.33
39 0.00 0.00 50.23 50.23 2951.64 103.25
38 0.00 0.00 50.23 50.23 2901.40 103.17
37 0.00 0.00 50.23 50.23 2851.17 103.08
36 0.05 1.98 49.44 51.42 2800.94 103.00
35 0.16 5.87 47.89 53.75 2749.52 102.92
34 0.28 10.15 46.17 56.32 2695.76 102.83
33 0.60 21.74 41.54 63.28 2639.44 102.75
32 0.80 28.86 38.69 67.55 2576.16 102.67
31 0.95 34.22 36.54 70.77 2508.61 102.58
30 1.07 38.68 34.76 73.44 2437.84 102.50
29 1.18 42.50 33.23 75.73 2364.40 102.42
28 1.27 45.56 32.01 77.57 2288.67 102.33
27 1.36 48.78 30.72 79.50 2211.10 102.25
26 1.45 52.35 29.29 81.64 2131.60 102.17
25 1.52 54.89 28.28 83.17 2049.95 102.08
24 1.58 56.96 27.45 84.41 1966.79 102.00
23 1.64 59.12 26.58 85.71 1882.38 101.92
22 1.70 61.18 25.76 86.94 1796.67 101.83
21 1.75 63.11 24.99 88.10 1709.73 101.75
20 1.80 64.90 24.27 89.17 1621.63 101.67
19 1.85 66.78 23.52 90.30 1532.46 101.58
18 1.89 68.15 22.97 91.12 1442.15 101.50
17 1.93 69.62 22.38 92.01 1351.03 101.42
16 1.97 71.10 21.79 92.89 1259.02 101.33
15 2.01 72.36 21.29 93.65 1166.13 101.25
14 2.04 73.62 20.79 94.41 1072.48 101.17
13 2.07 74.70 20.35 95.05 978.08 101.08
12 2.10 75.78 19.92 95.70 883.02 101.00
11 2.13 76.74 19.54 96.28 787.32 100.92
10 2.15 77.54 19.22 96.76 691.04 100.83
9 2.18 78.37 18.88 97.26 594.29 100.75
8 2.20 79.14 18.58 97.72 497.03 100.67
7 2.21 79.46 18.45 97.91 399.31 100.58
6 0.00 0.00 50.23 50.23 301.40 100.50
5 0.00 0.00 50.23 50.23 251.17 100.42
4 0.00 0.00 50.23 50.23 200.93 100.33
Appendix D — Stormwater
Maintenance Plan
STORM WATER MAINTENANCE PLAN
Autumn Grove Condominium
Owner's responsibility for routine inspection and maintenance
1. Keep the inlets of the facilities free of leaves,rocks,and other debris.
2. See that litter and other debris are removed from inlets, swales, and vegetated and
paved areas.
3. Maintenance of the underground systems are as follows:
• Per StormTech Maintenance Recommendations
• Minimum required maintenance includes a quarterly inspection during the
first year of operation and a yearly inspection thereafter. Utilize inspection
ports for inspections.
• The inspection ports can be used to pump water into the system and re-
suspend accumulated sediment so that is may be pumped out. Flush and
pump as inspections deem necessary.
• Utilize the adjacent upstreann storm sewer manhole for removal (vacuuming)
of debris from the end of the storm drain at the connection point with the
underground chamber.
4. Owner to maintain and fund Operation and Maintenance of stormwater facilities.
TruNorth,Owner
GWADISON ENGINEERING\PROJECTS\2021\21-104 Autumn Grove Condominium\Storm\STORMWATER MAINTENANCE
PLAN.doc
StormTecft4
Delenlion•Retention•Recharge
Subsurface Stormwater Management"
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Is olatorTM Row 08A4 Manual
StormTech' Chamber System for Stormwater Management
1.0 The Isolator"' Row
1.1 INTRODUMON The Isolator Row is typically designed to capture the
An important component of any Stormwater Pollution "first flush" and offers the versatility to be sized on a vol-
Prevention Plan is inspection and maintenance.The ume basis or flow rate basis.An upstream manhole not
StormTech Isolator Row is a patent pending technique only provides access to the Isolator Row but typically
to inexpensively enhance Total Suspended Solids (TSS) includes a high flow weir such that storm water flowrates
removal and provide easy access for inspection and or volumes that exceed the capacity of the Isolator Row
maintenance. overtop the over flow weir and discharge through a
manifold to the other chambers.
The Isolator Row may also be part of a treatment train.
j! I By treating storm water prior to entry into the chamber
%'' \�`• system,the service life can be extended and pollutants
\I such as hydrocarbons can be captured. Pre-treatment
!' best management practices can be as simple as deep
sump catch basins,oil-water separators or can be inno-
vative storm water treatment devices.The design of
r1 the treatment train and selection of pretreatment devices
by the design engineer is often driven by regulatory
1 requirements.Whether pretreatment is used or not,the
' Isolator Row is recommended by StormTech as an
effective means to minimize maintenance requirements
and maintenance costs.
Note:See the StormTech Design Manual for detailed
Looking down the Isolator Row from the manhole opening, woven information on designing inlets for a StormTech system,
geolextile is shown between the chamber and stone base. including the Isolator Row.
1.2 THE 190LATOR"ROW StormTech Isolator Row with Overflow Spillway
(not to scale)
The Isolator Row is a row of StormTech chambers, either
SC-740 or SC-310 models,that is surrounded with filter OPTIONAL
fabric and connected to a closely located manhole for PRE-TREATMENT
easy access. The fabric-wrapped chambers provide for
settling and filtration of sediment as storm water rises in STORMTECH
the Isolator Row and ultimately passes through the filter ISOLATOR ROW
fabric.The open bottom chambers and perforated side-
walls allow storm water to flow both vertically and horizon-
tally out of the chambers. Sediments are captured in the
Isolator Row protecting the storage areas of the adja- MANHWITH
cent stone and chambers from sediment accumulation. OVERFLOW
WEIR
Two different fabrics are used for the Isolator Row. A
woven geotextile fabric is placed between the stone
and the Isolator Row chambers.The tough geotextile
provides a media for storm water filtration and provides ECCENTRIC
a durable surface for maintenance operations. It is also HEADER
designed to prevent scour of the underlying stone and
remain intact during high pressure jetting.A non-woven
fabric is placed over the chambers to provide a filter
media for flows passing through the perforations in the
sidewall of the chamber.
OPTIONAL
ACCESS STORMTECH CHAMBERS
2 Call StormTech at 888.892.2694 or visit our website at www.stormtech.com for technical and product information.
2.0 Isolator Row Ins pection/Maintenance Storm Tech-
2.1 I NSPECII ON
The frequency of Inspection and Maintenance varies by location.A routine inspection schedule needs to be
established for each individual location based upon site
specific variables. The type of land use (i.e. industrial,
commercial residential), anticipated pollutant load, per-
cent imperviousness, climate, etc. all play a critical role
in determining the actual frequency of inspection and ?
maintenance practices.
At a minimum, StormTech recommends annual inspec-
tions. Initially,the Isolator Row should be inspected every
6 months for the first year of operation. For subsequent
years,the inspection should be adjusted based upon
previous observation of sediment deposition.
The Isolator Row incorporates a combination of standard ~ '
manhole(s)and strategically located inspection ports
(as needed).The inspection ports allow for easy access Examples of culvert cleaning nozzles appropriate for Isolator Row
to the system from the surface, eliminating the need to maintenance.(These are not StormTech products.)
perform a confined space entry for inspection purposes.
Maintenance is accomplished with the JetVac process.
If upon visual inspection it is found that sediment has The JetVac process utilizes a high pressure water noz-
accumulated, a stadia rod should be inserted to deter- zle to propel itself down the Isolator Row while scouring
mine the depth of sediment.When the average depth and suspending sediments.As the nozzle is retrieved,
of sediment exceeds 3 inches throughout the length of the captured pollutants are flushed back into the man-
the Isolator Row, clean-out should be performed. hole for vacuuming. Most sewer and pipe maintenance
companies have vacuum/JetVac combination vehicles.
2.2 MAINTENANCE Selection of an appropriate JetVac nozzle will improve
The Isolator Row was designed to reduce the cost of maintenance efficiency. Fixed nozzles designed for cul-
periodic maintenance. By"isolating" sediments to just verts or large diameter pipe cleaning are preferable.
one row, costs are dramatically reduced by eliminating Rear facing jets with an effective spread of at least 45"
the need to clean out each row of the entire storage are best. Most JetVac reels have 400 feet of hose allow-
bed. If inspection indicates the potential need for main- ing maintenance of an Isolator Row up to 50 chambers
tenance, access is provided via a manhole(s) located long.The JetVac process shall only be performed on
on the end(s)of the row for cleanout. If entry into the StormTech Isolator Rows that have AASHTO class 1
manhole is required, please follow local and OSHA rules woven geotextile(as specified by StormTech)over
for a confined space entries. their angular base stone.
StormTech Isolator Row(not to scale)
COVER ENTIRE ROW WITH AASHTO M288
12"MIN ID 25"MAX OD PIPE INSPECTION PORT CLASS 2 NON-WOVEN GEOTEXTILE
SET 1.5"FROM BOTTOM LOCATION PER / SC-740—8'WIDE STRIP -STORMTECH
OF CHAMBER ENGINEER'S DRAWING SC-310—5'WIDE STRIP J ENDCAP
CATCH - -d
BASIN -I
OR _
ANHOL
Ed
2FT MINI -I .
SUMP '-WOVEN GEOTEXTILE THAT MEETS AASHTO M288 CLASS 1
REQUIREMENTS,BETWEEN STONE BASE AND CHAMBERS
SC-740—5'-6'W I DE STRIP
SC-310—4'WIDE STRIP
Call StormTech at 888.892.2694 or visit our website at www.stormtech.com for technical and product information. 3
3 .0 Isolator Row Step By Step Maintenance Procedures
Step 1) Inspect Isolator Row for sediment StormTech Isolator Row(not to scale)
A) Inspection ports(if present) �faf 2 1)A)
i. Remove lid from floor box frame
ii. Remove cap from inspection riser
iii. Using a flashlight and stadia rod,
measure depth of sediment and
record results on maintenance log.
iv. If sediment is at,or above, 3 inch
depth proceed to Step 2. If not 4�
proceed to step 3.
B)All Isolator Rows
i. Remove cover from manhole at
upstream end of Isolator Row
ii. Using a flashlight, inspect down Isolator Row through outlet pipe
1.Mirrors on poles or cameras may be used to avoid a confined space entry
2.Follow OSHA regulations for confined space entry if entering manhole
iii. If sediment is at or above the lower row of sidewall holes(approximately 3 inches)proceed to Step 2.
If not proceed to Step 3.
Step 2)Clean out Isolator Row using the JetVac process
A)A fixed culvert cleaning nozzle with rear facing nozzle spread of 45 inches or more is preferable
B)Apply multiple passes of JetVac until backflush water is clean
C)Vacuum manhole sump as required
Step 3)Replace all caps, lids and covers, record observations and actions
Step 4) Inspect&clean catch basins and manholes upstream of the StormTech system
Sample Maintenance Log
Stadia Rod Readings
Sediment
Date Fixed point point Depth Observations/Actions Inspector
to chamber to .. .
.. sediment
3/15/01 6.3 ft. none Newinstallation.Fixed pant is ci frameat grade djm
9/24/01 62 0.1ft. Some grit felt sm
6/20/03 5B 0.5 ft. Mucky feel,debris visible in manhole and in ry
Isolator rang maint enanoe due
7/7/03 6.3 ft. 0 System jet ted and vacuumed djm
StormTech
Detention•Retention•Recharge
Subsurface Stormwater Management'
20 Beaver Fbad,Suite 104 Wethersfield Connecticut 06109
860.529.8188 888.892.2694 I fax 866.328.8401 www.stormtech.com
StormTech products are covered by one or more of the following patents: U.S.Patents:5,401,459;5,511,903;5,716,163;5,588,778;5,839,844;
Canadian Patents:2,158,418 Other U.S.and Foreign Patents PendingPrinted in U.S.A.
0 Copyright.All rights reserved.StormTech LLC,2004 S090104-1