HomeMy WebLinkAboutWPO201300032 Plan - As-built 2018-11-15 w-a xarEi , \ °e E
' As-Built Pond Storage Volume '- BEi LVD-1R1 a ,I ///►►�j 0) lggl"6o
Na Elevation(ft) Area(sq.k) Ave Area(sq.ft) Volume(Cu Ft) Cumulative(to Ft) Notes v'- weir, � �` C ` n
1 34499 0 0 0 0 .< §
2 345 00 28861 14431 144 144 Pond Toe POND 7(_ ' �t 4'w�. a• �® C vQ a<
3 346.00 28966 28914 28914 29058 ' r1 - / C CD i=0
4 348.00 33775 31371 62741 91799 �• ; t -^ / ( --- 7Ec
5 34990 37901 35838 68092 L,9891 BottomofEquaticBench3"Orifice Elevation/Wet • /6 350.38 47r-i80 42741 20515 180g06 Stoage • r rmanw %Planned Pond Storage Volume(Including Forebay) " !! •
No Elevation ft I Area • S
( ) (sq.k) Ave Area(sq-it)'.Volume(cu Ft) Cumulative(cu.FtJ Notese.
1 344 99 0 0 0 0 -0 z + d . �/ .yy`2 34500 28234 14117 85 85 Pond Toeto LOC OF a3 346.00 30fiO4 29419 29419 29504 , � •4 348.00 1 35380 32392 65984 95488 5 348.50 39242 37311 18656 114143 Bottom of Equatic Bench / eutH op `6 35000 50655 44949 67423 1815663"Orifice Elevation/Wets / # .Storage /rag MAP / , J
/ c 8L F
Storage Summaryt j / /t.ic no ivrza °
Storage Oesaiption Plan As-built DV(a Ft) %of Change ,KEY NOT SCAIE / j -10 01/08/18
Permanent Pool Storage(co Ft) 181566 180406 -11E0 -064% I / FCc,rw,i t``
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/ l f
As-Built Pond Stage Storage Volume 24 ,'
/No Elevation(ft) Area(sq,ft) Ave Area(sq-ft) Volume(cu.Ft) Cumulative(cu.Ft) Notes ,aw "ar'"""o. fff
1 350.37 0 0 0 0 rU KAN„'e - ) I / ihhuh/
,Acvxrs iticrsra+a�m.Ex2 35038 47580 23790 121 121 . '
3 35100 47858 47719 29586 29707 4 352.00 50781 49320 49320 79027 cn
Zz5 353.00 52933 51857 51857 130884 • / m
6 354.00 55106 54020 54020 184%3 i"'btiOCIL7 354.28 55715 55411 15515 200418 2-YR WSE /
8 35500 57299 56507 40685 241103 • a>"rwIll / [249 35592 59290 58295 53631 294734 10-YR WSESe 8
10 356.00 59517 59404 4752 299486 ire DAY ITV OF 10' �xs°„� \ (".".....r�� run /
11 356.06 59696 59507 4769 304255 Crest Elevation \
12 356.63 60888 60292 33161 337415 I Emergency Spillway °0 / •'� \�- / - - � ,/ / •f�j� tiiI
13 35/00 61728 61308 22684 360099 i _ -- .� ( I �� / 1
14 357 23 62242 61985 14257 374356 100-YR WSE - ' , -e z
15 358.00 64106 63174 48644 423000 OVITORI x ne ce.no.o ___�_ /// �+
16 358.10 65995 65051 6505 429505 Top of Dam MO r¢ '.0 a qq
50 0 50 100 150iip,i� i 150 R
r tin av�uaaa■ r_�r,r.rrr•r_r.ar•r•r.ar•r
Planned Pond Stage Storage Volume(Including Forebay) SCALE. 1 "= 50' ^ 'VII z /
No Elevation(ft)j Area(sq.ft) Ave Area(sq.ft) Volume(cu.Ft) Cumulative(cu.Ft) Notes / I / a
1 34999 0 0 0 0 2 POND CROSS SECTION (TYP) .POND # 2 AS-BUILT DRAWING POND 2 APPROVED PLAN co
�._
2 350.00 50655 25328 152 152 AB Nor TO SCALE - SCALE 1•.50' AB zs
SCALE'1-50 - O_
3 351.00 53745 52200 52200 52352 fn
4 35200 56765 55255 55255 107607 Pond # 2 Partial As-built - Narrative
5 353 00 58515 57640 57640 165247 Cd
6 354.00 60228 59372 59372 224618 The purpose of this plan is to indicate the current excavated
7 35428 60839 60534 16949 241568 2-YR WSE volume of the large sediment basin adjacent to Route 20 in
the Cascadia Subdivision The basin will ultimately be converted
8 35500 62524 61682 44411 285979 to a permanent wet pond that will provide stormwater
9 355.70 64155 63340 44338 330316 Crest Elevation management quantity and quality control for the 60 77-acreLi /
10 355.92 64649 64402 14168 344485 10-YR WSE Cascadia Subdivision The basin was originally constructed in
11 356.00 64856 64753 5180 349665 2015 at the start of land disturbing activities and continues to x LL y
12 356.10 65091 64974 6497 356162 Emergency Spillway serve os a temporary sediment basin Conversion of the
13 35700 67228 66160 59544 415706 sediment basin to the permanent stormwoter management pond
will not be authorized until after final site stabilization Full
14 357.23 67/62 67495 15524 431230 100-YR WSE build out of Cascadia is not anticipated until the end of 2019 7
15 358.00 69760 68761 52946 484176 of the earliest. For that reason, the partial as-built plan is
16 6 35833 71261 70511 23268 507444 Top of Darn being provided to establish the adequacy of the excavated �,,;
volume for the permanent facility Top of Dam L F,
Elev = 350.33 O I Z
Storage Summary Conversion to the permanent facility includes removal of the CaMEO
Storage Description Plan As-built AV(cu.Ft) %of Change dewatering structure and plugging of the dewatering orifice at - OU
2-YR Storage(cu Ft) 241568 200418 -41150 -170396 the pond riser structure, and construction of the sediment ihil E„y Cr)
10.YR Storage(cu Ft) 344485 294734 -49751 _ -14.44% forebay per the approved plans It is anticipated that i-�
additional pond excavation at the southern end of the basin i--•i Z..) E'
(�
Emergency Spillway(cu Ft) 356162 337415 -18747 -526% plus additional onsite fill will be used to construct the forebay ice- C)
:00-YR Storage(cu.Ft) 431230 374356 -56874 -13.19% I`bb 0°I Emergency Spillway= 35C,10 a
Top of Dam(cu Ft) 507444 429505 -77939 -15.36% The northeastern portion of the pond bottom and the eastern Crest Bee= 3S�7CINN ) C'1 I
2 1 pond upland slope was located in cut with depths of up to c Device Cr) 9 Q
30' Significant rock was encountered in these locations at the 6'Ornfice,Elev = 35140 0
pond elevations, which was fairly hard rock, but was also fairly 9" J/ 2
Planned Fore bay Storage Volume rippable The contractor ripped as much of the rock as Q' U O
No Elevation(ft) Aeea(sq.ft) Ave Area(sq.ft)'.Volume(cu.Ft) Cumulative(cu.Ft) Notes feasible and used a hoe ram, but encountered refusal at ' z-Impervious Core' i-i a Cl...
1 34599 0 0 0 0 bedrock For this reason, the provided pond volume will be Q E-i
2 346.00 670 335 2 2 Forebay Bottom 85% to 90% of the plan volume as summarized below 1 YR.WSE=354.09' Q C,
3 348 00 1965 1318 2635 2637 (� 2 YR WSE=354 28' Z =Plan Volume As-built Volume %difference 3" Orifice`, De = 35000 10 YR WSE=35592' O .cc4 348.50 2362 2164 1082 3719 Qi
5 350.00 3729 3046 4568 8727 Emergency Spillway Permanent Pool 181,566 Cu ft 180,406 cu ft -0 6 100 YR WSE=35723' Q•i iJ Z
6 35200 4782 4256 8511 16798 2-Year Capacity 241,568 cu.ft 200,418 cu ft -17.0 __ SW 00) l d il
7 352.25 4921 4852 1213 18011 Top of Dam P y
10-Sear Ca acit 344,485 cu f- 294,734 cu ft -14 4 Elev - 310 5 F
, 10' •quatic
r, 8-nch ® ®fi8-2'&-30"
It is the opinion of the submitting engineer that the resulting lov-34&13& HDPE ES w
as-built excavation was completed with adequate due diligence 134S 0:1 ®j--96SE rrii3%1 M,
to maximize the amount of volume that could practically be Bot Elev= 31S 09 8'0x1 5' ,
- - - - Inv=344-58 DOM.PROJECT NQ12.0065
achieved without being significantly detrimental to the economy Concrete
n6 POND # 2 VOLUME CALCULATIONS of the project The subrruttinc engineer has also walked 'he :ase Embed 6' "-
Cutoff Trench" • INDEX TITLE:
--.--------.---------------------------- outlet channel and there ore no significant signs of erosion in Concrete
\B/ that would have become evident over the post 3 years that the AB
pond has been in place Finally, the submitting engineer also I (DENOTES AS-BUILT INFORMATION
recommends that the turbidity curtain be removed since
temporary slope drains that had directed concentrated flow east
to west across the pond have been removed Concentrated 5 POND # 2 SCHEMATIC SHEET NO:1 OF 1
runoff enters the pond via the closed storm sewer system that AB _..- ... ......... - - _.._
outfalls into the pond from the south NOT TO SCALE
DATE. 01/08/18