HomeMy WebLinkAboutLot Certifications - 09/10/2007INTERWEST
September 5, 2007
Mr. Jay Barber
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, Colorado
RE: Drainage Certification
Holsinger Drywall (Prospect Industrial Park, Lot 19 Replat)
Dear Jay:
C O N S U L T I N G G R O U P
STORMWATER
RECEIVED
SEP 10 Z007
y// V%
Please accept this letter and the attached documents as the Drainage Certification for the
above project. Based on the survey provided by RJL Surveys, a site visit, and discussions
with the contractor regarding the presents of buried riprap, the project is in substantial
conformance with the approved plans and drainage report.
The attached documents show handwritten as built elevations for the site on the approved
grading plan as well as calculations for the detention and water quality pond. The only
issue with the original construction was that the east berm of the pond was lower than the
design. This has been rectified and was checked with a construction level on September
5, 2007. The culvert, parking lot, and all trickle pans drain per plan. The detention pond
has been built correctly, the water quality component is slightly less than the design size,
but two 8'x4'x7' pits were constructed in the pond and filled with rock to further enhance
water quality. Each of these has about 100 cubic feet of available storage, so the intent of
the pond has been achieved.
Please review this information and give me a call if you have any questions.
Sincerely,
Michael Oberlander, PE
1218 WEST ASH, SUITE C WINDSOR, COLORADO 80550
TEL. 970.674.3300 • FAX. 970.674.3303
RECORD Detention Pond - Stage/Storage
LOCATION: Lot 19, Prospect Industrial Park
PROJECT NO: 1053-038-00
COMPUTATIONS BY: MPO
DATE: 9/5/2007
WQ WSEL-
100-yr WSEL-
SPILLWAY -
TOP OF BERM -
V = 1/3 d (A + B + sgrt(A'B))
where V = volume between contours, ft3
d = depth between contours, ft
A = surface area of contour
WATER QUALITY READ: 862 (ft)
DETENTION REGD: 7865 (ft)
TOTAL REQD: 8727 (ft)
STORMWAT ER
RECEIVED
SEP 10 2007
Stage
(ft)
Surface
Area
(ft`)
Incremental
Storage
(ft)
Detention
Storage
(ft)
Total
Storage
(ft)
4894.84
0
4895.00
277
15
15
4895.50
1863
476
491
4895.60
2237
205
0
696
4896.00
6420
1660
1660
2355
4896.50
13470
4865
6524
7220
4896.60
15055
1426
7950
8646
ASB detention.xls
LOT 2 i LOT 9 I LOT B
V/AO/NT fX DMA
EX fFHK RJ A'EYMI - - - - - - - - - - f
EX MCM RDfSIAL m.iEVAM'.
Ex aEMmwe we< m rcvAxv
_ EX 75'VE Ex M T.IL mR w
x _ _ _ _ (A ST &cvAnm - BY oK$Cl
__ ___ _
____—_ _____
T =.
� PVI AT 1
/ � I
I_..------- I
I� I
4 / I
EX
LOT20 r -JI LOTIB LOTis
:I HOLSINGER DRYWALL
UMOFFICE/WAREHOUSE INIPENNGSAN
I I
I
I I
r A
SE 11 r WTI AND
� DA R
/ g
PUT
VAIE ♦ m
"AD S JAG AND RIAN15.
w1N 0Ac OF cmale m
B
NOTES:
1. PAVEMENTSECTONSPERGEOTECHNICALREPORr(B"FORILANDCEMENT
CONCRETE B 4.000 PSD,
2. LIMITS OF STREET OUT SHOWN ARE APPROXIMATE FINALUMISARETOBE
DETERMINED IN THE FIELD BY THE CITY ENGINEERINGINSPECTOR. ALL REPAIRS SHALL
BE IN ACCORDANCE WITH THE CITY STREET REPAIR STANDARDS.
& DAMAGED CURB, GUTTER AND SIDEWALK EXISTING PRIORTO CONSTRUCTION. AS
WELLASSTREETS. SIDEWALKS. CURBSAND GUTTERS. DESTROYED. DAMAGED, OR
REMOVED DUETO CONSTRUCTION OF THIS PROJECT. SHALL BE REPLACED OR
RESTORED IN LIKE KINDATTHE DEVELOPER'S DIPENBE PRIORTOTHEACCEPTANCE
OF COMPLETED IMPROVEMENTS AND/OR PRIOR TO THE ISSUANCEOFTHE FIRST
CERTIFICATE OF OCCUPANCT. THE LIMBS OFTHE REPAIRS WILL BE IDENTIFIED IN THE
FIELD BYTHE CRY ENGINEERING INSPECTOR PRIORTOAND OVERTHE COURSE OF
THE PROJECTAND WILL NOT SE SHOWN ON THE PLAITS.
20 10 0 20 40 4. ALL DISTURBED AREAS(ON AND OFF STD SHALL BE RESEEDED AND MULCHED(SEE
LANDSCAPEPLANANDDRAINAGEANDEROSIONCONTROLPL ),
SCALE: 1"'20' 5. THE FINISHED FLOOR MINIMUM OPENING ELEVATION SHOWN ISTHE MINIMUM
ELEVATION REQUIRED FOR PROTECTION FROMTHE IOOYEAR STORM.
S. NOGRADINGSHALLOCCURONAOJACENTPROPEATI CEPTASSHOWN.
1 r,r.j
w fj
BI!CIgICM
IMMINI
MAN
plimarm
WATER QUALITY AND DETENTION OUTLET STRUCTURE
CTA
DN
w00
CO 0o
EOc
3
Q ❑ OT
cd
O
n°v
A
i
W
aUo
w Z�
z
33z
0
Nua
=m0
^U.
CALL UlUTY D CENTER OF COLORADO
1.800-922=1987
ro a amB
--- Ex rAJIAO'AD W-K _ L�OR x- DID
OAn IN ADVANCE
--- _ _ Trn MG uArxwc rc uxDDOseuxD
�_—• • MILBA UID➢ES
\ _
� 6 WHJ( CN • ' � J
A5'n-R �ve. �RaTso�C 0-1 D
_ w,GO DCURS
Ii1TIFA idx lxST.WAMM <
s 5 BO' mw s = + 3 DM£ s NB 00MCN T CITY OF FORT COLLINS. COLORADO G U
— /
MmPo//yTOp/y[,rIXB s s s �RJE� �TL�-VE�S BI I UTILITY PLAN APPROVAL
W W
W / _�—
_________` — w— — —w w U / / -7 PROVED
w
------------- w rIf1D � an awxDx as
F_ T ___ --.'
1 ---11 o __ _ ______________i.b_---_l_ y— CHECEED BY: Wean SWASIEWAMR UMITY DAM
1 — — _ _ a _ _ _ _ —I,fk 49D1 _T a— CHECKED By:
1 0 e tMMUMAIFA "nlrtY DAM
xi 1 . I I I — — — - [ CHECKED BY: FmxS W TIE UI DAM
OT27 I 1 LOTZB I I x�M,T $.G PTwt HG. IOBsaBIHxo
1 I I I I f l LCT29 `!T4IfI0�' CHECKED BY:
DAM
1 mARM ___________� L I I E+<+ worm 60F9
CHECKED BY:
SEP 10 Z007