HomeMy WebLinkAboutSite Certifications - 01/30/2003January 30, 2003
Mr. Jay Barber J-R ENGINEERING
City of Fort Collins A Subsidiary of Westrian
Storm Water Utility 3
700 Wood Street
Fort Collins, CO 80521
Re: Atrix Laboratories — Detention and Water Quality Pond Certification
JR Project 39067.19 -7
Dear Jay,
This letter certifies that the constructed detention and water quality pond for Atrix Laboratories
is in general conformance to the approved drainage and grading plan. JR Engineering surveyed
the top, bottom and outlet structure of the pond_ on January 23, 2003. This survey indicated that
the record detention and water quality pond has adequate detention and water quality volume.
With this letter you will find record contour drawings and stage -storage calculations for the
water quality and detention pond. Also attached is an excerpt that contains the required water
quality capture volumes (WQCV) and the required detention volumes, obtained from the "Final
Drainage and Erosion Control Study Atrix Laboratories" (JR Eng. 2002). Note that the
elevations as depicted herein may change subsequent to the date of the surveys due to natural
and/or artificial actions.
If you,,h�ye any questions or comments please do not hesitate to contact me at my office.
Sihcer y,
2
�}`r'r s g• eVgiG; •• 'o
Jim B. Wright, P.E. •�'
Senior Technical Specialist /Gir��('A � nq
Attachment `•.,••t (3v��;.S`
O�SS�ONAL�G\
/mw
XA906719\1et1ers\1-24-3 Pond Certification.doc
2620 Fast Prosp= Road, Sure 190, Fort Collins, CO 80525
970-491-9888 • Fax: 970-491-9984 • www jrenginee i g.corn
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WATER QUALITY
OUTLET STRUCTURE
50 25 0
50 100 1
SCALE: 1 " = 50'
AREA OF INNUNDATION
(100—YEAR)
TOP OF POND
(SPILL ELEVATION)
ATRIX LABORATORIES
POND CERTIFICATION EXHIBIT
PROJECT NO. 39067.19
JANUARY 29, 2003
J•R ENGINEERING
A Subsidiary of Westrbm
60 Gfwvdood Plaza BW • Efgiew)4 CO 80M
303-740-9393 • Fax 303-721-9M
wwwfevw�qm
�L
Detention Pond
Record Detention Pond - Stage/Storage
LOCATION: Atrix
PROJECT NO: 9061.19
COMPUTATIONS BY: M. West
SUBMITTED BY: JR ENGINEERING
DATE: 3/29/2003
V =1 /3 d (A + B + sgd(A*B))
where V = volume between contours, ft3
d = depth between contours, ft
A = surface area of contour
POND AS -BUILT
WOM
100-yr WSEL-
Spill Elev. -
top of berm -
-_
Stage
(ft) _
- urface--
Area
(ft)
lncremental
Storage
(ac-ft)
--'Total --
Storage
(ac-ft)
5036.9
0
5037.0-
61.1-_
__ 0.00 _ _
_ 0.00_
5037.5
3052
0.02
0.02
5038.0 -
5493
0.05
0.07
5038.45
13895
0:10
0.17 --
5038.5
14828
0.02
0.18
5039.0
22483
0-.21-
0.39 - -
5039.5
26564
0.28
0.68
---5040.0 -
- 28671- _
--._ 0:32 -
--0.99- _-
5040. 5 .
30851
0.34
1.33
5040.89,
_ 32558 __
-_ _ 0.28 '_
1 M
5041.0
33039.
0.08
1.70
5041.54
35215
0.42
2.12
5041 89
36841
0.29
2.41
Required Water Quality Volume = . 0.17
Required Detention Volume = 1.45
Total Required Volume = 1.62
Total Provided Volume = 2.12
9067POND-cert.xls
Detention Pond
Proposed Detention Pond - Stage/Storage
LOCATION:
PROJECT NO:
COMPUTATIONS BY:
SUBMITTED BY:
DATE:
WQCV.
100-yr WSEL-
.Spill Elev. -
top of berm -
Atrix
9067.19
A. Reed
JR ENGINEERING
2/20/2002
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
FG SURFACE
Stage
_ (ft) _
Surface
Area
_ (- ) -- -
Incremental.
Storage
-- (ac-ft)
Total
Storage
- (ac-ft)-
5036,.85.
0
5037.0
383
0.00
.0.00
5037.5
1764
0.01
0.01
5038.0
7268
_0.05
0.06
5038.45
15019
0.11
0.17
5038-.5-
15880
0.02
0.19
5039.0
21744
0.22
0.41
5039.5
24839
0.27
0:67
5040.0
27549
0.30
0.97
__ 5040.5. _
30054
0.33- _- -_
_ _ 1.30 _- -
5040.94
32349
0.32
1.62
5041.0
32662
0.04
1.66
5041.5
35410
0.39
2.05
_5042.0 _
38433
0.42 _
_ 2.48. -
Required Water Quality Volume =
0.17
Required Detention Volume =
1.45
Total Required Volume =
1.62
Total Provided Volume =
2.05
9067POND-cert.xis