HomeMy WebLinkAboutSite Certifications - 05/10/2000May 10, 2000
Mr. Jay Barber
City of Fort Collins — Stormwater
P.O. Box 580
F C 11., C 1 .480522
J•R ENGINEERING
A Subsidiary of Westrian
or m oo s, o ora o L 1 0
Re: Partial Certification of Storm Sewer Facilities for Harmony Village P.U.D.
Dear Jay:
JR Engineering (JR) surveyed the existing storm drainage facilities for Harmony Village on
December 22, 1999, March 23, 2000, and May 4, 2000. In addition, the facilities were
reviewed in the field by David Klockeman of JR on February 10, 2000, March 28, 2000, May
2, 2000 and May 8, 2000. A site walk through was held on May 9, 2000 with Jay Barber of
the City Stormwater Department, John Tufte of JR and David Klockeman of JR. As a result
of these items, we offer the following for your review and comment:
In general, the overall site is in varying stages of construction. However, as all of the
improvements have not been installed and portions of the storm drainage facilities are tied
directly to these future improvements, this condition is not unexpected.
Completed Items:
The box culvert under Timberwood Drive just west of Timberline Road has been
constructed in general conformance to the approved plans.
2. The inlets on Timberwood Drive just west of Timberline Road have been constructed
in general conformance to the approved plans.
3. The crosspan at the intersection of Timberwood Drive and Delaney Drive -has been
constructed in general conformance to the approved plans.
4. The inlet on the east side of Delaney Drive just south of Timberwood Drive was
constructed in general conformance with the approved plans.
5. The pipe connecting the aforementioned inlets to the large junction box on the east
side of Delaney Drive south of, Timberwood Drive has been constructed in general
conformance to the approved plans.
6. The inlet within the parking lot on the west side of Delaney Drive just south, of..
Timberwood Drive was constructed in general conformance with the approved plans.
2620 Fast Prospect Road, Suite 190, Fort Collins, CO 80525
970A91-9888 • Fax: 970A91-9984 • wJrengineering.wm
Mr. Jay Barber
May 8, 2000
Page 2 of 3
7. The pipes connecting the aforementioned inlet to the large junction box on the east
side of Delaney Drive south of Timberwood Drive have been constructed in general
conformance to the approved plans.
8. The aforementioned large junction box has been constructed in general conformance
to the approved plans.
9. The pipes from the aforementioned large junction box to Detention Pond A have been
constructed in general conformance to the approved plans.
10. The main portion of Detention Pond A has been constructed in general conformance to
the approved plans. The work remaining includes completion of the fine grading and
the permanent vegetation. (Volume calculations are attached.)
11. The pipe from the trickle pan stated in the previous paragraph to the Detention Pond A
outlet has been constructed in general conformance to the approved plans.
12. The crosspan at the intersection of Delaney Drive and Wilmington Drive has been
constructed in general conformance to the approved plans.
13. The trickle channel and swale on the adjacent property west of the theater was
constructed in general conformance to the approved plans.
14. The pipe along the north side of the parking lot in the southwest corner of the site has
been constructed in general conformance to the approved plans. (However, the flared
end section at the west end of this pipe needs to be grouted at the connection, the silt
needs to be removed from the pipe and rip -rap needs to be placed.)
Items Requiring Further Work:
The channel along between Lots 5 and 6, north of Timberwood was not constructed
per the detail shown on the approved plans. The approved plans showed a grouted rip
rap section and the constructed channel has a concrete bottom with grassed lined sides.
The grouted rip rap channel was designed for aesthetic purposes and this section was
not required due to design parameters. In addition, the improvements to Lots 5 and 6
have not been completed (Lot 5 is under construction), leaving the channel unfinished.
2. Detention Pond B, along the west side of Timberline Road north of Timberwood
Drive, is not complete. However, the majority of the area contributing to this
detention pond has not been constructed.
3. The inlet along the west side of Detention Pond A on Lot 7, just south of Timberwood
Drive, is partially constructed. It is our understanding that this inlet will be completed
with the construction of the parking area for this lot. The construction of the building
on this lot is currently underway.
Mr. Jay Barber
May 8, 2000
Page 3 of 3
4. The main portion of Detention Pond A has been constructed in general conformance to
the approved plans. The major work remaining includes completion of the fine
grading and the permanent vegetation. In addition, the trickle channel at the outlet of
the quad -pipes needs to be cleaned of silt and re -surveyed to determine if adequate
grade exists.
5. The trickle channel south of Detention Pond A, adjacent to Harmony Crossing
Subdivision, was constructed with vertical curb. This pan needs to be backfilled to
determine if positive drainage will occur from the rear of the lots in Harmony
Crossing (a total of 3 lots).
6. The pipe along the north side of the parking lot in the southwest corner of the site has
been extended as part of the construction. However, the flared end section at the west
end of this pipe needs to be grouted at the connection, the silt needs to be removed
from the pipe and rip -rap needs to be placed.
7. As part of the completion of Item 6, additional rip rap needs to be placed along the
north side of the swale at the outlet of the RCP for erosion protection from the RCP
and the ADS pipe from the warehouse site.
8. The portion of the internal access road along the rear of the theater just north of
Wilmington Drive needs to be repaired to correct the large ponding area.
This letter certifies that the "Completed Items" listed above are in general conformance with
the plans. The remaining items will be completed as the remainder of the site is developed.
If you have any questions or comments, or need additional information, please do not hesitate
to contact me at my office. Thank you.
Sincerely,
JR Engineering
< 4
W - (
David W. Klockeman, I
Senior Project Manager
Attachments
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Project No.: 9168.00 By: DJC,JPZ,AR,DWK
Project Name: Harmony Village Date: 5/10/00
V = 1 /3 d (A + B + sgrt(A'B))
where V = volume between contours, fe
d = depth between contours, ft
A = surface area of contour
Pond Volume from Approved Drainage Report
Area A Volume Area B Volume
Contour
Elevation
(R.)
Surface
Area
(sq. ft.)
Incremental
Volume
(Cu. It.)
Cumulative
Volume
(cu. R.)
Contour
Elevation
(ft.)
Surface
Area
sq. /t.)
Incremental
Volume
cu. h.
Cumulative
Volume
cu. R.)
Total
Volume
(W. R.)
Total
Volume
(ac-ft)
50.74
0
0
0
51.00
1044
90
90
90
0.00
51.71
13640
4,368
4,459
-
-
4,459
0.10
52.00
18785
4,682
9,141
-
-
9,141
0.21
52.52
28143
12,120
21,260
52.52
0
-
-
21,260
0.49
53.00
36782
15,536
36,796
53.00
1989
318
318
37,114
0.85
53.18
37712
6,704
43,501
53.18
3195
462
781
44,281
1.02
53.52
39469
13,120
56,620
53.52
5472
1,456
2,237
58,857
1.35
54.00
41949
19,537
76,157
54.00
8687
3,369
5,605
81,763
1.88
54.45
45434
19,656
95,813
54.45
14387
5,138
10,743
106,556
2.45
55.00
49693
26,151
121,964
55.00
21354
9,766
20,509
142,474
3.27
55.45
53348
23,179
145,144
55.45
46192
14,843
35,352
180,496
4.14
55.50
53754
2,6781
147,821
55.50
48952
2,378
37,730
185,552
4.26
55.62
56201
6,597
154,418
55.62
59043
6,470
44,201
198,619
4.56
56.00
63949
22,813
177,231
56.00
90997
28,290
72,490
249,721
5.73
Total @ 100-yr
WSELI
3.39
1 1
Total @ 100-yr WSELI
0.87 1
4.26
POND A as -built
Contour
Elevation
(ft.)
Surface
Area
(sq. If.)
Incremental
Volume
(cu. ft.)
Cumulative
Volume
(cu. ft.)
50.89
0
0
0
51.00
4
0
0
51.71
9664
2,335
2,335
52.00
13610
3,358
5,694
52.53
26517
10,445
16,139
53.00
37963
15,073
31,212
53.52
39938
20,252
51,464
54.00
41762
19,606
71,070
54.45
43082
19,089
90,159
55.00.
44695
24,137
114,297
55.50
54322
24,715
139,012
56.00
63949
29.535
168,547
Total 41 100-yr
WSEL
3.19
The area for the 56.0 contour is an assumption because
the contour actually goes into the parking lot and that area
is currently under construction.
POND B as -built
Contour
Elevation
ft.
Surface
Area
(sq. R.
Incremental
Volume
cu. ft.
Cumulative
Volume
cu. ft.
52.32
0
-
-
53.00
1136
257
257
54.00
6702
3,532
3,790
55.00
13056
9,704
13,493
Total 4t 100-yr
WSEL
0.09
Pond B is not complete at this time.
10 YR
100 YR
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