HomeMy WebLinkAbout20063599.tiff Weld Ceunty Planning Department
GREELEY OFFICE
MEMORANDUM RECEIVED
O TO: Kim Ogle, Planning DATE: February 13, 2006
Peter Schei, Don Carroll, Public Works
COLORADO Frank Piacentino, Building Inspection
FROM: David Bauer, Public Works ..ax -
SUBJECT: USR-1499, Windsor Assembly of God Church
Weld County Public Works Depai Liuent has reviewed this revised drainage report for the Windsor Assembly of God
Church. The Windsor Assembly of God Church 14 acre site is located on the northeast corner of the intersection of
State Highway 292 and WCR 72, approximately 2 miles north of the Town of Windsor. The site is constrained by
drainage ditches located along the northwest property line and the southeast property line. Proposed site improvements
include a church building and parking lot, entry reatures and driveway access to WCR 72.
This site has been approved for construction under a prior drainage plan; the applicant has submitted a new drainage plan
to address newly identified conditions at the site. The letter submitted by the applicant's engineer (Nolte Associates, Inc.
Gary Iwata, P.E.) states that the revised grading plan lowering the site by approximately 1 foot in elevation was
necessitated to balance site soil volumes. The Nolte letter states that the original design engineer's (Latitude 39) detention
pond outlet structure design erroneously releases the detained water at a rate higher than the 5-year storm historic rate as -
required by Weld County Code. The Nolte letter states that all drainage improvements would be constructed as originally
designed(by Latitude 39)with the exception of a lowering of site elevations by approximately 1 foot and with a change of
the detention pond outlet structure to release at the required rate.
Comments
Drainage:
❑ Nolte's analysis and re-design of the revised detention outlet structure is an improvement over the previously
submitted and accepted design.
❑ Nolte's re-grading design does not substantially change any of the approved proposed site improvements.
❑ The proposed detention pond outlet design and regarding design are acceptable to Weld County Public Works.
❑ Weld County will not maintain drainage facilities located on private property.
❑ The area that includes the detention pond and outlet structure shall be placed in a recorded drainage easement.
❑ Final sediment control and erosion control measures (confoiniing to the revised drainage report)stamped, signed and
dated by a professional engineer licensed in the State of Colorado shall be installed prior to breaking ground. It is
recommended that the detention pond be constructed first to collect site runoff and sediment during construction.
❑ Applicant is requested to re-submit 3 complete sets of stamped and signed revised drainage and grading design
drawings for use by Public Works and Building Department inspectors and for the permanent project files.
Recommendation
❑ Approval.
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E►-d • Dave Bauer & Frank Piancentino DATE : February 10, 2006
Weld County
FROM : Gary Iwata PROJ # : DVB0204
Nolte Associates, Inc.
SUBJECT : Windsor Assembly of God Church
Nolte Associates, Inc. was hired by Colorado Commercial Developers to revise the grading for
the Windsor Assembly of God Church. The approved plans dated September 29, 2005 were
designed by Latitude 39 of Denver, Colorado . Upon initial grading of the site, the contractor,
Colorado Commercial Development, was short dirt when following the grading plan as proposed
by Latitude 39 . Nolte Associates, Inc. was instructed to keep the design of the site the same but
lower the building and parking lot so that there would not be a shortage of dirt.
The building was lowered by 0. 6 feet while the parking lot was generally lowered by 1 . 0 foot.
Lowering of these portions of the site required that the profile for the entrance to the church from
Weld County Road #72 be altered and that the proposed detention pond be lowered. These
changes can be seen on the following sheets which have been resubmitted to Weld County:
Sheet 5 of 13 "Grading"
Sheets 6 and 7 of 13 "Fine Grading"
Sheet 10 of 13 "Water Plan" (The elevation of the proposed fire hydrant has been updated. )
Sheet 11 of 13 "Storm Sewer and Detention Pond"
Sheet 12 of 13 "Storm Sewer and Detention Details"
The volume of the proposed detention pond has remained the same as was designed by Latitude
39 . However, it is the opinion of Nolte Associates, Inc. that the release structure for the
detention pond was incorrectly designed by Latitude 39 . As it was designed, the pond will not
release the Water Quality Volume in 40 hours as recommended by Urban Drainage and Flood
Control District. Additionally, the pond will drain much faster than the allowable 5 -year pre-
development flow rate. Sheet 12 of 13 "Storm Sewer and Detention Details" shows the outlet
structure as it has been re-designed. The orifice plate to drain the water quality volume of the
pond now has more holes of a larger size. This has been designed using Figure 5 "WQCV Outlet
Orifice Perforation Sizing" in UDFCD Criteria Manual Volume 3 . A 0 . 5 foot wide rectangular
weir has been added to the release structure to allow the pond to drain at the allowable 5 -year
pre-development release rate of 2 . 07 cfs. A steel orifice plate has been added to the entrance of
n:\dvb0204\documents\memos\drainage_memo-windsor.doc
MEMORANDUM (cont.) Page 2
the outlet pipe to restrict the flow out of the pond to the 5 -year pre-development release rate.
This orifice plate was designed using Figure ST-6 "Hydraulic Properties of Pipe Flow" in
UDFCD Criteria Manual Volume 1 .
Please contact us with any questions regarding the resubmittal of these construction plans .
Gary Iwata, PE
Nolte Associates, Inc.
8000 South Chester Street, Suite 200
Centennial, CO 80112
Office 303 . 220. 6400
Fax 303 .220. 9001
I
FEE 1 ao
3 2006 /+
WELD COUNTY PUBLIC WORKS DEPT
n:\dvb0204\documents\memos\drainage_memo-windsor. doc
RAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS
LO\I\ Sof ( 55n(1 6ki 4 oa chtveA-1
rb 0a Cup
Values of f and n
11 n
1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6
1.0 1 i
n,f Variable with Depth `k\\
0.9 ----n,f Constant / \ 1
---- Independent of n,f . / i
0.8 ---� t
Darcy-Weisbach r i
b 0.7 Friction Factor, f, f f/,
rz 0.6 Discharge,
8 s Ill Hydraulic
Radius, R
0.5 � Mannin4' '!;'_ .
0.4 �le00 � . ' —�
Area, A
0.2 ' --.,At-t___41....._
.�� x .... x
0.1
0 11
0 , 0.1 0.2 0.t 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3
o.I ,1
Hydraulic Elements �f Qf , A' , and R,
FIGURE ST-6
Hydraulic Properties of Pipe Flow
Forn Culix-(k i - 10" '( ai-- 1 170 , iA\)J= a833.c00, Tw.L-18 cs..yo[(o,l*p.)t imerkad=ye'..0.yo) &c: (,
(au..s...) 1^ e.. - 424-4_ 4 Q , 9.0-4/c„ . 0. ,24
1J ,c cote
dto= 0.4 O3V-eie `D= la„ (3= o 4CIa") d = 6"
° 1a"2cP
Culvert Calculator Report
12" Pond Release
Solve For:Discharge
Culvert Summary
Allowable HW Elevation 4,839.60 ft Headwater Depth/Height 3.30
Computed Headwater Elevation 4,839.60 ft Discharge 6.39 cfs N.
Inlet Control HW Elev. 4,839.60 ft Tailwater Elevation 4,836.40 ft y
Outlet Control HW Elev. 4,839.40 ft Control Type Inlet Control
Grades
Upstream Invert 4,836.30 ft Downstream Invert 4,836.00 ft
Length 27.00 ft Constructed Slope 0.011111 ft/ft
Hydraulic Profile
Profile CompositeM2PressureProfile Depth,Downstream 0.96 ft
Slope Type Mild Normal Depth N/A ft
Flow Regime Subcritical Critical Depth 0.96 ft
Velocity Downstream 8.23 ft/s Critical Slope 0.028158 ft/ft
Section
Section Shape Circular Mannings Coefficient 0.013
Section Material Concrete Span 1.00 ft
Section Size 12 inch Rise 1.00 ft
Number Sections 1
Outlet Control Properties
Outlet Control HW Elev. 4,839.40 ft Upstream Velocity Head 1.03 ft
Ke 0.50 Entrance Loss 0.51 ft
Inlet Control Properties
Inlet Control HW Elev. 4,839.60 ft Flow Control Submerged
Inlet Type Square edge w/headwall Area Full 0.8 ft2
K 0.00980 HDS 5 Chart 1
M 2.00000 HDS 5 Scale 1
C 0.03980 Equation Form 1
Y 0.67000
n:\dvb0204\documents\drainage\outlet pipe.cvm Nolte Associates Inc CulvertMaster v3.1 [03.01.003.00]
02/08/06 10:56:03,eOvBentley Systems, Inc. Haestad Methods Solution Center Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1
1 ,
JOB NO.DVB0204 Windsor Assembly of God Church 2/7/2006
9:08 AM
Water Quality Outlet Sizing(Dry Pond)
Northwest Detention Pond
WOCV: *Required Area Per Row(a):
3,217 ft3 0.4 in2
0.07 acre-ft
Depth at Outlet: **Number/Size of Holes per Row:
1.30 ft 4 Rows of 1 Holes at ll/16"Dia.
*From UDFCD Figure EDB-3"Water Quality Outlet Sizing-Dry Extended Basin w/a 40-Hour Drain Time of the Capture Volume"
nomograph equation. Where a=WQCV/K40,K41=(0.013DWQ2)+(0.22DWQ)-0.10
**From"Fig.5 WCQV Oulet Orifice Perforation Sizing"
NOLTE ASSOCIATES N::IDVB02041Documents\Drainage1 WQSizing.xls
Orifice Plate Perforation Sizing
Circular Perforation Sizing
Chart may be applied to orifice plate or vertical pipe outlet.
Hole Dia Hole Dia Min. Sc Area per Row (sq in)
(in) * (in) (in) n=1 n=2 n=3
1/4 0.250 1 0.05 0.10 0.15
5/16 0.313 2 0.08 0.15 0.23
3/8 0.375 2 0.11 0.22 0.33
7/16 0.438 2 0.15 0.30 0.45
1/2 0.500 2 0.20 0.39 0.59
9/16 0.563 3 0.25 0.50 0.75
5/8 0.625 3 0.31 0.61 0.92
P. 11/16 r 0.688 3 0,37 j 0.74 1.11
4 3 0.750 3 0.44 0.88 1.33
13/16 0.813 3 0.52 1.04 1.56
7/8 0.875 3 0.60 1.20 1.80
15/16 0.938 3 0.69 1.38 2.07
1 1.000 4 0.79 1.57 2.36
1 1/16 1.063 4 0.89 1.77 2.66
1 1/8 1.125 4 0.99 1.99 2.98
1 3/16 1.188 4 1.11 2.22 3.32
1 1/4 1.250 4 1.23 2.45 3.68
1 5/16 1.313 4 1.35 2.71 4.06
1 3/8 1.375 4 1.48 2.97 4.45
1 7/16 1.438 4 1.62 3.25 4.87
1 1/2 1.500 4 1.77 3.53 5.30
1 9/16 1.563 4 1.92 3.83 5.75
1 5/8 1.625 4 2.07 4.15 6.22
1 11/16 1.688 4 2.24 4.47 6.71
1 3/4 1.750 4 2.41 4.81 7.22
1 13/16 1.813 4 2.58 5.16 7.74
1 7/8 1.875 4 2.76 5.52 8.28
1 15/16 1.938 4 2.95 5.90 8.84
2 2.000 4 3.14 6.28 9.42
n = Number of columns of perforations
Minimum steel
plate thickness 1/4 '' 5/16 3/8 ''
* Designer may interpolate to the nearest 32nd inch
to better match the required area, if desired.
Rectangular Perforation Sizing
Only one column of rectangular perforations allowed. Rectangular Min. Steel
Hole Width Thickness
Rectangular Height = 2 inches 5" 1/4 "
Required Area per Row (sq in) 6" 1/4 "
Rectangular Width. (inches) = 7" 5/32 "
2"
8" 5/16 "
9" 11/32 "
10" 3/8 „
>10" 1/2 "
Urban Drainage and Figure 5
' Flood Control District
WQCV Outlet Orifice
Drainage Criteria Manual (V.3) Perforation Sizing
File: Details.dwg
'Design Procedure Form --Extended Detention Basin:(EDB) -Sedimentation Facility
Sheet 1 of 3
Designer: DMH
Company: Nolte Associates
Date: February 7,2006
Project: Windsor Assembly of God Church
Location: Windsor,Colorado-Weld County
1. Basin Storage Volume
la= 24.00 %
A)Tributary Area's Imperviousness Ratio(i=la/100) i= 0,24
B) Contributing Watershed Area(Area) Area= 6.33 acres
C) Water Quality Capture Volume(WQCV) WQCV= 0.13 watershed inches
(WQCV=1.0'(0.91'1'-1.19'1`+0.78"I))
D) Design Volume:Vol=(WQCV/12)*Area*1.2 Vol= "0.0830 `acre-feet
2. Outlet Works
A) Outlet Type(Check One) X Orifice Plate
Perforated Riser Pipe
Other:
B) Depth at Outlet Above Lowest Perforation(H) H= 1.30 feet
C) Recommended Maximum Outlet Area per Row,(AO) A0= 0.3;: square inches
D) Perforation Dimensions:
i) Circular Perforation Diameter or D= '0,625"4:inches
ii)2"Height Rectangular Perforation Width W= inches
E) Number of Columns(nc,See Table 6a-1 For Maximum) nc= 1; number
F) Actual Design Outlet Area per Row(A.3) A0= 0.3 square inches
G) Number of Rows(nr) nr= 4,?:: number
H) Total Outlet Area(Ao,) Ao,= 1.2 square inches
3. Trash Rack
A) Needed Open Area:A,=0.5"(Figure 7 Value)'A", A,= 43 square inches
B) Type of Outlet Opening(Check One) ` X ;,<2"Diameter Round
2"High Rectangular
Other:
C) For 2",or Smaller,Round Opening(Ref.: Figure 6a):
i) Width of Trash Rack and Concrete Opening(Woo„0)
from Table 6a-1 Woo== 3 !. a inches
ii) Height of Trash Rack Screen(HTR) H
TR= 46 inches
USDCM Vol 3 BMP Design Forms v2.05(20050912).xls,EDB 2/7/2006, 12:45 PM
Design.Procedure Farm Extended Detention Basin"(EDB) 5edgnentatton Factltty
Sheet 2 of 3
Designer: DMH
Company: Nolte Associates
Date: February 7,2006
Project: Windsor Assembly of God Church
Location: Windsor,Colorado-Weld County
iii) Type of Screen(Based on Depth H),Describe if"Other" X S.S.#93 VEE Wire(US Filter)
Other:
iv) Screen Opening Slot Dimension,Describe if"Other" X :?''0.139"(US Filter)
Other:
v) Spacing of Support Rod(O.C.) 0;75'"e"
inches
Type and Size of Support Rod(Ref.:Table 6a-2) #156 VEE
vi) Type and Size of Holding Frame(Ref.: Table 6a-2) 3/8 in.x 1.0 in.flat bar
D) For 2"High Rectangular Opening(Refer to Figure 6b):
I) Width of Rectangular Opening(W) W= :'':inches
ii) Width of Perforated Plate Opening(W,,,,„c=W+12") W
„c_ inches
iii) Width of Trashrack Opening(Wopen1 g)from Table 6b-1 Wuoe„ne= inches
iv) Height of Trash Rack Screen(HTR) HTR= , inches
v) Type of Screen(based on depth H)(Describe if"Other") Klemp'M KPP Series Aluminum
Other:
vi) Cross-bar Spacing(Based on Table 6b-1,Klemp'M KPP 3{inches
Grating). Describe if"Other" Other:
vii) Minimum Bearing Bar Size(Klemp'M Series,Table 6b-2)
(Based on depth of WQCV surcharge)
4. Detention Basin length to width ratio ( )
5 Pre-sedimentation Forebay Basin-Enter design values
A) Volume(no less than 5%of Design Volume from 1 D) acre-feet
B) Surface Area acres
C) Connector Pipe Diameter inches
(Size to drain this volume in 5-minutes under inlet control)
D) Paved/Hard Bottom and Sides
yes/no
USDCM Vol 3 BMP Design Forms v2.05(20050912).xls,EDB 2/7/2006, 12:45 PM
„
Note: Vertical WQCV Trash Racks are shown in Figures 6, 6—a, and 6—b for suggested standardized
outlet design. Adverse—Slope Trash Rack design may be used for non—standardized designs, but must
meet minimum design criteria.
Structural Steel Channel _ Stainless Steel Bolts
Formed Into Concrete. WConc. or Intermittent Welds,
See Figures 6—a, 6—b A See Figures 6—a, 6—b
— —� *-
705--
_ c 3 3
3 O ° H
7
� - Varies 2'-0"
o 3 O to 6'-0"
°
O O
° 0 J ° -
B •
B
D o 2'-4"
(minimum)
A-
WQCV Trash Racks: Elevation
1. Well—screen trash racks shall be stainless steel and shall be attached by intermittant
welds along the edge of the mounting frame.
2. Bar grate trash racks shall be aluminum and shall be bolted using stainless steel hardware.
3. Trash Rack widths are for specified trash rack material. Finer well—screen or mesh size
than specified is acceptable, however, trash rack dimensions need to be adjusted for
materials having a different open area/gross area ratio (R value)
4. Structural design of trash rack shall be based on full hydrostatic head with zero
head downstream of the rack.
Overflow Trash Racks:
1. All trash racks shall be mounted using stainless steel hardware and provided with
hinged and lockable or boltable access panels.
2. Trash racks shall be stainless steel, aluminum, or steel. Steel trash racks shall be hot
dip galvanized and may be hot powder painted after galvanizing.
3. Trash Racks shall be designed such that the diagonal dimension of each opening is
smaller than the diameter of the outlet pipe.
4. Structural design of trash rack shall be based on full hydrostatic head with zero
head downstream of the rack.
Urban Drainage and Figure 6
Flood Control District
Suggested WQCV Outlet Standardized
Drainage Criteria Manual (V.3) Trash Rack Design
Flle: Details.dwg
JOB NUMBER DVB0204 Windsor Assembly of God Church 2/10/2006
7:53 AM
DETENTION POND A - VOLUME
PRISMOIDAL METHOD
POND VOLUME=1/3(A1+A2+(A1*A2)^0.5)*D
DETENTION POND INCREM CUMM. CUMM.
ELEV AREA VOLUME VOLUME VOLUME
SQ FT CU FT CU FT ACRE-FT
4836.50 0 0 0 0.00
4837.00 1,050 175 175 0.00
WQCV 4837.50 3,847 1,151 1,326 0.03
4837.80 6,366 1,516 2,842 0.07
4837.85 6,847 330 3,173 0.07
4838.00 9,461 1,218 4,390 0.10
4838.50 12,158 5,391 9,781 0.22
100 YR DET
4839.00 16,594 7,159 16,941 0.39
4839.50 17,787 8,593 25,534 0.59
4839.60 18,054 1,792 27,326 0.63
4840.00 18,731 17,652 34,592 0.79
100 YR F.B.
4840.60 19,629 11,507 46,099 1.06
N:IDVB0204IDocuments IDrainagelPond-Sizing.xls
Weld County Planning Department
C;4EELEy OFFICE 41;1JA A 0 5 2006
RECEIVED
_ MEMORANDUM
TO: Kim Ogle, Planning Services DATE: January 4, 2006 Wlig FROM: Donald Carroll, Engineering Administrator
• jilt
COLORADO SUBJECT: USR 1499, Windsor Assembly of God Church
The applicant's engineer and contractor are requesting that the elevation of the site be lowered one foot to
accommodate balancing dirt work quantities on site.
REQUIREMENTS:
The requirements are as follows:
All existing elevations associated with the parking lot drainage, retention pond and release, and pipe elevations
shall all be lowered one foot. The existing grade of WCR 72 should match the elevation then taper downward
to the parking lot and church building.
All other affected agencies such as Building Inspection and the Health Department should clear on this
proposal.
pc: Latitude 39 (fax 303-451-7567)
Tracy Dyer, Inspection
USR-1499 M:\PLANNING-DEVELOPMENT REVIEW\USR-Use by Special Review\USR-1499-C.doc
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