HomeMy WebLinkAboutDrainage Reports - 05/13/20051
Addendum No. I
Project Development Plan Drainage and
Erosion Control Study for the
Lind Property
Filing 1
Fort Collins, Colorado
March 28, 2005
Stantec Consulting Inc
209 South Meldrum Street
Fort Collins CO 80521.2603
Tel: (970) 482-5922 Fax: (970) 482-6368 -
stanW.com
Stantet
March 28,
Mr. Basil Hamden
City of Fort Collins
Water Utilities--Stormwater
700 Wood Street
Fort Collins, Colorado 80521
RE: Addendum No. 1 Project Development Plan Drainage and Erosion Control Study for
Lind Property, Filing 1
Dear Basil:
As discussed we have re-examined the outfall from Pond 100 of Lind Farms Filing I (AKA
Brightwater Landings). We have prepared a short Addendum to the Filing I plans to address
this. We have also revised the plans to reflect the Filing two Outfall rate of 3 cfs and the
WQCV that will be required with Filing 2
We appreciate your time and consideration in reviewing this submittal. Please call if you have
any questions.
Respectfully,
Sear -Brown
A RE%�
Preps d by: P
Jim Allen -Morley,
Senior Project Ma
ADDENDUM No.1 .
PROJECT DEVELOPMENT PLAN DRAINAGE AND
EROSION CONTROL STUDY FOR
LIND PROPERTY
FILING I
FORT COLLINS, COLORADO
The purpose of this addendum it to address changes caused by the change in location of the
outfall from Pond 100. The outfall will now discharge to the existing Richards Lake
Subdivision Pond outfall. There are two reasons for this. One- If detention Pond 100 has an
outlet it can control the run-off in such a way that there will be no storm drainage over flow
from the Lind Farms Development to Maple Hill Development., Two — there is extra capacity
in the Richards Lake Outfall Pipe.
The Development of Lind Farms Filing II has further refined the hydrology of Pond 100 and
now Pond 100 is constructed to its full capacity. When an outlet structure is constructed to the
requirements of Filing II, Pond 100 will be able to detain all runoff from developed and historic
basins and release the outflow at 3.00 cfs. See Filing II Attachments.
The 3.0 cfs outflow from Detention Pond 100 will discharge fo the Richards Lake outfall pipe.
The outfall pipe -now receives 9.0 cfs from Richards Lake per the July 2000 City of Fort Collins,
Richards Lake PUD, Master Drainage Study (see attached table from the Master Drainage
Plan). The Capacity of the Richards Lake Outfall pipe is 16 cfs (see attached flow master work
sheet), which is greater than the 12 cfs required (9cfs from Richards Lake and 3cfs from Lind
Farm). There are no other developments other than Lind Farms(Brightwater Landings) and
Richards Lake contributing to this storm sewer.
r
At this time it is the intent to modify the current plans to reflect the Lind Farms Filing 1 and 2
outfall configuration. This will allow the connection to the Richards Lake Development and
eliminate an unnecessary 36" diameter pipe that was being built with the Maple Hill
Devlopment.
3
POND 100 OUTFALL STRUCTURE
CALCULATIONS
00
Stantec
--- ------ - --- - - --
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Designed by: Checked by:
Detention Pond Rating Curve
Used for SWMM Model
Pond 100
Elev
Depth
Area
Area
Storage
Storage
from Orifice
(ft)
(ft)
(ft2)
(ac)
(ac-ft)
(ac-ft)
Calc (cfs)
5013
0
8756.0051
0.2010102
0.00
0.00
0.00
5014
1
38699.931
0.8884282
0.50
0.50
1.07
5015
2
132893.87
3.0508234
1.86
2.37
1.51
5016
3
137252.62
3.1508865
3.10
5.47
1.86
5017
4
141668.14
3.2522529
3.20
F-8-67-1
2.14
5018
5
146140.43
3.3549225
3.30
11.97
2.40'
5019.
6
150669.49
3.4588955
3.41
15.38
2.62
5020
7
155255.32
3.5641717
3.51
18.89
2.83
5020.85
7.85
8.85
159197.91
163888.77
3.6546812
3.7623684
3.07
3.71
21.96
25.67.
3.00
3.19
5021.85
Orifice Calc
q=ca(2g(h))".5
c
0.65
WQCV
Diameter
0.10 ft
area
0.01
100-Year
Diameter
0.51 ft
area
0.21
300
S70f44t �tiA 10 I�� 41 il�lQiO.�+�.fn. l..�i 37•S
R501,4 76, `76i rx ;11'0691a , 4 " 2 54 _ _' , ;;1:54 x, 2 i ' 'u ,1'93 0>44� ; , <= WQSEL
,sx5020 84 ,7 84r< t159162 << `,3°65: r t 3:07r °,y4 2,1 93_ 3 00 "{t <= 100 Year
*100-year Required Storeage:1 20.00 acre-feet (from 100-year SWMM Model) *Add 1.93 ac-ft to account
for WQCV
Tailwatar•
5.Q13,00 €
0.00 8756 0.20 0.00
IV OO r~z;I
At tc = X
x5013`00 „,y
0.00 8756 0.20 0.00
}x, 0 00
At tc = X
I allwatPr,
`5Q13 OO u
0.00 8756 0.20 0.00
<. 0 QOA
At tc = X
10
0.00 8756 0.20 0.00e
0 OO�i
At tc = X
702100
1 Swmm Pond rating Curves 12-21-04.xls
Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility
Sheet 1 of 3
Designer:
John Gooch
Company:
Sear -Brown
Date:
February 26, 2004
Project:
Lind Filing 2
Location:
Fort Collins
1. Basin Storage Volume
A) Tributary Area's Imperviousness Ratio (i = 18 / 100)
B) Contributing Watershed Area (Area)
C) Water Quality Capture Volume (WQCV)
(WQCV =1.0 ' (0.91 ' 13 - 1.19' 12 + 0.78 ' 1))
D) Design Volume: Vol = (WQCV / 12)Area 1.2
Ia =
i =
Area =
WQCV =
Vol =
60.00
0.60
81.58
0.24
1.927
%
acres
watershed inches
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 =
1.84
feet
C) Required Maximum Outlet Area per Row, (A,)
Ao =
4.60
square inches
D) Perforation Dimensions (enter one only):
i) Circular Perforation Diameter OR
D =
1.0000
inches, OR
ii) 2" Height Rectangular Perforation Width
W =
inches
E) Number of Columns (nc, See Table 6a-1 For Maximum)
nc =
.6
number
F) Actual Design Outlet Area per Row (A.)
Ao =
4.71
square inches
G) Number of Rows (nr)
nr =
.6
number
H) Total Outlet Area (At)
At =
26.01
square inches
3. Trash Rack
A) Needed Open Area: A, = 0.5' (Figure 7 Value) ' Aot
At =
885
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 (Wwnc)
from Table 6a-1
W -
wnc -
36
inches
ii) Height of Trash Rack Screen (HTR)
HTR = .
46
inches
UDFCD Form Pond100.x1s, EDB
RICHARDS LAKE OUTFALL FLOW
CAPACITY CALCULATION
.. %
CITY OF FORT COLLINS
RICRARD'S LAKE P.U.D.
MASTER DRAINAGE STUDY
PREPARED FOR:
WINTERGREEN HOMES
P.O. ]BOX 978
AVON, COLORADO 81620
J ULY 2000
PROJECT NO. 95-0178
8392 Continental Divide Road, Suite #107 G Littleton, Colorado 80127 � Phone: 303/948-6220 • Fax: 303/948-6526
77 Metcalf Road, #200 - Box 978 ^ .Avon, Colorado 81620 0 Phone: 970/949-5072 ^ From Denver Direct: 893-1531
Richard's Lake Outfall
Worksheet for Circular Channel
Project Description
Worksheet
Circular Channel
Flow Element
Circular Channel
Method
Manning's Formu
Solve For
Full Flow Capacit
Input Data
Mannings Coeffic 0.013
Channel Slope 005000 ft/ft
Diameter 24.0 in
Results
Depth
2.00 ft
Discharge
16.00 cfs-
Flow Area
3.1 ft'
Wetted Perime
6.28 ft
Top Width
0:00 ft
Critical Depth
1.44 ft
Percent Full
1100.0 %
Critical Slope
006612 ft/ft
Velocity
5.09 f /s
Velocity Head
0.40 ft
Specific Energ:
2.40 ft
Froude Numbe
0.00
Maximum Disc
17.21 cfs
Discharge Full
16.00 cfs
Slope Full
Og5000 ft/ft^""'
Flow Type
N/A
Project Engineer: Alicia Forward
c:\program files\haestad\fmw\lindfiling2.fm2 Sear -Brown Group FlowMaster v7.0 [7.0005]
01/25/05 04:17:38 PM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1
u
TABLE 2-3
DEVELOPED BASIN DISCHARGE QUANTITIES
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