HomeMy WebLinkAboutDrainage Reports - 05/27/1997{. Rn
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} SHEAR
ENGINEERING
CORPORATION
Final Drainage and Erosion Control Report
for
1 pL9 ko �U�
h MAY 1 51997
The Howes Street Hideaways L_
Previously known as
Lots 12-14, Block 105, Harrison's Addition
Fort Collins, Colorado
Prepared for:
RAYLINE DEVELOPMENT CORPORATION
4712 Westbury Drive
Ft. Collins, Colorado 80526
Phone: (970) 204-0306
Prepared by:
SHEAR ENGINEERING CORPORATION
Project No: 1536-08-97
DATE: May, 1997
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-0311
PAGE 1
Project No 1536-08-97
Final Drainage and Erosion Control Report
I. GENERAL LOCATION AND DESCRIPTION:
A. Location
1. The project site is located in the Northeast One Quarter (1/4) of Section 14, UN,
Range 69 West of the 6th P.M., Ft. Collins, Colorado. The site is Lots 12-14, Block
105, Harrison's Addition.
2. More specifically; the project site is located between West Mulberry and Myrtle
streets in the middle of the westernmost lots of Block 105 (See Vicinity Map).
3. The site is a part of Old Town Fort Collins and is developed. The proposed duplexes
will be constructed along the existing alley at the rear of existing lots.
B. Description of Property
1. There are currently 3 single family residences on these lots. The existing houses front
on South Howes.
2. The site area is approximately 0.63 acres.
3. Development of the site will consist of the construction of 3 duplexes at the rear of
existing lots along the alley.
4. A gravel alley borders the site on the east side. This alley will be paved from the
southern property line of the recently completed Mulberry Green project along the
entire frontage the site in accordance with the requirements of the City of Fort
Collins.
a. The alley will be concrete paved and provided with an inverted crown section to
assist in the conveyance of stormwater to West Mulberry Street.
5. There are no major drainageways located on or within 150' feet the project site. See
Drainage and Erosion Control Plan in stuffer envelope.
U. DRAINAGE BASINS AND SUB -BASINS:
A. Major Basin Description
1. The site is situated within the Old Town Drainage Basin as designated on the City of
Fort Collins Stormwater Basin Map.
a. There are no drainage fees associated with the Old Town Basin.
2. The approximate limits of ponding in the area of Mason and Mulberry are shown on
fig 5.1 of the Old Town Report in appendix IV and the ponding exhibit on the
Drainage and Erosion Control plan
PAGE 2
Project No. 1536-08-97
Final Drainage and Erosion Control Report
II. DRAINAGE BASINS AND SUB -BASINS:
A. Major Basin Description (continued)
3. Stormwater from the site drains to conveyance element 205 as delineated on figure
4.1 of the Old Town Master Drainage Basin Plan.
a. According to the Old Town Master Drainage Basin Plan, stormwater flows in
conveyance element 205 are split at the intersection of Mason Street and
Mulberry Street.
b. Some of the flows are conveyed east in the existing storm sewer while others are
conveyed north on Mason when the storm sewer capacity is reached.
B. Sub -Basin Description
The site is extremely flat. We surveyed the property to determine if there was a
defined flow path. Slopes across the site range from 0.5% to 0.70% from west to east
and from south to north. The site slopes from the back of walk along South Howes to
the east between all the existing houses. At the rear of the existing houses the site
begins to slope to the north towards lot 11. Runoff then flows in a northeasterly
direction across lot 11 and 10 to the alley. There is a high point approximately 60 feet
west of the alley.which breaks the site into two sub -basins which we have designated
Ae and Aw.
a. Existing spot elevations are shown on the grading plan.
2. Development of the site will increase the area in basin Ae because this. area will be
developed and therefore it is deemed better to convey as much of of the runoff from
sub -basin Ae to the alley. The area of sub -basin Ae before development is
approximately 10,150 sf. (0.23 acres). The area of sub -basin Ae after development is
13,775 sf. (0.32 acres). The area of sub -basin Aw before development is
approximately 17,860 sf (0.41 acres). The area of sub -basin Aw after development is
13,775 sf. (0.32 acres).
III. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA:
A. Regulations
1. All storm drainage design criteria from the City of Fort Collins Drainage Criteria
Manual was considered.
2. Recommendations made in the Old Town Master Drainage Basin Plan prepared by
Resource Consultants & Engineers, Inc. were also considered.
a. Flood elevations noted in the Old Town Master Drainage Basin Plan were utilized
to establish the minimum allowable Finished Floor Elevations of the proposed
single family residences.
PAGE 3
Project No. 1536-08-97
Final Drainage and Erosion Control Report
M. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA:
A. Regulations (continued)
3. All erosion control design criteria from the City of Fort Collins Erosion Control
Reference Manual was considered.
B. Development Criteria Reference and Constraints
1. All grading design must match the existing elevations at the property line due to fully
developed properties adjacent to the site. Retaining walls are expected along the north
and south property lines.
2. The nearby intersection of Mason Street and West Mulberry Street is subject to
flooding due to insufficient capacity of the existing storm sewer.
a. According to the Old Town Master Drainage Basin Plan, the 100-year flood
elevation on Mulberry Street in the area of Howes Street Hideaways is
approximately 4993.5 feet. Refer to figure 5.6 in the Old Town Master Drainage
Basin Plan attached in Appendix IV.
b. The lowest existing elevation on the site based on survey information is 4993.93
feet.
3. Minimum Allowable finished floor elevations shall be 4995.0 feet in order to
provided the minimum 1.5 feet separation above the defined 100-year water surface
elevation. A note stating this is provided on the Master Grading, and the Drainage and
Erosion Control Plan.
4. Detention is required if the imperviousness of the site exceeds seventy percent
(70.0%). This is in accordance with the assumptions of the Stormwater Management
Model (SWMM) for subcatchment 205 in the Old Town Basin.
C. Hydrological Criteria
1. The Rational Method (Q = CIA) was used to determine the pre -developed and/or
post development peak flows for the 2, 10 and 100-year storm events at critical
points.
D. Hydraulic Criteria
1. Storm sewer and drainage channel capacities were based on the Mannings Equation.
The Mannings coefficients are as suggested by the City of Fort Collins Storm
Drainage Criteria Manual.
PAGE 4
Project No. 1536-08-97
Final Drainage and Erosion Control Report
IV. DRAINAGE FACILITY DESIGN:
A. General Concept
1. Stormwater is conveyed to West Mulberry Street by a combination of overland and
gutter flow.
2. The alley will be graded with an inverted crown to facilitate conveyance of
stormwater into Mulberry West Street.
3. Detention is not required because the imperviousness of the developed site does not
exceed 70%.
B. Specific Details
The following table summarizes the land cover and the appropriate percent
imperviousness on the existing site.
Area
Impervious
Runoff Coefficient
(acres)
%
"C"
Lawn
----------
0.53
-------------
0.00
----------------------
0.20
Roof
0.09
100.00
0.95
Concrete
0.01
100.00
0.95
Total
0.63
The imperviousness of the existing site is 15.87 %. This does not include the alley or
the 1/2 ROW which front on the property. The imperviousness percentages are taken
from Table 3-1 in the Urban Storm Drainage Criteria Manual - Volume 1. The
Runoff Coefficient is taken from the City of Fort Collins Drainage Criteria Manual..
2. The following table summarizes the land cover and the appropriate imperviousness
on the developed site:
Area
Impervious
Runoff Coefficient
(acres)
%
"C"
Lawn
-----------
0.33
---------------
0.00
----------------------
0.20
Roof
0.22
100.00
0.95
Concrete
0.02
100.00
0.95
Asphalt
0.06
100.00
0.95
Total
0.63
The resultant imperviousness of the developed site is 47.62%. This does not include
the alley or the 1/2 ROW which front on the property. The imperviousness
percentages are taken from Table 3-1 in the Urban Storm Drainage Criteria Manual -
Volume 1. The Runoff Coefficient is taken from the City of Fort Collins Drainage
Criteria Manual.
PAGE 5
Project No. 1536-08-97
Final Drainage and Erosion Control Report
IN. DRAINAGE FACILITY DESIGN:
B. Specific Details
3. The proposed development results in an increase from 15.87% impervious to 47.62%
impervious. Detention is not required because the site is less than 70% impervious.
4. The overall imperviousness of the developed site, the alley and the 1/2 ROW of
Howes Street is 57.47 percent.
5. There is an existing retaining wall / sidewalk along the south property line which the
proposed grading matches into.
6. The proposed grading at the rear (west side) of the proposed units matches the
existing drainage pattern conveying flow from south to north. The owners of the .
property to the north (Lots 10 and 11, Block 105 Harrison Addition) have written a
letter accepting runoff from the site. Copies of the letters are attached in Appendix V.
a. The proposed grading reduces the contribuitng area to Lot 11 from 0.41 acres
prior to development to 0.32 acres after development.
7. The alley has a .minimum slope of 0.50% Concrete will be used in the alley and
parking lot. The alley will act as a channel for the runoff from the site.
a. The peak 100-year flow from the site and the portion of the alley that borders the
site is 2.39 cfs.
b. The capacity of the alley at the minimum slope is 2.83 cfs.
c. Grading constraints do not allow an increase in the minimum slope of the alley
without adversely affecting the adjoining properties.
V. EROSION CONTROL:
A. General Concept
1. Erosion control measures will be as identified on the Final Grading, Drainage and
Erosion Control Plan.
2. An erosion control security deposit is required in accordance with City of Fort Collin
policy (Chapter 7, Section C: SECURITY; page 7.23 of the City of Fort Collin
Development Manual). In no instance shall the amount of the security be less than
$1,000.00.
3. Refer to the Erosion Control Security Document located in Appendix H for the
amount of the deposit.
4. Refer to the erosion control schedule on the Drainage and Erosion Control Plan for
installation schedule of the erosion control measures.
PAGE 6
Project No. 1536-08-97
Final Drainage and Erosion Control Report
VI. VARIANCE REQUEST:
A. Variance from City of Fort Collins Requirements
1. There will be no requests for any variances from the City of Fort Collins Storm
Drainage Criteria for The Howes Street Hideaways.
VII. CONCLUSIONS:
A. Compliance with Standards
1. All drainage analysis has been performed according to the requirements of the City of
Fort Collins Storm Drainage Criteria Manual, the City of Fort Collins policy, and the
Old Town Master Drainage Basin Plan.
2. All Erosion Control design complies with the City of Fort Collins Erosion Control
Reference Manual and generally accepted practices.
B. Drainage Concept
1. The drainage design for The Howes Street Hideaways is in accordance with the City
of Fort Collins requirements and the recommendations of the Master Drainage Basin
Plan for Old Town Basin.
2. There will be no adverse downstream effects due to the development of the site.
1. Fort Collins Storm Drainage Criteria Manual
2. Urban Drainage and Flood Control District Drainage Criteria Manual
3. Fort Collins Storm Erosion Control Reference Manual
4. Old Town Master Drainage Basin Plan; Prepared by Resource Consultants &
Engineers, Inc.; Dated January 7, 1993
5. Final Drainage and Erosion Control Report for Mulberry Green ; Prepared by Shear
Engineering Corporation; Project No: 1151-24-95; Dated: June, 1996
I APPENDIX I
Storm Drainage Calculations
APPENDIX I
Storm Drainage Calculations
PLOW SUMMARY FOR HOWES STREET HIDEAWAY
DESIGN CONTRIBUTING AREA C2 C10 C100 Tc Tc I2 I10 I100 Q2 Q10 Q100 PAGE
POINT SUB 2,10 100
BASIN(S) ac. min. min iph iph iph cfs cfs cfs
r rrrr+rrrrrrrrrrxrrrxrrrrrr+rr+rrxrxr+r+trrrtttr rtrttttrtrrr rrrrrr+r++♦+rrrrrrrrrrrr+rrrr+rrrrr rrrrr
1 Aw 0.32 0.43 0.43 0.54 11.00 11.00 2.46 4.31 6.92 0.34 0.59 1.20 5
2 Ae & ALLEY 0.39 0.72 0.72 0.90 11.50 11.50 2.42 4.24 6.82 0.68 1.19 2.39 6
3 ROW 0.17 0.77 0.77 0.97 7.50 7.50 2.92 5.05 8.22 0.38 0.66 1.36 0
C
I
SHEAR ENGINEERING
CORPORATION
PAGE 2
SUMMARY OF
SUBBASIN
BREAKDOWN
PROJECT: HOWES STREET HIDEAWAYS
DATE: 03/27/97
PROJ NO :1536-08-97
BY MEO
FILE: HSHBASIN
PLATTED AREA
HOWES STREET HIDEAWAYS
0.63
ACRES
ROW
0.17
ACRES
ALLEY
0.07
ACRES
TOTAL
0.87
ACRES
DEVELOPED CONDITIONS
IMPERVIOUS
PERVIOUS ,
SUB-
GRAVEL
ASPHALT
ROOF/ LAWN C2
C100
BASIN
CONCRETE
DRIVES
Cfactor
0.50
0.95
0.95 0.20
% IMPERVIOUS
13.00%
100.00%
100.00% 0.00%
ACRES
ACRES
ACRES
ACRES ACRES
trrrrrrr+rrrrrrrrrrrrrrrrrrrrrrrtr
rtrrrrrrrrrrrrrrtrtrrr
ttttrrt++rrr+rt+
SITE 0.63
0.00
0.08
0.22 0.33 0.56
0.70
1/2 ROW 0.17
0.00
0.13
0.00 0.64 0.77
0.97
ALLEY 0.07
0.00
0.07
0.00 0.00 0.95
1.00
TOTAL 0.87
0.00
0.28
0.22 0.37 0.63
0.79
Aw 0.32
0.00
0.01
0.09 0.22 0.43
0.54
Ae 0.32
0.00
0.07
0.13 0.12 0.67
0.84
Ae&ALLEY 0.39
0.00
0.14
0.13 0.12 0.72
0.90
% IMPERVIOUS =
57.47%
- INCLUDES 1/2 ROW AND ALLEY AND DEVELOPED SITE
% IMPERVIOUS =
47.62%
- SITE
ONLY- DEVELOPED CONDITIONS
% IMPERVIOUS =
15.87%
- SITE
ONLY- EXISTING CONDITIONS
SURFACE
CHARACTERISTICS
STREETS
ASPHALT
CONCRETE
GRAVEL
ROOFS
LAWNS SANDY SOIL
FLAT < 2%
AVERAGE 2 - 7%
STEEP > 7%
LAWNS HEAVY SOIL
SHEAR ENGINEERING CORPORATION
SUB -BASIN BREAKDOWN FOR HOWES STREET HIDEAWAYS
EXISTING CONDITIONS
PROJECT :HOWES STREET HIDEAWAYS
PROJ.NO. :1536-08-97 DATE: 03/27/97
LOCATION :OLD TOWN BY: MEO
FILE :HSHBASIN
NOTES :SITE ONLY
RUNOFF
COEF.
AREA
C
C+A
%
(acres)
IMPERVIOUS
0.000
0.950
0.000
100.00%
0.0000
0.010
0.950
0.010
100.00%
0.0100
0.000
0.500
0.000
50.00%
0.0000
0.090
0.950
0.086
100.001,
0.0900
0.000
0.100
0.000
0.00%
0.0000
0.000
0.150
0.000
0.00%
0.0000
0.000
0.200
0.000
0.00%
0.0000
FLAT < 21,
0.530
0.200
0.106
AVERAGE.2 - 7%
0.000
0.250
0.000
STEEP > 7% _
0.000
0.350
0.000
TOTAL AREA
0.630
0.201
C2
C10
C100
COMPOSITE C VALUE
0.319
0.319
0.399
% IMPERVIOUS
15.87%
SITE ONLY
0.00% 0.0000
0.00% 0.0000
0.00% 0.0000
0.1000
PAGE 3
SURFACE
CHARACTERISTICS
STREETS
ASPHALT
CONCRETE
GRAVEL
ROOFS
LAWNS SANDY SOIL
FLAT < 2%
AVERAGE 2 - 7%
STEEP > 7%
LAWNS HEAVY SOIL
SHEAR ENGINEERING CORPORATION
SUB -BASIN BREAKDOWN FOR HOWES STREET HIDEAWAYS
DEVELOPED CONDITIONS
PROTECT :HOWES STREET HIDEAWAYS
PROJ.NO. :1536-08-97 DATE: 03/27/97
LOCATION :OLD TOWN BY: HBO
FILE :HSHBASIN
NOTES :SITE ONLY
RUNOFF
COEF.
AREA C C*A %
(acres) IMPERVIOUS
0.060 0.950 0.057 100.00% 0.0600
0.020 0.950 0.019 100.00% 0.0200
0.000 0.500 0.000 50.00% 0.0000
0.220 0.950 0.209 100.00% 0.2200
0.000 0.100 0.000 0.00% 0.0000
0.000 0.150 0.000 0.00% 0.0000
0.000 0.200 0.000 0.00% 0.0000
FLAT < 21,
0.330
0.200
0.066
AVERAGE 2 - 7%
0.000
0.250
0.000
STEEP > 7%
0.000
0.350
0.000
TOTAL AREA
0.630
0.351
C2
C10
C100
COMPOSITE C VALUE
0.557
0.557
0.696
% IMPERVIOUS
47.62%
SITE ONLY
0.00% 0.0000
0.00% 0.0000
0.00% 0.0000
0.3000
PAGE 4
SHEAR ENGINEERING CORPORATION
FLOW TO CONCENTRATION POINT 1
FROM SUBBASIN Aw
PROJECT: HOWES STREET HIDEAWAY: DATE 03/27/97
LOCATION:FORT COLLINS PROS. NO.1536-08-97
FILE: HSHRUN BY MEO
NOTE: CP-1 IS NEAR THE CENTER OF THE SITE AT THE NORTH PROPERTY LINE
AREA (A)= 0.320 ACRES
RUNOFF CORF. (C) -
2 YEAR 10 YEAR 100 YEAR
C = �0.43 0.43 0.54
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 85 FEET SLOPE = 0.70 t
2 YEAR 10 YEAR 100 YEAR
C 0.20 0.20 0.25
Ti (min)= 17.45 17.45 16.48
TRAVEL TIME (Tt)=L/(60*V) FLOW TYPE
L (ft) = 145 S (It) _ 0.5 GUTTER
L (ft) _? S (}) _? ?
L (ft) _? S (t) _? ?
L (ft) _? S (4) _? ?
L (ft) _? S (i) _? ?
L (ft) _? S (i) =7 ?
L (ft) _? S (6) _? ?
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2
TOTAL LENGTH = 230 L/180+10= 11.28 <
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc.(min)= 11.28 11.28 11.28
USE Tc = 11 11 11
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 2.46 4.31 6.92
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cf6)
2 YEAR 10 YEAR 100 YEAR
Q = 0.34 0.59 1.20
PAGE 5
V (fps)
= 1.5
Tt(min)=
1.61
IV (fps)
_?
Tt(min)=
.0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
TOTAL TRAVEL TIME
(min) =
1.61
19.07 =Ti+Tt
CHOOSE LESSER
CONCLUDE:PEAK FLOW FROM WESTERN PORTION OF SITE AFTER DEVELOPMENT TO LOT 11
a
SHEAR ENGINEERING CORPORATION
PAGE 6
FLOW TO CONCENTRATION POINT 2
FROM SUBBASIN As & ALLEY
PROJECT: HOWES STREET HIDEAWAY DATE 03/27/97
LOCATION:FORT COLLINS PROJ. NO.1536-08-97
FILE: HSHRUN BY HBO
NOTE: CP 2 IS W NE CORNER OF SITE IN ALLEY
AREA (A)= 0.390 ACRES
RUNOFF COBF. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.72 0.72 0.90
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 100 FEET SLOPE = 0.50 lk
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 21.16 21.16 19.98
TRAVEL TIME (Tt)=L/(60*V) FLOW TYPE
L (ft) = 190 S (!) - 0.5 GUTTER
L (ft) _? S M _? ?
L (ft) _? S (%) _? ?
L (ft) _? S _? ?
L (ft) _? S _? ?
L (ft) _? S _? ?
L (ft) _? S (4) _? ?
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2
TOTAL LENGTH = 290 L/180+10= 11.61 <
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR .10 YEAR 100 YEAR
Tc (min)= 11.61 11.61 11.61
USE Tc = 11.5 11.5 11.5
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 2.42 4.24 6.82
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q = 0.68 1.19 2.39
CONCLUDE:PEAK FLOW FROM SITE TO ALLEY
MINIMUM SLOPE OF ALLEY = 0.005 FT/FT
CAPACITY OF ALLEY = 2.83 CPS
SEE PAGE 8
V (fps)
= 1.50
Tt(min)=
V (fps)
_?
Tt(min)=
V (fps)
_?
Tt(min)=
V (fps)
_?
Tt(min)=
V (fps)
_?
Tt(min)=
V (fps)
_?
Tt(min)=
V (fps)
_?
Tt(min)=
TOTAL TRAVEL TIME
(min) _
22.09
=Ti+Tt
2.11
0.00
0.00
0.00
0.00
0.00
0.00
2.11
SHEAR ENGINEERING .CORPORATION
PAGE 7
FLOW TO CONCENTRATION POINT 3
FROM SUBBASIN ROW
PROJECT: HOWES STREET HIDEAWAY DATE 03/27/97
LOCATION:FORT COLLINS PROD. NO.1536-08-97
FILE: HSHRUN BY MHO
NOTE: CP 1 IS NEAR THE CENTER OF THE SITE AT THE NORTH PROPERTY LINE
AREA (A)= 0.170 ACRES
RUNOFF COEF. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.77 0.77 0.97
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (TO
OVERLAND TRAVEL TIME (Ti)
LENGTH = 20 FEET SLOPE = 2.00 }
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 5.99 5.99 5.66
TRAVEL TIME (Tt)-L/(60*V) FLOW TYPE
L (ft) = 145 S (}) = 0.5 GUTTER
L (ft) _? S (}) _? ?
L (ft) =7 S (}) _? ?
L (ft) _? S (}) _? ?
L (ft) _? S (}) _? ?
L (ft) _? S (}) _? ?
L (ft) _? S (}) _? ?
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2
TOTAL LENGTH = 165 L/100+10= 10.92 >
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 7.60 7.60 7.60
USE Tc = 7.5 7.5 7.5
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 2.92 5.05 8.22
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q = 0.38 0.66 1.36
V (fps)
= 1.5
Tt(min)=
1.61
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
V (fps)
_?
Tt(min)=
0.00
TOTAL TRAVEL
TIME
(min) =
1.61
7.60
=Ti+Tt
CHOOSE LESSER
CONCLUDE:PEAK FLOW TO NORTWEST CORNER OF PROPERTY IN STREET FROM 1/2 ROW
SHEAR ENGINEERING CORPORATION
PAGE e
CHANNEL CAPACITY
PROJECT NAME: HOWES STREET HIDEAWAYS DATE: 03/27/97
PROJECT NO. 1536-08-97 BY : MEO
SWALE DESCRIPTION:PAVED ALLEY WITH INVERTED CROWN
PILE: HSHCHAN
CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL
CHANNEL CONFIGURATION: TRIANGULAR Q100 (cfa) = 2.74
CHANNEL LINING: CONCRETE REFER TO PAGE 6
Da Db Dc Sc n W I
(ft) (ft) (ft) (M) (ft) (ft)
---- ---- ---- ---- ----- ---- ----
10.00 10.00 0.20 0.500 0.016 0.00 0.05 -
0.02 = LEFT BANK SLOPE
0.02 = RIGHT BANK SLOPE
DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V
(ft) (ft) (s.f.) (ft) (A/P) (cfe) (ft/aec)
--------------------------------------------------------
0.20 20.00 2.00 20.00 0.22 0.07 2.83 1.41
0.15 15.00 1.13 15.00 0.18 0.07 1.31 1.17
0.10 10.00 0.50 10.00 0.14 0.07 0.45 0.89
0.05 5.00 0.13 5.00 0.09 0.07 0.07 0.56
0.00 0.00 0.00 0.00 0.00 0.07 0.00 0.00
r rrrrrr+xx++t+++r+x+r+rrrr++rrrrrrrrrrrrrrrrrrrrrrrrrrrrrxxrxr+xrr•rrrr•
DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V
(ft) (ft) (s.f.) (ft) (A/P) (cfs) (ft/sec)
CONCLUDE:ALLEY CAPACITY IS ADEQUATE
SLOPE OF ALLEY INCREASES TO NORTH
APPENDIX II
Erosion Control Calculations
Erosion Control Sequencing schedule
Erosion Control security deposit estimate
RAINFALL PERFORMANCE STANDARD EVALUATION
PROJECT:
HOWES STREET HIDEAWAYS
STANDARD FORM A
COMPLETED BY:
MARK OBERSCHMIDT
DATE: 03/27/97
r rrrrrr r.r:xxtttxxrttrtrrrrrrrrrrrrrrrrrrrrrtrretrrr
xrrrrrrrrrrrttrttxttrttrtrtxrxtxtrrrxrt
DEVELOPED
BRODIBILITY Asb
Lsb Ssb
Lb Sb PS
SUBBASIN
t♦rrrrrrrr rrrrrrrrrrrrr»rrrrrrrrrrt+rt•rrrrrrrrrrr
ZONE (ac) (ft) M
rrrrr+trttrrrerrrrrrrrrr
(feet) (t) M
rrrrr»rrrrrrrr
IA
MODERATE 0.47
100.00 1.00
47 0.47
1B
MODERATE 0.40
90.00 1.00
36 0.40
rr trrrtrxrrtrrtrx+rrtttxtrxttt+ttttrtxtxtxxtrtrtr+rrrr rrrtttr tt xxrrtrrtt
0.87 95.40 1.00
LINEAR INTERPOLATION NOT REQUIRED
USE L = 100
AND S = 1.00 THEREFORE THE PERFORMANCE STANDARD = 74.6 PERCENT
CONCLUDE:PERFORMANCE STANDARD = 0.00%
EROSION CONTROL PLAN OVERALL EFFECTIVENESS MUST EXCEED THIS
EFFECTIVENESS CALCULATIONS
STANDARD FORM B
PROTECT: HOWES STREET HIDEAWAY
PROJ. NO.1536-08-97
BY: MARK OBERSCHMIDT
DATE
03/27/97
------------------------------------------------------------------------------------------
EROSION CONTROL
C-FACTOR
P-FACTOR
COMMENT
METHOD
VALUE
VALUE
------------------------------------------------------------------------------------------
ROUGHBNED GROUND
1.00
0.9
ROOF AREAS SUBBASIN
Al ONLY
SILT PENCE
1.00
0.5
SUB -BASINS Al ONLY
ASPHALT
0.01
1.0
SUB -BASINS Al ONLY
SOD
0.01.
1.0
SUB -BASINS Al ONLY
ESTABLISHED VEGETATION
0.02
1.0
SUBBASIN A2 ONLY
------------------------------------------------------------------------------------------
MAJOR PS SUB
AREA
CALCULATIONS
BASIN t BASIN
acre
AREA
C.
P
------------------------------------------------------------------------------------------
ALL 74.60% Al
0.47
ROOF
0.09
ACRES 1.00
0.90
SOD
0.24
ACRES 0.01
1.00
EQUATIONS
ASPHALT
0.14
ACRES 0.01
1.00
C = WEIGHTED AVG OF C X AREA
P = (WEIGHTED AVG
OF P X AREA) X P.
C -
0.1996
EFF = (1 - P X C)
X 100
P =
0.4904
EFF
90.21%
------------------------------------------------------------------------------------------
NO WORK DONE IN SUBBASIN A2 0.40 ACRES
THEREFORE EFF = 100.00%
++r++rrx+x•x•x•xx+xx+xx+♦r+r+rrr+rxr+x+xxxx+xxx++r+xr+r++rx+++rexxxx xxxx+rx+r+r++rxxxrxxx•
TOTAL AREA = 0.87 ACRES
OVERALL EFFECTIVENESS = 94.71$ > 74.60$
CONCLUDH:HROSION CONTROL PLAN IS EFFECTIVE
Howes Street Hideaways
Const Seq
R-Client / Rayline/ Harrisons / Erosion / Const Seq.
1536-08-97
Date: 02/28/97
Revised: 02/28/97
CONSTRUCTION SEQUENCE
PROTECT: Howes Street Hideaways
STANDARD FORM C
SEQUENCE FOR 1997-1998 ONLY COMPLETED BY: MEO / Shear Engineering Corp.
Indicate by use of a bar line or symbols when erosion control measures will be installed. Major
modifications to an approved schedule may require submitting a new schedule for approval by the City
Engineer.
Year 197 98
Month J J A S O N D J F M A M J
OVERLOT GRADING
WIND EROSION CONTROL
* Soil Roughening
Perimeter Barrier
Additional Barriers
Vegetative Methods
Soil Sealant
Other
RAINFALL EROSION CONTROL
STRUCTURAL:
Sediment Trap/Basin
Inlet Filters
Straw Barriers
Silt Fence Barriers
Sand Bags
Bare Soil Preparation
Contour Furrows
Terracing
Asphalt/Concrete Paving
Other
VEGETATIVE:
Permanent Seed Planting
Mulching/Sealant
Temporary Seed Planting
Sod Installation
Nettings/Mats/Blankets
Other
***
***
*** *** *** ***
STRUCTURES: INSTALLED BY: OWNER MAINTAINED BY: OWNER
VEGETATION/MULCHING CONTRACTOR: OWNER
DATE PREPARED: 0212E 97 DATE SUBMITTED: 03/25/98
APPROVED BY THE CITY OF FORT COLLINS ON:
April 4, 1997
Project No: 1536-08-97
Basil Hamdan
City of Fort Collins Stormwater Utility
P.O. Box 580
Ft. Collins, Colorado 80522
Re: Erosion Control Cost Estimate
Howes Street Hideway
Lots 12-14, Block 105, Harrison's Addition; Fort Collins, Colorado
Dear Basil,
Attached is the erosion control security deposit estimate for Howes Street Hideaway
ESTIMATE 1:
145 LF of Silt Fence ® $ 3.00 per LF
TOTAL ESTIMATED COST:
ESTIMATE 2:
re -vegetate the disturbed area of 0.32 acres at $636.00 per acre
TOTAL ESTIMATED COST:
$ 435.00
$ 435.00
x 1.50
S 652.50
203.52
$ 203.52
x 1.50
$ 305.28
In no instance shall the amount of the security be less than $1,000.00. Therefore, the total
required erosion control security deposit for Lots 12-14, Block 5, Harrison's Addition will be
$ 1,000.00.
If you have any questions, please call at 226-5334.
Sincerely,
VF�
Mark Oberschmidt
Shear Engineering Corporation
MEO/ meo
cc: Rayline Development Corporation
Dave Stringer, City of Fort Collins
4836 S. College, Suite 12 Ft. Collins, CO 86525 (970) 226.5334 FAX (970) 282-0311
SHEAR'
ENGINEERING
CGRPGRATIGN
April 4, 1997
Project No: 1536-08-97
Re: EROSION CONTROL SECURITY DEPOSIT REQUIREMENTS:
Lots 12-14, Block 105, Harrison's Addition; Fort Collins, Colorado
A. An erosion control security deposit is required in accordance with City of Fort Collins
policy (Chapter 7, Section C: SECURITY; page 7.23 of the City of Fort Collins
Development Manual). In no instance shall the amount of the security be less than
$ 1000.00.
a. The cost to install the proposed erosion control measures is approximately $ 435.00
Refer to the cost estimate attached in Appendix I. 1.5 times the cost to install the
erosion control measures is $ 652.50
b. Based on current data provided by the City of Fort Collins Stormwater Utility, and
based on an actual anticipated net affected area which will be disturbed by
construction activity (approximately 0.32 acres), we estimate that the cost to re -
vegetate the disturbed area will be $ 203.52 ($ 636.00 per acre x 0.32 acres). 1.5
times the cost to re -vegetate the disturbed area is $ 305.28 The $ 636.00 per acre
for re -seeding sites of less than 5 acres was quoted to us by the City of Fort Collins
Stormwater Utility personnel.
CONCLUSION:
The erosion control security deposit amount required for Lots 12-14, Block 5, Harrison's
Addition will be $ 1,000.00.
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-031 1
APPENDIX III
Backup Diagrams and Exhibits
Table 3-3; Rational Method Runoff Coefficients for Composite Analysis
Table 3-4; Rational Method Frequency Adjustment Factors
Figure 3-2; Estimate of Average Flow Velocity for Use with the Rational Formula
Figure 3-1; City of Ft. Collins Rainfall Intensity Duration Curve
R-M-P Medium Density Planned Residential District — designation for medium density
areas planned as a unit (PUD) to provide a variation in use and building placements
with a minimum lot area of 6,000 square feet.
R-L-M Low Density Multiple Family District — areas containing low density multiple family
units or any other use in the R-L District with a minimum lot area of 6,000 square feet
for one -family or two-family dwellings and•9,000 square feet for multiple -family
dwellings.
M-L Low Density Mobile Home District — designation for areas for mobile home parks
containing independent mobile homes not exceeding 6 units per acre.
M-M Medium Density Mobile Home District — designation for areas of mobile home
parks containing independent mobile homes not exceeding 12 units per acre.
B-G General Business District — district designation for downtown business areas,
including a variety of permitted uses, with minimum lot areas equal to 1/2 of the total
floor area of the building.
B-P Planned Business District — designates areas planned as unitdevelopments to
provide business services while protecting the surrounding residential areas with
minumum lot areas the same as R-M.
H-B Highway Business District — designates an area of automobile -orientated busi-
nesses with a minimum lot area equal to 1/2 of the total floor area of the building.
B-L Limited. Business District — designates areas for neighborhood convenience
centers, including a variety of community uses with minimum lot areas equal to two
times the total floor area of the building.
C Commercial District —designates areas of commercial, service and storage areas.
I-L Limited Industrial District — designates areas of light industrial uses with a minimum
area of lot equal to two times the total floor area of the building not to be less than
20.000 square feet.
I-P Industrial Park District —designates light industrial park areas containing controlled
industrial uses with minimum lot areas equal to two times the total floor area of the
building not to be less than 20,000 square feet.
I-G General Industrial District — designates areas of major industrial development.
T Transition District — designates areas which are in a transitional stage with regard
to ultimate development.
For current and more explicit definitions of land uses and zoning classifications, refer to the
Code of the City of Fort Collins, Chapters 99 and 118.
Table 3-3
RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS
Character of Surface Runoff Coefficient
Streets, Parking Lots, Drives:
Asphalt................................................................................................ 0.95
95
Concrete............................................................................................. 0.
Gravel................................................................................................. 0.50
Roofs.......................................................................................................... 0.95
Lawns, Sandy Soil:
0.1
Flat<2%.............................................................................................
0.5
Average2 to 7%..................................................................................
0.20
Steep>7%..........................................................................................
Lawns, Heavy Soil:
Flat<2%.............................................................................................
0.20
Average2 to 7%..................................................................................
0.25
Steep>7%......... :................................................................................
0.35
MAY 1984 3-4 DESIGN CRITERIA
3.1.7 Time of Concentration
In order to use the Rainfall Intensity Duration Curve, the time of concentration must be
known. This can be determined either by the following equation or the "Overland Time of
Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See
Figure 3-2).
Tc= 1.87 (1.1 -CC,) D"Z
S t�
Where Tc = Time of Concentration, minutes
S = Slope of Basin, %
C = Rational Method Runoff Coefficient
D = Length of Basin, feet
C, = Frequency Adjustment Factor
Time of concentration calculations should reflect channel and storm sewer velocities as well
as overland flow times.
3.1.8 Adjustment for Infrequent Storms
The preceding variables are based on the initial storm, that is, the two to ten year storms. For
storms with higher intensities an adjustment of the runoff coefficient is required because of
the lessening amount of infiltration, depression retention, and other losses that have a
proportionally smaller effect on storm runoff.
These frequency adjustment factors are found in Table 3-4.
Table 3-4
RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS
Storm Return Period
(years)
2to10
11 to 25
26 to 50
51 to 100
3.2 Analysis Methodology
Frequency Factor
C,
1.00
1.10
1.20
1.25
Note: The product of C times C, shall not exceed 1.00
The methods presented in this section will be instituted for use in the determination and/or verification
of runoff at specific design points in the drainage system. These methods are (1), the Rational Method
and (2) the Colorado Urban Hydrograph Procedure (CUHP). Other computer methods, such as
SWMM, STORM, and HEC-1 are allowable if results are not radically different than these two. Where
applicable, drainage systems proposed for construction should provide the minimum protection as
determined by the methodology so mentioned above.
3.2.1 Rational Method
For drainage basins of 200 acres or less, the runoff may be calculated by the Rational
Method, which is essentially the following equation:
Q = C,CIA
Where Q = Flow Quantity, cfs
A =Total Area of Basin, acres
C, = Storm Frequency Adjustment Factor (See Section 3.1.8)
C = Runoff Coefficient (See Section 3.1.6)
1 = Rainfall Intensity, inches per hour (See Section 3.1.4)
3.2.2 Colorado Urban Hydrograph Procedure
For basins larger than 200 acres, the design storm runoff should be analyzed by deriving
synthetic unit hydrographs. It is recommended that the Colorado Urban Hydrograph
Procedure be used for such analysis. This procedure is detailed in the Urban Storm Drainage
Criteria Manual, Volume 1, Section 4.
MAY 1984 3-5 DESIGN CRITERIA
No Text
DRAINAGE CRITERIA MANUAL
RUNOFF
5C
30
F 20
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10
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011
MEN
ON
5�
4 .0 •3 1 2 3 5 10 20
VELOCITY AN FEET PER SECOND
FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR
USE WITH THE RATIONAL FORMULA.
*MOST FREQUENTLY OCCURRING "UNDEVELOPED"
LAND SURFACES IN THE DENVER REGION.
REFERENCE: "Urban Hydrology For Small Watersheds" Technical
Release No. 55, USDA, SCS Jan. 1975.
5 =1-84
URBAN DRAINAGE & FLOOD CONTROL DISTRICT
r—
DRAINAGE CRITERIA MANUAL
50
30
F- 20
z
w
U
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10
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I
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►�.
C
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MEN
s 5 1 2 3 5 10 20
VELOCITY IN FEET PER SECOND
FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR
USE WITH THE RATIONAL FORMULA.
*MOST FREQUENTLY OCCURRING"UNDEVELOPED"
LAND SURFACES IN THE DENVER REGION.
REFERENCE: "Urban Hydrology For Small Watersheds" Technical
Release No. 55, USDA, SCS Jan. 1975.
5 =1-84
URBAN DRAINAGE & FLOOD CONTROL DISTRICT
APPENDIX IV
Portions of the Old Town Master Drainage Basin Plan
—f\ rnln W.V 7cz-7
r
:R
Pros ect Rd.
Rect Rd.
Williams
ra e Rd.1
Figure 1.1:
GENERAL. LOCATION MAP
z MASTER DRAINAGE
TOLD TOWN
Scale: BASIN PLAN for the
CITY of FORT COLLINS
1.2
LLJ
N
ua» r:
LU =
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Table 4.1.
Design Storms for Old Town Basin.
Rainfall 1'nt s:
Ending
in
2 Year
X V
5 Year
10 Year
25 Year
100=Year
5
0.12
0.36
0.48
0.48
0.60
10
0.36
0.60
0.60
0.72
0.96
15
0.48 1
0.60
0.72
0.96
1.44
20
0.60
0.84
0.96
1.32
1.68
25
0.84
1.56
2.16
2.28
3.00
30
1.80
2.52
3.12
3.72
5.04
35 =
3.24
4.68
5.64
6.84
9.00
40
1.08
2.04
2.28
2.88
3.72
45
0.84
1.08
1.12
1.56
2.16
50
0.48
0.72
0.84
1.08
1.56
55
0.36
0.48
0.72
0.84
1.20
60
0.36
0.48
0.60
0.72
0.84
65
0.36
0.48
0.60
0.72-
0.60
70
0.24
0.36
0.48
0.48
0.48
75
0.24
0.36
0.36
0.36
0.36
80
0.24
0.24
0.24
0.36
0.36
85
0.24
0.24
0.24
0.36
0.24
90
0.12
0.24
0.12
0.36
0.24
95
0.12
0.12
0.12
0.24
0.24
100
0.12
0.12
0.12
0.12
0.24
105
0.12
0.12
0.12
0.12
0.24
110
0.12
0.12
0.12
0.12
0.24
115
0.12
0.12
0.12
0.12
0.12
120
0.12
0.12
0.12
0.12
0.12
at hand, recognizing that it is always possible to make additional refinements or revisions
to any model.
4.1.2 Basin Subdivision
As can be seen from Figure 4.1, the Old Town Basin below Larimer County Canal
No. 2 was subdivided into three smaller subbasins numbered 1, 2, and 3. Subbasin 1
encompassed the area in the northern part of the drainage; Subbasin 2 encompassed the
central part, including the downtown area; and Subbasin 3 covered the southern part.
Each of the subbasins was drained by a major storm sewer.
4.3
Table 4.3.
Differences in Impervious Area Percentages for
Existing
and Future Conditions.
Subcatchment...
Percent Impervious
Number
Existm g
Future
6
40
70
102
50
70
108
40
60
109
40
60
201.
40
60
203
50
70
204
60
70
205
50
70
206
40
60
211
40
60
304
40
60
305
40
60
312
40
50
360
20
40
361
60
100
4.9
No Text
No Text
Storage functions were used at elements 203, 204, 205, and 206 in Subbasin 2 to
simulate the ponding of floodwaters behind the various north -south streets with high
crowns. During the 100-year flood, these ponds filled before the peak runoff. Once filled,
the ponds did little to attenuate flood peaks; the inflow rate essentially equaled the outflow
rate. However, this was not the case with the less severe storms.
.Snlitter_functions were used at elements.227 228 2�9 4 F 99r�
distribute spillsAam the aondina areas behind College and Mason to either the downtown
area or eet. Splitter functions were used at elements 215-216-217 and 218- ;>
219-220 to direct a portion of the runoff near the intersection of Myrtle and Peterson
Streets into Subbasin 3.• Splitter functions were also used at elements 324-325-326 and
327-328-329to determine the amount of water that would be carried under Riverside
through the storm drains and the amount that would be left flowing down Riverside parallel
to the railroad tracts. A splitter function was used at elements 357-358-359to account
for surface returns back to Mulberry along Smith Street...,
Runoff in Upper Part of Subbasin 3. In the upper partof Subbasin 3, most of the .
flood runoff, which included spills from the Larimer County.Canal No. 2, collected along
Elizabeth Street. The runoff moved across Shields and onto CSU property. Storm drains
diverted some of the runoff to the south and into the Spring Creek drainage, although most
of the runoff flowed across CSU through the intramural field and eventually discharged into
an open reach of the Arthur Ditch. The Arthur Ditch diverted much of the intercepted..
flood runoff into a box culvert that extended under the CSU campus. The culvert, in turn,
carried water out of the Old Town drainage and into the Spring Creek drainage.' The
capacity of the open reach of the ditch was exceeded during the course of the 100-year
flood, resulting in excess waters spilling into the CSU lagoon located immediately.
.downstream of the ditch near the CSU Student Center:
77.
Routing and storage of floodwaters in the Arthur Ditch and CSU lagoon were
simulated through the use of splitter functions at elements 353-354-355 and 336-337-338
and through the use of the storage*function.for element 315., It was assumed that the
Arthur Ditch was carrying 60 cfs of irrigation water for the duration of the flood. It was
estimated that the ditch could carry an additional 35 cfs before water, would overtop the.:
ditch banks and spill into the CSU lagoon. - Inflows exceeding 35 cfs were routed into the
lagoon using the splitter function for elements 353-354-355. It was further estimated that
releases through the Arthur Ditch box culvert under the CSU campus would increase once .
the water elevation in the lagoon reached the top of the open ditch. The dam creating the
CSU lagoon is higher in elevation than the Arthur Ditch.: Estimates for the additional .
surcharged capacity of the box culvert were incorporated into the release rates for the
storage pond function at element 315. Surface spills, which would result from a complete
filling of the lagoon; were simulated to occur first at the low spot near the intersection of
Pitkin and Center Streets and then over the top of the dam itself near the Student Center.
The splitter function for elements 336-337-338 was used to distribute any surface spills.
Surface spillage did not occur from the lagoon for the future condition runs. The.
regional detention pond near Skyline and Elizabeth Streets coupled with improvements to
the Larimer #2 Canal, reduces the current spilling into the Old Town Basin. The future
condition runs assumed those proposed improvements. The simulated spillage from the
lagoon for existing: conditions was all to the south, near the intersection of Pitkin and
Center; no spillage occurred over the top of the dam into the lower part of Subbasin 3.
4.18
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Figure 5.15:
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Legend:
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Appendix V
Correspondence
A' -14-97 MON 09:48 CZE)TWE 9
FAX NO. 303 4! 2 . �_G0 . - G i; � ;
April 10, 1997
Basil l tamddn
City of Ft. Collins Storrnwater Utility
P.O. Box 580
Ft Collins, CO 80524
RE' Howes Street Hideaways
Previously, Lots 12-14, Block 105 Harrison's Addition
Dear Basil.
This letter i$ provided as statement of my OPProval and acceptance of storm
flows from the neighboring property due to the improvements proposed by
Rayline DeVelopment-Corp., with the project referred to as "Howes Stroot
Hideaways". I understand that storm drainage patterns my be slightly adjusted
from historic drainage. patterns which may have existed prior to completion of the
proposed improvements, Please provide plan approval for "Howes Street
Hideaways" Utilizing this letter as my approval and acceptance of drainage
Patterns which my be slightly modified by the project.
If you have questions concerning this statenlent, please do not hesitato to call at
6-74067.
OW is7
Sincerely,
W,�.
Darrel Hardy
Owner of Lot lo, Block 105 Harrivon's Addition
1536-08-97
APR-01-97 11:IF. AM RAYLINE. 970 223 06E:O P.01
April 1, 1997
Basil Hamdan
City of Ft. Collins Stormwater Utility
P.O. Box 580
Ft. Collins, CO 80524
RE: The Howes Street Hideaways
Previously, Lots 12-14, Block 105 Harrison's Addition; Ft. Collins, Colorado
Dear Basil,
This letter is provided as statement of my approval of grading on my property
and acceptance of storm flows from the neighboring property due to the
improvements proposed by Rayline Development Corporation with the project
referred to as Howes Street Hideaways". 1 understand that storm drainage
patters my be slightly adjusted from historic drainage patters which my have
existed prior to completion of the proposed improvements. Please provide plan
approval for "Howes Street Hideaways" utilizing this letter as my approval and
acceptance of drainage patters which my be slightly modified by the project.
If you have questions concerning this statement, please do not hesitate to call at
970-927-4887.
Sincere ,
Doug
Owner of Lot 11, Block 105, Harrison's Addition
Stuffer Enveloue
Drainage and Erosion Control Plan
• I I
_ NOTE: MINIMUM ALLO\VAIILL MIS11ED FLOOR
k( } -----. ^ �I I - ELEVA'l10\ Ib 95.0 FEEL' LV UROLIt to PROVIDE
L ` _6_e -- ' ---- YEAR
REQUIRED 1 SEPARATION DRIN'THTHE OLD
00.
H----- �yTr•h--- ( VEER FLOOD ELEVATION NOTED W '1'RL OLD
-� (_ 'MOWN MASTER DRAINAGE BASIN PLAN. THE 1W-
_ - YEAR FLOOD ELEVATION LY 93.5 ACCORDINC TO
THE OLDTOWN HARDER DRAINAGE BASIN PLAN.
k Sli few
y
It
I -I ---}- B I STANDARD EROSION CON FROL CONSTRUCTION PLAN NOILS
I 1 I R yI I Ir IWO
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i1 f I �I I Y j 1. i (sink Wb pp data 1 All all u 1 r lCA b° fl J lt.
[f I w IklAmPliltmwlA w ar larappo Ill tireVV Iv l+
' 41 i i-5--�•- I O / '1iN k 4 I PI xl rvl -
il di 9 li r h,,•-.,I BLOCK 105 ,I j i BLOCK '105 _ 7 vrv.11, Io-.K Sws wli b"P`i 14 en-11 `IwCto ��INI firer or
ytlrsurbav or rie r
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l� , • e I ) Iwalll 1111 y 1J Il bu kvµll rvuyl d JI by Ntl J L
yy j \ r � / I - . � '. & ) PII tl.+IdPV tl tlnJin utility :
a is Arm]
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1 f- �.• ma wel tlS YilWI pw y
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it
l I —•-Ysn \ All _ ''V+Y_Halt'yy'Fl _�i'_ G __-_ t( � ) ___ 1�'w 1. M' a Pwe.dMn Rson 1 U Y
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IL
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1 r�� -,iL. 'y`�reagig ka esseq an nc rr J G 1 a r
t va I TK."/'4>•1 1 .. ,;'r :��'] 5♦'w.._ 1� +. .'3fv 1 R'll drl kdwr YeL AII. 1 F"n IY1 P W d Y
- ae� Cl,- <• aba116eK WJu IuU a IJI wl W"se llv4:el" ___ :..rt Ix'Ix'- . 6 N oi2 .'. .nor a,F`Fr,--,^E'A4yyc„ I .'•'Till exYJ� "NR P
N »i.> ++4� ,� X, T 0� r 1•= ' V No scilCast¢Imll .eJ
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—I—SIG°a"—I
I / • 91]d C11Y Opinions,Partially pP k y dropping. J 1 'A I larqu
50. n I • Y Y 9 pslw we 1 al II h. c6 u.J
/ City since b I rlc. Nry laJvµW l d' I k
all S LmneJ IY by I o ,
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11 I F I / II Xzs iaam tiffs Ro �„ ICAP A
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J 'S'•°'- i EXImNG h
2 STORY Y
l II`4 i �I I a , r IIxSTORY I I BRICK k FRMIE-� -
ii J EMS INC r All
BRICK k PR E rj
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SOU H HOWES STREET
100- RICNT-Of-WAY
1 ,
I
- - - - - - - - - - - - - - - - - - - - - City of Fort Collins, Colorado
UTMR PLAN APPROVAL
APPROVED'
•. ' ,wx,a wrt
CHECKED AT
..�..�..... c3 __ _ _ __4
CHECKED
art
. - . .:
CHECKED BY _
A.
snm nrmurcx v <
_ _ _ _ _ _ _ _ _ _ _ ,.. CHECKED By.M
. 'C: - CHECKED 9 :. +, ;
9[Y15wX5 OIA PRIL 1997 NM CADIraK _ aul - nr[[ MA"TEfl GHADINO ELAN PROJECT 00.
Site— m o`"'9o-" B.ws: RATLINE DEVELDPMENT CORPORATION �I SHEAR ENGINEERING CORPORATION 'pppjSHEETHiETS
Car—w— Mral, FeD LbN. CM.kN L836 50, COLLEGE AVE. SUITE 12, PoBT COLLINS, COLOPADO 80525 LOTS 1%.-14-6LGOaK .1D5I HARRISON'S ADDITION 1536-08 97 _
Rm, 4 B,.�s. Smk '^ 1 = 20' APpraeE B.W.S. PHONE: (920) 226-5334 (970) 226-4451 PAX: (970) 282-0311 FORT COLWNS. COLORADO RATSrt .