HomeMy WebLinkAboutMARTINEZ PUD - PRELIMINARY - 4-97 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTAPPENDIX H
Erosion Control Calculations
Erosion Control Sequencing schedule
Erosion Control security deposit estimate
January 16, 1997
Project No: 1558-01-97
Basil Hamdan
City of Ft. Collins Stormwater Utility
P.O. Box 580
Ft. Collins, Colorado 80524
Re: Martinez P.U.D.; Ft. Collins, Colorado
Dear Basil,
Enclosed, please find the Preliminary Drainage and Erosion Control Report for Martinez
P.U.D. The hydrology data and the hydraulic analysis presented in this report complies with the
requirements of the City of Fort Collins Storm Drainage Criteria Manual dated March, 1984, the
City of Fort Collins Erosion Control Reference Manual and the Old Town Master Drainage
Basin Plan for the City of Fort Collins.
If you have questions, or require further information on any item, please call me or Mark
Oberschmidt at (970) 226-5334.
Shear Engineering Corporation
BWS / meo
cc: James W. Leach; Wonderland Hill Development Company
Mikal Stephen Torgerson; M Torgerson Architects
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-031 l
jov
Figure 4:
FLOODED AREAS for I
100 YEAR STORM
OLD TOWN
MASTER DRAINAGE
BASIN PLAN for the
CITY of FORT COLLINS F
RCE if
Legend:
FLOODED AREAS MAPPED WITH DETAILED MAPPING
APPROXIMATE LIMITS o1 POTENTIAL SHALLOW
�u FLOODING LESS THAN 1.5- IN DEPTH
f i
w:. t
_ I
i= mamma t s ;;
Figure 2:
J11
-_ - MAJOR STORM SEWERS
---,�--CIA= OLD TOWN MASTER DRAINAGE
- BASIN PLAN for the
Ex
�-; � F _,_I`;_,_(� J �'� !_, � ! � •- ;�. CITY of FORT COLLINS
i.�.�J ��:.J • L..J % ht CWIm CaaWe
- _ Legend:
.t
(/ I` D4Mtt ! •- D AE OMMTER OR GREATER
ict
• - \\ `'
..t:no .rli �• �r �i Dktt e p �- �\ i <e — _:. 100
• N 111 _��.�L- _PVCNUE .-. :Li—, R _._
a-.• 2x vrot
�r { J — ;o Z Scale
�:• .... �.. r DutEkt e� i— -
--- Cam' Imo— J 77
FF T J
Obtrkt , 2
iTp i
jA==FC
r
from flooding in the Old Town Basin indicated that the average annual damage of
flooding in the basin is $585,000 per year.
The first level of improvements are the minor capital improvements which solve
the localized problem. The localized improvements include replacement of inlets and
lateral pipes where routine problems exist. A program of asphalt removal should occur
for street overlays to reestablish curb and gutter sections and to lower street crowns
that inhibit the overland flow of water when storm sewer capacity is exceeded or inlets
clogged. This increase in pavement height results in increased ponding depths above
these paving areas. Improvements to curb extensions ("pedestrian bulbs") should be
made to assure that drainage waters are not ponded or diverted toward the buildings
where inlet capacity is exceeded or inlets become clogged.
A five phase program of major improvements has been recommended. The first
phase is the construction of a new storm sewer system along Mountain Avenue. The
second phase is the construction of an outfall channel and improved overland flow
system near Laurel Street and Riverside Avenue.. The third phase of the improvements
is the construction of a new outfall channel near Mason Street and Cherry Street..Thd
fourth phase is the improvement of street grades along Plum Street, Whedbee Street,
and Locust Street, to provide for street capacity to carry overland flows during major
storm events. The final phase of improvements would be to regrade Canyon Avenue
and Howes Street thus diverting overland flow to the new outfall channel at Mason
Street and Cherry Street.
The overall cost benefit ratio of these improvements is 1.12 with the
improvements being paid for by either a combination of stormwater utilities and other
revenues. The average annual benefits resulting from the project would be $405,30O
per year.
Other specific improvements recommended include intersection improvements at
five intersections in the upper reaches of the basin, installation of a new storm sewer
system along Linden Street, and water quality enhancement facilities at three major
storm sewer outfalls.
15
location of sites available for treatment are located in an area which may be enhanced
by the creation of wetlands.
This study investigated the cost of establishing water quality enhancement
facilities at the Locust outfall, the Mountain Avenue system east of Lincoln Avenue,
and the Laporte Avenue system north of Cherry Street in addition to replacement of the
storm sewers along Mountain Avenue in Old Town. Recent redevelopment plans in the
downtown area have include the removal of some of the railroad tracks northeast of
Jefferson will allow redevelopment of this area at Linden and Jefferson Streets. The
existing storm sewer system in this area is undersized and in need of repair. It is
anticipated that new storm sewers will be installed as part of new development.
As part of the overall project planning, the timing and phasing of construction
was considered. Table 3 presents refined cost estimates for the recommended project
phasing. Phasing of the construction would be as follows:
Phase I - Downtown Storm Sewer
The downtown area is in immediate need of these improvements. Damages
occur almost every summer because of the inadequate storm sewer system.
Phase II - Locust Outfall
The east end of the Locust storm sewer system is in need of improvement due
to poor drainage conditions at the east end of Laurel Street. In addition, these
improvements should occur prior to new development in the area.
Phase III - Howes -Mason Outfall
The north end of .the Laporte Avenue system experiences surcharging almost
every year. This area would benefit from improvements prior to new
development occurring in this area.
Phase IV - Elizabeth -Plum Street Regrading
The area near Whedbee and Plum frequently causes basement flooding. This
area would be of next importance for improvements. These improvements
e cannot be installed until Phase II improvements are in place.
Phase V - Canyon Avenue Street Regrading
The improvements along Canyon and Howes would be the final phase of
improvements to be completed. These improvements cannot be installed before
the Reach 6 improvements are complete.
In addition to the improvements discussed above, cost estimates were included
for the other improvements identified. These include the street intersection
improvements and the water quality improvements. Cost estimates were also prepared
for the Linden Street storm sewer improvements.
The timing of the improvements was discussed with the staff and reviewing
agencies and public. As a result, it is -envisioned that the improvements will be
constructed as fees are collected.
13
APPENDIX IV
Portions of the Old Town Master Drainage Basin Plan
No Text
DRAINAGE CRITERIA MANUAL
RUNOFF
6Y�7
30
I— 20
z
w
U
Ir
w
a 10
z ;
w
a f;
O 5
w
¢ 3
O
U 2
CC)
w
E--
a
1
5
.1
,�■ I I
rI■
����
ONE
�■�_�
�■■■N
MEN
NONNI
•I
•
Il ,'
��.....►..►.■
:.�C....■�C■■■■EMNO.
A.►�.�.I..■►....
.�■�.�.■■..��
■INVAN1■eii■
i�0
missi
2 .3 .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
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'
Where Tc = Time of Concentration, minutes
S = Slope of Basin, %
C = Rational Method Runoff Coefficient
D = Length of Basin, feet
Cf = 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 Frequency Factor
Nears) C,
2 to 10 1.00
11 to25 1.10
26 to 50 1.20
51 to 100 1.25
Note: The product of C times C, shall not exceed 1.00
3.2 Analysis Methodology
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
Cf = 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 ana!ysis. This procedure is detailed in the Urban Storm Drainage
Criteria Manual, Volume 1, Section 4.
MAY 1984 3-5 DESIGN CRITERIA
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 unit developments 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.
1-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:
0.95
Asphalt................................................................................................
0.95
Concrete
0.50
Gravel................................................................................................
0.95
Roofs .............................. ..................................................
Lawns, Sandy Soil:
0.1
Flat <2% .............................................................. ...............................
0. 5
Average2 to 7%..................................................................................
0.20
Steep>7%..........................................................................................
Lawns, Heavy Soil:
0.2
Flat<2%.............................................................................................
0.25
Average2 to 7%..............................:...................................................
0.35
Steep>7%......... :.................................................. .............
.................
MAY 1984 3-4 DESIGN CRITERIA
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
CONSTRUCTION SEQUENCE
PROJECT: Martinez P.U.D.
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 I
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: 01 15 97 DATE SUBMITTED: 01116197
APPROVED BY'THE CITY OF FORT COLLINS ON:
RAINFALL PERFORMANCE STANDARD EVALUATION
PROJECT:
MARTINEZ PUD
PROJ. NO. 1558-01-97
STANDARD
FORM A
COMPLETED BY:
MARK OBERSCHMIDT
DATE:
01/16/97
f tffr##f+f4+*#f*f##tfi
txxxxx+xxx++Yf
rfifi#rxxxxxxx+##f#k*rfi**k**t*fi *fi rfi rx+xxx+f xf+x+Yf #*t***
DEVELOPED
BRODIBILITY
Aob Lob Sob
Lb
Sb PS
SUBBASIN
ZONE
(ac) (ft) (1)
(feet)
M (t)
*#xfirtxxxxrtrtxrtxxrt*x+fr#rr+x*r+xxrtx+#r+r#frrxxxxxrtx+rrrf
rrrrrr:f#*+rr#r#x#xr#xtfirtrt*rtr+rrfifirt*
la
MODERATE
7.28 1300.00 1.00
9464
7.28
lb
MODERATE
4.10 200.00 1.10
820
4.51
0
0.00
0
0.00
0
0.00
+++rrxx#+rr*rtrtrtrtrtrrfx#rrrrfixrfi xrtxrt#+++frrrrr#rr#r+++++++xrtr+#f rff #txtx*+fir+++++++
11.38 903.69 1.04
LINEAR INTERPOLATION
SLOPE
LENGTH 1.00 1.04 1.50
900 78.2 78.32 79.8
904 78.32
1000 78.3 78.42 79.9
CONCLUDE: PERFORMANCE STANDARD = 78.32%
EROSION CONTROL PLAN OVERALL EFFECTIVENESS MUST EXCEED THIS
EFFECTIVENESS CALCULATIONS PRELIMINARY
STANDARD FORM
B
PROJECT: MARTINEZ PUD
PROD. NO.1558-01-97
BY: MARK OBBRSCHMIDT
DATE
O1/16/97
------------------------------------------------------------------------------------------
EROSION CONTROL C-PACTOR
P-FACTOR
COMMENT
METHOD
VALUE
VALUE
------------------------------------------------------------------------------------------
ROUGHENED GROUND
1.00
0.90
ROOF AREAS
ASPHALT
0.01
1.00
SUB BASIN 1
SOD
0.01
1.00
SUB BASIN 1
SILT FENCE
1.00
0.60
SUB BASIN 1
HAYBALE BARRIERS
1.00
0.80
SUB BASIN 1
------------------------------------------------------------------------------------------
MAJOR PS SUB
AREA
CALCULATIONS
BASIN % BASIN
acre
AREA
C
P
------------------------------------------------------------------------------------------
1 78.32% la
7.28
ROOF
4.14 ACRES
1.00
0.90
SOD
2.18 ACRES
0.01
1.00
ASPHALT
0.96 ACRES
0.01
1.00
SILT FENCE
1.00
0.50
EQUATIONS
HAYBALB
1.00
0.80
C = WEIGHTED AVG OF
C X AREA
P= (WEIGHTED AVG OF
P X AREA) X
P C=
0.5730
BFP = (1 - P X C) X
100
P =
0.3773
EPF
78.38%
------------------------------------------------------------------------------------------
lb
4.10
ROOF
2.33 ACRES
1.00
0.90
SOD
1.23 ACRES
0.01
1.00
ASPHALT
0.54 ACRES
0.01
1.00
SILT PENCE
1.00
0.50
HAY BALE
1.00
0.80
C =
0.5726
P =
0.3773
EFF
78.40%
------------------------------------------------------------------------------------------
r++xrrrr+++tr+r++rrtrr++rtt+r+rttt+++rtrttr+r+rtt+rrrtttrrttrr++r+rttrtr+++rrrtrxrr+++rrxx
TOTAL AREA =
11.38 ACRES
OVERALL EFFECTIVENESS = 78.39%
>
78.32%
CONCLUDE: EROSION CONTROL PLAN IS EFFECTIVE
January 16, 1997
Project No: 1558-01-97
-Re: EROSION CONTROL SECURITY DEPOSIT REQUIREMENTS:
Erosion Control Cost Estimate for Martinez P.U.D.; 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
$ 5,025.00 Refer to the cost estimate attached in Appendix I. 1.5 times the cost to
install the erosion control measures is $ 7,537.50.
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 8.5 acres), we estimate that the cost to re -
vegetate the disturbed area will be $ 4,250.00 ($ 500.00 per acre x 8.5 acres). 1.5
times the cost to re -vegetate the disturbed area is $ 6,375.00. The $ 500.00 per acre
for re -seeding sites greater than 10 acres was quoted to us by the City of Fort
Collins Stormwater Utility personnel.
CONCLUSION:
The erosion control security deposit amount required for Martinez P.U.D. will be
$ 7,537.50.
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-031 1
January 16, 1997
Project No: 1558-01-97
Basil Hamdan
City of Fort Collins Stormwater Utility
P.O. Box 580
Ft. Collins, Colorado 80522
Re: Erosion Control Cost Estimate for Martinez P.U.D. Fort Collins, Colorado
Dear Basil,
Attached is the erosion control security deposit estimate for Martinez P.U.D.
ESTIMATE 1:
1600 LF of Silt Fence Q $ 3.00 per LF
3 Haybale barriers O $75.00 each
TOTAL ESTIMATED COST:
ESTIMATE 2:
re -vegetate the disturbed area of 8.5 acres at $500.00 per acre
TOTAL ESTIMATED COST:
$ 4, 800.00
$ 225.00
$ 5,025.00
x 1.50
$ 77537.50
$ 4,250.00
$ 4,250.00
x 1.50
$ 6,375.00
In no instance shall the amount of the security be less than $ 1,000.00. Therefore, the total
required erosion control security deposit for Martinez P.U.D. will be $ 7,537.50.
If you have any questions, please call at 226-5334.
Sincerely,
Mark Oberschmidt
Shear Engineering Corporation
MEO/meo
cc: James W. Leach; Wonderland Hill Development Company
Dave Stringer; City of Fort Collins
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-031 1
SHEAR ENGINEERING
CORPORATION
PRELIMINARY
DEVELOPED
PAGE
FLOW TO MARTINEZ
PARK FROM MINOR
BASIN 1b
PROJECT: MARTINEZ PUD
DATE
01/16/97
LOCATION:FORT COLLINS
PROJ.
NO.1558-01-97
PILE: MARTRUN
BY
MHO
AREA (A)= 4.100 ACRES
RUNOFF CORP. (C)
2 YEAR
10 YEAR
100 YEAR
C = 0.73
0.73
0.91
SEE SPREAD SHEET ATTACHED ON PAGE
2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 240 FEET
SLOPE = 2.00
%
2 YEAR
10 YEAR
100 YEAR
C = 0.20
0.20
0.25
Ti (min)= 20.74
20.74
19.59
TRAVEL TIME (Tt)=L/(60*V)
FLOW TYPE
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) =? S (%) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2
TOTAL TRAVEL
TIME
(min) =
0.00
TOTAL LENGTH = 240
L/180+10= 11.33
<
19.59
CHOOSE LESSER
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR
10 YEAR
�100 YEAR
Tc (min)= 11.33
11.33
11.33
USE Tc = 11.0
11.0
11.0
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) (cfs)
2 YEAR
10 YEAR
100 YEAR
Q = 7.32
12.82
25.74
CONCLUDE:SHBET FLOW INTO MARTINEZ PARK
8
SHEAR ENGINEERING
CORPORATION .
PRELIMINARY
DEVELOPED
PAGE
FLOW TO MARTINEZ PARK FROM MINOR
BASIN Is
PROJECT:
MARTINEZ PUD
DATE
O1/16/97
LOCATION:FORT
COLLINS
PROJ.
NO.1558-01-97
FILE:
MARTRUN
BY
MHO
AREA (A)= 7.280 ACRES
RUNOFF CORP. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.73 0.73 0.91
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (TO
OVERLAND TRAVEL TIME (Ti)
LENGTH = 60 FEET SLOPE = 2.00 $
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 10.37 10.37 9.79
TRAVEL TIME (TO=L/(60;V) FLOW TYPE
L (ft) = 1600 S (%) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 13.33
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S M = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (6) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 13.33
TOTAL LENGTH = 1660 L/100+10= 19.22 < 23.13 CHOOSE LESSER
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 19.22 19.22 19.22
USE Tc = 19.0 19.0 19.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
1 1.91 3.35 5.38
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 10.07 17.69 35.51
CONCLUDE: FLOW TO PROPOSED PARK ACCESS ROAD
7
SHEAR ENGINEERING CORPORATION
PRELIMINARY
DEVELOPED
PAGE
FLOW TO MARTINEZ PARK
FROM OVERALL AREA
PROTECT:
MARTINEZ PUD
DATE
01/16/97
LOCATION:FORT
COLLINS
PROS.
NO.1558-01-97
FILE:
MARTRUN
BY
MEO
AREA (A)= 21.76 ACRES
RUNOFF COEF. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.70 0.70 0.86
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (TO
OVERLAND TRAVEL TIME (Ti)
LENGTH = FEET SLOPE = k
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 0.00 0.00 0.00
TRAVEL TIME (It) =L/(60*V) FLOW TYPE
L (ft) = 1140 S (k) = 0.70 SWALE V (fps) = 1.33 Tt(min)= 14.29
L (ft) = 520 S (k) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 4.33
L (ft) =? S (k) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (k) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (k) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 18.62
ADD Tt USING L/180+10 TO HISTORIC Tc WITH L = 600 L/180+10= 13.33 MIN
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 31.95 31.95 31.95
USE Tc = 32.0 32.0 32.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
1 = 1.41 2.51 4.04
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q = 21.48 38.27 77.02
VERSUS HISTORIC FLOWS
Qhist = 12.15 21.95 44.14
CONCLUDE:LET IT FLY
6
SHEAR ENGINEERING CORPORATION
PRELIMINARY HISTORIC PAGE
FLOW TO MARTINEZ PARK
FROM OVERALL AREA
PROJECT: MARTINEZ PUD DATE 01/16/97
LOCATION:PORT COLLINS PROJ. NO.1558-01-97
FILE: MARTRUN BY MHO
AREA (A)= 21.76 ACRES
RUNOFF CORP. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.43 0.43 0.54
SHE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE
LENGTH = FEET SLOPE = 6
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 0.00 0.00 0.00
TRAVEL TIME (TO=L/(60-V) PLOW TYPE
L (ft) = 1140 S W = 0.70 SWALE V (fps) = 1.33 Tt(min)= 14.29
L (ft) = 520 S (6) = 2.00 LAWN V (fps) = 1.00 Tt(min)= 8.67
L (ft) =? S (8) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S M = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (k) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S M = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 22.95
ADD Tt USING L/180+10 TO HISTORIC Tc WITH L = 600 L/180+10= 13.33 MIN
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 36.29 36.29 36.29
USE Tc = 36.0 36.0 36.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 1.30 2.34 3.77
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q 12.15 21.95 44.14
CONCLUDE:COMPARE WITH DEVELOPED FLOWS
5
SHEAR ENGINEERING
CORPORATION
PRELIMINARY
DEVELOPED
PAGE
FLOW TO MARTINEZ
PARK
FROM SITE
PROJECT: MARTINEZ PUD
DATE
01/16/97
LOCATION:FORT COLLINS
PROJ.
NO.1558-01-97
FILE: MARTRUN
BY
HBO
AREA (A)= 11.380 ACRES
RUNOFF COEF. (C)
.2 YEAR 10 YEAR 100 YEAR
C = 0.73 0.73 0.91
SHE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 60 FEET SLOPE = 2.00 %
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 10.37 10.37 9.79
TRAVEL TIME (TO=L/(60*V) FLOW TYPE
L (ft) = 1600 S (%) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 13.33
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (%) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 13.33
TOTAL LENGTH = 1660 L/180+10= 19.22 < 23.13 CHOOSE LESSER
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 19.22 19.22 19.22
USE Tc = 19.0 19.0 19.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
1 = 1.91 3.35 5.38
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q = 15.75 27.65 55.50
VERSUS HISTORIC FLOWS
Qhist = 4.11 7.22 14.53
CONCLUDE:LBT IT FLY
4
SHEAR ENGINEERING CORPORATION
PRELIMINARY HISTORIC
PLOW TO MARTINEZ PARK
FROM SITE
PROJECT: MARTINEZ PUD
LOCATION:PORT COLLINS
FILE: MARTRUN
AREA (A)= 11.380 ACRES
DATE O1/16/97
PROD. NO.1558-01-97
BY MEO
PAGE 3
RUNOFF CORP. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.21 0.21 0.26
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 0 FEET SLOPE = 0.00 $
2 YEAR 10 YEAR 100 YEAR
C = 0.20- 0.20 0.25
Ti (min)= 0.00 0.00 0.00
TRAVEL TIME (TO=L/(60*V) PLOW TYPE
L (ft) = 1140 S ($) = 0.70 SWALE V (fps) = 1.33 Tt(min)= 14.29
L (ft) = 520 S ($) = 2.00 LAWN V (fps) = 1.00 Tt(min)= 8.67
L (ft) _? S ($) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S ($) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S ($) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S ($) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S ($) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 22.95
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 22.95 22.95 22.95
USE Tc = 23.0 23.0 23.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 1.72 3.02 4.86
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q 4.11 7.22 14.53
CONCLUDE:COMPARB WITH DEVELOPED FLOWS
SHEAR ENGINEERING CORPORATION
PRELIMINARY
SUBBASIN BREAKDOWN PAGE 2
PROJECT: MARTINEZ PUD DATE 01/16/97
LOCATION:FORT COLLINS BY MBO
PROD. NO.MARTRUN
TOTAL SITE AREA = 11.38 TOTAL BASIN AREA = 21.76
ASSUMPTIONS: SITE IS 70% IMPERVIOUS AND 30% LAWNS, HEAVY SOIL
TOTAL AREA INCLUDES RESIDENTIAL AREA NORTH OF CHERRY AND EAST OF SHERWOOD
OFFSITE AREA = 452250 SF = 10.38 ACRES
OFFSITE AREA IS ASSUMED TO BE SPLIT 55/37/7/1 ROOF/GRASS/ASPHALT/CONRETE
SITE HISTORIC DEVELOPED
HISTORIC DEVELOPED OFFSITE OVERALL OVERALL la lb
ASPHALT 0.00 6.47 0.73 0.73 7.20 4.14 2.33
CONCRETE 0.00 0.00 0.10 0.10 0.10 0.00 0.00
GRAVEL 0.38 0.00 0.00 0.38 0.00 0.00 0.00
ROOFS 0.00 1.50 5.71 5.71 7.21 0.96 0.54
LAWNS,SANDY SOIL
FLAT < 2% 0.00 0.00 0.00 0.00 0.00 0.00 0.00
AVERAGE 2 TO 7% 0.00 0.00 0.00 0.00 0.00 0.00 0.00
STEEP > 7% 0.00 0.00 0.00 0.00 0.00 0.00 0.00
LAWNS, HEAVY SOIL:
FLAT < 2% 11.00 3.41 3.84 14.84 7.25 2.18 1.23
AVERAGE 2 TO 7% 0.00 0.00 0.00 0.00 0.00 0.00 0.00
STEEP > 7% 0.00 0.00 0.00 0.00 0.00 0.00 0.00
TOTAL 11.38 11.38 10.38 21.76 21.76 7.28 4.10
RUNOFF COEFFICIENT SUB BASINS AND / OR BASINS
HISTORIC DEVELOPEDOFFSITE OVERALL OVERALL la lb
C2-C10 0.21 0.73 0.67 0.43 0.70 0.73 0.73
C100 = 1.25*C2 0.26 0.91 0.84 0.54 0.88 0.91 0.91
C100 IS NEVER GREATER THAN 1.0
PRELIMINARY FLOW SUMMARY FOR MARTINEZ PUD
PAGE 1
DESIGN
CONTRIBUTING
AREA
C2
CIO
C100
Tc
Tc
I2
I10
I100
Q2
Q10
Q100
PAGE
POINT
SUB
2,10
100
BASINS)
ac.
min.
min
iph
iph
iph
cfa
cfo
cfo
*rrrrr+rrr+rrrr+rrrrrrr*rrrr
r:+r+rrrr
*errrrrr****rrrrrrrrrrr**r****+rrrr+:+rrrr*rrrrrrr+r******rrr****
HISTORIC
CONDITIONS
PARK
SITE
11.38
0.21
0.21
0.26
23.00
23.00
1.72
3.02
4.86
4.11
7.22
14.53
3
PARK
OVERALL
21.76
0.43
0.43
0.54
36.00
36.00
1.30
2.34
3.77
12.15
21.95
44.14
5
DEVELOPED CONDITIONS
PARK
SITE
11.38
0.73
0.73
0.91
19.00
19.00
1.91
3.35
5.38
15.75
27.65
55.50
4
PARK
OVERALL
21.76
0.70
0.70
0.88
32.00
32.00
1.41
2.51
4.04
21.48
38.27
77.02
6
MINOR BASINS DEVELOPED CONDITIONS
A
1a
7.28
0.73
0.73
0.91
19.00
19.00
1.91
3.35
5.38
10.07
17.69
35.51
7
PARK
ib
4.10
0.73
0.73
0.91
11.00
11.00
2.46
4.31
6.92
7.32
12.82
25.74
8
u
APPENDIX I
Storm Drainage Calculations
PAGE 6
Project No. 1558-01-97
Preliminary 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 Martinez P.U.D.
VIE. 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, 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 Martinez P.U.D. 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.
VIM REFERENCES:
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; Resource Consultants & Engineers, Inc.;
Dated January 7, 1993
PAGE 5
Project No. 1558-01-97
Preliminary Drainage and Erosion Control Report
IV. DRAINAGE FACILITY DESIGN:
B. Specific Details
1. Historic and developed peak flows from the site and the overall contributing area to
Martinez Park are summarized in the table below.
Area
Q2
Q100
Description
acres
C2
C100
cfs
cfs
Historic Site
11.38
0.21
0.26
4.1
15.5
Developed Site
11.38
0.73
0.91
15.7
55.5
Historic Overall
21.76
0.43
0.54
12.1
44.1
Developed Overall
21.76
0.70
0.88
21.5
77.0
2. Specific details will be submitted with the Final Plans.
V. EROSION CONTROL:
A. General Concept
1. Erosion control measures will be as identified on the Preliminary Drainage and
Erosion Control Plan.
2. 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
$1,000.00.
3. According to current City of Fort Collins policy, the erosion control security deposit
is figured based on the larger amount of 1.5 times the estimated cost of installing the
approved erosion control measures or 1.5 times the cost to re -vegetate the anticipated
area to be disturbed by construction activity.
a. The cost to install the proposed erosion control measures is approximately
$ 5,025.00. Refer to the cost estimate attached in Appendix H. 1.5 times the cost
to install the erosion control measures is $ 7,537.50.
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 8.5 acres), we estimate that the cost. to re -
vegetate the disturbed area will be $ 4,250.00 ($ 500.00 per acre x 8.5 acres). 1.5
times the cost to re -vegetate the disturbed area is $ 6,375.00. The $ 500.00 per
acre for re -seeding sites greater than 10 acres was quoted to us by the City of Fort
Collins Stormwater Utility personnel.
c. The erosion control deposit for the Martinez P.U.D. will be $ 7,537.50. This
deposit is refundable.
PAGE 4
Project No. 1558-01-97
Preliminary Drainage and Erosion Control Report
M. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA:
C. Hydrological Criteria
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.
1V. DRAINAGE FACILITY DESIGN:
A. General Concept
1. Onsite stormwater will have 2 different travel paths. A portion of the site (Minor
Basin la) will contribute stormwater to proposed low point located at the proposed
access to the park from the entry drive. The remainder of the site (Minor Basin lb)
will contribute stormwater directly to Lee Martinez Park.
2. Offsite flows will be conveyed east along the north side of the railroad tracks via an
existing swale. Some grading will occur on the south side of the proposed
commercial building to better define the swale and convey flows around the building
into the parking lot.
a. Any grading which occurs within the railroad ROW or easement will require the
approval of the railroad and the Public Utility Commission W.U.C.).
3. No detention will be provided for this site because of its proximity to the river and the
fact that all stormwater flows into Lee Martinez Park, much of which is within the
limits of the 100-year floodplain.
4. The portion of the property east of the entry drive off of Cherry Street will not be
affected by this development. It is our understanding that this area may be purchased
by the City of Fort Collins Parks and Recreation Department in order to provide
additional parking facilities for Lee Martinez Park.
a. A concept plan of the proposed improvements are available at the City of Fort
Collins Parks and Recreation Department.
PAGE 3
Project No. 1558-01-97
Preliminary Drainage and Erosion Control Report
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.
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 all property lines.
2. Stormwater improvements are proposed with the Old Town Master Drainage Basin
Plan for this area. These improvements include a 3'x30' Reinforced Box Culvert to be
installed at the intersection Cherry and Mason Streets.
a. Stormwater runoff will be conveyed in the box culvert to an open channel through
the eastern portion of this site, then to a proposed settling basin north of the site,
then to the Cache La Poudre River.
b. Refer to figure 8.6 of the Old Town Master Drainage Basin plan attached in
Appendix IV. Adequate land area at the eastern portion of the site will have to be
provided to facilitate this proposed improvement.
c. The proposed entry drive into the site at Cherry Street does not conflict with the.
proposed location of the box culvert as shown figure 8.6.
3. There is an existing 48" storm sewer which crosses the property just east of the
proposed commercial building.
a. The easement is situated in an existing 50' ROW that is recorded in the Latimer
County records at Book 446 and Page 338.
b. Stormwater improvements proposed with the Old Town Master Drainage Basin
Plan indicate that this storm sewer will be daylighted at the proposed settling
pond located downstream of the site.
c. Refer to figure 8.6 of the Old Town Master Drainage Basin plan attached in
Appendix IV.
4. The 100-year flood plain is delineated on the Preliminary Drainage and Erosion
Control Plan. The floodplain was taken from Flood Insurance Rate Map (FIRM)
Panel 2 of 7; Coinmunity Panel Number 080102 0002 B; map revised February 15,
1984.
PAGE 2
Project No. 1558-01-97
Preliminary Drainage and Erosion Control Report
H. 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. The drainage fees associated with the Old Town Basin are $4,150.00 per acre.
2. The eastern portion of the site is subject to shallow flooding of less than .1.5 feet in
depth according to figure 4 of the Old Town Master Drainage Basin Plan. This area
will not be subject to development with this project.
3. No portion of the site is located in the 100-year floodplain. Reference the Flood
Insurance Rate Map (FIRM) Panel 2 of 7; Community Panel Number 080102 0002 B;
map revised February 15, 1984. Floodplain elevations across the site range from
approximately 4966 to 4971 feet from east to west. The lowest elevation across the
northern property line of the site range from approximately 4970 to 4987 from east to
west.
A. Some offsite contribution is expected from the properties to the south. The offsite
contributing area is bounded by Sherwood Street on the west and Cherry Street on the
south. The offsite contributing area consists of portions of subcatchments 136 and
108 as designated on Figure 4.1 of the Old Town Master Drainage Basin Plan.
a. The majority of the offsite stormwater will be conveyed to the east in the existing
swale along the north side of the railroad tracks. The stormwater will be
conveyed around the proposed commercial building and then north to Martinez
Park.
5. The offsite contributing area is approximately 10.38 acres.
B. Sub -Basin Description
1. The site slopes to the east and north. Historically stormwater flows overland east to a
low point. The low point exists north of the intersection of Cherry and Mason
Streets. From the low point, storm water runoff is conveyed into Lee Martinez Park
via a natural swale eventually reaching the Cache La Poudre River.
a. A 3' x 30' concrete box culvert is proposed with the Old Town Master Drainage
Basin Plan to convey stormwater from the southwest corner of Mason and Cherry
streets under Cherry Street to the existing swale. The outfall of the box culvert
will be located east of the proposed entry drive off Cherry Street.
2. There is an existing Swale along the north side of railroad tracks to the south which
conveys offsite water to the east. The water is conveyed north overland into Lee
Martinez Park when the defined Swale terminates near the location of the proposed
commercial building.
PAGE 1
Project No. 1558-01-97
Preliminary Drainage and Erosion Control Report
L GENERAL LOCATION AND DESCRIPTION:
A. Location
1. Martinez P.U.D. is located in the Northeast One Quarter (1/4) of Section 11, 17N,
R69W of the 6th P.M., City of Ft. Collins, County of Larimer, State of Colorado.
2. More specifically, Martinez P.U.D. is located directly south of Lee Martinez Park
and north of the railroad tracks located north of Cherry Street near the vicinity of the
intersection of Cherry Street and Mason Street. The western end of the site borders
on Sherwood Street. The eastern end of the site borders on North College Avenue.
(See Vicinity Map).
3. The site is bounded entirely on the north by Lee Martinez Park. It is bounded on the
east by College Avenue, on the west by Sherwood Street and on the south by the
Burlington Northern railroad property and Cherry Street.
4. The Cache La Poudre River is approximately 600 feet north of the site at its closest
point near the eastern end of the site.
B. Description of Property
1. The site is directly adjacent to Burlington Northern railroad property and was
previously utilized as a railroad switching yard. Historic use of the property can be
visualized on the City of Fort Collins aerial photo dated May 8, 1984.
2. The site area is approximately 11.38 acres.
3. Development of the site will consist of a co -housing portion to the west, 10 single
family lots, a commercial tract currently planned for a 12,200 SF commercial
building, a tract to. the east of the commercial area which may ultimately be
purchased by the City of Fort Collins Parks and Recreation Department. The co -
housing area will provide 8-4-plex units and a duplex unit. Adequate parking for the
co -housing units and the commercial building will be provided.
4. The site is encumbered by several existing utilities. Additional utilities will be
installed as needed to service the site. There are two (2) existing City of Fort Collins
sanitary sewer lines. There is also an existing North Weld County water transmission
line and a 12" City of Fort Collins water line running through the site.
5. Development of the site with this project will be limited to the portion of the property
west of the intersection of Cherry and Mason Streets. It is our understanding that the
area east of Mason Street (extended) may be purchased by the City of Fort Collins
Parks and Recreation Department to allow expanded parking for Lee Martinez Park.
6. There is an existing 48" storm sewer running in a northeasterly direction across the
site immediately east of the proposed commercial building. The storm sewer is
situated in an existing 50' ROW.
No Text
Preliminary Drainage and Erosion Control Report
for
MARTINEZ P.U.D.
Fort Collins, Colorado
Prepared for:
Wonderland Hill Development Company
745 Poplar Avenue
Boulder, Colorado 80304
INITIAL, $UBMIWAL
dated 2 zA -
Prepared by:
SHEAR ENGINEERING CORPORATION
Project No: 1558-01-97
DATE: January, 1997
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282-0311
APPENDIX V
Stuffer Envelope
Preliminary Drainage and Erosion Control Plan
KEY TO MAP
SOONear Flood Boundary ZONE B
100-Year Flood Boundary
Zone Designations* With
Date of Identification
e.g., 12/2/74
IOONear Flood Boundary
fi.'�j.. ZONEB
500-Year Flood Boundary
Base Flood Elevation Line 513
With Elevation In Feet**
Base Flood Elevation in Feet (EL 987)
Where Uniform Within Zone**
Elevation Reference Mark RM7x
Zone D Boundary
River Mile • M 1.5
**Referenced to the National Geodetic Vertical Datum of 1929
*EXPLANATION OF ZONE DESIGNATIONS
ZONE EXPLANATION
A Areas of 100-year flood; base flood elevations and
flood hazard factors not determined.
AO Areas of 100-year shallow flooding where depths
are between one (1) and three (3) feet; average depths
of inundation are shown, but no flood hazard factors
are determined.
AH Areas of 100-year shallow flooding where depths
are between one (1) and three (3) feet; base flood
elevations arc shown, but no flood hazard factors
are determined,
Al-A30 Areas of 100-year flood; base flood elevations and
flood hazard factors determined.
A99 Areas of 100-year flood to be protected by flood
protection system under construction; base flood
elevations and flood hazard factors not determined.
B Areas between limits of the 100-year flood and 500-
year flood; or certain areas subject to 100-year flood-
ing with average depths less than one (1 ) foot or where
the contributing drainage area is less than one square
mile; or areas protected by levees from the base flood.
(Medium shading)
C Areas of minimal flooding. (No shading)
D Areas of undetermined, but possible, flood hazards.
V Areas of 100-year coastal flood with velocity (wave
action); base flood elevations and flood hazard factors
not determined.
V1-V30 Areas of 100-year coastal flood with velocity (wave
action); base flood elevations and flood hazard factor;
determined.
NOTES TO USER
Cervin areas not in the special flood hazard areas (zones A and V)
may be protected by flood control structures.
This map is for flood insurance purposes only; it does not neces-
sarily show all areas subject to flooding in the community or
all planimetric features outside special flood hazard areas.
For adjoining map panels, see separately printed Index To Map
Panels.
INITIAL IDENTIFICATION:
JUNE 28, 1974
FLOOD HAZARD BOUNDARY MAP REVISIONS:
LI I NATIONAL FLOOD INSURANCE PROGRAM
FIRM
FLOOD INSURANCE RATE MAP
CITY OF
FORT COLLINS,
COLORADO
LARIMER COUNTY
PANEL 2 OF 1
(SEE MAP INDEX FOR PANELS NOT PRINTED)
COMMUNITY -PANEL NUMBER
080102 0002 B
MAP REVISED,
tµ,Y MAN
FEBRUARY 15, 1984
Federal Emergency Management Agency
4980
4970
4960
• + m /
.1 a Tby ay .L
•y�\.fir'' '�i=l tom' ' .t` f "•...: 'Gii �$a
NOTE: Replace Anlata With Standard Cure Inlet At New Street Grace Ad Required
----- _--- -- - -
:Construct Wetland Areox3.5ac.s,
Conat t'Seitlin -
Pond"Irea .75ae
-Construct 490 L.F. of Graaa Lined
Channel Wish DropStructures Sae
Construct
3 % 30
Construct 410 ELF of 6rasi
Lined. Channel of 0.5° See �
Construct
4 X20
j 600 L.F. otCan
_ '. See Detail
-
Detail 5, Figure 41 and
Bo* 'Culvert
Detail6, Flqure 4J„__.��—'
CLlrert
u
-----pi73
Detail 9L. Ft9vre 42
,.
_-_..
pproa 100r�.�
t
9
•—
.
s
'
100rr. WS E PaudrR.
41 Cb,' `•
i�
V
Appros. W.S.E Old Torn e
Drop Structure
n
y
E a
See Detail I,
_
Figure
9
Drop Structure
See Detail I,
V g
8 S.
sheer !o
i
Kl
r a
W
0.00 2.00 4.00 6.00 8-00 10.00 12.00 14.00 16-00 1111•00 z0.0u
LW 1f� t
c
c
f'
L
J � n
o e V
c
m
= ` e
m G m
As
.a
t r „
\
i \ PENN
: � r ; e ♦
1
i t
m C G
LLE
{-
HmYw 9
zo
wwm
NnTM
wV
ZZ�y
y� ei 2 yg
mNOr.'12
rats -channel a' 0.5%
i ura 41
Reconstruct LePurte'Arenue
;See Detail 2 Figure 4
y6 ZW
W tg..O f 2 m u,
`. O O O 2
z2z
f�
0 v.-�w
z
in
W 0
- �_.. ....
._ _.._
W o
S
0toL)
CO Mx
0 a c7 0
e
Q U-
W
W cc O
ti
U) ." W
° U
cc
o_
22.00 24-00 26.00 28-00
Figure 51:
REACH DESIGNATION for
FLOODED AREA MAPPING
OLD TOWN
MASTER DRAINAGE
BASIN PLAN for the
A CITY of FORT COLLINS
=`-
Legend:
FLOODED AREAS MAPPED WITH DETAILED MAPPING
APPROXIMATE LIMITS of POTENTIAL SHALLOW
FLOODING LESS THAN 1.5' IN DEPTH
2�� 500
71.77
111111 '\JZV 0 Scale i201F.t
"M;;1
!e 55113;li
LIE
w