HomeMy WebLinkAboutMARTINEZ PUD - FINAL - 4-97A - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTAPPENDIX V
Staffer Envelope
Final Drainage and Erosion Control Plan
Offshe Drainage Exhibit - 2 sheets
ZONE A4
7/16/79
ZONE C
Larimer Countv
AREA NOT INCLUDED
1 (,
1":.600•
FLOQIDPLAINJ EXHIB�Jr
ZO,
rrZONI
fit
`."ZONE.B
VEN E F
�
F7 F7
GZ
KEY TO MAP
500-Year Flood Boundary
100-Year Flood Boundary
Zone Designations* With
Date of Identification
e.g.,12/2/74
100-Year Flood Boundary
500-Year Flood Boundary —
Base Flood Elevation Line
With Elevation In Feet**
Base Flood Elevation in Feet
Where Uniform Within Zone**
Elevation Reference Mark
Zone D Boundary
ZONE B
2bN EIA1 ��`
�DA�TEt�
0NE9A
:~,DATA:.
ZONE B
513
(EL 987)
RM7X
River Mile *M1.5
**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.
AI-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 factors
determined.
NOTES TO USER
Certain 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:
Il ® NATIONAL FLOOD INSURANCE PROGRAM
I
FIRM
r;
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 R
FEBRU RY 5, 198
Federal Emergency Management Agency
A A N
m � m
J O
O O
fTA.O.00
09
m s
a I -• _i .j� tea. 7�,-0 `} T � 1 ai
O I 8 o m N a �` i� •.W !j I
i o n
A !TA NOa cONSYPOCT oix[ WITH LG1Y Fq
o
OUTLET AND MEe FLOW SPILLWAY Yl9 p
0
O
A. 495eD
m Do* k m
O o \ D f* \ w �• C.
An
e _ n
AA Yj Y
• N— OO y
i N L 49T1.0 i 1 0�•i4 W �. .. • K �`p /�
.r ^.L r 1. Ce •;.
p Cherry Street ; <c r 5 7f -,* n
Ar"34 No
1j\ YaT� - :ti- .yu.�e".--_�...I✓ - d '� y ,>< ,ter
It
al -
A_
o 16 Y. n
c w .YS .4 a...
STA: 1741N)
o
a _I-MaPle Streit; gl
STA Ia.TO 1 �i. a e'St
y
p I' ,I.1 r Yt '�� •S� 1
O I O ,9F •AYp, aO .4KS t J VV
of vim. at 1 13p..
IL
NT
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4•} I.1 �'/
STA. t.iTO
AL 4911r.50
at
l o- r Li l•1 d C � S ,
IN
I ` _TB �L � •-. ��feN 'aW ::f t L fi :SP
i 1 0 •R. 11 t ..
N TA. e1•fM7 �r-�- '' •
g Figure 6.6: NOTES: LEGEND:
THIS DMVANG REPRESENTS CONCEPTUAL ----- Water Line
PROPOSED IMPROVEMENTS AND PRELIMINARY ENGINEERING AND SHALL
NOT BE USED FOR CONSTRUCTION Inlet ---- Sanitary Sewer Line
REACH 6 PURPOSES. TOPOGRAPHY, UTILITY AND SITE /////
City of Fort Collins CONDITIONS MUST BE FIELD VERIFIED PRIOR o Manhole Streit Reconstruction
TO BEGINNING DETAILED DESIGN.
RCE VNNU BASE MAP FROM MAY,97e MAPPING BY Mill AALX _--_ Storm Sewer Line �000j Gross Llney Channel BASE M ENGINEERS AND MAY 19 8 MAPPING
BYBy
Figure 51:
REACH DESIGNATION for
FLOODED AREA MAPPING
OLD TOWN
2. MASTER DRAINAGE
BASIN PLAN for the
J. y "li . - :.
T. � I j ", CITY of FORT COLLINS
R CH-78,713,7-_ EA KsouK*
See Figures 5.9,561,EAC 6
R C r= AIfLH ar.. E� C+...r
Legend:
FLOODED AREAS MAPPED WITH DETAILED MAPPING
APMOXNATE LIMITS of POTENTIAL SHALLOW
FLOOONG LESS THAN 1.5' IN DEPTH
—REACH 8'�
—-r`---� —
Figures 5.10 Sc.0
See Fi r
.20 '1
5.85 .11 7L.77
4 0 2DC Fewl
L
EACH c �.REACH-5 a 58
iffl.-."Som Nares 5.7& 5.16
F
-VV
goras .11111 a z
EAC 4L15�
See Figures 5.6 a 5J5
N
N
_Se�@_ FigJres
5.7 5.16
4W --W— F a IB N
— 40 n , ,
EACH 7— --ECT.—i
Our FREACH T3 a 5.12
It i See Figuras-5.4 th 5A13 Z,
:3
J.
cot
r
-0I
-
, I !
. ;
Epl LL
No Text
, .:.��. •- ,i � - . - � Sr4 � �' A'{pd�'.. of Ay � 1�' kl� .. '.r nA.4...
ssifsmnmmnnn
-
�
Figure 4•
44
c
--------
FLOODED AREAS for
f
— --- - -
�_I
100 YEAR STORM
OLD TOWN
MASTER DRAINAGE
j
BASIN PLAN for the
CITY of FORT COLLINS
CE
i
legend:
f
•-� _ _ _ ....
FLOODED AREAS MAPPED WITH DETAILED MAPPING
.lF1
APPROXIMATE LIMITS f POTENTIAL MALLOW
FLOODING LESS THAN 15o IN DEPTH
I
- Figure 2:
' I. _---' MAJOR STORM SEWERS
----- ------
C OLD TOWN
MASTER DRAINAGE
BASIN PLAN for the
~] CITY of FORT COLLINS
REi�E7S aOMWWt!C
����'� ,..rJ�� — �:��� �i,�';. ,_ • � _J '� it � :�� Legend
�. �(_'� ^ •••"'T-..� .-..�1 _.i -^1 ��,/ % �, STORM SEWER ,e' N
D4Met e DIAMETER OR GREATER
�` X en _ I '• jj 11 I akL t/ l 1 i i, o:, Dktr{GL a.••ro, • �`�\ I �. 27: 500
• l _
n
�,�r < ^-!• �� — _ of J \ Z ` SCaje ax'inr
: —.....- - —
Dis
Subp D4V,c1 8 d
DI�Met T •-.........� _—
CI.VIe, , �'''"j -•�� .• is • !• .
I� s , W� ; 11 D4Vk1 S -
Y
wla
D4trkt tip
Iq YIi!.
if L
I I, I - ism � I � � 11' _•_.
from flooding in the Old Town Basin indicated that the average annual damage of
flooding in the basin is $585,000per 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. 4The
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, outf all 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 $4051300
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,1aporte Avenue. system, experiences surchargmg'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
cannot be installed until Phase II improvements are in place.
Phase V - Canyon Avenue Street Regradinq
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
I!
AN
30
I— 20
Z
w
U
Cr
w
Z10
w
a t,
OJ 5
Cn
w
cc 3
O
U 2
Cr
w
t—
Q
1
milli
�■.�.■��
jib ,
' ,
:::
,.,,11_
•
11
■w■■�
IANI�■E11�
II
III
■■MMWMPFA
■ICI
���t♦■■■
■_�
�•�F0111
i■
..C■.l�
5'
.1
.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 (Sec
Figure 3-2).
Tc =1.87 (1.1 — CC,) D 112
Sri
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
(years)
3.2 Analysis Methodology
Frequency Factor
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
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
3.2.2
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)
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 forsuch analysis. This procedure is detailed in the Urban Storm Draina
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.
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:
Flat<2%.............................................................................................
0.15
Average 2 to 7% ................................................................................
.. 0.
Steep>7%..........................................................................................
0.20
Lawns, Heavy Soil:
Flat<2%.............................................................................................
0.20
Average2 to 7% ..................................................................................
0.25
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
1
EFFECTIVENESS CALCULATIONS
STANDARD FORM B
PROJECT: MARTINEZ PUD
PROJ. NO.1558-01-97
BY: MARK OBERSCHMIDT
DATE
07/07/97
------------------------------------------------------------------------------------------
BROSION CONTROL
C-FACTOR
P-PACTOR
COMMENT
METHOD
VALUE
VALUE
------------------------------------------------------------------------------------------
ROUGHENED GROUND
1.00
0.90
ROOF ARRAS
ASPHALT
0.01
1.00
SUB BASIN 1
& 2
SOD
0.01
1.00
SUB BASIN 1
& 2
SILT FENCE
1.00
0.50
SUB BASIN 1
& 2
HAYBALBBARRIERS
1.00
0.80
SUB BASIN 1
& 2
GRAVEL INLET FILTERS
1.00
0.80
SUB BASIN 1
------------------------------------------------------------------------------------------
MAJOR PS SUB
AREA
CALCULATIONS
BASIN. i BASIN
acre
AREA
C
P
------------------------------------------------------------------------------------------
78.374 1
4.86
ROOF
0.64 ACRES
1.00
0.90
•
SOD
1.46 ACRES
0.01
1.00
ASPHALT
2.76 ACRES
0.01
1.00
SILT PENCE
1.00
0.50
HAYBALR
1.00
0.80
EQUATIONS
GRAVEL INLET FILTER
1.00
0.80
C = WEIGHTED AVG
OF C X AREA
C =
.0.1404
P= (WEIGHTED AVG
OF P X AREA) X
P P-
0.3158
EFF = (1 - P X C)
X 100
Epp
95.57,
------------------------------------------------------------------------------------------
2
4.10
ROOF
0.62 ACRES
1.00
0.90
SOD
1.42 ACRES
0.01
1.00
ASPHALT
2.68 ACRES
0.01
1.00
SILT PENCE
1.00
0.50
HAY BALE
1.00
0.80
C =
0.1612
P =
0.4544
EFF
92.674
------------------------------------------------------------------------------------------
xx♦rrrrrrrrr:x rrrrrrrrrrrrxrxxxrxxrxrxrrrrrrrrrrrxrxrrrrxrrrxr
rx xx: xx:x xtrx
xx xxxrxrrtrrrrx
TOTAL AREA =
8.96 ACRES
OVERALL EFFECTIVENESS - 94.24t
>
78.37%
CONCLUDE: EROSION CONTROL PLAN IS EFFECTIVE
RAINFALL PERFORMANCE STANDARD EVALUATION
PROTECT:
MARTINEZ PUD
PROD. NO. 1558-01-97
STANDARD FORM A
COMPLETED BY:
MARK OBERSCHMIDT
DATE: 07/07/97
:+r•+fr+w+fr#rrT»rrrr#ifi♦f#w•f+•ffw+r++++T++r+r}rif
r++r#ri•++:#rrtYf TT#iif#r+rw+wTT#»1w
DEVELOPED
BRODIBILITY
Aob Lob Sob
Lb Sb PS
SUBBASIN
ZONE
(ac) (ft) (4)
(feet) (;) M
flrlfi#r#r######T##r#fr♦f iff•wff!•w•w+Tort#T#r##f
if ♦rrf+etrrr#1f ftT+TrT#if lrwrlrrif wtf r#:f
1
MODERATE
4.86 1600.00 1.00
7776 4.86
2
MODERATE
4.71 200.00 1.10
942 5.18
1tTt+t}t}T#YYY#iT#T#if##tif iff+f}t}ttT}T#T##TYf 1f#lfft!}tttTf Yffffflrf!}ir####fi#
9.57 910.97 1.05
LINEAR INTERPOLATION
SLOPE
LENGTH
1.00
1.05
1.50
900
78.2
78.36
79.8
911
78.37
1000
78.3
78.46
79.9
CONCLUDE:PERFORMANCE STANDARD - 78.374 .
EROSION CONTROL PLAN OVERALL EFFECTIVENESS MUST EXCEED THIS
1
CONSTRUCTION SEQUENCE
PROJECT: Martinez P.U.D.
STANDARD FORM C
SEQUENCE FOR 1997-1998 ONLY COMPLETED BY: MEO / Shear Engineering Coro
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 A S O N D J F M A M J J A
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: 07/03/97 DATE SUBMITTED: 07/09
APPROVED BY THE CITY OF FORT COLLINS ON:
July 8, 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
$ 5,325.00 Refer to the cost estimate attached in Appendix I. 1.5 times the cost to
install the erosion control measures is $ 7,987.50.
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 9.5 acres), we estimate that the cost to re -
vegetate the disturbed area will be $ 5,044.50 ($ 531.00 per acre x 8.5 acres). 1.5
times the cost to re -vegetate the disturbed area is $ 7,566.75. The $ 500.00 per acre
for re -seeding sites less 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
$ 79987.50.
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 FAX (970) 282.0311
July 8, 1997 .
Project No: 1558-01-97
Basil Harridan
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 ® $ 3.00 per LF $ 4,800.00
3 Haybale barriers ® $75.00 each $ 225.00
2 - Gravel Inlet Filters ® 150.00 each $ 300.00
TOTAL ESTIMATED COST: $ 5,325.00
x 1.50
$79987.50
ESTIMATE 2:
re -vegetate the disturbed area of 9.5 acres at $531.00 per acre $ 5,044.50
TOTAL ESTIMATED COST: $ 5,044.50
x 1.50
$ 7,566.75
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 $ 7,987.50.
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) 282-0311
APPENDIX H
Erosion Control Calculations
Erosion Control Sequencing schedule
Erosion Control security deposit estimate
SHEAR RNGINERRING CORPORATION
PAGE 13
CHANNEL CAPACITY- SECTION Z-Z
PROJECT NAME: MARTINEZ PUD DATE: 07/07/97
PROJECT NO. : 1558-01-97 BY : HBO
SWALE DESCRIPTION:SWALE ALONG SOUTH SIDE OF FILE: MARTRUN
COMMERCIAL BUILDING
CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL
CHANNEL CONFIGURATION: TRAPEZOIDAL
CHANNEL LINING: GRASS/CONCRETE Qdesign AMAP
Da Db Dc Sc n W I
(ft) (ft) (ft) (4) _ (ft) (ft)
---- ---- ---- ---- ----- --- ----
3.00 3.00 0.75 0.77 0.027 3.00 0.25
0.25 FT/FT = LEFT BANK SLOPE 4 :1 (H:V)
0.25 FT/FT = RIGHT BANK SLOPE 4 :1 (H:V)
DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V
(ft.) (ft) (s.f.) (ft) (A/P) (cfe) (ft/sec)
--------------------------------------------------------
0.75 9.00 4.50 9.18 0.62 0.09 13.51 3.00
0.50 7.00 2.50 7.12 0.50 0.09 6.01 2.40
0.25 5.00 1.00 5.06 0.34 0.09 1.64 1.64
0.00 3.00 0.00 3.00 0.00 0.09 0.00 0.00
t xrxwwxwwwrrrrrxtrxrrxxwwwwxwwwwwwwwwrrtrrttrrtxxxwxwwwwwwwwrwxwttxrtxxx
DEPTH WIDTH AREA PBRIM R 2/3 Sc 1/2 Q V _
(ft.) (ft) (B.f.) (ft) (A/P) (cfe) (ft/sec)
CONCLUDE:FLOWS WHICH EXCEED THE CAPACITY WILL OVERFLOW TRACKS AND CONTINUE EAST OR
WILL FLOW AROUND BUILDING INTO PAT TIRE LANE
SHEAR ENGINEERING CORPORATION
PAGE 12A
CHANNEL CAPACITY- SECTION Y-Y
PROJECT NAME: MARTINEZ PUD DATE: 07/07/97
PROJECT NO. : 1558-01-97 BY : MEO
SWALE DESCRIPTION:SWALE ALONG RAILROAD FILE: MARTRUN
SECTION Y-Y
CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL
CHANNEL CONFIGURATION: TRAPEZOIDAL 0100 (CPS) = 46.35
CHANNEL LINING: GRASS WITH PAN Qdeeign = 61.65
Da Db Dc Sc n W I
(ft) (ft) (ft) (i) (ft) (ft)
---- ---- ---- ---- ----- ---- ----
9.00 50.00 1.00 0.67 0.029 3.00 0.25
0.11 FT/FT = LEFT BANK SLOPE 9 :1 (H:V)
0.02 PT/FT = RIGHT BANK SLOPE 50 :1 (H:V)
DEPTH WIDTH AREA PBRIM R 2/3 Sc 1/2 Q V
(ft.) (ft) (e.f.) (ft) (A/P) (cfe) (ft/eec)
------- -------------------------------------------------
1.00 62.00 32.50 62.07 0.65 0.08 88.56 2.72
0.75 47.25 18.84 47.30 0.54 0.08 42.79 2.27
0.50 32.50 8.88 32.53 0.42 0.08 15.66 1.76
0.25 17.75 2.59 17.77 0.28 0.08 3.02 1.16
0.866 54.09 24.72 54.15 0.59 0.08 61.48 2.49
0.867 54.15 24.78 54.21 0.59 0.08 61.66 2.49
r rrr+rr+r+r+rrr+x+x+++r++r++r+rrrrr++++r+r+r++++r+r+rrrr+rrr rr+rrr rrrrrr
DEPTH WIDTH AREA PBRIM R 2/3 Sc 1/2 Q V
(ft.) (ft) (e.f.) (ft) (A/P) (cfe) (ft/sec)
FLOW DEPTH FOR THE DESIGN FLOW IS APPROXIMATELY 0.87 FEET
CONCLUDE:CHANNEL IS ADEQUATE
FLOWS WILL SPLIT AT THE COMMERCIAL BUILDING
WHEN THE CAPACITY OF THE SWALE ON SOUTH SIDE OF BUILDING IS EXCEEDED
WATER WILL BE DIVERTED AROUND THE WEST SIDE OF BUILDING INTO THE SITS.
SHEAR ENGINEERING CORPORATION
PAGE 12
FLOW TO DP 3
FROM OBPSITE
PROJECT: MARTINEZ PUD DATE 07/07/97
LOCATION:FORT COLLINS PROJ. NO.1558-01-97
FILE: MARTRUN BY HBO
NOTE: FLOW FROM SUB CATCHMENT 136 IN OLD TOWN BASIN _
AREA (A)- 23.770 ACRES
RUNOFF COEP. (C)
2 YEAR 10 YEAR 100 YEAR
C 0.33 0.33 0.42
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 230 FEET SLOPE 1.00
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 25.52 25.52 24.11
TRAVEL TIME (TO=L/(60*V) FLAW TYPE
L (ft) 960 S (1) = 0.50 GUTTER V (fps) = 1.50 Tt(min)= 10.67
L (ft) = 100 S M - 4.00 LAWN V (fps) - 1.47 Tt(min)= 1.13
L (ft) = 100 S (4) - 2.00 GUTTER V (fps) - 2.83 Tt(min)= 0.59
L (ft) = 1200 S (i) - 1.00 GUTTER V (fps) = 2..00 Tt(min)= 10.00
L (ft) _? S (4) = 1.00 NONE V (fps) - 0.00 Tt(min)= 0.00
L (ft) _? S (4) = 1.00 NONE V (fps) - 0.00 Tt(min)= 0.00
L (£t) _? S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 22.39
TOTAL LENGTH = 2590 FEET L/180+10 = 24.39 < 46.50
Tc
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 24.39 24.39 24.39
USE Tc = 24.5 24.5 24.5
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 1.65 2.91 4.69
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 13.07 23.00 46.35
CONCLUDE:HLOW FROM SOUTH AND EAST TO RR TRACKS ON SOUTH SIDS OF PROJECT
SIZE SWALE FOR Q100*1.33 = 61.65 CPS
SEE SWALE DESIGN ON PAGE 12 A
SHEAR ENGINEERING CORPORATION
DEVELOPED PAGE 11
FLAW TO INLET AT DP 1C
FROM MINOR BASIN 1C
PROJECT: MARTINEZ PUD DATE 07/07/97
LOCATION:FORT COLLINS PROD. NO.1558-01-97
FILE: MARTRUN BY MEO
NOTE: SIZE INLET AND PIPE FOR Q100 FROM SITE
OFFSITE FLOWS WILL OVERFLOW BANK
AREA (A)= 0.860 ACRES
RUNOFF COEF. (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 = 160 FEET SLOPE = 1.00
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)- 21.29 21.29 20.11
TRAVEL TIME (Tt)-L/(60*V) FLAW TYPE
L (ft) 200 S (e) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 1.67
L (ft) =7 S (4) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (a) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (i) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (4) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =7 S (i) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =7 S (i) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) 1.67
TOTAL LENGTH - 360 L/180+10= 12.00 c 21.77 CHOOSE LESSER
Tc -Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 12.00 12.00 12.00
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) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q 1.50 2.63 S.28
CONCLUDS:SIZB INLET FOR 100 YEAR SIZE PIPE FOR 100 YEAR
FLOW DEPTH (Yo) = 0.50 ft PIPE SIZE 1.50 FEET
H = 0.50 PT Yo/H = 1.00. PIPE TYPE ADS MANNINGS N = 0.012
CAPACITY/LP 1.13 cfe SLOPE 0.0100 FT/FT
REFER TO FIGURE 5-2 CAPACITY= 11.38 CPS PIPE CAPACITY OK
INLET SIZE = 10 ft
INLET CAPACITY = 9.60 cfe INLET CAPACITY OK
NOTE: INLET CAPACITY INCLUDES REDUCTION FACTOR
1i
SHEAR ENGINEERING CORPORATION
DEVELOPED PAGE 10
FLOW TO INLET AT DP 1B
FROM MINOR BASIN 1B
PROJECT: MARTINEZ PUD DATE 07/07/97
LOCATION:FORT COLLINS PROD. NO.1558-01-97
FILE: MARTRUN BY MHO
NOTE: SIZE INLET AND PIPE FOR Q100 FROM SITE
OFFSITE FLOWS WILL OVERFLOW BANK
AREA (A)= 0.210 ACRES
RUNOFF CORP. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.91 0.91 1.00
SHE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti) NA
LENGTH =NA FEET SLOPE =NA a
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) FLOW TYPE
L (ft) 200 S (i) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 1.67
L (ft) _? S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (i) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (4) = 1.00 NONE V (fps) - 0.00 Tt(min)= 0.00
L (ft) _? S (4) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
li (ft) _? S (7) = 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
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 1.67
TOTAL LENGTH = 200 L/180+10- 11.11 > 1.67 CHOOSE LESSER
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 1.67 1.67 1.67
USE Tc = 5.0 5.0 5.0
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 3.29 5.64 9.30
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
Q = 0.63 1.08 1.95 OVERSIZE INLET
Qpipe = 1.50 2.63 5.28
Qtotal = 2.13 3.71 7.24 SIZE PIPE FOR THIS
CONCLUDE:SIZE INLET FOR 100 YEAR SIZE PIPS FOR 100 YEAR
FLOW DEPTH (Yo) = 0.50 ft PIPE SIZE 1.50 FEET
H = 0.50 PT Yo/H = 1.00 PIPS TYPE RCP MANNINGS N = 0.013
CAPACITY/LF = 1.13 cfe SLOPS 0.0100 PT/FT
REFER TO FIGURE 5-2 CAPACITY= 10.50 CPS PIPS CAPACITY OK
INLET SIZE = 10 ft
INLET CAPACITY = 9.60 cfs INLET CAPACITY OK
NOTE: INLET CAPACITY INCLUDES REDUCTION FACTOR
SHEAR ENGINEERING CORPORATION
DEVELOPED PAGE
FLOW TO INLET AT DP lA
FROM MINOR BASIN lA
9
PROJECT: MARTINEZ PUD
DATE
07/07/97
LOCATION:FORT COLLINS
PROD. NO.1558-01-97
FILE: MARTRUN
BY
HBO
NOTE: SIZE INLET AND PIPE FOR Q100 FROM
SITE
OFFSITE FLOWS WILL
OVERFLOW BANK
AREA (A)= 3.800 ACRES
RUNOFF CORP. (C)
2 YEAR
10 YEAR
100 YEAR
C = 0.71
0.71
0.89
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 (t) -
1.00 GUTTER
V (fps) = 2.00
Tt(min)= 13.33
L (ft) _? S (t) -
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) =7 S (t) -
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 (t) -
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
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
I = 1.91
3.35
5.38
NOTE: INTENSITIES TAKEN
FROM FIGURE
3-1
RUNOFF (Q= CIA) (CE9)
2 YEAR
10 YEAR
100 YEAR
Q = 5.15
9.04
18.14 SIZE INLET FOR THIS
Qpipe = 2.13
3.71
7.24 FLOW IN
PIPE FROM INLET
OPPOSITE
Qtotal = 7.28
12.75
25.38 SIZE PIPE FOR THIS
CONCLUDE:SIZE INLET FOR
100 YEAR
SIZE PIPE FOR
100 YEAR
PLOW DEPTH (Yo) =
0.50 ft
PIPS SIZE 2.50
FEET
H = 0.50
PT Yo/H 1.00
PIPS TYPE ADS
MANNINGS N =
0.012
CAPACITY/LF =
1.13 cfe
SLOPE 0.0050
FT/FT
REFER TO FIGURE 5-2
CAPACITY= 31.42
CPS PIPE CAPACITY OK
INLET SIZE =
20 ft
INLET CAPACITY =
20.34 cfe
INLET CAPACITY OK
NOTE: INLET CAPACITY INCLUDES
ABDUCTION FACTOR OF
0.9
SHEAR ENGINEERING CORPORATION
PAGE 8 A
CHANNEL CAPACITY- SECTION X-X
PROJECT NAME: MARTINEZ PUD DATE: 07/07/97
PROJECT NO. : 1558-01-97 BY : HBO
SWALE DESCRIPTION:SWALE ALONG BALL FIELDS FILE: MARTRUN
SECTION X-X
CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL
CHANNEL CONFIGURATION: TRAPEZOIDAL Q100 (CPS) 29.53
CHANNEL LINING: GRASS Qdeeign o 39.27
Da Db Dc Sc n W I
(ft) (ft) (ft) (i) (ft) (ft)
---- ---- ---- ---- ----- ---- ----
6.00 6.00 1.50 1.00 0.032 2.00 0.25
0.25 FT/FT = LEFT BANK SLOPE 4 :1 (H:V)
0.25 FT/PT = RIGHT BANK SLOPE 4 :1 (H:V)
DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V
(ft.) (ft) (e.f.) (ft) (A/P) (cfe) (ft/eec)
-------------- ---------------------------- --------------
1.50 14.00 12.00 14.37 0.89 0.10 49.42 4.12
1.25 12.00 8.75 12.31 0.80 0.10 32.37 3.70
1.00 10.00 6.00 10.25 0.70 0.10 19.50 3.25
0.75 8.00 3.75 8.18 0.59 0.10 10.35 2.76
1.365 12.92 10.18 13.26 0.84 0.10 39.66 3.89
1.364 12.91 10.17 13.25 0.84 0.10 39.59 3.89
x xrrrrrr++rr++xxrxr•rrrrrrrxxxrrerrrrrrrrr+r+rr+rrxxrxxxxxxxrx+xr++r+r+r
DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V
(ft.) (ft) (e.f.) (ft) (A/P) (cfe) (ft/sec)
FLOW DEPTH FOR THE DESIGN FLOW IS APPROXIMATELY 1.36 FEET
CONCLUDE:CHANNEL IS ADEQUATE
SHEAR ENGINEERING CORPORATION
DEVELOPED
FLOW TO MARTINEZ PARK FROM MINOR
BASIN 2
PROJECT:
MARTINEZ PUD
DATE
07/07/97
LOCATION:FORT
COLLINS
PROD.
NO.1558-01-97
FILE:
MARTRUN
BY
MEO
NOTE:
SHEET FLOW DIRECTLY INTO PARK
AREA (A)= 4.710 ACRES
PAGE 8
RUNOFF COEF. (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 FRET
SLOPE = 2.00
i
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 (4) -
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 (3) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (i) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (4) =
1.00 NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (4) -
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 YRAR
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) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 8.40 14.72 29.57
CONCLUDS:SHEET FLOW INTO MARTINEZ PARK
DESIGN SWALE TO INTERCEPT AND DIVERT FLOWS TO EAST ON SOUTH SIDE OF
BALLFIELDS
SIZE SWALE FOR 1.33*Q100
SEE SWALE DESIGN ON PAGE 8 A
SHEAR ENGINEERING CORPORATION
DEVELOPED
PAGE 7
FLOW TO MARTINEZ PARK (DP)
1
FROM SUB BASIN 1
PROJECT:
MARTINEZ PUD
DATE
07/07/97
LOCATION:FORT
COLLINS
PROJ.
NO.1558-01-97
FILE:
MARTRUN
BY
MEO .
NOTE:
FLOW TO NORTHEAST
PORTION OF SITE AND INTO PARK
AREA (A)- 4.860 ACRES
RUNOFF COEF. (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 = 60 FEET
SLOPE =
2.00
k
2 YEAR
10 YEAR
100 YEAR
C 0.20
0.20
0.25
Ti (min) = 10.37
10.37
9.79
TRAVEL TIME (Tt)=L/(60*V)
FLOW TYPE
L (ft) = 1600 S (4) -
1.00
GUITBR
V (fps) =
2.00
Tt(min)=
13.33
L (ft) _? S (i) -
1.00
NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (4) -
1.00
NONE
V (fps) =
0.00
Tt(min)-
0.00
L (ft) _? S (4)
= 1.00
NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (If)
- 1.00
NONE
V (fps) _
0.00
Tt(min)=
0.00
L (ft) _? S (4)
- 1.00
NONE
V (fps) =
0.00
Tt(min)=
0.00
L (ft) _? S (4)
= 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
I = 1.91
3.35
5.38
NOTE: INTENSITIES TAKEN
FROM FIGURE
3-1
RUNOFF (Q- CIA) (cfs)
2 YEAR
10 YEAR
100 YEAR
Q = 6.73
11.81
23.71
CONCLUDE:SIZE PIPE FOR
100
YEAR
PIPE SIZE 2.50
FEET
PIPE TYPE ADS
MANNINGS
N =
0.012
SLOPE 0.0050
FT/FT
CAPACITY= 31.42
CPS
PIPE CAPACITY OK
SHEAR ENGINEERING CORPORATION
DEVELOPED
FLOW TO MARTINEZ PARK
FROM OVERALL AREA
PROJECT: MARTINEZ PUD
LOCATION:FORT COLLINS
PILE: MARTRUN
AREA (A)= 33.35 ACRES
RUNOFF COEF. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.45 0.45 0.56
SHE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH = 230 FEET SLOPE = 1.00 t
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 25.52 25.52 24.11
DATE 07/07/97
PROJ. NO.1558-01-97
BY MHO
PAGE 6
TRAVEL TIME (Tt)=L/(60*V) FLOW TYPE
L (ft) = 960 S (4) - 0.50 GUTTER V (fps) = 1.50 Tt(min)- 10.67
L (ft) = 100 S (4) _ 4.00 LAWN V (fps) = 1.47 Tt(min)- 1.13
L (ft) = 100 S (3) = 2.00 GUTTER V (fps) = 2.83 Tt(min)- 0.59
L (ft) = 1200 S (L) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 10.00
L (ft) _? S (i) - 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (4) = 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
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 22.39
TOTAL LENGTH 2590 FRET L/180+10 24.39 < 46.50
Tc
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 24.39 24.39. 24.39
USE Tc = 24.5 24.5 24.5
INTENSITY (I) (iph)
2 YEAR 10 YSAR 100 YEAR
I = 1.65 2.91 4.69
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfe)
2 YEAR
10 YEAR
100 YEAR
Q
= 24.55
43.21
87.07
VERSUS
HISTORIC FLOWS
Qhiet
= 16.42
28.91
58.25
CONCLUDE:CONVEY OFFSITE WATER THROUGH AND AROUND SITE
SHEAR ENGINEERING CORPORATION
HISTORIC
FLOW TO MARTINEZ PARK
FROM OVERALL AREA
PROJECT: MARTINEZ PUD
LOCATION:FORT COLLINS
PILE: MARTRUN
AREA (A)= 33.35 ACRES
RUNOFF COSP. (C)
2 YEAR 10 YEAR 100 YEAR
C = 0.30 0.30 0.37
SEE SPREAD SHEET ATTACHED ON PAGE 2
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (TO
LENGTH = 230 PERT SLOPE = 1.00 s
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)- 25.52 25.52 24.11
DATE 07/07/97
PROJ. NO.1558-01-97
BY HBO
PAGE 5
TRAVEL TIME (TO =L/(60*V) PLOW TYPE
L (ft) = 960 S (t) = 0.50 GUTTER V (fps) - 1.50 Tt(min)= 10.67
L (ft) = 100 S (t) - 4.00 LAWN V (fps) = 1.47 Tt(min)= 1.13
L (ft) = 100 S (i) = 2.00 GUTTER V (fps) = 2.83 Tt(min)= 0.59
L (ft) = 1200 S M - 1.00 GUTTER V (fps) = 2.00 Tt(min)= 10.00
L (ft) _? S (4) - 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (ft) - 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) _? S (3) - 1.00 NONE V (fps) = 0.00 Tt(min)- 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 22.39
TOTAL LENGTH = 2590 FEET L/180+10 = 24.39 < 46.50
Tc
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 24.39 24.39 24.39
USE Tc = 24.5 24.5 24.5
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 1.65 2.91 4.69
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 16.42 28.91 58.25
CONCLUDE: COMPARE WITH DEVELOPED PLOWS
SHEAR ENGINEERING CORPORATION
DEVELOPED
FLOW TO MARTINEZ PARK
FROM SITE
PROJECT: MARTINEZ PUD
LOCATION:FORT COLLINS
FILE: MARTRUN
AREA (A)= 9.580 ACRES
RUNOFF COEF. (C)
2 YEAR 10 YEAR
C 0.73 0.73
SEE SPREAD SHEET ATTACHED ON PAGE
2
100 YEAR
0.91
TIME OF CONCENTRATION (Tc)
OVERLAND TRAVEL TIME (Ti)
LENGTH 60 FEET SLOPE = 2.00 t
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 10.37 10.37 9.79
DATE 07/07/97
PROJ. NO.1558-01-97
BY HBO
PAGE 4
TRAVEL TIME (Tt)=L/(60*V) FLOW TYPE
L (ft) = 1600 S (t) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 13.33
L (ft) _? S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =7 S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)- 0.00
L (£t) =7 S (t) - 1.00 NONE V (fps) = 0.00 Tt(min)- 0.00
L (ft) _? S (4) - 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =7 S (t) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =7 S (t) - 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 a 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
I 1.91 3.35 5.38
NOTE: INTENSITIES TAKEN FROM FIGURE 3-1
RUNOFF (Q- CIA) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 13.26 23.28 46.73
VERSUS HISTORIC FLOWS
Qhiet = 3.87 6.80 13.65
SHEAR ENGINEERING CORPORATION
HISTORIC PAGE
FLOW TO MARTINEZ PARK
FROM SITE
PROJECT: MARTINEZ PUD DATE 07/07/97
LOCATION:FORT COLLINS PRAT. NO.1558-01-97
FILE: MARTRUN BY MEO
AREA (A)= 9.580 ACRES
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 -? FEET SLOPE _? •
2 YEAR 10 YEAR 100 YEAR
C = 0.20 0.20 0.25
Ti (min)= 0.00 '0.00 0.00
TRAVEL TIME (Tt) =L/(60-V) PLOW TYPE
L (ft) = 1140 S (t) = 0.70 GUTTER V (fps) = 1.72 Tt(min)= 11.05
L (ft) 520 S (i) - 2.00 LAWN V (fps) - 1.00 Tt(min)= 8.67
L (ft) =7 S (1k) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
L (ft) =? S (4) = 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 (i) = 1.00 NONE V (fps) - 0:00 Tt(min)= 0.00
L (ft) _? S (1) = 1.00 NONE V (fps) = 0.00 Tt(min)= 0.00
ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 19.71
TOTAL LENGTH = 1660 L/180+10= 19.22 < 19.71 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
I 1.91 3.35 5.38
NOTE: INTENSITIES TAKEN. FROM FIGURE 3-1
RUNOFF (Q= CIA) (cfe)
2 YEAR 10 YEAR 100 YEAR
Q = 3.87 6.80 13.65
CONCLUDE: COMPARE WITH DEVELOPED PLOWS
3
SHEAR ENGINEERING CORPORATION
SUBBASIN
BREAKDOWN
PAGE
2
PROJECT: MARTINEZ
PUD
DATE
07/07/97
LOCATION:FORT COLLINS
BY
HBO
PROJ.NO.:1558-01-97
FILE:
MARTRUN
TOTAL SITE AREA
9.58 ACRES TOTAL
BASIN AREA =
33.35
OFFSITE AREA =
23.77 ACRES
SUBCATCHMENT 136
26.82 ACRES A PORTION
OF THIS BASIN
IS ONSITE
ASSUMPTIONS:
SITE IS 70% IMPERVIOUS AND
30'k LAWNS, HEAVY SOIL
TOTAL AREA
INCLUDES RESIDENTIAL
AREA NORTH OF
CHERRY AND EAST OF LOOMIS
MINOR
MINOR
MINOR
SITE
SUBBASIN
SUBBASIN
BASIN
BASIN
BASIN
HISTORIC
DEVELOPED
OFFSITE
1
2
1C
1A
1B
ASPHALT
0.00
5.45
3.84 2.76
2.68
0.44
2.12
0.20
CONCRETE 0.00
0.00
0.00 0.00
0.00
0.00
0.00
0.00
GRAVEL
0.38
0.00
1.67 0.00
0.00
0.00
0.00
0.00
ROOFS
0.00
1.26
0.24 0.64
0.62
0.16
0.48
0.00
LAWNS,SANDY SOIL
FLAT <
24 0.00
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
0.00
STEEP >
7% 0.00
0.00
0.00 0.00
0.00
0.00
0.00
0.00
LAWNS,
HEAVY SOIL:
FLAT <
2% 9.20
2.87
'21.07 1.46
1.42
0.25
1.20
0.01
AVERAGE
2 TO 714 0.00
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
0.00
TOTAL
9.58
9.58
26.82 4.86
4.72
0.85
3.80
0.21
RUNOFF
COEFFICIENT
SUB BASINS
AND / OR MINOR BASINS
HISTORIC
DEVELOPED
HISTORIC
DEVELOPED
SITE
SITE
OPFSITS
1
2
IS.
1A
1C OVERALL
OVERALL
C2-C10
0.21
0.73
0.33 0.73
0.72
0.73
0.71
0.91 0.30
0.45
C100 =
1.25*C2 0.26
0.91
0.42 0.91
0.91
0.91
0.89
1.00 0.37
0.56
C100 IS
NEVER GREATER THAN
1.0
FLOW SUMMARY FOR MARTINEZ PUD
PAGE 1
DATE 07-Jul
DESIGN CONTRIBUTING AREA C2 C10 C100 Tc Tc I2 I10 I100 02 Q10 Q100 PAGE
POINT SUB/MINOR 2,10 100
BASIN(S) ac. min. min iph iph iph cfe cfe cfe
rrr+r++rrrerree•rrrre•rrrr++r+rrrrrrrr r++++++++re+rrrrrrrrrrrr rr++rrr:errrrrrrr+r+++++++r+r rrrr rrrrr
HISTORIC CONDITIONS
PARK SITE 9.58 0.21 0.21 0.26 19.00 19.00 1.91 3.35 5.38 3.87 6.80 13.65 3
PARK OVERALL 33.35 0.30 0.30 0.37 24.50 24.50 1.65 2.91 4.69 16.42 28.91 58.25 5
DEVELOPED CONDITIONS
PARK SITE 9.58 0.73 0.73 0.91 19.00 19.00 1.91 3.35 5.38 13.26 23.28 46.73 4
PARK OVERALL 33.35 0.45 0.45 0.56 24.50 24.50 1.65 2.91 4.69 24.55 43.21 87.07 6
SUB BASINS DEVELOPED CONDITIONS
1 1 4.86 0.73 0.73 0.91 19.00 19.00 1.91 3.35 5.38 6.73 11.81 23.71 7
2 2 4.71 0.72 0.72 0.91 11.00 11.00 2.46 4.31 6.92 8.39 14.70 29.53 8
STORM SEWER DESIGN FLOWS
lA 1A 3.80 0.71 0.71 0.89 19.00 19.00 1.91 3.35 5.38 5.15 9.04 18.14 9
1B 1B 0.21 0.91 0.91 1.00 5.00 5.00 3.29 5.64 9.30 0.63 1.08 1.95 10
1C 1C 0.85 0.73 0.73 0.91 11.50 11.50 2.42 4.24 6.82 1.50 2.63 5.28 11
OFFSITE FLOWS TO SITE
3 OPPSITS 23.77 0.33 0.33 0.42 24.50 24.50 1.65 2.91 4.69 13.07 23.00 46.35 12
STORM SEWER INFRASTRUCTURE SUMMARY
DP DESIGN Q INLET INLET Q PIPE MANNINGS SLOPE PIPE
STORM INLET SIZE CAP. PIPE SIZE N CAP.
YEAR CPS FT CPS CPS FT FT/FT CPS
IA 100 18.14 20.00 20.34 25.38 2.50 0.012 0.005 31.42
1B 100 1.95 10.00 9.60 7.24 1.50 0.013 0.010 10.50
SC 100 5.28 10.00 9.60 5.28 1.50 0.012 0.010 11.38
SWALB SUMMARY
SECT. DESIGN Q DEPTH SIDE SLOPE BOTTOM MANNINGS SWALE
STORM SLOPE WIDTH N CAP
YEAR CPS FT H:1 il PT CPS
X-X 100 39.26 1.50 4 1.00 2.00 0.032 49.41
Y-Y 100 61.64 1.00 9 0.67 3.00 0.029 88.55
Z-Z NA AMAP 0.75 4 0.77 3-00 0.027 13.50
NOTE: Q = 1.33*Q100 - FOR SWALES ONLY
CAPACITY OF SECTION C-C IS LIMITED BY ITS PROXIMITY
TO THE TRACKS AND THE COMMERCIAL BUILDING
EXPECT A SPLIT FLOW CONDITION AT SW CORNER OF BUILDING
AMAP - AS MUCH AS POSSIBLE
APPENDIX I
Storm Drainage Calculations
PAGE 9
Project No: 1558-01-97
Final Drainage and Erosion Control Report
V. EROSION CONTROL:
B. Specific Details
4. Riprap will be placed on the bank below the inlets at the low point on Fat Tire Lane
to prevent bank erosion when the curb is overtopped.
5. Riprap will be placed at the outfall of the storm sewer.
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.
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, 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 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 8
Project No: 1558-01-97
Final Drainage and Erosion Control Report
IV. DRAINAGE FACILITY DESIGN:
B. Specific Details ( continued)
7. The tables below summarizes the design flows and the inlet and pipe design. The
pipe under the street will be Reinforced Concrete (RCP) which has a Mannings n
value of 0.013. The pipe under the lawn areas will be ADS N-12 which has a
Mannings n value of 0.012. All pipe capacities are based on a HW/D ratio of 1.0.
Design
Design
Inlet
Flow
Inlet
Point
Flow
Length
Depth
Capacity
cfs
ft.
ft.
cfs
lA
18.1
20
0.5'
20.3
1B
1.9
10
0.5'
9.6
1C
5.3
10
0.5
9.6
Design
Design
Pipe
Slope
Pipe
Point
Flow
Size
Capacity
cfs
ft.
ft./ft.
cfs
lA
25.1
2.5
0.005
31.4
1B .
7.2
1.5
0.01
10.5
1C
5.3
1.5
0.01
10.5
V. EROSION CONTROL:
A. General Concept
1. Erosion control measures will be as identified on the Final 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. Refer to the Erosion Control Security Document located in Appendix II for the
amount of the deposit.
B. Specific Details
1. Silt Fence will be provided along the downstream property line.
2. Haybales will be provided in all swales.
3. Gravel inlet filters will be provided at the inlets.
PAGE 7
Project No: 1558-01-97
Final Drainage and Erosion Control Report
IV. DRAINAGE FACILITY DESIGN:
B. Specific Details ( continued)
5. A swale along the north side of the railroad tracks (Section Y-Y) will be constructed
to convey, the offsite flows along the north side of the tracks to the proposed
commercial building. The design flow is 61.6 cfs which is 133% of the Q100 at
Design Point 3. The grading will be done on the north side of the tracks. The grade
of the tracks will not be changed. The proposed swale section is a combination of the
proposed grade and the existing grade from the tracks south. The proposed
trapezoidal swale has the following geometric and hydraulic characteristics.
Side
Depth Bottom Slope Mannings slope Capacity
ft. Width ft. ft.� n HV cfs
1.0 3.0 0.67 0.029 9:1 & 50:1 88.50
6. A swale along the north side of the railroad tracks and south of the commercial
building (Section Z-Z) will be constructed to convey some of the offsite flows to the
parking lot. The proximity of the existing tracks and the proposed building limit the
capacity of Section Z-Z. Therefore the offsite flows will exceed the capacity of the
swale. We have assumed that a split flow condition will occur when the capacityHof
section Z-Z ' is exceeded. The split flow will go north and east. The proposed
trapezoidal swale has the following geometric and hydraulic characteristics.
Side
Depth Bottom Slope . Mannings slope Capacity
ft. Widthft. ft.L n H:V cfs
0.75 3.0 0.0077 0.027 4:1 13.50
7. Two type R inlets will be installed at the low point of the entry road at the eastern end
of the site (DP lA & 1B). A 10' Type R inlet will be installed at the low point in the
parking lot of the commercial building (DP 1C).
a. The inlets are sized to intercept the runoff, generated by the ofsite minor basins
lA-lC during the 100-year event.
b. Allowable flow depth on a local street for the 100-year event is 6" over the crown
(0.89 feet at the flowline).
c. Water will begin to overflow into the park when it exceeds a depth of
approximately 0.5 feet at the flowline on the north side of the entry drive.
Therefore street capacity is not exceeded.
PAGE 6
Project No: 1558-01-97
Final Drainage and Erosion Control Report
IV. DRAINAGE FACILITY DESIGN:
A. General Concept
4. a. A concept plan of the proposed improvements is available at the City of Fort
Collins Parks and Recreation Department.
IV. DRAINAGE FACILITY DESIGN:
B. Specific Details
1. Historic and developed peak flows from the portion of the site to be developed 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
9.58
0.21
0.26
3.9
13.6
Developed Site
9.58
0.73
0.91
13.6
46.7
Historic Overall
33.35.
0.30
0.45
16.4
58.2
Developed Overall
33.35
0.45
0.46
24.5
87.1
2. A channel is proposed on the south side of the existing ballfields in Lee Martinez
Park. The swale will intercept the sheet flow from sub -basin 2 and convey it east to ..
the existing swale at the eastern end of the site and the park. This Swale will meander
among the existing trees. The City of Fort Collins Parks and Recreation Department
has agreed to provide construction easements for construction of the channel.
3. The channel in Lee Martinez Park (Section X-X) is designed to convey 39.3 cfs to the
east. This is 133% of the Q100 from sub -basin 2. The proposed swale will convey
the runoff to an existing swale on park property near the eastern end the site. This
existing swale then conveys the runoff to the Cache La Poudre River.
4. The proposed trapezoidal swale on the park property (Section X-X) has the following
geometric and hydraulic characteristics.
Side
Depth Bottom Slope Mannings
slope Capacity
ft. Width ft. ft.� n
H_V cfs
1.0 2.0 0.01 0.032
4:1 49.41
PAGE 5
Project No: 1558-01-97
Final 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.
Only the 2 and 100-year flows are included in the body of the report. Refer to
Appendix I for the 10-year peak flows.
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.
IV. DRAINAGE FACILITY DESIGN:
A. General Concept
Onsite stormwater will have 2 different travel paths. A portion of the site (Sub -Basin
1) will contribute stormwater to a proposed low point located near the access to the -
park from the entry drive. The remainder of the site (Sub -Basin 2) will contribute
stormwater directly to Lee Martinez Park. Parks Department approvals are required.
Easements may be requested.
a. The Parks Department has agreed to grant easements if required.
Offsite flows will be conveyed east along the north side of the railroad tracks via an
existing swale. There will be some grading done on the north side of the tracks to
create a more efficient Swale. Some grading will also 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 and to the east. These swales, along with the on site
grading, will redirect the offsite runoff around the proposed commercial building to
the east and north.
a. Any grading which occurs within the railroad right-of-way or easement, will
require the approval of the railroad and/or the Public Utilities Commission
W.U.C.).
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. This area has not been considered in any calculations
or design. The total area of the entire site is approximately 11.38 acres. The portion
to be developed has an area of approximately 9.58 acres. It is our understanding that
this area has been purchased by the City of Fort Collins Parks and Recreation
Department in order to provide additional parking facilities for Lee Martinez Park.
PAGE 4
Project No: 1558-01-97
Final Drainage and Erosion Control Report
M. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA:
B. Development Criteria Reference and Constraints
2. 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 has been
provided to facilitate this proposed improvement.
c. The Old Town Master Drainage Basin represents the open channel on the north
side .of Cherry Street in line with the extension of Mason Street, which is where
the entrance to the site is located. The proposed box culvert was shown in the
preliminary submittal with a larger skew in order to locate the channel east of the
Martinez P.U.D. entrance drive. The box culvert was represented being extended
to the north because the Parks Department is planning to provide additional
parking for Martinez Park in the future. The alignment noted was conceptual.
d. It is our understanding that the final details of the design of the box culvert are not
complete at this time. The box culvert shown in the Old Town. Master Drainage
Basin Plan is only designed based on the expected flows. Together with the
potential for parking east of the site and potential conflicts with existing
undergroundutilities, there is a very good possibility that.the culvert may have to
be extended further north than the master plan shows.
e. The proposed final site grading reflects matching existing conditions at the
eastern property line.
3. There is an existing 48" storm sewer which crosses the property just east of the
proposed commercial building. The 48" storm sewer extends across Lee Martinez
Park and currently daylights at the Cache la Poudre river.
a. The easement is situated in an existing 50' easement that is recorded in Larimer
County records at Book 446, 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 Final Drainage and Erosion Control
Plan. The floodplain was taken from Flood Insurance Rate Map (FIRM) Panel 2 of 7;
Community Panel Number 080102 0002 B; map revised February 15, 1984. A copy
of the flood plain map is included with this report in the Appendix IV
PAGE 3
Project No: 1558-01-97
Final Drainage and Erosion Control Report
H. DRAINAGE BASINS AND SUB -BASINS:
B. Sub -Basin Description
1. The site slopes to the east and north. Historically much of the onsite stormwater
flows overland east to a low point at the northeastern corner of the property. The low
point is located north of the intersection of Cherry and Mason Streets. From the low
point, storm water runoff is conveyed north into Lee Martinez Park via a natural
swale eventually reaching the Cache La Poudre River.
a. A 3'x30' concrete box culvert is proposed with the Old Town Master Drainage
Basin Plan. This box culvert would convey stormwater from the southwest corner
of the intersection of Mason and Cherry streets under Cherry Street to the existing
swale.
i. It is our understanding that the design of the box culvert noted with the Old
Town Master Drainage Basin Plan is conceptual only.
ii. It is our understanding that the box culvert noted with the Old Town Master
Drainage Basin Plan will not be constructed in the immediate future. .
b. The outfall of the future box culvert will be located east of the proposed entry
drive off -of Cherry Street.
M. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA:
A. Regulations
1. All storm drainage design criteria from the City of Fort Collins Drainage Criteria
Manual were 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 were considered.
B. Development Criteria Reference and Constraints
1. All grading design must match the existing elevations at all property lines unless a
temporary construction easement is provided.
2. Stormwater improvements are proposed with the Old Town Master Drainage Basin
Plan for this area. These improvements include a 3'x30' Reinforced Concrete Box
Culvert to be installed at the intersection of Cherry and Mason Streets.
a. Stormwater runoff will be conveyed in the box culvert to an open channel along
the eastern portion of this site, then to a proposed settling basin north of the site in
Lee Martinez Park, then to the Cache La Poudre River.
PAGE 2
Project No: 1558-01-97
Final 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. Portions of the site are located in Subcatchment
136 of the Old Town Basin. The drainage fees associated with the Old Town Basin
are $4,150.00 per acre.
2. The eastern parking area 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. Figure 4 is
attached in Appendix IV. This has also been delineated on the Drainage and Erosion
Control Plan.
3. No portion of the Martinez P.U.D. site is located within 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 elevations across the northern property line of the site range from
approximately 4970 to 4987 from east to west.
4. Some offsite contribution is expected from the properties to the south and west. The
offsite contributing area is bounded by Loomis.Avenue on the west and Cherry Street
on the south. The offsite contributing area consists of subcatchment 136 and 108.as '
designated on Figure 4.1 of the Old Town Master Drainage Basin Plan. A 2 (two)
sheet exhibit is attached in Appendix V which delineates the offsite basins.
a. The majority of the offsite stormwater from subcatchment 136 is conveyed
easterly along the north side of the existing railroad tracks. There is a poorly
defined swale along the northern side of the tracks. Development of the site will
include some grading in the railroad right-of-way to better define the swale.
Subcatchment 136 has an area of approximately 26.8 acres. This compares to an
area of 17.0 acres which is listed the Old Town Master Drainage Plan.
Historically, much of the offsite stormwater flows east along the track to the
location of the proposed entry drive where it turns north towards the Cache La
Poudre River (refer to aerial exhibits included with this report).
b. Historically stormwater is conveyed easterly along the north side of the tracks to a
point east of the site of the proposed commercial building where the water begins
to flow in a northeasterly direction.
c. The proposed commercial building is situated in the historic flow path. Grading
on the west side of the building will divert the, offsite stormwater to the north and
the east around the building.
5. Much of the runoff from subcatchment 108 will be conveyed underground through
the site via the future box culvert (represented in the Old Town Basin Master Plan)
and the existing storm sewer across the property.
PAGE 1
Project No: 1558-01-97
Final Drainage and Erosion Control Report
I. GENERAL LOCATION AND DESCRIPTION:
A. Location
1. Martinez P.U.D. is located in the Northeast One Quarter (1/4) of Section 11, UN,
R69W of the 6th P.M., City of Ft. Collins, County of Latimer, 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 that is to be developed is approximately 9.58 acres. The total site has an
area of approximately 11.38 acres. The eastern portion of the site has been sold to the
City of Fort Collins for use by the Parks and Recreation Department.
3. Development of the site will consist of a co -housing (multi -unit) area to the west, 10
(ten) single family lots, a commercial tract currently planned for a 12,200 square foot
commercial building, and a tract to the east of the commercial area which has been _
purchased by the City of Fort Collins Parks and Recreation Department. 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) has been purchased by the City of Fort Collins
Parks and Recreation Department to create 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.
July 8, 1997
Project No: 1558-01-97
Basil Harridan
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 Final 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 and revised this
year, 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.
Sincerely,
i4 L
Brian W. Shear, P.E.
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) 282.0311
Final 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
Prepared by:
SHEAR ENGINEERING CORPORATION
Project No: 1558-01-97
DATE: July, 1997
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226.5334 FAX (970) 282-0311