HomeMy WebLinkAboutDrainage Reports - 09/21/1993Y
Preliminary Drainage and Erosion Control Report
for
WILDFLOWER RIDGE P.U.D.
Larimer County, Colorado
Prepared for:
Peterson Design
2717 W. County Road 38E
Fort Collins, Colorado 80526
Prepared by:
SHEAR ENGINEERING CORPORATION
Project No: 1382-01-93
DATE: September 1993
4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334
I hereby certify that this Preliminary Report for the Drainage and Erosion Control design of
"Wildflower Ridge P.U.D.", was prepared under my direct supervision in accordance with the
provisions of the Latimer County Storm Water Management Manual for the owners thereof.
Brian W. Shear, P.E.
Registered Professional Engineer
State of Colorado No: 20262
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PAGE 1
Wildflower Ridge P.U.D.
Preliminary Drainage Report
L GENERAL LOCATION AND DESCRIPTION:
A. Location:
1. Wildflower Ridge P.U.D. is generally located in the southwest 1/4 of section 33,
17N, R69W, Larimer County Colorado.
2. More specifically, it is located approximately one quarter (1/4) of a mile west of the
intersection of Larimer County Road 38E (Horsetooth Road) and Taft Hill Road
and five hundred (500) feet south of Larimer County Road 38E (Horsetooth Road).
3. The site is bounded on the. north, partially by Larimer County Road 38E
(approximately 407 and partially by unplatted property. It is bounded on the east
by Red Fox Road and currently unplatted property which is in the conceptual design
phase as Fox Hills P.U.D. - Phase 2. It is bounded on the south by Fox Hills P.U.D.
- Phase 1, which has gained preliminary plat approval through the County and is
currently in the final design phase. It is bounded on the west by unplatted property.
Westridge MRD is located to the southwest, due west of Fox Hills P.U.D. -Phase
1.
4. Wildflower Ridge P.U.D. is located within the City of Fort Collins Urban Growth
Area (UGA).
B. Description of Property:
1. Wildflower Ridge P.U.D. covers approximately 12.15 acres. The site is pasture
land with a ground cover consisting primarily of dry land grasses.
2. Wildflower Ridge P.U.D. will consist of 23 single family residences and the
necessary infrastructure to service them. There is an existing residence on the
property which will remain.
H. DRAINAGE BASINS AND SUB -BASINS:
A. Major Basin Description:
1. The majority of the site is located within the Fossil Creek Basin as delineated on the
Fort Collins Storm Water Basin Map. A small portion of the site is located in the
Wiring Creek Basin. 1%. g-#5a- otru,uernr otv r#w PuvNs
2. The site is situated below the Spring Creek Dam of Horsetooth Reservoir.
B. Sub -Basin Description:
1. A ridge line running north to south is located approximately 150 feet west of the
western property line. Another ridge line running west to east is located on the
property to the south currently being designed for development as Fox Hills P.U.D.
- Phase 1.
PAGE 2
Wildflower Ridge P.U.D.
Preliminary Drainage Report
M DRAINAGE BASINS AND SUB -BASINS:
B. Sub -Basin Description: (continued) %�'�u 4"e, r'
2. Historically, there is an area upstream of the site ontributing storm water to the
property. The historic basin is divided into 3 sub basins: two in the ossil Creek
Drainage Basin and the other in the Spring Creek inage Basin.
3. Development of Fox Hills P.U.D. - Phase 1 will significantly reduce the upstneamm l�.O ?
contributing area,'by routing much of the offsite storm water from the west, to Red/
Fox Road, thus bypassing the Wildflower Ridge P.U.D. site. The developed basin
is .divided into four (4) sub -basins; three (3) in the Fossil Fossil Creek Drainage
Basin and one (1) in the Sprinif eek Drainage Basin.
4. The site has approximately 46 feet of relief from the southwest corner to the
northeast corner. �
f��Ps�sc sow CJ�er� i�e
�ssiL G✓ee,� 5'- SPZi��G G�C�.e c�itsiws GYc�,es
III DRAINAGE DESIGN CRITERIA:
A. Regulations: fL sloes p�of,�k-f co�✓''�.s of�/�K
f+uid Discuss i Y�c'S repo�� f cR�rs�f �rF.�iwg ,6
1. Design Criteria from the Larimer County Storm Water Management Manual were be"
utilized.
B. Development Criteria Reference and Constraints:
1. The design of Red Fox Road is being provided with the design of Fox Hills P.U.D. -
Phase 1. The majority of the storm water from the Wildflower Ridge P.U.D. and
Fox Hills P.U.D - Phase 1, will be released into Red Fox Road and conveyed either
north to County Road 38E or east through the Fox Hills P.U.D. - Phase 2 site.
Thew wheJc 7 j5js a/i i�e✓er From fhsr�o�,c a/i.9�r9+ric
C. Hydrological Criteria: p f!s'? /few ,�� �- se�Gf
1. The Rainfall -Intensity -Duration curves for Larimer County were used (Figure 3.3.1-
1, attached for reference), in conjunction with the "Rational Method" for
determining peak flows at various concentration points.
2. Detention pond requirements were determined utilizing the "Cumulative Runoff
Method" as presented in the Larimer County Storm Water Management Manual.
This method is also accepted by the City of Fort Collins.
3. The 2 and 100 year storms were used in the design of the storm water management
infrastructure in accordance with Larimer County storm water management criteria.
PAGE 3
Wildflower Ridge P.U.D.
Preliminary Drainage Report
11 1 ; 1► 0 51.3 celam
D. Hydraulic Criteria:
1. Street capacity references provided in the Latimer County Storm Water
Management Manual and street capacity exhibits which were prepared by this
office, based on the Mannings equation, were used.
2. Storm sewer and drainage channel capacities were based on the Mannings
Equation. The Mannings coefficients are as suggested by Latimer County Storm
Water Management Manual.
IV DRAINAGE FACILITY DESIGN:
A. General Concept:
1. The northeast corner of the site will be designated as a detention facility (Tract A).
Detention will be provided in order to restrict storm water runoff rates to historic
(Pre -development) levels. 2e yr hKV16 tic T
2. A majority of the storm water will be conveyed to the detention facility via a
combination of overland, gutter and storm sewer conveyance.
3. A small portion of the site will continue to contribute storm water directly to
Latimer County Road 38E without benefit of detention. This area is a part of Tract
which has been designated as open space. There will be absolutely no increase in
runoff from this area due to development of Wildflower Ridge P.U.D.
4. References located in Appendix II were obtained from the Latimer County Storm
Water Management -Manual. The Grading and Drainage Plan is also included in
Appendix III.
B. Specific Details:
1. Specific design details will be provided with final utility plans and final Drainage
and Erosion Control report at time of final subdivision application.
2. Maintenance of the storm drainage detention facility will be the responsibility of the
developer until completion of Wildflower Ridge P.U.D. Upon completion of the
project, maintenance responsibilities will then be assumed by the Wildflower Ridge
P.U.D. Homeowners Association.
PAGE 4
Wildflower Ridge P.U.D.
Preliminary Drainage Report
V. EROSION CONTROL:
A. General Concept:
1. Erosion control measures are specified on the Preliminary Grading and Drainage
Plan included with this report. These measures will effectively reduce the amount
of soil erosion potential created during the construction of the project. .
a. Maintenance of erosion control devices, both offite and offsite, will remain the
responsibility of the developer until the subdivision is totally developed.
B. Specific Details
1. Erosion control will consist of silt fence along all unprotected downstream property
lines, hay bale dikes in all swales, and gravel filters at all inlets. These will be
shown on the Final utility drawings.
VL CONCLUSIONS:
A. Compliance with Standards:
1. All drainage design conforms with the criteria and requirements of the Larimer/
County Storm Water Management Manual.
2. Proposed erosion control measures conform with generally accepted erosion control
measures and Larimer County requirements.
B. Drainage Concept:
1. The design of the drainage infrastructure effectively controls any increase in storm
water runoff due to the development of Wildflower Ridge P.U.D.
2. The erosion control measures specified will effectively reduce erosion potential
during construction.
VIL REFERENCES:
1. Larimer County Storm Water Management Manual.
2. Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual.
3. Preliminary Grading and Drainage plan for Fox Hills P.U.D. - Phase 1; prepared by
Stewart & Associates, dated July, 1993
APPENDIX I
Storm Drainage Calculations
I
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SHEAR ENGINEERING CORPORATION
PAGE 3 1S'\T
WILDFLOWER RIDGE PUD
HISTORIC FLOW TO A FROM SUB BASIN I
QVo5 v
�( p�,
DATE
PROJ.
TIME
09/17/93
NO.1382-01-93
1147 HOURS
FILE NAME WILD
BY
MEO
AREA (A)= 20.46 ACRES
RUNOFF COEF. (C)
2 YEAR 10 YEAR 100 YEAR
t.
C = 0.30 0.30 0.375
FOR PASTURE, LOAM, LIGHT VEGETATION REFER TO TABLE 4.2.1-1
TIME OF CONCENTRATION (Tc) �/ �$Jpµ 15 Sam
OVERLAND TRAVEL TIME (TO(1.87(1.1-CCf)*(L)A0.5)/(S)A0.33 Mkx Imov'�
LENGTH = 570 FEE SLOPE = 7.20 Y I„
2 YEAR 10 YEAR 100 YEAR
C = 0.30 0.30 0.375
Ti (min)= 18.62 18.62 16.87
TRAVEL TIME (TO=L/(60*V) FLOW TYPE
L (ft) = 190 S M _ "PASTURE
L (ft) _ .LM S M _ "WwaL
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR
Tc (min)= 35.97 35.97
USE Tc = 36 36
INTENSITY (I) (iph)
2 YEAR 10 YEAR
I = 1.30 2.25
NOTE: INTENSITIES TAKEN FROM FIGURE
RUNOFF (0= CIA) (cfs)
2 YEAR 10 YEAR
0 = 7.98 13.81
100 YEAR
34.23
34
100 YEAR
3.75
3.3.1-1
100 YEAR
28.77
V (fps) = 1.80 Tt(min)= 1.76
V (fps) _ Ja Tt(min)= 15.60
TOTAL TRAVEL TIME (min) = 17.35
qeve�W
P� ( w
SHEAR ENGINEERING CORPORATION
PAGE ZPD
WILDFLOWER DATE 09/17/93
HISTORIC FITE AND UPSTREAM AREA PROD. NO.1382-01-93
TIME 1147 HOURS
FILE NAME BY MEO
d� �xlen+ Of Vi4LS 6A!rw ow 4, Pl.Iu5.
AREA CA)=,D, '�('RUNOFF COEn�s) �^ �"°� +� Y- RLi- `fir- l�� A re4 r- wA q,.e, /,4�l
2 YEAR 10 YEAR 100 YEAR c*t4 - i-t,u w6o4 M4 keS vP +IY- 12 &% 4<,
C = 0.30 0.30 0.375 cqw Set kvi4 r _ fler _ ew � �/ CW
FOR PASTURE,LOAM, LIGHT VEGETATION REFER TO TABLE 4.2.1-1 r yeci� P
P,tYeS, bu% c.b-wet wwiirrt your
TIME OF CONCENTRATION (TO ✓*Ioe.s �y Ioa k;ws 4v6 'mac. oetx,, . ,, PjAKa.
OVERLAND TRAVEL TIME (Ti) (1.870.1-CCf)*(L)^0.5)/(S)^0.33
LENGTH = .jMFEET SLOPE _ 7.20 Y.
2 YEAR 10 YEAR 100 YEAR
C = ...Q. 0.375
: Ti (min)= 18.62 18.62 16.87
TRAVEL TIME (TO=L/(60*V) FLOW TYPE
L (ft) _ �. S a) = n en PAc V (fps) = I An Tt(min)= 1.76
L (ft) = = S (R) = J& PASTURE V (fps) = .1..51, Tt(min)= 15.60
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 17.35
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Tc (min)= 35.97 35.97 34.23
USE Tc = 36 �36 34
INTENSITY (I) (iph)
2 YEAR 10 YEAR 100 YEAR
I = 1.30 �2.25 3.75
NOTE: INTENSITIES TAKEN FROM FIGURE 3.3.1-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
0 = 8.92 15.44 32.16
CONCLUDE: THIS IS THE TOTAL HISTORICAL FLOW OFF OF THE SITE a THE LONGEST Tc
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SHEAR ENGINEERING CORPORATION
PAGE (,
WILDFLOWER RIDGE PUD
DATE 09/20/93
HISTORIC FLOW FOR ENTIRE SITE
PROJ. NO.1382-01-93
INCLUDES 0.97 ac. OFFSITE
FLOW
TIME 1448 HOURS
FILE NAME WILD
8Y NEO
AREA (A)= 13.12 ACRES
RUNOFF COEF. (C)
2 YEAR
10 YEAR
100 YEAR
.
C = 030
0y_30
0.375
PASTURE , LOAM , LIGHT VEGETATION"
�vy,
UM IZ (ESL•' Iv-' $('VWTlUK-) TS Sa1>�
TIME OF CONCENTRATION
OVERLAND TRAVE I "(Ti)
(1.87(1.1-CCf)*(L)AO.5)/(S)AO.33
LENGTH = FEET
SLOPE =
6.00 %
2
10 YEAR
100 YEAR
C = 0.30
0.30
0.375-
Ti (min)= 19.42
19.42
17.60
TRAVEL TIME (Tt)
L (ft) = 700 S (X)
_ 0 PASTURE
V (fps) Tt(min)=. 7.78
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2
TOTAL TRAVEL TIME (min) = 7.78
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR
10 YEAR
100 YEAR
Tc (min)= 27.20
27.20
25.38
USE Tc = 27
27
25.5
INTENSITY (I) (iph)
2 YEAR
10 YEAR
100 YEAR
I = 1.50
2.60
4-35
NOTE:, INTENSITIES TAKEN
FROM FIGURE
3.3.1-1
RUNOFF (0= CIA) (cfs)
2 YEAR
10 YEAR
100 YEAR
0 = 5.90
10.23
21.40
I
rnce
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17
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22
OFF Si E N Is YTE
TOTAL
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20
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SURFACE
CHARACTERISTICS
PAVEMENT ASPHALT OR CONCRETE
GRAVEL
ROOFS
LAWNS(irrigated) SANDY SOIL
FLAT < 2%
AVERAGE 2 - 7%
STEEP > 7%
LAWNS(irrigated) HEAVY SOIL
FLAT < 2%
AVERAGE 2 - 7%
STEEP > 7%
PASTURE AND NON IRRIGATED LAWNS
SAND
BARE
LIGHT VEGETATION
LOAM
BARE
LIGHT VEGETATION
CLAY
BARE
LIGHT VEGETATION
COMPOSITE AREAS
URBAN
SINGLE FAMILY, 4-6 UNITS/AC.
MULTI -FAMILY, > 6 UNITS/AC.
RURAL (mostly nonirrigated Lawn area)
< 1/2 ac. - 1 ac.
1 TO 3 ACRES
INDUSTRIAL
LIGHT
HEAVY
BUSINESS
DOWNTOWN
NEIGHBORHOOD
PARKS
RURAL OPEN SPACE
TOTALS
COMPOSITE C VALUE
USE
SHEAR ENGINEERING CORPORATION
PAGE
PROJECT :WILDFLOWER RIDGE P DATE: D9/20/93
PROJ.NO. :1382-01-93 TIME: 1504 HOURS
LOCATION :LARIMER COUNTY, BY: MEO
FILE NAME:WILD
NOTES :DEVELOPED SITE.PLUS 0.97 ACRES UPSTREAM
RUNOFF
COEF.
AREA RANGE C C*A
(acres)
0.960 0.70-0.95 0.90 0.864
0.000 0.25-0.70 0.50 0.000
1.320 0.70-0.95 0.90 1.188
0.000 0.05-0.15 0.10 0.000
0.000 0.15-0.20 0.17 0.000
0.000 0.20-0.30 0.25 0.000
0.000 0.13-0.17 0.15 0.000
6.370 0.18-0.22 0.20 1.274
0.000 0.25-0.35 0.30 0.000
0.000 0.15-0.50 0.30 0.000
0.000 0.10-0.40 0.25 0.000
0.000 0.20-0.60 0.40 0.000
4.470 0.10-0.45 0.30 1.341
0.000 0.30-0.75 0.50 0.000
0.000 0.20-0.60 0.40 0.000
0.000 0.25-0.5 0.40 0.000
0.000 0.50-0.75 0.60 0.000
0.000 0.20-0.50 0.35 0.000
0.000 0.15-0.50 0.30 0.000
0.000 0.50-0.80 0.65 0.000
0.000 0.60-0.90 0.75 0.000
0.000 0.70-0.95 0.85 0.000
0.000 0.50-0.70 0.60 0.000
0.000 0.10-0.40 0.20 0.000
0.000 0.10-0.40 0.20 0.000
13.120 4.667
C2 CS CIO C100
0.356 0.356 0.356 0."5
0.36 0.36 0.36 0.45
c
{ SHEAR ENGINEERING CORPORATION
PAGE , U
WILDFLOWER RIDGE PUD DATE 09/20/93
DEVELOPED FLOW FOR ENTIRE SITE PROJ. N0.1382-01-93
INCLUDES 0.97 ac. OFFSITE FLOW TIME 1447 HOURS n
FILE NAME WILD BY NED (YJ�
AREA (A)= 13.12 ACRES
RUNOFF COEF. '(C)
2 YEAR 10 YEAR 100 YEAR
C = 0.36 0.36 0.450
SEE ATTACHED SPREAD SHEET AND CALCULATIONS
TIME OF CONCENTRATION (TO
OVERLAND TRAVEL TIME (Ti)(1.87(1.1-CCf)*(L)A0.5)/(S)AO.33
LENGTH = 450 FEET SLOPE = 7-10 Y_
2 YEAR 10 YEAR 100 YEAR
C = �0.30 �QJL .QrV.L
Ti (min)= 16.62 16.62 15.06
TRAVEL TIME (TO=L/(60*V) FLOW TYPE
L (ft) = S M = j,QQ QJTTFR Finw V (fps) = j�¢j�. Tt(min)= 1.85
L (ft) = 3,jg, S M = ' ..3,& GUTTER FLOW V (fps) = Tt(min)= 2.48
NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 4.33
Tc =Ti+TOTAL TRAVEL TIME
2 YEAR 10 YEAR 100 YEAR
Te (min)= 20.95 20.95 19.39
USE Tc = 21 �� 195
INTENSITY (I) (iph)
2 YEAR 10 YEAR
I = 1.75 3.10
NOTE: INTENSITIES TAKEN FROM FIGURE
100 YEAR
5.25
3.3.1-1
RUNOFF (Q= CIA) (cfs)
2 YEAR 10 YEAR 100 YEAR
0 = 8.27 14.64 31.00
NOTE THIS IS THE TOTAL FLOW OFF THE SITE a THE LONGEST Tc. STORMWATER
LEAVES THE SITEIAT TWO (2) DIFFERENT LOCATIONS
\► (:4w 4ts be- +kt +t�W Plow I � - )OW )ea,veS
i e 5i {e iw Z d,-PFer.Gnt? ?)Z4.st.
reC� f-ct Vow- Use of -{fie rwhow"- Frawlct..
APPENDIX II
Backup Diagrams and Exhibits
Table 4..2,6-1
Runoff Coefficients for Rational Method
(From: American Soc. of Civil Engineers and Water
Pollution Control Fed. [1970] and Seelye [1960])
Character of surface Runoff coefficients
Range Recommended
Pavement --asphalt or concrete
0.70-0.95
0.90
Gravel, from clean and loose
to clayey and compact
0.25-0.70
0.50
Roofs
0.70-0.95
0.90
Lawns (irrigated) sandy soil
Flat, 2 percent
0.05-0.15
0.10
Average, 2 to 7 percent
0.15-0.20
0.17
Steep, 7 percent or more
0.20-0.30
0.25
Lawns (irrigated) heavy soil
Flat, 2 percent
0.13-0.17
0.15
Average, 2 to 7 percent
0.18-0.22
0.20
Steep, 7 percent
0.25-0.35
0.30
Pasture and non -irrigated lawns
Sand
Bare
0.15-0.50
0.30
Light vegetation
0.10-0.40
0.25
Loam
Bare
0.20-0.60
0.40
Light vegetation
0.10-0.45
0.30'
Clay
Bare
0.30-0.75
0.50
Light vegetation
0.20-0.60
Composite areas
Urban
Single-family, 4-6 units/acre
0.25-0.50
0.40
Multi -family, >6 units/acre
0.50-0.75
0.60
Rural (mostly non -irrigated lawn area)
<1/2 acre - 1 acre
0.20-0.50
0.35 .
1 acre - 3 acres
0.15-0.50
0.30
Industrial
Light
0.50-0.80
0.65
Heavy
0.60-0.90
0.75
Business
Downtown
0.70-0.95
0.85
Neighborhood
0.50-0.70
0.60
Parks
0.10-0.40
0.20
Rural open space
LCS-WM Manual 4.2 --- 4 April 1979
\A
SHEAR ENGINEERING CORPORATION
PROJECT: WILDFLOWER RIDGE PUD DATE: 09/20/93
PROJ.NO. 1382-01-93 TIME: 1502 HOURS
PROD. DESCRIPTION:23 LOT SUBDIVISION BY MEO
PROJ. LOCATION: LARIMER COUNTY
FILE NAME: WILD
COLORADO CUMULATIVE HYDROGRAPH PROCEDURE
FOR
SIZING DETENTION PONDS
DESIGN STORM: 100 YEAR RUNOFF COEFFICIENT 0.45
RELEASE RATE: 21.40 CFS \\\ AREA:3.12 1(ACRES
INITIAL TIME: 5 MINUTES )CA$c dj5L Uss iJhy
TIME INCREMENT: 5 MINUTES ✓1,)Cc.Se rwAe JQ y%is si tC,
*OUTPUT* ******** ******** ********
INFLOW INFLOW RELEASE STORAGE
TIME TIME INTENSITY RATE VOLUME VOLUME VOLUME
min sec iph cfs cf cf cf
******** ******** ******** ******** ******** ******** ********
5 300 8.70 51.36 15409.4 6420.0 8989.4
10 600 7.14 42.15 25292.7 12840.0 12452.7
15 900 6.06 35.78 32200.4 19260.0 12940.4
20 1200 5.21 30.76 36911.8 25680.0 11231.8
25 1500 4.63 27.34 41003.3 32100.0 8903.3
30 1800 4.20 24.80 44634.2 38520.0 6114.2
35 2100 3.81 22.49 47237.9 44940.0 2297.9
DRAINAGE CRITERIA MANUAL
RUNOFF
M1
3C
F- 2 0
z
w
U
cc
uj
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z
w
0-
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5
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cc 3
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5
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_�_MEN
WOMEN
z s .5 1 2 3 5 10 20
VELOCITY IN FEET PER SECOND
FIGURE
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
No Text
Table 5.1-1
Allowable Use of Streets and of Cross Street Flow as Part of
Drainage System during Minor and Major Storm Runoff
Street
classifi- Minor storm runoff
cation l/ (Maximum roadway encroachment)
Local No curb overtopping; where no
curbing exists, encroachment
shall not extend over property
lines. Flow may spread to
crown of street.
Collector No curb overtopping; (same
as above).
Flow spread must leave at
least one lane free of
water.
Arterial No curb overtopping;
(same as above).
Flow spread must leave at
least one lane free of
water in each direction.
Major storm runoff
(Allowable depth & inundation)
Inundation: Residential dwell-
ings, public, commercial, and
industrial buildings shall not
be inundated at ground line,
unless buildings.are flood -
proofed.
Depth of water over gutter
flowline shall not exceed 18".
(same as above)
Inundation: (same as above).
Depth of water at street crown
- shall not exceed 6", to allow
operation of emergency vehi-
cles.
Depth of water over gutter
flowline shall not exceed 18".
Freeway No encroachment is allowed (same as above)
on any traffic lane.
Allowable Cross Street Flow
Local and Where cross pans allowed, Depth of water over gutter flow -
Collector depth of flow shall not line shall not exceed 18".
exceed 6".
Arterial None
and
Freeway
Depth of water at crown shall
not exceed 6".
1/Refer to Larimer County Board of.Commissioners
of street classifications.
(1972) for definitions
LCS-WM Manual 5.1 --- 2 April 1979
I
CAN
p��Mwmw�
I
APPENDIX III
Stuffer Envelope
Preliminary Grading and Drainage Plan
-----------------
IDLEDALE DRIVE
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DETENTION AREA,Tnnc A v A
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C�UNDARY
o
v v v v v\ BOUNDARY
i 14.
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BOUND PqD BASItl ( T \( �,e �O5 .i ;r y FRI
1 v v � vo
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Devewem BnsIN BolmvnaY AEr
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NsSI BASM BOUN "Y lk 4 Z NOTcv:
it lI I l V SUB BASIN BOUNDARY �4,�1:n l' �'V'D wN OPTHE DEl1!KIION FACD]9Y TO BE COORDDIATPD Wl1H
/ \ - iP Ally THE OVERALL DESIGN OF FOX FULLS PHASES I AND 2.
SUNK ]RESIGNATIAT[ON 2 EROSION AGNNDORDDNTWOLR NMAkS64N MCLUTHE FEN®,HAYBALFS P'
I \
\ I SUHEASIN ]RESIGNATION SWAt cc AND O'RIEIt MLASDRES PS REQUIRED.
IB
® CONCENTRATION POBiT _
—
�— FLOW DULEC'1'ION /
IBAVBL PATH
Date_ SEPT 1993
eeew
coca
SHEAR ENGINEERING
CORPORATION
Gv
LP --
PETERSON DESIGN
.0,
Feld Soot
BWS
2717 W. COUNTY fl0A0 M
4836 SO. COLLEGE AVE.
FORT COLLINS, COLORADO
N
N REVISIONS
oeoR._ _--
Checked
•
Sm1e I'=100
FORT COLLINS, COE 80326
PHONE (303226-533a
(303)226-aa51
-•— -- el
Dewne�—
APv�ea
sees
GJ iO4 b e
L
ELIMINARY GRADING AND DRAIN*GE PLAN +ea 2
WILDFLOWER RIDGE P.U.D.NNINNINNIN �2sez-
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