HomeMy WebLinkAboutDrainage Reports - 09/26/2016STORMWATER & EROSION
CONTROL REPORT
FOR
City of Fort Collins Approved Plans
Approved by:
Date: q-2(o- /(o
KIND CARE
6617 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO 80525
Project Number 2360-15
'October 10, 2015 ,
Revised April 10, 2016
Revised June 10, 2016
Prepared for:
6617 South College LLC
6617 South College Avenue
Fort Collins, CO 80525
Prepared by:
Forbes Engineering
2908 Cherly Street
Fort Collins, CO 80524
Phone: (970) 295-4874
TABLE OF CONTENTS
PAGE
CERTIFICATION 1
I. GENERAL LOCATION AND DESCRIPTION
A. Site Location 2
B. Description of Property 2
C. Flood Hazards 2
II. DRAINAGE BASINS AND SUB -BASINS
A. Major Basin Description 3
B. Sub -basin Description 3
III. DRAINAGE ANALYSIS CRITERIA
A. Regulations 3
B. Hydrological Criteria 4
IV. DRAINAGE FACILITY & DESIGN
A. General Proposed Concept 4
B. Specific Drainage Design Details 4
V. SWMP CONCLUSION 5
VI. EROSION & SEDIMENT CONTROL
A. Analysis of Site & Proposed -Construction 6-8
B. Stormwater Management Controls 9
C. Dry land vegetation 10
D. Detailed sequence of construction activities 11
E. Erosion Control Security Calculations 12
VII. EROSION CONTROL CONCLUSION 12
VIII. REFERENCES 12
VIII. APPENDICES 13
CERTIFICATION:
I hereby certify that this preliminary stormwater plan & report for the Kind Care
site development located at 6617 South College Avenue was prepared by me and
meets or exceeds the criteria in the City of Fort Collins Stormwater Management
Manual.
Kevin Forbes
Registered Professional Engines
State of Colorado No. 35265
1
t I. GENERAL LOCATION AND DESCRIPTION
A. Site Location
The Kind Care Site Development is located in the Northeast quarter of
' Section 14, Township 6 North, Range 69 West of the 6 h Principal Meridian,
County of Larimer, State of Colorado. The property lies on the west side of
US Highway 287 (South College Avenue) approximately 100 feet south of
West Trilby Road. See Vicinity Map in the Appendix.
B. Description of Property
' Currently, the property area is approximately 141,957 square feet (3.26
acres). Of this 6175 square feet will to be dedicated to US Highway 287,
leaving 135,782 square feet (3.12 acres) as the site development area. The
' lot is currently developed for commercial use with two businesses on site.
The west portion contains a gravel yard, an open shed and a 9200 square
' foot building used as an office/warehouse. The east portion contains the
Kind Care business which is made up of three buildings, a gravel parking
area, an asphalt drive and various concrete walks and pads. Landscaping
' borders the project site on all sides.
' Other than a very small portion of landscaping located at the northwest
corner of the property, the site has a very slight slope towards the east
(approximately 1%). Currently there isn't any detention on the site although
' it appears that because of the shallow grade there has been an uncertain
amount of surface run-off that pools along the landscaping area along the
east side of the property.
The soil classification for the Site is a Fort Collins loam (3-5% slopes). Fort
' Collins loams belong to the hydrologic soil group B, as assigned by the
Natural Resources Conservation Service. Run-off is moderate and the
hazards of wind and water erosion are slight to moderate. Depth to seasonal
' high water table is greater than 6 feet.
' C. Flood Hazards
The Site does not lie within any floodplain. No known drainage studies
' exist for this Site and there are no wetlands associated with the Site.
2
H. DRAINAGE BASIN AND SUB -BASINS
A. Major Drainage Basin
The property is located southwest of and drains into the Stone Creek Basin
which is part of the Fossil Creek Drainage Basin. The property drains into
the west street gutter system of South College Ave which enters the
stormwater system and the intersection of Trilby & College. From there
stormwater run-off is transported to Stone Creek. No adverse effects to the
Stone Creek Basin are anticipated with this development.
B. Sub -Basins
Both the existing & proposed drainage for the site is broken up into 3 sub -
basins (see historic & developed drainage sub -basin maps in the appendix).
Sub -basin A contains the majority of the site and is located in the southern
portion of the property. It is fairly flat with an average slope of 1 % towards
the east. The outfall is at the landscaping area along the west side of College
Ave. Sub -basin B lies in the northwest portion of the property and also
slopes east at a 1% slope. The outfall for Sub -basin B is into an existing
pipe system that spills into Sub -basin A. Sub -basin C is located in the
northeast portion of the property, it slopes east at an approximate grade of
2% with a non -concentrated sheet flow release into the west gutter system of
South College Ave.
The difference between the historic and developed sub -basins concerns the
areas of the sub -basins only with a larger portion directed towards and into
Sub -basin A as a result of the new building roof lines.
III. DRAINAGE ANALYSIS CRITERIA
A. Regulations
The analysis of the storm drainage system for this project was prepared in
accordance with the criteria set forth in the City of Fort Collins Stormwater
Criteria Manual and the Urban Drainage and Flood Control District's
Urban Storm Drainage Criteria Manual (USDCM.
3
' B. Hydrological Criteria
1. Design Rainfall Intensity -Duration -Frequency
' Table for City of Fort Collins
2. Runoff Method Rational
3. Design Storms
a. Minor 2-year
b. Major 100-year
IV. DRAINAGE FACILITY & DESIGN
A. General Proposed Concept
As expressed in the sub -basin descriptions, the change between the historic
and developed drainage patterns is minimal. Existing drainage patterns will
be maintained and utilized as well as a portion of the existing pipe system.
Surface stormwater run-off will be detained and released at the two year
historic flow rate into the west gutter system of South College Avenue.
Additional volume in the detention pond has been added to account for the
water quality capture volume. The WQCV has been calculated at 1846
cubic feet.
' B. Specific Drainage Design Details
' As described above, the existing drainage patterns will be maintained and
erosion control measures will be installed (see Erosion & Sediment Control
' section in report). The Low Impact Development design method chosen for
this project is in the form of a 1507 square foot rain garden. The location of
' the LID will be on the north side of the detention pond and will receive
stormwater from approximately 72% of the site area.
' The detention pond outlet orifice has been design for a release rate of 2.44
cubic feet per second. The water quality capture volume has been calculated
' at 1846 cubic feet and the required 24 hour drawdown water quality orifice
has been designed using six (6)'/4" diameter holes.
4
V. SWMP CONCLUSIONS
Stormwater Management Conclusion
' A high water (no build) line has been added to the drainage map that
' delineates the 100 year watershed elevation with a 1/2 foot freeboard. The
closest building is approximately 45 feet away & 2.32 feet above this line
and will not be affected by the 100 year storm water detention or run-off.
' The analysis of the storm drainage system for this project was completed in
accordance with the criteria set forth in the City of Fort Collins Stormwater
Criteria Manual and the USDCM.
No adverse effects to surrounding properties are anticipated from the
proposed improvement of this site.
5
VI. EROSION & SEDIMENT CONTROL
A. Analysis of Site & Proposed Construction
Current Developed Condition
The total site area (excluding the ROW dedication to US Hwy 287) is
approximately 135,782 square feet (3.12 acres). The entire lot is currently
developed for commercial use with two existing businesses on site. The
western portion contains a gravel yard, an open shed and a 9200 square foot
building used as an office/warehouse. The eastern portion contains the Kind
Care business which is made up of three buildings, a gravel parking area, an
asphalt drive and various concrete walks and pads. Landscaping borders the
project site on all sides and the existing percent of vegetation has been
estimated at approximately 35%.
Nature & Purpose of Construction
The proposed development is a split of the current single lot into 3 separate
lots with site improvements to lots one and three. Lot one will contain the
' Kind Care business and the site improvements for the lot include; an
increase in area of the asphalt parking and drive aisle, a sidewalk connection
to the sidewalk along College Avenue, a 6 foot wide sidewalk along the
south side of the drive aisle, demolition and reconstruction of the western
warehouse and the construction of an office addition between the two
existing buildings. The site improvements to lot three will include the
removal of the existing gravel parking lot and the construction of a detention
pond to serve the entire site.
' The site improvements will disturb approximately 44,540 square feet (1.02
acres) on -site and approximately 4077 square feet off -site. Some of the Site
will be graded with topsoil & gravel stripped and stockpiled. The total
quantity of cut from the detention pond has been estimated to be 540 cubic
yards. It is possible that the estimated amount of cut will exceed the
required amount of fill, so some of the existing soil could be exported off of
the Site.
' The property is located southwest of and drains into the Stone Creek Basin
P
1 which is part of the Fossil Creek Drainage Basin. The property drains into
the west street gutter system of South College Avenue, travels north and
' crosses the west side of the Trilby & College intersection. From there the
6
' stormwater run-off continues north and enters an area inlet approximately
200' north of the Trilby & College intersection. From this point the
stormwater run-off enters the existing stormwater pipe system and is
transported to Stone Creek. No adverse effects to the Stone Creek Basin are
anticipated with this development.
1
Rainfall Erodibility and Erosion Sediment Control Measures
1 Temporary and permanent erosion control measures for the site are shown
on the Erosion Control Plans (see sheets C4.0 & C4.1 in insert). The
' construction entrance will be at the existing curb cut along College Avenue.
A vehicle tracking mat and concrete washout area will be provided for at the
west end of Lot Three. Any and all stock piles for excess cut shall also be
located at the west end of Lot Three and will be maintained with a silt fence
along the lower end of its base. The location of these areas insures that any
erosion sediments will be required to pass through the detention pond area
and through the sediment trap located at the outlet box. Other graded areas
' will be left in rough surface condition until covered with planting and wood
or stone mulch. The north east portion of the site has a grass surface and
releases un-detained via sheet flow towards and into the west gutter system
' of South College Ave. This area will maintain the grass surface as best as
possible while the foundation of the new addition is excavated and will have
' a perimeter silt fence constructed on the east end to catch any sediments
prior to entering into the gutter system.
It is the intention of the erosion control plans that the existing drainage paths
will be maintained and left in original conditions & locations. This insures
' that the majority of the site (all but for the northeast portion of the site) will
drain towards the detention pond area which will trap erosion sediments
prior to exiting from the site.
Silt fencing will be installed at the perimeter of the site and at the top of
detention area as appropriate to intercept and detain sediment from runoff
leaving the site. Other measures utilized in order to control sediment during
construction include rock sock bags at curb cuts, curb inlets and at the
detention pond outlet structure, as well as permanent seeding in the
detention area. Rip rap will be installed as needed at the northern pipe inlet
as well as a rock filter installed at the detention pond outlet structure in order
to reduce/prevent erosion.
7
Timing & Sequence of BMP Installation
Timing sequence of BMP installation is as follows:
• Installation of silt fence perimeter barriers at northeast corner and
along south and east end of the detention pond area
• Construct vehicle tracking pad at the west end of Lot 3 and the
detention pond area
• Provide downstream inlet protection (rock socks) at existing area inlet
located approximately 200' north of Trilby & College intersection
• Rough grading with contour furrows for detention pond along with
construction of outlet structure and outlet protection (rock filter)
• Construct sediment trap at detention pond outlet box
• Site Grading, subgrade preparation and foundation excavation
• Install base course and rough surface all exposed soil areas
• Utility construction — install storm water pipe system.
• Footing & foundation installation
• Paving and landscaping
• Removal of Erosion Control Measures
• Permanent seeding in detention areas
• Sod Installation as needed
g
B. Stormwater Management Controls
Description of Stormwater Management Controls
Stormwater will sheet flow from the building areas toward the ponds. Ponds
will be constructed early in the development process, including the
bioretention/rain garden feature, outlet structures with water quality plates,
rock socks and permanent seeding. The pond will also provide post -
development stormwater quality control, as will grass -lined swales and
permanent landscaping. All areas that will not be intercepted at ponds will
' be protected with silt fence during construction.
' Stormwater Management Plan Administrator
1 The owner of the property, 6617 South College LLC, shall act as the
stormwater management plan administrator.
' Potential Pollutant Sources
Disturbed and stored soils. Sediment generation due to disturbed areas
(grading & clearing) is anticipated and will be controlled using the lower
portion of the detention pond as a sediment trap. The sediment trap will be
cleaned out as required. Stored soils are not anticipated but if so then the
upper portion of the detention pond (west end of lot 3) will be used to stock
pile soil and or rock. The stock piles will be limited to 10' maximum in
height and will be required to have downstream toe protection using silt
barriers.
Vehicle tracking of sediment. A VTC will be installed at the west end of lot
' 3 and connected to the asphalt drive aisle.
' Management of contaminated soils. In the case of a release of fuel or other
chemicals, absorbent booms or earthen berms will be immediately
constructed to contain the spill and prevent runoff to adjacent surface waters.
' The contractor will be responsible for the cleanup of the released materials
and for the removal of any contaminated soils.
Loading & unloading operations. These operations will be executed in the
area designated for the VTC or the upper detention pond.
9
1
Out -door storage. No out -door chemical storage is anticipated for this
project, out -door storage will be limited to building materials and stored near
the construction site.
Equipment maintenance and fueling. During construction, no on -site
equipment fueling or equipment maintenance is anticipated.
Significant particulate generating. Due to the sandy loam nature of the site
soil, it is not anticipated to have a significant particulate generation, but if so
the construction manager is to bring in a water truck to abate the dust
generation.
Routine maintenance activities & on -site waste management. Good site
' house -keeping procedures including routine cleanup of construction debris
and trash removal will be regularly maintained.
' Concrete washing. A dedicated concrete washout area, as shown on the
enclosed Erosion Control and Detail sheets (see insert), will be constructed
' prior to placement of any concrete.
' Dedicated asphalt or concrete batch plants. Neither of these construction
activities is anticipated for this site.
' Non -industrial waste sources. Both an individual worker trash roll -off as
well as portable toilets are anticipated to be installed on this site. The
portable toilets shall be anchored and located away from the drainage
swales. The location of the roll -off will be up to the contractor, probably set
up near the construction trailer or the building site or an area where it can be
' easily emptied or removed.
' C. Dry Land Vegetation
The percentage of vegetative ground cover prior to construction is estimated
to be approximately 32 percent. Vegetation includes sparse native and non-
native grasses.
' The soil classification for the Site is a Fort Collins loam (3-5% slopes). Fort
Collins loams belong to the hydrologic soil group B, as assigned by the
Natural Resources Conservation Service. Run-off is moderate and the
10
hazards of wind and water erosion are slight to moderate. Depth to seasonal
high water table is greater than 6 feet.
The seed mix shall be a dryland seed mix and shall conform to the City of
Fort Collins standards and specifications.
D. Detailed Sequence of Construction Activities
Final Stabilization
Final stabilization at this site includes:
• Building and paved areas
• An on -site detention pond with a water quality structure, rip rap
overflow, culvert and outlet protection
• Storm drain pipes with inlet & outlet protection
• Re -vegetation of disturbed areas with dryland seed mix
Maintenance
The General Contractor (GC) will perform a stormwater inspection of the
site at least once per week during construction activities as well as within 24
hours of a storm event. The inspection will be documented on an inspection
form appropriate for the Site. As stormwater maintenance issues are
identified, the SWMP administrator will direct GC and sub -contractor
personnel to execute the appropriate maintenance in a timely fashion.
Documentation of the following events will be generated as they occur:
• Records of spills, leaks, or overflows, including time and date,
weather conditions, etc.
• Implementation of specific items in the SWMP
• Contacts with regulatory agencies and personnel
Along with inspections; silt fence, rock socks and curb inlet protection will
be cleaned of excessive sediment when necessary. Rock socks will be
checked for undermining or bypass and repaired or expanded as needed.
Mulching of bare soils will be checked regularly and areas where it was lost
or damage will be re -mulched within seven working days when needed.
11
E. Erosion Control Security Calculations
' Security calculations
' The estimated cost of the erosion control measures is $5,122.50.
A detailed spreadsheet is attached to this report.
VH. CONCLUSIONS
Erosion Control Conclusion
The Erosion and Sediment Control Plan will be placed in the City of Fort
' Collins file for this project. The plan fulfills the City of Fort Collins criteria
for erosion control. It is understood that additional erosion control measures
may be needed if unforeseen erosion problems occur or if the submitted plan
does not function as intended. The requirements of this plan shall run with
the land and be the obligation of the land owner until such time as the plan is
' properly completed, modified or voided. Details for the erosion control
measures can be found on sheets C4.0 and C4.1 of the construction plans.
' VIII. REFERENCES
1. Urban Storm Drainage Criteria Manual Volumes 1 and 2, Urban
Drainage and Flood Control District, June 2001, and Volume 3,
' September 1999.
' 2. City of Fort Collins Stormwater Criteria Manual, City of Fort Collins
Stormwater Department, 2009.
3. Soil Survey of Larimer County Area, Colorado, U.S. Department of
' Agriculture, Soil Conservation Service and Forest Service, December,
1980.
12
IX. APPENDICES
1. Vicinity Map
' Existing Impervious Area Exhibit
Existing Drainage Sub -basins
' 2. Proposed Site Development Layout
Proposed Impervious Area Exhibit
Developed Drainage Sub -basins
3. Existing Stormwater Run-off Calculations
Proposed Stormwater Run-off Calculations
4. Low Impact Development Calculations
Rain Garden Spreadsheet
Rain Garden Exhibit — Site Capture Percentage
5. Detention Pond Volume Calculations
Mass Balance Spreadsheet
Detention Pond Volume Calc.
Extended Detention Volume Calc.
' Pond Outlet Orifice Plate Sizing Calculations
Water Quality Orifice Sizing Calculations
6. Pipe Capacity Calculations
' 7. Tables & Figures
8. Erosion & Sediment Control Escrow Calculations
9. Developed Drainage Plan (insert)
' 10. Erosion Control Plans (insert)
13
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•
PROPOSED
STORMWATER
� RUN-OFF
� CALCULATIONS
FORBES ENGINEERING
STORM WATER RUNOFF CALCULATIONS
KIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
Table RO-11 Rational Method Runoff
Coefficients for Composite Analysis
Steep, >7%
0.35
Job # 2460
Client: HIND CARE
Date: 2/20/16
By: KEF
Composite Runoff Coefficient
Using Formula RO-8
Where:
C = 21 Ci Ai / At
0
C = Composite Runoff
Coefficient
C 1= Runoff Coefficient for
Specific Area (Ai)
A i = Area of Surface with
Runoff Coefficient
of Ci, (acres or feet2)
n = Number of different
surfaces to be considered
At= Total Area over which C is
applicable, (acres or feet2)
NOTE:
Landscaping considered as Lawns,
Heavy Soil, Flat, <2% C = 0.20
Existing Conditions for Basin A
Watershed Note:
Historic stormwater run—off for this area sheet flows for approximately 204 feet
from the west property line to the paved area, then enters a shallow concrete
pan and travels approximately 67' to enter into a pipe system approximately
212 feet long that discharges at the east end on the property. From there the
stormwater enters the west curb & gutter system of US 287.
Basin A Areas
1 AL(Landscape)
Sq Ft
21.271
Ac(Conc) AR(Roofe)
Sq Ft Sq Ft
632 7696
Using the Infrequent Storm
Adjustment Factor (Table RO-12)
Storm Return
Period (years)
Frequency
Factor Cf
2 to 10
1.00
11 to 25
1.10
26 to 50
1.20
51 to 100
1.25
AG(Gravel) Ap(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft
52,007 18,226 99,832
C = 0.50 (2.29 AC)
Adjusted Composite
Runoff Coefficients
C 2 C 100
0.50 0.63
Page 1
Storm Water Runoff Calculations Continued
Calculated Using Rational Method
Notes:
1. Runoff Coefficients (C) are from the City of Fort Collins Stormwater
Criteria Manual, Table RO-11 and the Composite Runoff Coefficients
are from the previous calculations
2. Rainfall Intensity (I) is from the Developed Intensity —Duration —Frequency
Curve for the Fort Collins area
Basin A Existing Conditions Cz Cloo
Area (A) = 99,832 'SF = 2.29 Acres 0.50 0.63
Time of Concentration TC = T1 + TT
— Initial Flow Time TI = [(1.87)(1.1—CxCf )(D)1/$]/(S)1/3
C5= 0.50, D = 204 ft, Drop = 3.5 ft, S = 1.72%
T1= 13.4 Min & 10.5 Min
— Overland Travel Time (paved & shallow gutter)
L=67ft, Drop =1.7ft, S=2.5%
From Fig. RO-1 V = 1.5 fps TT = 45 sec = .75 min.
— Travel Time in pipes
L=212ft, S=0.9% V=5.26fps
TT = 40 sec = .67 mina
Total Time of Concentration
2yr, T c = 14.8 Minutes
100yr, T c = 11.2 Minutes
Rational Equation (Q=CIA) (AA) = 2.29 Acres
C2 = .50 I2 = 1.9 Q2 = (C2)(I2)(A) = 2.18 CFS
C1oo = .63 I1oo = 7.2 Q1oo = (C1oo )(I1oo )(A) = 10.39 CFS
Page 2
Storm Water Runoff Calculations Continued
Basin B Existing Conditions
Watershed Note:
Historic stormwater run—off for Sub —basin B sheet flows for approximately 336
feet from the west property line to the east along the
north side of the
existing building, from there it enters a shallow grass
swale for approximately
1 78 feet. It then enters an 8"0 pipe approximately 42 feet long that then
discharges into Sub —basin A.
Basin B Areas
'
A (landscape) Ac(Conc) As(Roofs) AG(Gravel) Ap(Pavement) At (Total)
L Sq Ft Sq Ft Sq Ft Sq Ft
Sq Ft Sq Ft
13,846 0 5307 243
0 19,396
(0.45 AC)
C = 0.41
' Adjusted Composite C2
C loo
Runoff Coefficients 0.41
0.51
Area (B) = 0.45 Acres
Time of Concentration TC = T1 + TT
— Initial Flow Time Tl = [(1.87)(1.1—CsCf )(D)1/2]/(S)'"
C2= 0.41 & C100= 0.51, D = 336 ft, Drop
= 3.2 ft, S = 0.95%
Tl= 24.0 Min & 20.2 Min
— Overland Travel Time (Shallow grass Swale)
L = 78 ft. Drop = 1.5 ft, S = 1.9 %
'
From Fig. RO-1 V = 0.9 fps TT = 87
sec = 1.44 min.
' — Travel Time in pipes
L=42ft, S=2.4% V=8.6fps
TT = 5 sec = 0 min.
Total Time of Concentration
2yr, Tc = 25.4 Minutes
100yr, Tc = 21.7 Minutes
Rational Equation (Q=CIA)
C2 = .41 I2 = 1.4
C100 = .51 I100 = 5.4
(AB) = 0.45 Acres
Q2 = (C2)(I2)(A) = 0.26 CFS
Qloo = (Cloo )(Iloo )(A) = 1.24 CFS
Page 3
Storm Water Runoff Calculations Continued
Basin C Existing Conditions
Watershed Note:
There is not a concentration point for this area, stormwater sheet flows east
& enters the west gutter system of South College Avenue
Basin C Areas
AL(Landscape) Ac(Conc)
Sq Ft Sq Ft
11,585 827
C = 0.42
AR(Roofs)
Sq Ft
1213
AG(Gravel)
Sq Ft
255
Adjusted Composite
Runoff Coefficients
Ap(Pavement)
Sq Ft
2694
Cs
0.42
Area (A) = 0.38 Acres
Time of Concentration TC = T1 + TT
— Initial Flow Time Tl = [(1.87)(1.1—CxCf )(D)1/2]/(S)1/s
C2= 0.42 & C100= 0.53, D = 207 ft, Drop = 4 ft,
T1= 14.69 Min & 12.31 Min
Overland Travel Time TT = 0
Total Time of Concentration
2yr, Tc = 14.7 Minutes
100yr, Tc = 12.3 Minutes
Rational Equation (Q=CIA) (AC) = 0.38 Acres
At(Total)
Sq Ft
16,554
(0.38 AC)
C 100
0.53
S = 1.93%
C2 = .42 I2 = 1.9 Q2 = (C2)(12)(A) = 0.30 CFS
C1oo = •53 Iioo = 6.6 Qloo = (Cloo )(I1oo )(A) = 1.33 CFS
Page 4
Storm Water Runoff Calculations Continued
EXISTING SUB —BASINS
PERCENT IMPERVIOUS VALUES
BASED ON THE FOLLOWING
Basin A Areas
Character
of Surface
Streets
Paved
Gravel
Walks
Roofs
Lawns
Percent
Impervious
100
40
90
90
0
A (Landscape) Ac(Conc) AR(Roofs) AG(Gravel) AG(Pavement) At(Total)
Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft
21,271 632 7896 52,007 18,226 99,832
Percent Impervious 46.6%
Basin B Areas
AL(Landscape) Ac(Conc) Aa(Roofs) AG(Gravel) AG(Pavement) At(Total)
Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft
13,846 0 5307 243 0 19,396
Percent Impervious 25.1%
Basin C Areas
A (Landscape) Ac(Conc) AH(Roofs) AG(Gravel) AG(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft
11,585 827 1213 255 2694 16,574
Percent Impervious 27.9%
Page 5
Storm Water Runoff Calculations Continued
Basin A Proposed Conditions
Watershed Note:
Proposed stormwater run-off for Sub -basin A conforms to the historic as it will
sheet flow. for approximately 204 feet from the west property line to
the paved
portion, then travels east within a shallow grass swale for approximately 157
feet and into the detention pond located in the southeast portion of
the
property. This sub -basin will contain the detention pond which will
release
into the west gutter system of South College Avenue.
Basin A Areas
A (landscape) Ac(Conc) As(Roofs) As(Gravel) Ap(Pavement)
At (Total)
Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft
Sq Ft
39,197 3743 9314 29,840 17,583
99,677
(2.29 AC)
C = 0.52 Adjusted Composite C2 C loo
Runoff Coefficients 0.52 0.65
Area (A) = 2.29 Acres
' Time of Concentration To = Tl + TT
' - Initial Flow Time Tl = [(1.87)(1.1-CsCf )(D)1/2]/(S)l/3
C2= 0.52 & C1oo= 0.65, D = 268 ft, Drop = 3.7 ft, S
= 1.38%
Tl = 15.9 Min & 12.4 Min
I- Overland Travel Time (Shallow grass swale)
L = 157 ft, Drop = 2.5 ft, S = 1.6 %
From Fig. RO-1 V = 2.6 fps TT = 60.4 sec = 1.0
min.
Total Time of Concentration
2yr, T c = 15.9 Minutes
100yr, Tc = 13.4 Minutes
Rational
Equation (Q=CIA)
(AA)
= 2.29 Acres
C2 =
.52 I2 = 1.8
Q2 =
(C002)(A) = 2.14 CFS
Cloo =
.65 1100 = 6.8
Qloo =
(Cloo )(1100 )(A) = 10.12 CFS
Page 6
Storm Water Runoff Calculations Continued
Basin B Provosed Conditions
Watershed Note:
Proposed stormwater run-off for Sub -basin B conforms to the historic as it will
sheet flow for approximately 336 feet from the west property line to the east
and into a grass swale for approximately 78 feet. From there the run-off
enters a pipe system which discharges into sub -basin A.
Basin B Areas
A (Landscape)
Sq Ft
12,563
C = 0.45
Ac(Conc)
Sq Ft
652
As(Roofs)
Sq Pt
5145
Adjusted Composite
Runoff Coefficients
AG(Gravel) Ap(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft
570 620 19,550
(0.45 AC)
C2 C100
0.45 0.57
Area (B) = 0.45 Acres
Time of Concentration TC = T1 + TT
- Initial Flow Time Tl = [(1.87)(1.1-CxCf )(D)'/E]/(S)'"
C2= 0.45 & C100= 0.57, D = 336 ft, Drop = 3.2 ft, S = 0.95%
T1= 22.6 Min & 18.5 Min
- Overland Travel Time (Shallow grass swale)
L=32ft, Drop =0.6ft, S= 1.8%
From Fig. RO-1 V 0.9 fps TT = 35 sec = 0.6 min.
- Travel Time in pipes
L=42ft, S=2.4T V=8.6fps
TT = 5 sec = 0 min.
Total Time of Concentration
2yr, T c = 23.2 Minutes
100yr, Tc = 19.1 Minutes
Rational Equation (Q=CIA)
C2 = .45 I2 = 1.5
C1oo = .57 I100 = 5.7
(AB) = 0.45 Acres
Q2 = (C2)(I2)(A) = 0.30 CFS
Qloo = (Cloo )(I1oo )(A) = 1.46 CFS
Page 7
Storm Water Runoff Calculations Continued
Basin C Proposed Conditions
Watershed Note:
There is not a concentration point for this area, stormwater sheet flows east
& enters the west gutter system of South College Avenue
Basin C Areas
AL(LandeCape) AC(Conc) As(Roofe) AG(Gravel) Ap(Pavement) At(Total)
Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft Sq Ft
9206 2565 2829 0 1955 16,555
(0.38 AC)
C = 0.53 Adjusted Composite
Runoff Coefficients CZ C1oo
0.53 0.67
Area (A) = 0.38 Acres
Time of Concentration Tc = T1 + TT
— Initial now
Time
Tl =
((1.87)(1.1—CsCf )(D) 1/2 ]I(S) 1/3
C2= 0.53 &
C100=
0.67,
D = 207 ft, Drop = 4 ft, S = 1.93%
Ti = 12.31
Min &
9.29
Min
Overland Travel Time TT = 0
Total Time of Concentration
2yr, Tc = 12.3 Minutes
100yr, Tc = 9.3 Minutes
Rational Equation (Q=CIA) (AC) = 0.38 Acres
C2 = .53 I2 = 2.0 Q2 = (C2)(12)(A) _
0.40 CFS
C1oo = .67 I100 = 7.9 Qioo = (Cloo )(Iloo )(A) = 2.01 CFS
Page 8
Storm Water Runoff Calculations Continued
PROPOSED SUB -BASINS
PERCENT IMPERVIOUS VALUES
BASED ON THE FOLLOWING
Basin A Areas
A (landscape) Ac(Conc) As(Roofs)
Sq Ft Sq Ft Sq Ft
39,197 3743 9314
Percent Impervious 41.4%
Basin B Areas
A (Landscape) Ac(Conc)
As(Roofs)
Sq Ft Sq Ft
Sq Ft
12,563 652
5145
Percent Impervious
31.0%
Basin C Areas
AL(Landscape) Ac(Conc)
As(Roofs)
Sq Ft Sq Ft
Sq Ft
9206 2565
2629
Percent Impervious
41.1%
Character
of Surface
Streets
Paved
Gravel
Walks
Roofs
Lawns
Percent
Impervious
100
40
90
90
0
As(Gravel) Ap(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft
29,840 17,583 99,677
AG(Gravel) Ap(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft
570 620 19,550
AG(Gravel) Ap(Pavement) At (Total)
Sq Ft Sq Ft Sq Ft
0 1955 16,555
Page 9
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Page 10
� LOW IMPACT
DEVELOPMENT
� SPREADSHEET
& EXHIBIT
Designer:
Company:
' Date:
Project;
Location:
May 20, 2016
Kind Care
Design Procedure Form: Rain Garden (RG)
Sheet t of 2
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, I,
I, =
40.0 %
(100% it all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = I,/100)
1=
0.400
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time
WQCV -
O.14 watershed Inches
(WOCV= 0.8 - (0.91- i'- 1.19 - iE. 0.78' i)
D) Contributing Watershed Area (including rain garden area)
Area -
119,227 sq ft
E) Water Quality Capture Volume(WOCV) Design Volume
Vwacv=
1,429 cuff
Vol = (WQCV / 12) ' Area
F) For Watersheds Outside of the Denver Region, Depth of
ds=
In
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region,
Vwacv or ER =
cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume
Vwacv USER =
cu If
(Only 0 a d'dferem WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum)
Dwocv =
In
B) Rain Garden Side Slopes (Z = 4 min., honz. dial per unit vertical)
Z =
1t / It
(Use'0'd rain garden has vertical walls)
C) Minimum Flat Surface Area
Aµ„ =
sq ft
D) Actual Flat Surface Area
AawE =
sq It
E) Area at Design Depth (Top Surface Area)
ATM =
$q It
F) Rain Garden Total Volume
VT=
cu If
(VT= ((AT, . Aft, ) / 2) ' Depth)
3. Growing Media
Choose One
18" Rain Garden Growing Media
Q Other (Explain):
City of Fort Collins Standard
4. Underdrain System
A) Are underdrains provided?
Choose One
® Np
B) Underdrain system orifice diameter for 12 hour drain time
—
i) Distance From Lowest Elevation of the Storage
y=
N/A ft
Volume to the Center of the Orifice
if) Volume to Drain in 12 Hours
Voi.,z =
WA cu If
III) Orifice Diameter, 3/8' Minimum
Do =
WA in
UD-BMP_y3.03.xlsm, RG 5120/2016, 1:50 PM
Design Procedure Form: Rain Garden (RG)
Sheet 2 of 2
Designer:
Company:
Date: May 20, 2016
Project: Kind Care
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
rChooso Ona —
0 YES
A) Is an impermeable liner provided due to proxlm0y
0 No
of structures or groundwater comammation?
6. Inlet / Outlet Control
r Choose One
Sheet Flow- No Energy Dissipation Required
A) Inlet Control
I 0 Concentrated Flow- Energy Dissipation Provided
Chnnw One
7. Vegetation
Seed (Plan for frequent weed control)
�@)
0 Plantings
0 Sand Grown or Other High Infiltration Sod
8. Irrigation
r Choose One
0 YES
A) Will the rain garden be irrigated?
0 NO
Notes'.
UD-BMP_v3.03.xlsm, RG 5/20/2016, 1 50 PM
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w 0
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w LL.
F- LLI
LLJ m
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0.
I
1
1
DETENTION
POND
VOLUME
CALCULATIONS
Detention Volume - Mass Balance Method-100-yr (Major Storm)
Input
Runoff Coefficient, C.=
0.60
Frequency Factor, Cf'= 4
1.25
2-yr Release,
2.44
cfs
Area =
3.12
acres
Results
Time (min)
intensity (in hr)
Q,,, (cfs)
-Volume;, (ft3)
5
9.96
23.31
6991.92
2.44
10
7.74
18.11
10866.96
2.44
15
6.52
15.26
13731.12
2.44
20
5.61
13.13
15752.88
2.44
25
4.97
11.63
17437.68
2.44
30
4.52
10.58
19038.24
2.44
35
4.08
9.55
20049.12
2.44
40
3.74
8.74
20975.76
2.44
45
3.45
8.08
21818.16
2.44
50
3.23
7.55
22660.56
2.44
55
3.03
7.10
23418.72
2.44
60
2.86
6.69
24092.64
2.44
65
2.71
6.35
24766.56
2.44
70
2.59
6.06
25440.48
2.44
75
2.48
5.80
26114.40
2.44
80
2.38
5.56
26704.08
2.44
85
2.29
5.35
27293.76
2.44
90
2.21
5.16
27883.44
2.44
95
2.13
4.98
28388.88
2.44
100
2.06
4.83
28978.56
2.44
105
2.00
4.68
29484.00
2.44
110 1
1.94
4.54
29989.44
2.44
115
1.88
4.41 1
30410.64 1
2.44
120
1.835
4.29 1
30916.08 1
2.44
Volume,,,t W
Volume detained
(acre-feet) -.�
732.00
0.144
1464.00
0.216
2196.00
0.265
2928.00
0.294
3660.00
0.316
4392.00
0.336
5124.00
0.343
5856.00
0.347
6588.00
0.350
7320.00
0.352
8052.00
0.353
8784.00
0.351
9516.00
0.350
10248.00
0.349
10980.00
0.347
11712.00
0.344
12444.00
0.341
13176.00
0.338
13908.00
0.332
14640.00
0.329
15372.00
0.324
16104.00
0.319
16836.00
0.312
17568.00
0.306
FORBES ENGINEERING
STORM WATER RUNOFF CALCULATIONS
KIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
DETENTION POND VOLUME CALCULATIONS
PROPERTY
I� LINE
i
i
—zo
3-7
DETENTION POND PARAMETERS
INVERT OUT = 5036.67
HIGH WATER ELEVATION = 5038.6
WATER DEPTH = 1.93 FEET
RAIN GARDEN AREA = 1507 SF
JOB # 2360
CLIENT: KIND CARE
DATE: 2/20/16
BY: KEF
REQUIRED DETENTION
VOL = 0.353 AC -FT
(FROM MASS BALANCE SPREAD SHEET)
VOL = 15,377 CF
WATER QUALITY CAPTURE VOLUME
1,846 CF
TOTAL REQUIRED VOLUME
17,223 CF
DETENTION
POND VOLUME
RAIN
GARDEN
AREA
VOLUME
CONTOUR
SF
CF
OUTLET
0 36.67
0
543
5037
3293
7,857
5038
12,420
9,874
5038.E
20,493
— OUTLET
_ STRUCTURE
& PIPE
TOTAL 18,274 CF
0.42 AC -FT
PROVIDED VOLUME (0 5038.6)
U.S. HIGHWAY 287 18,274 CF
(SOUTH COLLEGE AVENUE)
FORBES ENGINEERING
STORM WATER RUNOFF CALCULATIONS
HIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
EXTENDED DETENTION VOLUME
TOTAL SITE IMPERVIOUSNESS
EXISTING = 40.0%
PROPOSED = 40.9%
JOB # 2360
CLIENT: KIND CARE
DATE: 10/3/15
BY: KEF
WQCV = Water Quality Capture Volume (watershed inches)
WQCV =a[(0.9)I3— (1.19)I2+(0.78)I]
a = coefficient corresponding to WQCV drain time (table 3-2)
Use, a = 0.9 for 24 hour drain time
I = imperviousness (in %/100)
I = 40.9 / 100 = 0.409
WQCV = 0.9 [ (0.9)(0.409) s — (1.19)(0.409)2+ (0.78)(0.409) ]
WQCV = 0.163
REQUIRED STORAGE VOLUME (AC —FT)
V = ( WQCV 1 A
12
V = ( 0.163 )(3.12)
12
A = 3.12 ACRES
V = 0.042 AC —FT
V = 1846 CUBIC FEET
FORBES ENGINEERING
KIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
STORMIMATER CALCULATIONS
Job J
2460
Client.
KIND CARE
Date:
2120116
8y:
KEF
Subject: Detention Pond Outlet Orifice Plate
Detention Pond release point
12"0 storm pipe connected to existing west curb & gutter system for
South College Avenue
Maximum Release Rate out of pond, Qout
2.44 cfs, historic 2 year run—off value
On —site Pond size
4 to 1 side slope, 1.93 foot depth at outlet
Approximately 18,274 cubic feet = 743 cubic yards
Detention Pond Outlet Restrictor Plate
Q = AV, A = Q/V, V = (.6) 2 32.2 1.9 )
V = (.6)( (2 (32.2)(1.9 )
V = 6.64 fps
A = 2.44/6.64 fps A = 0.367 ft 2 = 52.92 in
Use 8Y4" diameter hole Or 7Y4"x7X" Square Orifice
GRATE
12"0 STORM
I I DRAIN (BEYOND)
I
WATER QUAL;
' PLATE
' /1.5'H x 1.5'W x 1/4" STEEL PLATE —
W/ ORIFICE AS INDICATED — BOLT TO
CONCRETE W/(4) 3/8"0 STAINLESS
STEEL BOLTS AND ANCHORS
12"0 STORM
DRAIN
SPILL WAY
INV OUT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
FORBES ENGINEERING
KIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
STORMWATER CALCULATIONS
Job #
2460
Client.
KIND CARE
Dote:
4114116
By:
KEF
Subject: Water Quality Orifice Sizing Calculations
Using Average Hydraulic Head and Average Discharge
Water Quality Volume (WQv) = .04 ac—ft = 1,846 ft3
Wet Pond, Extended Detention Volume (EDv) = .75 (WQv) = 1,385 ft3
Drawdown Time, td = 24 hr.
EDv depth, d = 12"
Hydraulic Head (Havg) = 12"/2 = 6"
Average release rate to discarge water quality volume over a
24—hour time period.
Qavg = 0.75 x (WQv) = 0.75 x 1,846
t d (24hr)(3600)s/hr
Qavg = 0.016 cfs
WQv Orifice Sizing Calculations
Q=ca( 2g H ) a= Q
c ( (2 (g) CHT)
_ 0.016 cfs
a (0.6) (2)((32.2)(0.5) )
a = 0.0047 ft 2 = 0.68 in 2
Using %" min.
diameter holes
d=0.375in
a = 0.11 in2
1/4' (MIN.) THICK
Wp STEEL FLOW CONTROL
(Wo+61 PLATE
F-1 WATER HOLE (TYP.).
SE (WO)
�� o o �� TABLE
BOTTOM ROW OF
HOLES TO BE AT
INVERT OF PLATE
A
# of holes = 0.68 / 0.11 = 6.18
3• (TYP.) STAINLESS STEEL
ANCHOR BOLT (TYP.)
FLOW CONTROL PLATE
Use (6) %" diameter holes spaced ® 4" o.c.
' PIPE CAPACITY
� CALCULATIONS
FORBES ENGINEERING
KIND CARE SITE DEVELOPMENT
FORT COLLINS, COLORADO
STORMWATER CALCULATIONS
PIPE CAPACITY CALCULATIONS
43'
DETEN M
POND
INV our �1ooY
HGL
APPROXIMATEOURET BOX EXISnNG GRADE
12"0 OUTLET PIPE
NOT TO SCALE
APPROXIMATE
EXISMG GRADE
8"0 NORTH DRAINAGE PIPE
NOT TO SCALE
APPROX 43 LF OF 12'0 PVC
PIPE SLOPED O 0.5R
Job if 2460
Client: KIND CARE
Dote: 2120116
By: KEF
qRm
PIPE CAPACITY CALCULATIONS
12*0 PVC PIPE n - 0.011 A = .785 SO FT
SLOPED ® 0.5% S = 0.005 P = 31.27' = 2.61 FT
R=A/P=0.30
Q - (1.486/n)(A)(RP(sy/2
Q =(1.486/0.011)(0.785)(0.30)2/3(0.005)1/'
Q=3.36CFS
L
TOP OF 100Y NGL EXISTING 8'0
ASPHALT (2' DEPTH) C DRAINAGE PIPE
APPROX 42 LF OF 8'0 PVC
PIPE SLOPED O 0.5X
55i
PIPE CAPACITY CALCULATIONS
8'0 PVC PIPE n = 0.011 A = 0.349 SO FT
SLOPED ® 0.5% S = 0.005 P = 20.85' = 1.738 FT
�
Q (1.486/n)(A)(R) (S)'2 R-A/P-0.20
Q =(1.486/0.011)(0.349)(0.20)nO.005)1/2
Q = 1.14 CFS
' TABLES
� AND
FIGURES
i
EROSION
CONTROL
WORKSHEETS
Erosion and Sediment Control Escrow/Security Calculation
for The City of Fort Collins
Project:, Wnd Care I Disturbed Acres:g0.55
EROSION CONTROL BMPs
Silt Fence (SF)
Inlet Protection (IP)
Concrete Washout (CW)
Vehicle Tracking Control (VI
- R6rk .gnPkc
bMP Amount..
Estimated Unit Total
Units Quantity Price Price
Ea.
Ea
Sub -Total: $3,415.00
1.5 x Sub -Total: $5,122.50
Amount of security: $5,122.50
Reseeding Amount
Total Acres x Price/acre: $550.00
Unit Price of Seeding per acre: $1,000.00 Sub -Total: $550.00
1.5 x Sub -Total: $825.00
Amount to Re -seed: $825.00
Miniumum�EscroW Amount '>
Minimum escrow amount: $1,500.00
Erosion Control Escrow: $5,122.50
1 Fields in yellow should be amended for this project.
"The amount ojthe sewrhy mast be based on one and one-half dater the asdmate of the cost to install the approved measures, or one and one halfntnea
the cost to re -vegetate the disturbed land to dry land grasses based upon unit cost determined 4 the Chy s Annual Revegetadon and S'tabUkadon Rid,
whichever is greater. In no instance, will the amount ofsecur4 be kss than one thousand five hundred dollars (S],500) for raidendal development or three
thousand dollars ($3,000) for commercial development"
6/10/2016 2:27 ?M CiCLIENTMWoddag FlIea12M KNdCaMWAV1nd Set 6816Z-1616 K6d Cam Ee jft
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KEF
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PROPOSED
DRAINAGE PUN
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I
EROSION CONTROL
CONSTRUCTION SEQUENCE
1. INSTALL PERIMETER EROSION CONTROL
MEASURES.
2. STRIP AND ROUGH GRADE SITE AND FILL
AREAS.
3. PROVIDE EROSION CONTROL PROTECTION.
(I.E. SILT FENCE) AND TEMPORARY
SEEDING, WHERE REQUIRED.
4. GENERAL SITE STRIPPING AND TOPSOIL
STOCK PILE.
5. FINAL GRADING OF FIRE ACCESS ROAD.
6. REMOVE ACCUMULATED SEDIMENT AND
CONSTRUCT PERMANENT EROSION/DRAINAGE
CONTROL STRUCTURES (IF REQUIRED).
LEGEND
SITE BOUNDARY/PROPERTY LINE
EXISTING BUILDING
PROPOSED BUILDING
EXISTING EOC
PROPOSED EOC
EXISTING CURB & GUTTER --
PROPOSED CURB & GUTTER
EXISTING EDGE OF GRAVEL ---
PROPOSED EDGE OF GRAVEL
EXISTING FENCE 1
EXISTING CONTOUR --------5042-----
PROPOSED CONTOUR
RR)PROanE
MP-XIP
GRAVEL YARD
EROSION CONTROL SYMBOLS
/VTy\�\Cyr' VEHICLE i KING MAT , M
\/ i PERMANENT SEEDING
I
SF ! SILT FENCE * X
OP ROOK W PROIEGIXIN RLTFR
I
W WMia rt WAvwuT enFA
ROCK SOCK INLET PKGTECIION I
limilimmil
CURB ROCK SOCKS I p p a- I
RR)RP-W PROIECW)N
i UGW
CONCRETE
ASPHALT
ma
EROSION & SEDIMENT CONTROL NOTES
1. THE CITY STORMWATER DEPARTMENT EROSION
CONTROL INSPECTOR MUST BE NOTIFIED AT
LEAST 24 HOURS PRIOR TO ANY
CONSTRUCTION ON THIS SITE.
2. ALL REQUIRED BMPB SHALL BE INSTALLED
PRIOR TO ANY LAND DISTURBING ACTIVITY
(STOCKPILING. STRIPPING,' GRADINO,JTC).
ALL OF THEIR REQUIRED EROSION CONTROL
MEASURES SHALL BE INSTALLED AT THE
APPROPRIATE TIME IN THE CONSTRUCTION
SEQUENCE AS INDICATED IN THE APPROVED
PROJECT SCHEDULE, CONSTRUCTIONS PLANS
AND EROSION CONTROL REPORT.
3. PRE-DISTRUBANCE VEGETATION SHALL BE
PROTECTED AND RETAINED WHEREVER
POSSIBLE. REMOVAL OR DISTURBANCE OF
EXISTING VEGETATION SHALL BE LIMITED TO
THE AREA REQUIRED FOR IMMEDIATE
CONSTRUCTION OPERATIONS, AND FOR THE
SHORTEST PRACTICAL PERIOD OF TIME.
4. ALL $OILS EXPOSED DURING LAND
DISTURBING ACTIVITY (STRIPPING. GRADING,
UTILITY INSTALLATIONS, STOCKPILING, FIWNG.
ETC.) SHALL BE KEPT IN A ROUGHENED
CONDITION BY RIPPING OR DISKING ALONG
LAND CONTOURS UNTIL MULCH, VEGETATION,
OR OTHER PERMANENT EROSION CONTROL IS
INSTALLED. NO SOILS IN AREAS OUTSIDE
PROJECT STREET RIGHT OF WAYS SHALL
REMAIN EXPOSED BY LAND DISTURBING
ACTIVITY FOR MORE THAN THIRTY (30) DAYS
BEFORE REWIRED TEMPORARY OR
PERMANENT EROSION CONTROL (E.G.
SEFD/MULCH, LANDSCAPING, ETC.) IS
INSTALLED, UNLESS OTHERWISE APPROVED
BY THE STORMWATER DEPARTMENT.
PS
5. THE PROPERTY MUST BE WATERED AND
MAINTAINED AT ALL TIMES DURING
CONSTRUCTION ACTIVITIES SO AS TO
PREVENT WIND -CAUSED EROSION. ALL
LAND DISTURBING ACTIVITIES SHALL BE
IMMEDIATELY DISCONTINUED WHEN FUGITIVE
DUST IMPACTS ADJACENT PROPERTIES, AS
DETERMINED BY THE CITY ENGINEERING
DEPARTMENT.
6. ALL TEMPORARY (STRUCTURAL) EROSION
CONTROL MEASURES MUST BE INSPECTED
AND REPAIRED OR RECONSTRUCTED AS
NECESSARY AFTER EACH RUNOFF EVENT AND
EVERY 14 DAYS IN ORDER TO ASSURE
CONTINUED PERFORMANCE OF THEIR
INTENDED FUNCTION. ALL RETAINED
SEDIMENTS, PARTICULARLY THOSE ON PAVED
ROADWAY SURFACES, SHALL BE REMOVED
AND DISPOSED OF IN A MANNER AND
LOCATION SO AS NOT TO CAUSE THEIR
RELEASE INTO ANY DRAINAGE WAY.
7. NO SOIL STOCKPILE SHALL EXCEED TEN (10)
FEET IN HEIGHT. ALL SOIL STOCKPILES
SHALL BE PROTECTED FROM SEDIMENT
TRANSPORT BY SURFACE ROUGHING,
WATERING, AND PERIMETER SILT FENCING.
ANY SOIL STOCKPILE REMAINING AFTER 30
DAYS SHALL BE SEEDED AND MULCHED.
B. CITY ORDINANCE PROHIBITS THE TRACKING.
DROPPING, OR DEPOSITING OF SOILS OR
ANY OTHER MATERIAL ONTO CITY STREETS
BY OR FROM ANY VEHICLE. ANY
INADVERTENT DEPOSITED MATERIAL SHALL
BE CLEANED IMMEDIATELY BY THE
CONTRACTOR.
TEMP.
SEE N
-C
SF
IP-1 & IP-2
NOTE: PROVIDE ROCK SOCK INLET
PROTECTION & CURB ROCK SOCKS AT
EXISTING CURB INLET LOCATED AT
WEST FLOWLINE SPLATTER ISLAND,
APPROXIMATELY 250' NORTH OF
TRILBY & SOUTH COLLEGE
INTERSECTION
C
TEMPORARY VTC NOTE
NOTES:
1. CONTRACTOR SHALL PROVIDE A
TEMPORARY VIC AT AN EXIT LOCATION
BEST SUITED FOR THE CONSTRUCTION
PHASES OF THE SPLATTER ISLAND (SEE
SHEET C4.1 FOR SIZE & DEPTH
SPECIFICATIONS).
2. CONTRACTOR SHALL REMOVE ANY
EXISTING ASPHALT IN THE AREA FOR
THE TEMPORARY VTC PRIOR TO
INSTALLATION.
3. ANY & ALL SEDIMENT DEPOSITED
ON HIGHWAY 287 BECAUSE OF
CONSTRUCTION ACTIVITIES SHALL BE
ADDRESSED & CLEANED WITHIN A 24
HOUR TIME PERIOD.
EROSION CONTROL PLAN
SCALE 1" = 30'
30 0 w 0
GRAPHIC SCALE - FEET
i of Fort Collins, Colorado
UTILITY PLAN APPROVAL
City Engineer
Dote
BY:
Water & Wartewater UOlity
Dale
BY:
Stormwabr utility
Dole
BY:
Porky k Recreo0on
Dlrte
BY:
Traffic Engineer
Dote
BY:
Emironmenlal Planner
Dote
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—° AS NOTED
eroin KEF
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ar°'"°m' 24'K36'
5 M XOM
EROSION
CONTROL PLAN
PwYq Kn
C4.0
A CURB INLET
ROCK -- Z_ SEE ROCK SOCK DESIGN SYM
SOCK
S DETAIL FOR JOINTING R
SOCKS 16" CINDER OCKS
16" CINDER BLOCKS
_ BLOCKS
FLOW
- 2"%4" WOODCURB STUD ; X�--
_ 1' MIN
i CURB INLET
2"%4" WOOD STUD SECTION A
IP-1 BLOCK AND ROCK SOCK SUMP OR ON GRADE
INLET PROTECTION
RI nrK AND CURB SOCK INLET PROTECTION INSTALLATION NOTES
1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS
2. CONCRETE "CINDER" BLOCKS SHALL BE LAID ON THEIR SIDES AROUND THE INLET IN A
SINGLE ROW, ABUTTING ONE ANOTHER WITH THE OPEN END FACING AWAY FROM THE CURB
3. GRAVEL BAGS SHALL BE PLACED AROUND CONCRETE BLOCKS, CLOSELY ABUTTING ONE
ANOTHER AND JOINTED TOGETHER IN ACCORDANCE WITH ROCK SOCK DESIGN DETAIL
MINIMUM OF APPROX BLOCK AND ROCK SOCK INLET
TWO CURB 30 DEG PROTECTION (SEE DETAIL IP-1)
SOCKS
L
_- _._.._.,SYM
W
t_
5' MIN 3L-5L TYP
IP-2, CURB ROCK SOCKS UPSTREAM OF
INLET PROTECTION
CURB SOCK INLET SOCK INLET PROTECTION INSTALLATION NOTESINST�LATION NOTES
1. SEE ROCK SOCK DESIGN DETAIL FOR INSTALLATION REQUIREMENTS
2. PLACEMENT OF THE SOCK SHALL BE APPROXIMATELY 30 DEGREES FROM PERPENDICULAR
IN THE OPPOSITE DIRECTION OF FLOW.
3. SOCKS ARE TO BE FLUSH WITH THE CURB AND SPACED A MINUMUM OF 5 FEET APART.
4. AT LEAST TWO CURB SOCKS IN SERIES ARE REQUIRED UPSTREAM OF ON —GRADE INLETS.
^^'r'"o" ELEVAIION
MIRAFI MODEL 10100
SILT FENCE
FENCE
/ DETAIL
L1 1/2" SQUARE
x 48' LONG,
DRIED
ATTACH SILT FENCE
BETWEEN LATHE &
POSTS W/1 1/4"
ROOFING NAILS
COMPACTED BACKFILL
6" % 6" EXCAVATED
TRENCH
RUNOFF FLOW
NATIVE SOIL
KILN
POSTS
SECTION
/L
INSPECT AND REPAIR FENCE AFTER
I
EACH STORM EVENT. REMOVE
SEDIMENT WHEN 6" OF THE HEIGHT
^
OF THE FENCE HAS BEEN FILLED.
SEDIMENT CONTROL
FENCE
REMOVED SEDIMENT SHALL BE
l l
P LD
PLACED IN TOPSOIL PILE.
NOT TO SCALE
0
�v PLAN
3' - 6' RUCK
1.
VEONHIDIE KING LONIRCL PID SIWL BE LO 1 AT 11 ACCESS POINT TO THE
SLRUC N SITE.
2.
A SIGN S L BE PIACEO HFM TO 1XE YEHICIE TRACKING CONTROL PRO TO
DESIGNATE TIE LOCATION AS THE COXSTRIIRION EMNHCE/IXR.
3.
WHICLE KING CONTROL DRUG SHALL CONSIST OF HARD, DENSE. DURABLE STORE,
NCUVR SHME AND RESISTANT TO WEATHERING ROUNDED STONE (I... RIVER MEN
O COBB`ES) SHALL NOT BE USED. THE STONES SENATE BE A MINIMUM OP 3- AND
A MAXIMUM OF 6L DWAETER. THE STONES SHNL LANE A SPELFIC OPANIY OF AT
LEA B 6I CONTROL OF QROM10N WILL BE BY NSWL INSPECTION.
C
CBALNED 04 WMAGED CURB AND CUTTER AND MERGER SHALL BE REPLACED BY
COnIFACTgR.
S.
ALT UCHINOT NORMALLY USED THE CITY RESERNES THE RIGHT TO REQUIRE WHOLE
{
TRACKING CONTROL WITH A TEMPORARY CATTLE CWRO AND/OR WHEEL WASH FACILITIES
AT SITES ����,,,,yyyyHEERE TRACKINGONTOFARM AREAS BECOMES A SIGNIFICANT PROBLEM AS
D ERMNp THE
6,
i VEHFLE TRACERS CONTROL WITH WHEEL WASH FALIIIDES ARE REQUIRED, ALL
WHEELS EVERY VEHICLE LEAVING THE SITE SHNL BE CLEANED OF MUD DOING A
-
PRESSVREjWASHER. THE CONTRACTOR SHAL BE RESPONSIBLE FOR OBWNING A
WATER SOURCE AND CONSTRUCTING A WASHWATER SEDIMENT TRAP.
$0'MIX.
MAINTFINANCF
I.
NOTES
CONTRACTOR SHALL INSPECT VEHICLE TRACKING CONTROL PAD ONLY ROCK SURFACE
SHALL BE CLEAN AND LOOSE ENOUGH TO PUT SLIGHTLY UNDER WHEEL LEADS AND
CAUSE LOUSE ROCK TO DISLODGE MUD FROM THE WREN ROCK BECOMES
COMPACTED OR FILLED WITH SEDIMENT SO THATTHE EETECRNENESS OF ME PAD G
CONTRACTOR SHAH RIP. TURN MR, OR OTHERWISE LOOSEN BEEN.
-- -
PLACE ADDITIONAL NEW ROCK. OR REPLACE WITH NEW ROCK AS NECESSARY M
RESIORE EFFECTRINESS.
2.
SEDIMENT AND OTHER MATERIAL SPILLED. DROPPED OR TRUCKED ONTO PAWD
SURFACES SHALL BE IMMEDIATELY OR BY THE END OF EACH WORKING DAY.
s.
XEEMMDOLED
VEHICLE TRACKING .0 PAD SHALL BE REMOVED AT THE END OF
CONSTRUMION. THE ARIA SHOULD BE TOPSOILED, SEEDED. CRIMPED, AND NUDGED)
OR GTHERMSE SPAIMED
4.
IF VEHICLE WHEEL WASH RACEMES ME REQUIRED. WNTRACTOfl SKILL INSPECT
VEHICLE TfMgNG CONTROL AND WHEEL WASH FACRRIES WIRY.
ACCUMVUIED SEDIMENTS SHNL BE REMOVED FROM THE PAD SURFACE.
3.
ACCUMULATED SFDIMLM IN T{ WASMW.AIfR/SEOINEM TRAP SEAL BE REMOVED
WHEN ME;SEpMEM REACHES AN AVERAGE DEPTH OF 1$-INCHES.
Y MIN. 6' MIN.
PAVED SURFACE L pPg12Z-e'IWN.
�_r-6'MCI
NO wTERWS INCUumw ROCS. IRP6, DIRT, -
GMYEL OR MPHI SIWL BE PLACED IN
CUTER TO FACILITw1E MOLMRNO CURER
FEMME. CURB BE CUT DEAN TO A
HEIGHT OF 2' OR HIGHER FOR OWNER SECTION A
ACCESS AND REPIACED AT PROTECT
COMPLERCN. OTHER ACCESS OENCES WY BE
USED AS ACCEPTED BY THE CRY.
I I/T AGOIEGTE PLED TO TOP
OF =TOME 1 ro I WAGE LME-
FLOW
CONCRETE WASHOUT NOTES
1. CONCRETE WASHOUT AREA S BE RESEALED
PReOH TO MY CONCISTE PVCEMFNT ON STF.
2. VEHICLE TRACKING CONTROL IS REWIRED IF
ACCEss TO CONCRETE WAS MG 5 OFF
DARTMEM
3 SIGNS SINGLE BE FVCD) AT THE
CONSTRUCTION ENIIt4RCE AT T WMHWF
AHEAD AND R]SEWHERE AS NECESSARY ro
CLEMLY INDICATE THE LOCATOR OF THE
CONCRETE WASHOUT MG TO CPERMORS OF
CONCRETE TRUCKS AND PUMP WERE
a, THE CONCRETE WASHOUT MCA SIWL BE
REPARM MD ENLARGED OR CLEWED GORE M
NECESSARY TO MOUNTAIN GPMRRY FOR WASTED
CONCRETE
5, AT TIE ETD OF CONSTRUCTION. ALL CONCRETE
SRWL OE RE FRO! THE SRE ND
DISPOSED OF AT M ACCEPTED NOTICE DOE
6. WHEN THE CONCRETE YUSEVT MCA 6
READABLE). THE MOURBFD MIA SWL BE
SEEDED AND MULCHED OR OTHERWISE STMU2ED
IN A BANNER ACCEPTED WE THE BEEF
T. EQUATION OF CONCRETE WAWDIIr .UffA OR
SHEET IS CONCEPIINL BILE.. FINAL LOCA,EM
TO BE DETERMINED IN TIE REED AT
LCNRRA;TORS D5GEEM
BLOW
COMRICL
PLATE
DEe
OU11Fr PIPE
ROCK
OUTLET
PROTECTION
FILTER
NOT TO
SCALE
OP
'71
SON W roIGTE THE UOMIGN
OF THE CONCRETE W0.9MR AREA
E—GROUND MR.
SURFACE
I T
z-0- NOR u
I I
4WACIm FYflAL10E21r
MATERIAL TN.
]I11V CN FLATTER!
IWE MIN. SIDE STAPES
OR M (DOMINIONREWPH MASSIVE COHCIONCR
EIE
CONCRETE WASHOUT AREA / IAfn\
NOT TO SCALE
CONTROL TRACKING PAD
PL
AN
S L N VIEW
HIS
ICRAWL FILTER NOTES
1. SEDIMENT SHALL SE REMOVED WHEN ME HALF
BE THE BASIN DESIGN DEPTH HAS BEEN MICRO.
$. REMOVED SEDIMENT SIWL BE DEFROSTED IN
I MI MCA TRI&TA% TO A SEDIMENT BASIN.
City of Fort Collins, Colorodo
UTILITY PLAN APPROVAL
C'M Engineer Date
BY:
Water h Waetawaler Utility Oats
CHECKED BY:
SlHermWoler Utility Dote
CHECKED BY:
Pvb h Recreogon DRAW
CHECKED BY:
Traffic Engineer Dote
BY:
Environmental Planner Date
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Date 2-22-16
stli AS NOTED
AA KEF
Mere KEF
ARAWF We" 240K36"
AeW mew -
EROSION CONTROL
DETAILS
D,ewq w
C4.1