HomeMy WebLinkAboutWHITMAN STORAGE FACILITY II AND ADDITION OF PERMITTED USE - FDP200017 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDRAINAGE INVESTIGATION
&
SEDIMENT EROSION CONTROL REPORT
for
WHITMAN STORAGE FACILITY II
Located in the Southwest Quarter of Section 12,
Township 6 North, Range 69 West of the 6th P. M.
(Lot 3, Block 1, Lynn Acres)
CITY OF FORT COLLINS, LARIMER COUNTY , COLORADO
Prepared for:
RANDY WHITMAN
209 E. SKYWAY DRIVE
FORT COLLINS, COLORADO 80525
Revised August 2016
Project No. 1032 - GRD - 13
Prepared by:
DENNIS R. MESSNER , P.E.
221 East 29th Street, Suite 157 Loveland, Colorado 80538 Telephone: (970) 461-3501
Dennis R. Messnen P. E.
Consulting Civil Engineer
August 11,2016
Project No. 1032-GRD-13
Stomiwater Utility
Service Center
700 Wood Street
Fort Collins, Colorado 80522-0580
Re: Final Drainage Investigation and Erosion Control Report for
Whitman Storage Facility II - P. D. P,, Fort Collins, Colorado
Gentlemen:
I am pleased to submit, for your review and comment, this "Drainage Investigation and Erosion
Control Report for Whitman Storage Facility H - P. D. P., Fort Collins, Colorado."
This investigation was based upon the proposed site development plan; on-site observation; and
available topographic infomiation. The investigation and design within this report have been
performed according to the criteria established in the City of Fort Collins' Storm Drainage Criteria.
This report has been revised to address staff review comments.
I sincerely appreciate your time and consideration m the review of this project. If you should have any
questions, please feel free to contact this office.
RespectMly^ubmitted,
I hereby state that the attached "Drainage Investigation and Erosion Control Report for Whitman
Storage Facility 11 - P. D. P., Fort Collins, Colorado" was prepared by me or under my direct
supervision in accordance with the provisions of the City of Fort Collins' Drainage Criteria for the
cc: Randy Whitman
owners thereof
221 East 29'" Street., Ste#157 Telephone: (970) 461-3501
TABLE OF CONTENTS
Description Page
LETTER OF TRANSMITTAL i
TABLE OF CONTENTS ii & iii
I GENERAL LOCATION AND DESCRIPTION
A. Location 1
B. Description of Property 1
I DRAINAGE BASINS
. Major Basin Description 2
. Sub-basin Description 2
III DRAINAGE DESIGN CRITERIA
A. Development Regulations 2
B. Development Criteria Reference and Constraints 2
C. Hydrologic Criteria 3
D. Hydraulic Criteria 3
I DRAINAGE FACILITY DESIGN
. General Concept 4
. Specific Details - Detention Facility 4
V EROSION CONTROL
. General Concept 5
VI CONCLUSIONS
A. Compliance with Standards 6
B. Drainage Concept 6
VII REFERENCES 7
ii
TABLE OF CONTENTS (CONTINUED):
EXHIBITS
Vicinity Map
Existing Conditions Exhibit
Proposed Conditions Exhibit
Offsite Conditions Exhibit
Utility Plan Set
APPENDIX I
Drainage Calculations
APPENDIX II
Charts, Graphs, Figures and Details
iii
I. General Location and Description:
A. Location
1. The proposed Whitman Storage Facility II is located in the Southwest Quarter
of Section 12, Township 6 North, Range 69 West of the 6th P.M. in the City of Fort
Collins, Larimer County, Colorado.
2. The site is more specifically located south of Skyway Drive and east of South
College Avenue. (Refer to the included Vicinity Map.)
3. The Whitman Storage Facility borders the site along its north boundary. To the
west of the site lies commercial properties and US Highway 287. The Discovery
Montessori School is located directly to the east. Immediately south of the site is
undeveloped Cherelyn Street and the Prairie Dog Meadows Natural Area to the
south of Cherelyn Street.
B. Description of property
1. The Whitman Storage Facility II - P. D. P. site consists of approximately 3.21
acres and is undeveloped.
2. The existing ground cover consists mainly of sparse non-irrigated grasses and
native vegetation.
3. The “Soil Survey of Larimer County Area, Colorado” prepared by the U.S.
Department of Agriculture, Soil Conservation Service, indicates that the surface
soils consist of “Midway clay loam.” The soil typical of this series is described as
a shallow, well-drained soil that formed in material from clay shale. The “Soil
Survey” identifies the runoff potential as rapid, and the hazard of erosion as
severe. The soil type is classified in the ‘D’ hydrologic group.
4. The site is generally considered moderate, with slopes between 3% and 6%.
5. The Whitman Storage Facility II - P. D. P. will involve the construction of an
outdoor storage area. The proposed outdoor storage area is to be approximately
2.54 acres.
II. Drainage Basins and Sub-basins:
A. Major Basin Description
1. The subject area is located on Lot 3, Block 1 of the Lynn Acres Subdivision.
1
2. The site is located within the Stone Creek sub-basin of the Fossil Creek
Drainage Basin as identified by the City of Fort Collins’ Master Drainage Plan.
The site is not located within a designated flood way or flood plain.
B. Sub-basin Description
1. The historic drainage pattern of the property flows from west to east. Runoff is
directed to Stone Creek at the southeast corner of the site.
2. The northern 2.03 acres of the site drains to the northeast corner of the site
where runoff is directed into the northern branch of Stone Creek.
3. The southern 1.18 acres of the site drains to the southeast corner of the site
where runoff is directed into Stone Creek. (The southern 1.18 acres is to consist of
0.51 acres of proposed open storage and 0.67 acres of open space.)
III. Drainage Design Criteria:
A. Development Regulations
1. Design criteria from the current City of Fort Collins Storm Drainage Criteria
and Construction Standards, the Urban Storm Drainage Manuals, Volumes I, II,
and III and the Larimer County Urban Area Street Standards were utilized.
B. Development Criteria Reference and Constraints
1. The historic drainage pattern will be affected by the development of the site in
that flow will be concentrated and channelized. The development of this site will
produce more runoff than the historic amount, however, the historical runoff from
the property will be maintained through the use of detention facilities and flow
control devices.
a. Stormwater will be released according to the historic 2 Year storm
peak flow rate as established in the City of Fort Collins Storm Drainage
Design Criteria.
b. The storm water is to be released at controlled rates onto the adjacent
property in the historic drainage way. An easement for conveyance of
stormwater will be obtained from the property owner.
c. The offsite runoff from the west is to be intercepted by a drainage swale
located along the along the western property line. The runoff is to be
directed in the swale to the existing drainage swale situated along the
northern border of the site. The runoff will then be conveyed in the swale
2
to the natural drainage course located on the property to the east.
2. The drainage impact of this site will not adversely affect streets or utilities.
C. Hydrological Criteria
1. The Rainfall-Intensity-Duration-Frequency Table for the City of Fort Collins,
Table RA-7 as amended for Section 4.0 of the Urban drainage and Flood Control
District Criteria, was used in conjunction with the Rational Method for
determining peak flows at various concentration points.
a. Spreadsheets from the Urban Storm Drainage Criteria Manual were
used to first determine the weighed imperviousness for a contributing sub-
basin, and then to calculate the peak runoff rates. (See the Drainage
Calculation Section of this report.)
b. Tables RO-10 and RO-11 as amended for the City of Fort Collins for
the Urban Storm Drainage Criteria Manual were used for recommended
run-off coefficients values for various land cover.
c. The hydrological group ‘D’ was used in the Urban Storm Drainage
Criteria Spreadsheets for the on-site soils.
2. The 2-Year, 10-year and 100-year storms were analyzed in the design of the
storm water management infrastructure in accordance with the City of Fort
Collins Storm Drainage Criteria and Construction Standards.
3. The proposed detention facility was sized for the 100-year storm event plus the
estimated Water Quality Capture Volume. The maximum release rates are based
on the Fort Collins Storm Drainage Criteria and Construction Standards, which
prescribes a unit release rate equal to the historic release rate for the 2-year storm.
The release rate was determined by the U.D.F.C.D. Rational Method.
D. Hydraulic Criteria
1. A stormwater quality structure was designed for the project based upon the
requirements found in Volume III of the Urban Storm Drainage Criteria Manual.
a. Sizing of structures are based on the design figures and spreadsheets
provided in Volume III of the Urban Storm Drainage Criteria Manual.
2. Proposed storm drain pipes onsite are designed using smooth interior wall
High Density Polyethylene (HDPE) pipe.
a. A Mannings ‘n’ value of 0.013 is to be used for all storm pipe according
3
to Sec.4.4.2 of the City of Fort Collins Storm Drainage Design Criteria.
3. Recommended Channel Design Roughness Coefficients are per Table MD-1 of
the Urban Storm Drainage Criteria Manual Volume I.
IV. Drainage Facility Design:
A. General Concept
1. During a large rainfall event, storm water will be conveyed to two detention
facilities for the site. The western, southern and eastern edges of the site will be
conveyed in drainage swales around the perimeter of the site and into the two
detention facilities. The open areas located at the northeast and the southeast
corners of the property will be utilized as a stormwater quality/detention facilities
to capture and temporarily store stormwater from the remainder of the site that
otherwise would be routed directly off site.
B. Specific Details - Detention Facility
1. Sub-Basin ‘A’, as identified on the Proposed Drainage Exhibit, comprises
the northern portion of the site that contains 2.03 acres. The peak runoff rate
during the 2-year storm is 1.83 c.f.s., the 10-year storm is 3.13 c.f.s. and the 100-
year peak runoff rate is 7.99 c.f.s.
a. Surface run-off will be conveyed as sheetflow across the gravel drives
and open storage area of this basin and is to be directed to the detention
facility located in the northeast corner and along the eastern boundary of
the site. The area will be utilized as a stormwater quality/detention facility
to capture and temporarily store stormwater that would otherwise be
routed directly off site.
b. The proposed drainage swale along the east edge of the site will
prevent runoff from passing off site. The swale will be incorporated with
the detention facility to be located along the eastern boundary of the site.
c. An 8-inch diameter HDPE storm drain will extend east from the inlet
and discharge into a swale that will discharge into the existing drainage
course.
e. A multi-stage outlet structure will be constructed at the inlet to the
proposed 8-inch diameter HDPE storm drain. The outlet structure will
incorporate a perforated steel orifice plate to allow for a 40-hour drain
time of the WQCV. A steel restrictor plate is to be installed over the outlet
4
pipe to act as a flow regulator for the detention area during a 100-year
storm event.
f. The 100-year maximum release rate from the detention facility will be
1.06 c.f.s. Based on this outflow rate, the detention facility will require
0.201 acre-feet (0.189 acre-feet of storage + 0.012 acre-feet of WQCV).
g. Proposed rip rap at the pipe outlet will reduce erosion and scouring
along the discharge swale.
h. In the event the outlet structure or storm pipe becomes blocked, the
detention area will overflow at the 100-year Water Surface Elevation
through an emergency overflow spillway and discharge to the adjacent
drainage course.
i. The 100-year Water Surface Elevation plus the WQCV is to be at
elevation = 4967.10.
2. Sub-Basin ‘B’, as identified on the Proposed Drainage Exhibit, comprises the
southern portion of the proposed storage area onsite that contains 0.51 acres. The
peak runoff rate during the 2-year storm is 0.50 c.f.s., the 10-year storm is 0.85
c.f.s. and the 100-year peak runoff rate is 2.17 c.f.s.
a. Surface run-off will be conveyed as sheetflow across the gravel drives
and open storage area of this basin and be directed to the Detention
Facility located in the southeast corner of the site. The open area will be
utilized as a stormwater quality/detention facility to capture and
temporarily store stormwater that otherwise would be routed directly
offsite.
b. Proposed drainage swales along the south and east edges of the site will
prevent runoff from passing offsite and will direct flow to the detention
facility.
c. A proposed 8-inch diameter HDPE storm drain will extend east from
the inlet and discharge into the existing drainage course.
e. A proposed multi-stage outlet structure will be constructed at the inlet
to the proposed 8-inch diameter HDPE storm drain. The outlet structure
will incorporate a perforated steel orifice plate to allow for a 40-hour drain
time of the WQCV. A steel restrictor plate will be installed over the outlet
pipe to act as a flow regulator for the detention area during a 100-year
storm event.
5
f. The 100-year maximum release rate from the Detention Facility will be
0.27 c.f.s. Based on this outflow rate, the detention facility will require
0.058 acre-feet (0.047 acre-feet of storage + 0.011 acre-feet of WQCV).
g. Proposed rip rap at the pipe outlet will reduce erosion and scouring
along the side of the ditch.
h. In the event the outlet structure or storm pipe becomes blocked, the
detention area will overflow at the 100-year Water Surface Elevation
through an emergency overflow spillway and discharge to the natural
drainage course offsite.
i. The 100-year Water Surface plus the WQCV is at elevation = 4964.80.
V. Erosion Control:
A. General Concept
1. Temporary erosion control measures will be implemented during the
construction of this project. These measures will include:
a. Silt fence along the east, and south property lines.
b. Wattle Inlet Protection installed around the proposed outlet structures
and along open drainage swales.
2. Long term erosion control measures will be implemented after the
construction of this project. These measures will include:
a. Landscape planting and seeding.
b. Surface treatments for drives and open storage area.
c. Rip rap lining the area surrounding the outlet pipe.
3. Maintenance of all erosion control devices will remain the responsibility of
the developer until the completion of the project.
4. Wind erosion measures considered for the site during construction are
roughening and water application.
5. Water quality measures will be provided by detaining the Water Quality
Capture Volume for 40 hours.
6
VI. Conclusions:
A. Compliance with Standards
1. All drainage design conforms to the criteria and requirements of the City of
Fort Collins Storm Drainage Criteria and Construction Standards.
2. Proposed drainage improvements generally conform to the concepts and
recommendations of the City of Fort Collins Master Drainage Plan.
3. Proposed erosion control measures conform to the recommendations of City of
Fort Collins standards and generally accepted erosion control procedures.
4. Proposed water quality measures will be provided to remove sediment from
the flow discharged from the two detention facilities.
B. Drainage Concept
1. The final drainage design for the Whitman Storage Facility II is effective for
the control of storm water runoff with little or no effect on the City of Fort Collins
Master Drainage Plan recommendations.
2. The computed 100-year Water Surface Elevation is 4967.75 feet in the
northern storm water detention facility to be constructed on site and the computed
100-year Water Surface Elevation is 4965.10 in the southern storm water
detention facility to be constructed on the site.
3. Emergency overflow beyond the limits of the 100-year High Water Elevation
will spill offsite to natural drainage courses.
4. With the implementation of the proposed detention facilities and controlled
release rates, the development of this site will not result in an increase of runoff
compared to the historic rates. The total released runoff during the 100-year
storm event is estimated to be the 2-year historic release rate as prescribed by the
City of Fort Collins Storm Drainage Criteria and Construction Standards.
VII. References:
A. City of Fort Collins Storm Drainage Criteria and Construction Standards
B. City of Fort Collins Master Drainage Plan
C. City of Fort Collins Development Standards
7
D. Soil Survey of Larimer County Area, Colorado
E. Urban Drainage and Flood Control District Drainage Criteria Manuals, Volumes
1, 2 and 3. (City of Fort Collins Addendum)
F. Larimer County Urban Area Street Standards
8
EXHIBITS
APPENDIX I
DRAINAGE CALCULATIONS
EXISTING CONDITIONS
Area-Weighting for Runoff Coefficient Calculation
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #1
Illustration
Instructions: For each catchment subarea, enter values for A and C.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
Roof 0.50 90.00 45.00
Pavement 1.85 90.00 166.50
Undevel 1.15 2.00 2.30
Sum: 3.5d Sum: 213.80
Area-Weighted Runoff Coefficient (sum OA/sum A) = 61.09
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
OFFSITE 1 EXIST 2YR.xls, Weighted C 07/06/2016, 16:50:13
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #1
I. Catchment Hydrologic Data
Catchment ID = #1
Area = 3.50 Acres
Percent Imperviousness = 61.09 %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = 01 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr = 2 years
C1 =
C2=
C3=
P1 =
28.50
"lOOO
0.95 incties
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
(input one-hr precipitation--see Sheet "Design Info")
. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.42
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.46
(enter an overide C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0,0333 360 0.46 N/A 0.41 14.65
1 0.0570 280 20.00 4.77 0.98
2
3
4
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1. Lynn Acres)
Catchment ID: OFFSITE AREA #1
I. Catchment Hydrologic Data
Catchment ID = #1
Area = 3.50 Acres
Percent Imperviousness = 61.09 %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * PI /(C2 + Td)*C3
Design Storm Return Period, Tr = 10 years
CI 28.50
C2= 10.00
C3= 0.786
P1= 1.55 inches
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
(input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.52
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.46
(enter an overide C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 1 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0333 360 0.46 N/A 0.41 14.65
1 0.0570 280 10.00 2.39 1.95
2
3
4
5
Sum 640 Computed Tc =
Regional Tc =
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #1
I. Catchment Hydrologic Data
Catchment ID = #1
Area = 3.50 Acres
Percent Imper^/iousness = 61.09 %
NRCS Soil Type = DA, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * PI /(C2 + Td)*C3
Design Storm Return Period, Tr = 100 years
CI =
C2=
C3=
P1 =
28.50
looo -0786
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.60 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.64
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.46
(enter an overide C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
LEGEND
O Begiimijig
Finn' Dimtion
•*
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID s L Runoff Convey- Velocity Tinne
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0333 360 0.46 N/A 0.41 14.65
1 0.0570 280 10.00 2.39 1.95
2
3
4
5
Sum 640 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 1B.6U
Regional Tc =
User-Entered Tc =
13.56
Computed Tc =
Regional Tc =
User-Entered Tc = 13.56
IV. Peak Runoff Prediction
Area-Weighting for Runoff Coefficient Calculation
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #2
Illustration
Instructions: For each catchment subarea, enter values for A and 0.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
Roof 0.15 90.00 13.50
Pavement 0.60 90.00 54.00
Undevel 1.70 2.00 3.40
Sum: 2.45 Sum: 70.90
Area-Weighted Runoff Coefficient (sum CA/sum A) = 28.94
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
OFFSITE 2 EXIST 2YR.xls, Weighted C 07/06/2016, 16:57:49
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #2
I. Catchment Hydrologic Data
Catchment ID = #2
Area = 2.45 Acres
Percent Imperviousness = 28.94 %
NRCS Soil Type = ' ~D" A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 ="
C2="
C3='
P1='
2 years
•28:50
"looo
"0786
0.95 inches
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
(input one-hr precipitation-see Sheet "Design Info")
. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.22
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.30
(enter an ovende C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Watenways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0278 360 0.30 N/A 0.31 19.56
1 0.0870 230 20.00 5.90 0.65
2 0.0476 210 7.00 1.53 2.29
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #2
I. Catchment Hydrologic Data
Catchment ID = #2
Area = 2.45 Acres
Percent Imperviousness = 28.94 %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
CI ="
C2='
C3="
P1 = "
10 years
"28:50
10.00
"0786
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
1.55 inches (input one-hr precipitation-see Sheet "Design Info")
Hi. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.38
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dvehde 5-yr. Runoff Coefficient, C =
0.30
(enter an ovende C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0278 360 0.30 N/A 0.31 19.56
1 0.0870 230 20.00 5.90 0.65
2 0.0476 210 7.00 1.53 2.29
3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: OFFSITE AREA #2
I. Catchment Hydrologic Data
Catchment ID = #2
Area = 2.45 Acres
Percent Imperviousness = 28.94" %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 =•
02="
03="
P1 = '
100 years
•2830
10.00
-0785-
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.60 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = 0.57
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.30
(enter an ovende C value if desired, or leave blank to accept calculated C.)
(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Watenvays
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0278 360 0.30 N/A 0.31 19.56
1 0.0870 230 20.00 5.90 0.65
2 0.0476 210 7.00 1.53 2.29
3
Area-Weighting for Runoff Coefficient Calculation
Project Title: WHITMAN STORAGE FACILITY II
Catchment ID: ONSITE BASIN 'A'
Illustration
Instructions: For each catchment subarea, enter values for A and C.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
Pasture 2.03 0,25 0,51
Sum: 2.03 Sum: 0.51
Area-Weighted Runoff Coefficient (sum OA/sum A) = 0.25
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
EXIST 'A' Q2.xls, Weighted C 07/08/2016, 13:54:00
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "A" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "A"
Area = 2.03 Acres
Percent Imperviousness = %
NRCS Soil Type = DA, B, C, or D
II. Rainfall Information I (inch/hr) = 01 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 ="
C2="
C3="
P1 = "
2 years
"2830
10.00
"0786
0.82 inches
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
(Input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Ovende Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.25 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.25 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.'
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly j
Bare
Ground j
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ftffl ft C-5 fps minutes
input input output input output output
Overland 0.0387 155 0,25 N/A 0.21 12,22
1 0.0313 145 10.00 1.77 1.37
2
3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Blocl< 1, Lynn Acres)
Catchment ID: ONSITE AREA "A" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "A"
Area = 2.03 Acres
Percent Imperviousness = %
NRCS Soil Type = DA, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
CI ='
C2="
C3='
P1 = "
10 years
10.00
"0786
1.40 inches
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
(input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.25 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.25 (enter an ovende C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Beginning
FhwDimtion
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0387 155 0.25 N/A 0.21 12.22
1 0.0313 145 10.00 1.77 1.37
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "A" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment \D =
Area = 2.03 Acres
Percent Imperviousness = %
NRCS Soil Type D"A, B, C, or D
II. Rainfall Information I (inch/hr) = 01 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
CI ='
C2="
C3="
100 years (input return period for design storm)
28.50 (inputthe value of C1)
(input the value of C2)
(input the value of C3)
10.00
"0786
P1= 2.86 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.31 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.31 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
LEGEND
O Bt^mii^
Flow Dimtion
NRCS Land
Type
Heavy
Meadov/
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Watenways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
m ft C-5 fps minutes
input input output input output output
Overland 0.0387 155 0.31 N/A 0,23 11.33
1 0.0313 145 10.00 1.77 1.37
2
3
4
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE H (Lot 3. Block 1, Lynn Acres)
Catctiment ID: ONSITE AREA "B" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "B"
Area = 0.51 Acres
Percent Imperviousness = ~ %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr = 2 years (input return period for design storm)
CI = 28.50 (input the value of CI)
C2= 10.00 (input the value of C2)
C3= 0.786 (input the value of C3)
P1= 0.82 inches (input one-hr precipitation--see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient C =
0.25 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.25 (enter an overide C-5 value if desired, or leave blank to accept calculated 0-5.^
Illustration
LEGEND
O Begtiming
Flow Direction
Catchnunt
Boimdaiy
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly j
Bare
Ground j
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
1 Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0500 115 0.25 N/A 0.20 9.68
1 0.0270 122 10.00 1.64 1.24
2
3
4
5
Sum 237 Computed Tc = 10.91
Regional Tc = 11.32
User-Entered Tc = 10.74
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "B" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "B"
Area = 0.51 Acres
Percent Imperviousness = %
NRCS Soil Type = D A, B, C, or D
II. Rainfall Information I (inch/hr) = CI * PI /(C2 + Td)*C3
Design Storm Return Pehod, Tr =
C1 ="
C2="
C3="
P1 = "
10 years
"2830
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
1.40 inches (input one-hr precipitation-see Sheet "Design Info")
10.00
"0786
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.25 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.25 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Beginning
Fbni'Direction
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0500 115 0.25 N/A 0.20 9.68
1 0.0270 122 10.00 1.64 1.24
2
3
4
5
Sum 237 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 1U.91
Regional Tc =
User-Entered Tc =
11.32
Computed Tc =
Regional Tc =
User-Entered Tc = 10.74
IV. Peak Runoff Prediction
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "B" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "B"
Area = 0.51 Acres
Percent Imperviousness = %
NRCS Soil Type = D"A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * PI /(C2 + Tdj^CS
Design Storm Return Period, Tr =
CI ="
C2='
C3='
P1 = '
100 years
"2830
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.86 inches (input one-hr precipitation-see Sheet "Design Info")
10.00
"0786
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.31 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.31 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Beginning
* Floiv Dimtion
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID s L Runoff Convey- Velocity Time
Coeff ance V Tf
ftffi ft C-5 fps minutes
input input output input output output
Overland 0,0500 115 031 N/A 021 8.96
1 0.0270 122 10 00 1.64 1.24
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITIVIAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "C" EXISTING CONDITION
Catchment Hydrologic Data
Catchment ID = "C"
Area = 0.67 Acres
Percent Imperviousness = %
NRCS Soil Type = DA, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Penod, Tr =
C1 ="
C2='
C3='
P1 = '
2 years
"2830
(input return period for design storm)
(input the value of C1)
(input the value of C2)
(input the value of C3)
0.82 inches (input one-hr precipitation-see Sheet "Design Info")
10.00
"0786
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Dveride 5-yr. Runoff Coefficient, C =
0.25 (enter an overide C value If desired, or leave blank to accept calculated C.)
0.25 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearty
Bare
Ground j
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID s L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland O0510 50 0.25 N/A 013 6.34
1 00510 200 1O00 2,26 1.48
2
3
4
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:
Catchment ID:'
WHITMAN STORAGE II (Lot 3, Blocl< 1, Lynn Acres)
ONSITE AREA "C" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID = "C"
Area =
Percent Imperviousness =
NRCS Soil Type =
0.67 Acres
%
T5"A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Penod, Tr =
01 ="
C2="
C3='
10 years (input return period for design storm)
28.50 (inputthe value of CI)
(input the value of C2)
(input the value of C3)
10.00
"0786
P1= 1.40 inches (input one-hr precipitation-see Sheet "Design Info")
111. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.25 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.25 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Beglimijig
FUw Direction
<
NRCS Land
Type
Heavy
Meadow
Tillage/
Field
Short
Pasture/
Lawns
Nearly j
Bare
Ground
Grassed
Swales/
Waterways
Paved Areas &
Shallow Paved Swales
(Sheet Flow)
Conveyance 2.5 5 7 1 10 1 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Blocl< 1, Lynn Acres)
Catchment ID: ONSITE AREA "C" EXISTING CONDITION
I. Catchment Hydrologic Data
Catchment ID =
Area = 0.67 Acres
Percent Imperviousness = %
NRCS Soil Type = D A, B, C, or D
11. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
CI ="
02="
03="
P1="
100 years
"^aso
10.00
"0786
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.86 inches (input one-hr precipitation-see Sheet "Design Info")
II. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.31 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.31 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Beglimuig
* Flow Direction
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 1 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland O0510 50 031 N/A 0,14 5.87
1 O0510 200 1O00 2.26 1.48
2
3
4
5
Sum 250 Computed Tc = /,3b
Regional Tc = 11.39
User-Entered Tc = 11,67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I = '
Rainfall Intensity at User-Defined Tc, I =
8,65 inch/hr
7.34 inch/hr
7,26 inch/hr
Peak Flowrate, Qp 1.81 cfs
PROPOSED CONDITIONS
Area-Weighting for Runoff Coefficient Calculation
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: PROPOSED CONDITION - ONSITE AREA "A"
Illustration
Instructions: For each catchment subarea, enter values for A and C.
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
Gravel 1.77 0.50 0.89
Landscape 0.26 0.20 0.05
Sum: 2.03 Sum: 0.94
Area-Weighted Runoff Coefficient (sum OA/sum A) = 0.46
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
PROP % Imprv A, Weighted C 7/6/2016, 12:10PM
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:
Catchment ID:
WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
ONSITE AREA "A" PROPOSED CONDITION - Q2
I. Catchment Hydrologic Data
Catchment ID = A'
Area =
Percent Imperviousness =
NRCS Soil Type =
2.03 Acres
%
D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 ='
C2="
C3="
P1 = "
28.50
10,00
2_years (input return period for design storm)
(input the value of C1)
(input the value of C2)
0.786 (input the value of C3)
0.82 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =_
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.46 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.46 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Bcguming
Flmv Dim-tion
•*
Catchment
Bom\dary
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Waterways (Sheet Flowj
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0700 55 0.46 N/A 0.20 4.51
1 0.0050 210 10.00 0.71 4.95
2 0.0060 325 10.00 0.77 6.99
3 0.1000 20 10.00 3.16 0.11
4
5
Sum 610 Computed Tc = 16,56
Regional Tc = 13.39
User-Entered Tc = 13.39
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 1.78 inch/hr
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: _
Catchment ID:
WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
ONSITE AREA "A" PROPOSED CONDITION - Q10
I. Catchment Hydrologic Data
Catchment ID = A'
Area =
Percent Impen/iousness =
NRCS Soil Type =
2.03 Acres
%
D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 ='
C2='
C3='
P1 = "
28.50
10.00
10^years (input return period for design storm)
(input the value of C1)
(input the value of C2)
0.786 (input the value of C3)
1.40 inches (input one-hr precipitation-see Sheet "Design Info")
II. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.46 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.46 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
LEGEND
O Bfguming
Fhw Direction
Catchjneni
Boundary
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)^
Conveyance Z5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0700 55 0.46 N/A 0.20 4.51
1 0.0050 210 10.00 0.71 4,95
2 0.0060 325 10.00 0.77 6.99
3 0.1000 20 10.00 3.16 0.11
4
5
Sum 610 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 16.56
Regional Tc =
User-Entered Tc =
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:
Catchment ID:
I. Catchment Hydrologic Data
Catchment ID = A'
WHITMAN STORAGE II (Lot 3, Blocl< 1, Lynn Acres)
ONSITE AREA "A" PROPOSED CONDITION - Q100
Area = _
Percent Imperviousness =
NRCS Soil Type="
2.03 Acres
D A, B, C, or D
II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Tdj^CS
Design Storm Return Period, Tr = 100 years
CI =
02=
C3=
P1 =
28.50
10.00
0.786
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.86 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.58 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.58 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
LEGEND
Floiv Direction
Catchment
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Watenways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0700 55 0.58 N/A 0.25 3.70
1 0.0050 210 10.00 0.71 4.95
2 0.0060 325 10.00 0.77 6.99
3 0.1000 20 10.00 3.16 0.11
4
5
Sum 610 Computed Tc = 15.75
Regional Tc = 13.39
User-Entered Tc = 13.39
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 6.34 inch/hr
Rainfall Intensity at Regional Tc, I = 6.84 inch/hr
Rainfall Intensity at User-Defined Tc, I = 6.84 inch/hr
Peak Flov^rate, Qp = 7.40 cfs
Area-Weighting for Runoff Coefficient Calculation
Project Title: WHITMAN STORAGE 11 (Lot 3, Block 1, Lynn Acres)
Catchment ID: PROPOSED CONDITION - ONSITE AREA "B"
Illustration
Instructions: For eacti catchment subarea, enter values for A and C,
Subarea Area Runoff Product
ID acres Coeff.
A C* CA
input input input output
Gravel 0.43 0.50 0.22
Landscape 0.08 0.25 0.02
Sum: 0.51 Sum: 0.24
Area-Weighted Runoff Coefficient (sum CA/sum A) = 0.46
*See sheet "Design Info" for inperviousness-based runoff coefficient values.
PROP % Imprv B, Weighted C 7/14/2016, 3:08 PM
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Blocl< 1, Lynn Acres)
Catchment ID: ONSITE AREA "B" PROPOSED CONDITION
I. Catchment Hydrologic Data
Catchment ID = B'
Area = 0.51 Acres
Percent Imperviousness = %
NRCS Soil Type = D_ A, B, C, or D
IL Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
CI =•
C2="
03="
P1 = "
28.50
10,00
2_years (input return period for design storm)
(input the value of CI)
(input the value of C2)
0.786 (input the value of C3)
0.82 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C = _
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.46 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.46 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type (Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0500 115 0.46 N/A 0.26 7.29
1 0.0270 122 10.00 1.64 1.24
2
3
4
5
Sum 237 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 8.52
Regional Tc =
User-Entered Tc =
11.32
Computed Tc =
Regional Tc =
User-Entered Tc = 11.19
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 2.36 inch/hr
Rainfall Intensity at Regional Tc, I = 2.11 inch/hr
Rainfall Intensity at User-Defined Tc, I = 2,12 inch/hr
Peak Flowrate, Qp = 0.55 cfs
Peak Flowrate, Qp = 0.49 cfs
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:
Catchment ID:
WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
ONSITE AREA "B" PROPOSED CONDITION
I. Catchment Hydrologic Data
Catchment ID = B'
Area =
Percent Imperviousness =
NRCS Soil Type =
0.51 Acres
%
D A, B, C, or D
II. Rainfall Information I (inch/hr) = CI * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr =
C1 ="
C2="
C3="
P1 = '
28.50
10.00
1CI_years (input return period for design storm)
(input the value of CI)
(input the value of C2)
0.786 (input the value of C3)
1.40 inches (input one-hr precipitation-see Sheet "Design Info")
III. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =_
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.46 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.46 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.;
Illustration
LEGEND
Floiv Direction
Catchment
Boundary
NRCS Land Heavy Tillage/ Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Watenways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0500 115 0.46 N/A 0.26 7.29
1 0.0270 122 10.00 1.64 1.24
2
3
4
5
Sum 237 Computed Tc = 8.52
Regional Tc = 11.32
User-Entered Tc = 11.19
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 4.02 inch/hr
Rainfall Intensity at Regional Tc, I = 3.60 inch/hr
Rainfall Intensity at User-Defined Tc, I = 3.62 inch/hr
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title: WHITMAN STORAGE II (Lot 3, Block 1, Lynn Acres)
Catchment ID: ONSITE AREA "B" PROPOSED CONDITION
I. Catchment Hydrologic Data
Catchment ID =_B]
Area = 0.51 Acres
Percent Imperviousness = %
NRCS Soil Type = D_ A, B, C, or D
II. Rainfall Information I (inch/hr) = 01 * P1 /(C2 + Td)*C3
Design Storm Return Period, Tr = 100 years
CI =
C2=
C3=
P1 =
28.50
(input return period for design storm)
(input the value of CI)
(input the value of C2)
(input the value of C3)
2.86 inches (input one-hr precipitation-see Sheet "Design Info")
10.00
0.785
in. Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =
Overide Runoff Coefficient, C =
5-yr. Runoff Coefficient, C-5 =
Overide 5-yr. Runoff Coefficient, C =
0.58 (enter an overide C value if desired, or leave blank to accept calculated C.)
0.46 (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/ Short Neariy Grassed Paved Areas &
Type Meadow Field Pasture/ Bare Swales/ Shallow Paved Swales
Lawns Ground Watenways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations: Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey- Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0500 115 0.46 N/A 0.26 7.29
1 0.0270 122 10.00 1.64 1.24
2
3
4
5
Sum 237 Computed Tc = 8.52
Regional Tc = 11.32
User-Entered Tc = 11.19
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 8.22 inch/hr
Rainfall Intensity at Regional Tc, I = 7.36 inch/hr
Rainfall Intensity at User-Defined Tc, I = 7.39 inch/hr
Peak Flov/rate, Qp = 2.41 cfs
Peak Flowrate, Qp = 2.16 cfs
Peak Flowrate, Qp - 2.17 cfs
PROP 'B'QIOO, Tc and PeakQ 7/14/2016, 3:07 PM
DETENTION
ONSITE AREA “A”
Whitman Basin A
Equations: A trib. To pond = 2.03 acre
QD = CiA C100 = 0.46
Vi = T*CiA = T*QD Developed C*A = 0.93 acre
Vo =m*QPO*(60*T) QPO = 1.06 cfs
S = Vi - Vo tc = 5 min
Rainfall intensity from Larimer County Area 1 IDF Curve
Storm Rainfall QD Vol. In Outflow Vol. Out Storage Storage
Duration, T Intensity, i (cfs) Vi Adjustment Vo S S
(min) (in/hr) (ft3) Factor, m (ft3) (ft3) (ac-ft)
5 9.95 9.3 2787 1.00 318 2469 0.057
10 7.72 7.2 4325 0.75 477 3848 0.088
20 5.60 5.2 6275 0.63 795 5480 0.126
30 4.52 4.2 7597 0.58 1113 6484 0.149
40 3.74 3.5 8382 0.56 1431 6951 0.160
50 3.23 3.0 9049 0.55 1749 7300 0.168
60 2.86 2.7 9614 0.54 2067 7547 0.173
70 2.62 2.4 10276 0.54 2385 7891 0.181
80 2.38 2.2 10668 0.53 2703 7965 0.183
90 2.22 2.1 11194 0.53 3021 8173 0.188
100 2.05 1.9 11486 0.53 3339 8147 0.187
110 1.93 1.8 11895 0.52 3657 8238 0.189
120 1.80 1.7 12102 0.52 3975 8127 0.187
130 1.60 1.5 11654 0.52 4293 7361 0.169
140 1.40 1.3 10981 0.52 4611 6370 0.146
150 1.20 1.1 10085 0.52 4929 5156 0.118
160 1.15 1.1 10309 0.52 5247 5062 0.116
170 1.10 1.0 10477 0.51 5565 4912 0.113
180 1.05 1.0 10589 0.51 5883 4706 0.108
Required Storage Volume: 8238 ft3
0.189 acre-ft
Project:
Basin ID:
Design Information (Input):
Width of Basin Bottom, W = ft Right Triangle OR…
Length of Basin Bottom, L = ft Isosceles Triangle OR…
Dam Side-slope (H:V), Zd = ft/ft Rectangle OR…
Circle / Ellipse OR…
Irregular (Use Overide values in cells G32:G52)
MINOR MAJOR
Storage Requirement from Sheet 'Modified FAA': 0.00 0.24 acre-ft.
Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft.
Storage Requirement from Sheet 'Full-Spectrum': acre-ft.
Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes
for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor,
& Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage
Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes
(input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek)
4964.00 (input) 0 0.000 0.000
4964.25 0.00 0.00 15 2 0.000 0.000
OUTLET 4964.50 0.00 0.00 35 8 0.001 0.000
4964.75 0.00 0.00 919 127 0.021 0.003
4965.00 0.00 0.00 4,162 763 0.096 0.018
4965.25 0.00 0.00 4,532 1,849 0.104 0.042
WQCV 4965.50 0.00 0.00 4,905 3,029 0.113 0.070 0.073 ac-ft
4965.75 0.00 0.00 5,281 4,302 0.121 0.099
4966.00 0.00 0.00 5,662 5,670 0.130 0.130
4966.25 0.00 0.00 6,656 7,210 0.153 0.166
4966.50 0.00 0.00 7,681 9,002 0.176 0.207
WQCV+VOL100 4966.75 0.00 0.00 8,212 10,989 0.189 0.252 0.262 ac-ft
4967.00 0.00 0.00 9,190 13,164 0.211 0.302
4967.25 0.00 0.00 11,320 15,728 0.260 0.361
4967.50 0.00 0.00 13,450 18,824 0.309 0.432
TOP OF BERM 4967.75 0.00 0.00 15,580 22,453 0.358 0.515
4968.00 0.00 0.00 17,710 26,614 0.407 0.611
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Project:
Basin ID:
STAGE-STORAGE SIZING FOR DETENTION BASINS
4964.00
4964.50
4965.00
4965.50
4966.00
4966.50
4967.00
4967.50
4968.00
4968.50
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70
Stage (ft. elev.)
Storage (acre-feet)
STAGE-STORAGE CURVE FOR THE POND
VOID DETENTION A VOID, Basin 8/11/2016, 4:43 PM
Project:
Basin ID:
WQCV Design Volume (Input):
Catchment Imperviousness, Ia = 66.0 percent
Catchment Area, A = 2.03 acres Diameter of holes, D = 0.420 inches
Depth at WQCV outlet above lowest perforation, H = 1 feet Number of holes per row, N = 1
Vertical distance between rows, h = 4.00 inches OR
Number of rows, NL = 3.00
Orifice discharge coefficient, Co = 0.60 Height of slot, H = inches
Slope of Basin Trickle Channel, S = 0.005 ft / ft Width of slot, W = inches
Time to Drain the Pond = 72 hours
Watershed Design Information (Input): 1
Percent Soil Type A = 0 %
Percent Soil Type B = 0 %
Percent Soil Type C/D = 100 %
Outlet Design Information (Output):
Water Quality Capture Volume, WQCV = 0.360 watershed inches
Water Quality Capture Volume (WQCV) = 0.061 acre-feet 0.00
Design Volume (WQCV / 12 * Area * 1.2) Vol = 0.073 acre-feet
Outlet area per row, Ao = 0.14 square inches
Total opening area at each row based on user-input above, Ao = 0.14 square inches
Total opening area at each row based on user-input above, Ao = 0.001 square feet
3
Row 1 Row 2 Row 3 Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 Row 19 Row 20 Row 21 Row 22 Row 23 Row 23 S
4964.50 4964.83 4965.17 Flow
4964.00 0.0000 0.0000 0.0000 0.00
4964.25 0.0000 0.0000 0.0000 0.00
4964.50 0.0000 0.0000 0.0000 0.00
4964.75 0.0023 0.0000 0.0000 0.00
4965.00 0.0033 0.0019 0.0000 0.01
4965.25 0.0040 0.0030 0.0013 0.01
4965.50 0.0046 0.0038 0.0027 0.01
4965.75 0.0052 0.0044 0.0035 0.01
4966.00 0.0057 0.0050 0.0042 0.01
4966.25 0.0061 0.0055 0.0048 0.02
4966.50 0.0065 0.0060 0.0053 0.02
4966.75 0.0069 0.0064 0.0058 0.02
4967.00 0.0073 0.0068 0.0063 0.02
4967.25 0.0077 0.0072 0.0067 0.02
4967.50 0.0080 0.0076 0.0071 0.02
4967.75 0.0083 0.0079 0.0074 0.02
4968.00 0.0086 0.0082 0.0078 0.02
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Project:
Basin ID:
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
WHITMAN STORAGE II
BASIN 'A'
4963.50
4964.00
4964.50
4965.00
4965.50
4966.00
4966.50
4967.00
4967.50
4968.00
4968.50
0.00 0.01 0.01 0.02 0.02 0.03 0.03
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE
VOID DETENTION A VOID, WQCV 8/11/2016, 4:40 PM
Project:
Basin ID:
X
1
Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input)
Water Surface Elevation at Design Depth Elev: WS =
Pipe/Vertical Orifice Entrance Invert Elevation Elev: Invert =
Required Peak Flow through Orifice at Design Depth Q =
Pipe/Vertical Orifice Diameter (inches) Dia =
Orifice Coefficient Co =
Full-flow Capacity (Calculated)
Full-flow area Af =
Half Central Angle in Radians Theta =
Full-flow capacity Qf =
Percent of Design Flow =
Calculation of Orifice Flow Condition
Half Central Angle (0<Theta<3.1416) Theta =
Flow area Ao =
Top width of Orifice (inches) To =
Height from Invert of Orifice to Bottom of Plate (feet) Yo =
Elevation of Bottom of Plate Elev Plate Bottom Edge =
Resultant Peak Flow Through Orifice at Design Depth Qo =
Width of Equivalent Rectangular Vertical Orifice Equivalent Width =
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE AREA "A"
RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFIC
VOID DETENTION A VOID, Restrictor Plate 8/11/2016, 3:57 PM
#1 Vertical #2 Vertical
Orifice Orifice
4,966.75 feet
4,964.50 feet
1.06 cfs
8.0 inches
0.60
0.35 sq ft
3.14 rad
2.3 cfs
220%
1.47 rad
0.15 sq ft
7.96 inches
0.30 feet
4,964.80 feet
1.1 cfs
0.50 feet
FOR CIRCULAR VERTICAL ORIFICES
VOID DETENTION A VOID, Restrictor Plate 8/11/2016, 3:57 PM
Project:
Basin ID:
Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert.
Circular Opening: Diameter in Inches Dia. = 8.00 inches
OR
Rectangular Opening: Width in Feet W = ft.
Length (Height for Vertical) L or H = ft.
Percentage of Open Area After Trash Rack Reduction % open = 100 %
Orifice Coefficient Co = 0.60
Weir Coefficient Cw =
Orifice Elevation (Bottom for Vertical) Eo = 4,964.50 ft.
Calculation of Collection Capacity:
Net Opening Area (after Trash Rack Reduction) Ao = 0.35 sq. ft.
OPTIONAL: User-Overide Net Opening Area Ao = sq. ft.
Perimeter as Weir Length Lw = ft.
OPTIONAL: User-Overide Weir Length Lw = ft.
Top Elevation of Vertical Orifice Opening, Top = 4965.17 ft.
Center Elevation of Vertical Orifice Opening, Cen = 4964.83 ft.
Horizontal Orifices Vertical Orifices
Labels Water WQCV #1 Horiz. #1 Horiz. #2 Horiz. #2 Horiz. #1 Vert. #2 Vert. Total Target Volumes
for WQCV, Minor, Surface Plate/Riser Weir Orifice Weir Orifice Collection Collection Collection for WQCV, Minor,
& Major Storage Elevation Flow Flow Flow Flow Flow Capacity Capacity Capacity & Major Storage
W.S. Elevations ft cfs cfs cfs cfs cfs cfs cfs cfs Volumes
(input) (linked) (User-linked) (output) (output) (output) (output) (output) (output) (output) (link for goal seek)
OUTLET 4964.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4964.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4964.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4964.75 0.00 0.00 0.00 0.00 0.00 0.22 0.00 0.23
WQCV 4965.00 0.01 0.00 0.00 0.00 0.00 0.63 0.00 0.64
4965.25 0.01 0.00 0.00 0.00 0.00 1.08 0.00 1.09
4965.50 0.01 0.00 0.00 0.00 0.00 1.37 0.00 1.38
4965.75 0.01 0.00 0.00 0.00 0.00 1.61 0.00 1.62
4966.00 0.01 0.00 0.00 0.00 0.00 1.82 0.00 1.83
4966.25 0.02 0.00 0.00 0.00 0.00 2.00 0.00 2.02
4966.50 0.02 0.00 0.00 0.00 0.00 2.17 0.00 2.19
VOL100+WQCV 4966.75 0.02 0.00 0.00 0.00 0.00 2.33 0.00 2.35
4967.00 0.02 0.00 0.00 0.00 0.00 2.47 0.00 2.49
4967.25 0.02 0.00 0.00 0.00 0.00 2.61 0.00 2.63
4967.50 0.02 0.00 0.00 0.00 0.00 2.74 0.00 2.77
4967.75 0.02 0.00 0.00 0.00 0.00 2.87 0.00 2.89
4968.00 0.02 0.00 0.00 0.00 0.00 2.99 0.00 3.02
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Project:
Basin ID:
Status: Sheet Contains Warnings. See Culvert_ErrorList Range
Design Information (Input):
Circular Culvert: Barrel Diameter in Inches D = 8 in.
Circular Culvert: Inlet Edge Type (choose from pull-down list) Grooved End with Headwall
OR:
Box Culvert: Barrel Height (Rise) in Feet Height (Rise) = ft.
Box Culvert: Barrel Width (Span) in Feet Width (Span) = ft.
Box Culvert: Inlet Edge Type (choose from pull-down list) Square Edge w/ 90-15 deg. Flared Wingwall
Number of Barrels No = 1
Inlet Elevation at Culvert Invert Ielev = 4964.50 ft. elev.
Outlet Elevation at Culvert Invert Oelev = 4964.40 ft. elev.
Culvert Length in Feet L = 20.0 ft.
Manning's Roughness n = 0.0130
Bend Loss Coefficient Kb = 0.00
Exit Loss Coefficient Kx = 1.00
Design Information (calculated):
Entrance Loss Coefficient Ke = 0.20
Friction Loss Coefficient Kf = 1.07
Sum of All Loss Coefficients Ks = 2.27
Orifice Inlet Condition Coefficient Cd = 1.02
Minimum Energy Condition Coefficient KElow = -0.16
Calculations of Culvert Capacity (output):
Water Surface Tailwater Culvert Culvert Flowrate Controlling Inlet
Elevation Surface Inlet-Control Outlet-Control Into Culvert Culvert Equation
From Sheet Elevation Flowrate Flowrate From Sheet Flowrate Used
"Basin" ft cfs cfs "Outlet" cfs
(ft., linked) (input if known) (output) (output) (cfs, linked) (output) (output)
4964.00 0.00 0.00 0.00 0.00 0.00 No Flow (WS < inlet)
4964.25 0.00 0.00 0.00 0.00 0.00 No Flow (WS < inlet)
4964.50 0.00 0.00 0.00 0.00 0.00 No Flow (WS < inlet)
4964.75 0.00 0.20 0.43 0.23 0.20 Min. Energy. Eqn.
4965.00 0.00 0.60 0.56 0.64 0.56 Regression Eqn.
4965.25 0.00 1.10 0.68 1.09 0.68 Regression Eqn.
4965.50 0.00 1.50 1.03 1.38 1.03 Regression Eqn.
4965.75 0.00 1.80 1.28 1.62 1.28 Regression Eqn.
4966.00 0.00 2.10 1.54 1.83 1.54 Regression Eqn.
4966.25 0.00 2.30 1.71 2.02 1.71 Regression Eqn.
4966.50 0.00 2.60 1.88 2.19 1.88 Regression Eqn.
4966.75 0.00 2.80 2.05 2.35 2.05 Orifice Eqn.
4967.00 0.00 3.00 2.18 2.49 2.18 Orifice Eqn.
4967.25 0.00 3.20 2.31 2.63 2.31 Orifice Eqn.
4967.50 0.00 3.30 2.44 2.77 2.44 Orifice Eqn.
4967.75 0.00 3.50 2.56 2.89 2.56 Orifice Eqn.
4968.00 0.00 3.60 2.69 3.02 2.69 Orifice Eqn.
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
Project:
Basin ID:
Design Information (input):
Bottom Length of Weir L = 2.50 feet
Angle of Side Slope Weir Angle = 62.70 degrees
Elev. for Weir Crest EL. Crest = 4,966.75 feet
Coef. for Rectangular Weir Cw = 3.33
Coef. for Trapezoidal Weir Ct =
Calculation of Spillway Capacity (output):
Water Rect. Triangle Total Total
Surface Weir Weir Spillway Pond
Elevation Flowrate Flowrate Release Release
ft. cfs cfs cfs cfs
(linked) (output) (output) (output) (output)
4964.00 0.00 0.00 0.00 0.00
4964.25 0.00 0.00 0.00 0.00
4964.50 0.00 0.00 0.00 0.00
4964.75 0.00 0.00 0.00 0.20
4965.00 0.00 0.00 0.00 0.56
4965.25 0.00 0.00 0.00 0.68
4965.50 0.00 0.00 0.00 1.03
4965.75 0.00 0.00 0.00 1.28
4966.00 0.00 0.00 0.00 1.54
4966.25 0.00 0.00 0.00 1.71
4966.50 0.00 0.00 0.00 1.88
4966.75 0.00 0.00 0.00 2.05
4967.00 1.04 0.00 1.04 3.22
4967.25 2.94 0.00 2.94 5.25
4967.50 5.41 0.00 5.41 7.84
4967.75 8.33 0.00 8.33 10.89
4968.00 11.63 0.00 11.63 14.33
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STAGE-DISCHARGE SIZING OF THE SPILLWAY
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE AREA “B”
Whitman Basin B
Equations: A trib. To pond = 0.51 acre
QD = CiA C100 = 0.46
Vi = T*CiA = T*QD Developed C*A = 0.23 acre
Vo =m*QPO*(60*T) QPO = 0.27 cfs
S = Vi - Vo tc = 5 min
Rainfall intensity from Larimer County Area 1 IDF Curve
Storm Rainfall QD Vol. In Outflow Vol. Out Storage Storage
Duration, T Intensity, i (cfs) Vi Adjustment Vo S S
(min) (in/hr) (ft3) Factor, m (ft3) (ft3) (ac-ft)
5 9.95 2.3 700 1.00 81 619 0.014
10 7.72 1.8 1087 0.75 122 965 0.022
20 5.60 1.3 1577 0.63 203 1374 0.032
30 4.52 1.1 1909 0.58 284 1625 0.037
40 3.74 0.9 2106 0.56 365 1741 0.040
50 3.23 0.8 2273 0.55 446 1828 0.042
60 2.86 0.7 2415 0.54 527 1889 0.043
70 2.62 0.6 2582 0.54 608 1974 0.045
80 2.38 0.6 2680 0.53 689 1992 0.046
90 2.22 0.5 2812 0.53 770 2043 0.047
100 2.05 0.5 2886 0.53 851 2035 0.047
110 1.93 0.5 2988 0.52 932 2057 0.047
120 1.80 0.4 3040 0.52 1013 2028 0.047
130 1.60 0.4 2928 0.52 1094 1834 0.042
140 1.40 0.3 2759 0.52 1175 1584 0.036
150 1.20 0.3 2534 0.52 1256 1278 0.029
160 1.15 0.3 2590 0.52 1337 1253 0.029
170 1.10 0.3 2632 0.51 1418 1215 0.028
180 1.05 0.2 2660 0.51 1499 1162 0.027
Required Storage Volume: 2057 ft3
0.047 acre-ft
Project:
Basin ID:
Design Information (Input):
Width of Basin Bottom, W = 65.00 ft Right Triangle X OR…
Length of Basin Bottom, L = 60.00 ft Isosceles Triangle OR…
Dam Side-slope (H:V), Zd = 0.33 ft/ft Rectangle OR…
Circle / Ellipse OR…
Irregular (Use Overide values in cells G32:G52)
MINOR MAJOR
Storage Requirement from Sheet 'Modified FAA': 0.00 0.06 acre-ft.
Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft.
Storage Requirement from Sheet 'Full-Spectrum': acre-ft.
Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes
for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor,
& Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage
Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes
(input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek)
BOTTOM 4963.50 (input) 65.00 60.00 1,950.0 0.045 0.000 BOTTOM
4963.60 65.04 60.03 1,952.2 195 0.045 0.004
4963.70 65.07 60.07 1,954.3 390 0.045 0.009
WQCV 4963.80 65.11 60.10 1,956.5 586 0.045 0.013 0.010 ac-ft
4963.90 65.14 60.13 1,958.7 782 0.045 0.018
4964.00 65.18 60.17 1,960.8 978 0.045 0.022
4964.10 65.22 60.20 1,963.0 1,174 0.045 0.027
4964.20 65.25 60.23 1,965.2 1,370 0.045 0.031
4964.30 65.29 60.27 1,967.4 1,567 0.045 0.036
4964.40 65.32 60.30 1,969.5 1,764 0.045 0.040
4964.50 65.36 60.33 1,971.7 1,961 0.045 0.045
4964.60 65.40 60.37 1,973.9 2,158 0.045 0.050
4964.70 65.43 60.40 1,976.1 2,356 0.045 0.054
VOL100+WQCV 4964.80 65.47 60.43 1,978.2 2,553 0.045 0.059 0.059 ac-ft
4964.90 65.51 60.47 1,980.4 2,751 0.045 0.063
4965.00 65.54 60.50 1,982.6 2,949 0.046 0.068
4965.10 65.58 60.53 1,984.8 3,148 0.046 0.072
4965.20 65.61 60.57 1,987.0 3,346 0.046 0.077
4965.30 65.65 60.60 1,989.2 3,545 0.046 0.081
4965.40 65.69 60.63 1,991.3 3,744 0.046 0.086
4965.50 65.72 60.67 1,993.5 3,943 0.046 0.091
4965.60 65.76 60.70 1,995.7 4,143 0.046 0.095
4965.70 65.79 60.73 1,997.9 4,343 0.046 0.100
TOP OF BERM 4965.80 65.83 60.77 2,000.1 4,542 0.046 0.104 TOP OF BBERM
4965.90 65.87 60.80 2,002.3 4,743 0.046 0.109
4966.00 65.90 60.83 2,004.5 4,943 0.046 0.113
4966.10 65.94 60.87 2,006.7 5,144 0.046 0.118
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Project:
Basin ID:
STAGE-STORAGE SIZING FOR DETENTION BASINS
4963.50
4964.00
4964.50
4965.00
4965.50
4966.00
4966.50
0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14
Stage (ft. elev.)
Storage (acre-feet)
STAGE-STORAGE CURVE FOR THE POND
DET B 8-10-16, Basin 8/11/2016, 3:29 PM
Project:
Basin ID:
WQCV Design Volume (Input):
Catchment Imperviousness, Ia = 36.0 percent
Catchment Area, A = 0.51 acres Diameter of holes, D = 0.230 inches
Depth at WQCV outlet above lowest perforation, H = 1 feet Number of holes per row, N = 1
Vertical distance between rows, h = 4.00 inches OR
Number of rows, NL = 3.00
Orifice discharge coefficient, Co = 0.60 Height of slot, H = inches
Slope of Basin Trickle Channel, S = 0.005 ft / ft Width of slot, W = inches
Time to Drain the Pond = 72 hours
Watershed Design Information (Input): 1
Percent Soil Type A = 0 %
Percent Soil Type B = 0 %
Percent Soil Type C/D = 100 %
Outlet Design Information (Output):
Water Quality Capture Volume, WQCV = 0.240 watershed inches
Water Quality Capture Volume (WQCV) = 0.010 acre-feet 0.00
Design Volume (WQCV / 12 * Area * 1.2) Vol = 0.012 acre-feet
Outlet area per row, Ao = 0.03 square inches
Total opening area at each row based on user-input above, Ao = 0.04 square inches
Total opening area at each row based on user-input above, Ao = 0.000 square feet
3
Row 1 Row 2 Row 3 Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 Row 19 Row 20 Row 21 Row 22 Row 23 Row 23 S
4963.50 4963.83 4964.17 Flow
4963.50 0.0000 0.0000 0.0000 0.00
4963.60 0.0004 0.0000 0.0000 0.00
4963.70 0.0006 0.0000 0.0000 0.00
4963.80 0.0008 0.0000 0.0000 0.00
4963.90 0.0009 0.0004 0.0000 0.00
4964.00 0.0010 0.0006 0.0000 0.00
4964.10 0.0011 0.0007 0.0000 0.00
4964.20 0.0012 0.0008 0.0002 0.00
4964.30 0.0012 0.0009 0.0005 0.00
4964.40 0.0013 0.0010 0.0007 0.00
4964.50 0.0014 0.0011 0.0008 0.00
4964.60 0.0015 0.0012 0.0009 0.00
4964.70 0.0015 0.0013 0.0010 0.00
4964.80 0.0016 0.0014 0.0011 0.00
4964.90 0.0016 0.0014 0.0012 0.00
4965.00 0.0017 0.0015 0.0013 0.00
4965.10 0.0018 0.0016 0.0013 0.00
4965.20 0.0018 0.0016 0.0014 0.00
4965.30 0.0019 0.0017 0.0015 0.01
4965.40 0.0019 0.0017 0.0015 0.01
4965.50 0.0020 0.0018 0.0016 0.01
4965.60 0.0020 0.0018 0.0017 0.01
4965.70 0.0021 0.0019 0.0017 0.01
4965.80 0.0021 0.0019 0.0018 0.01
4965.90 0.0021 0.0020 0.0018 0.01
4966.00 0.0022 0.0020 0.0019 0.01
4966.10 0.0022 0.0021 0.0019 0.01
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Worksheet Protected
Project:
Basin ID:
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
WHITMAN STORAGE II
BASIN 'B'
4963.00
4963.50
4964.00
4964.50
4965.00
4965.50
4966.00
4966.50
0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01
Stage (feet, elev.)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE
DET B 8-10-16, WQCV 8/11/2016, 3:32 PM
Project:
Basin ID:
X
1
Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input)
Water Surface Elevation at Design Depth Elev: WS =
Pipe/Vertical Orifice Entrance Invert Elevation Elev: Invert =
Required Peak Flow through Orifice at Design Depth Q =
Pipe/Vertical Orifice Diameter (inches) Dia =
Orifice Coefficient Co =
Full-flow Capacity (Calculated)
Full-flow area Af =
Half Central Angle in Radians Theta =
Full-flow capacity Qf =
Percent of Design Flow =
Calculation of Orifice Flow Condition
Half Central Angle (0<Theta<3.1416) Theta =
Flow area Ao =
Top width of Orifice (inches) To =
Height from Invert of Orifice to Bottom of Plate (feet) Yo =
Elevation of Bottom of Plate Elev Plate Bottom Edge =
Resultant Peak Flow Through Orifice at Design Depth Qo =
Width of Equivalent Rectangular Vertical Orifice Equivalent Width =
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE AREA "B"
RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFIC
DET B 8-10-16, Restrictor Plate 8/11/2016, 3:33 PM
#1 Vertical #2 Vertical
Orifice Orifice
4,964.80 feet
4,963.50 feet
0.27 cfs
8.0 inches
0.60
0.35 sq ft
3.14 rad
1.9 cfs
700%
0.90 rad
0.05 sq ft
6.25 inches
0.13 feet
4,963.63 feet
0.3 cfs
0.38 feet
FOR CIRCULAR VERTICAL ORIFICES
DET B 8-10-16, Restrictor Plate 8/11/2016, 3:33 PM
Project:
Basin ID:
Design Information (Input): #1 Horiz. #2 Horiz. #1 Vert. #2 Vert.
Circular Opening: Diameter in Inches Dia. = 8.00 inches
OR
Rectangular Opening: Width in Feet W = ft.
Length (Height for Vertical) L or H = ft.
Percentage of Open Area After Trash Rack Reduction % open = 100 %
Orifice Coefficient Co = 0.60
Weir Coefficient Cw =
Orifice Elevation (Bottom for Vertical) Eo = 4,963.50 ft.
Calculation of Collection Capacity:
Net Opening Area (after Trash Rack Reduction) Ao = 0.35 sq. ft.
OPTIONAL: User-Overide Net Opening Area Ao = 0.05 sq. ft.
Perimeter as Weir Length Lw = ft.
OPTIONAL: User-Overide Weir Length Lw = ft.
Top Elevation of Vertical Orifice Opening, Top = 4964.17 ft.
Center Elevation of Vertical Orifice Opening, Cen = 4963.83 ft.
Horizontal Orifices Vertical Orifices
Labels Water WQCV #1 Horiz. #1 Horiz. #2 Horiz. #2 Horiz. #1 Vert. #2 Vert. Total Target Volumes
for WQCV, Minor, Surface Plate/Riser Weir Orifice Weir Orifice Collection Collection Collection for WQCV, Minor,
& Major Storage Elevation Flow Flow Flow Flow Flow Capacity Capacity Capacity & Major Storage
W.S. Elevations ft cfs cfs cfs cfs cfs cfs cfs cfs Volumes
(input) (linked) (User-linked) (output) (output) (output) (output) (output) (output) (output) (link for goal seek)
4963.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4963.60 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01
4963.70 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.02
4963.80 0.00 0.00 0.00 0.00 0.00 0.04 0.00 0.04
4963.90 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.07
4964.00 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.09
4964.10 0.00 0.00 0.00 0.00 0.00 0.12 0.00 0.12
4964.20 0.00 0.00 0.00 0.00 0.00 0.15 0.00 0.15
4964.30 0.00 0.00 0.00 0.00 0.00 0.16 0.00 0.17
4964.40 0.00 0.00 0.00 0.00 0.00 0.18 0.00 0.18
4964.50 0.00 0.00 0.00 0.00 0.00 0.20 0.00 0.20
4964.60 0.00 0.00 0.00 0.00 0.00 0.21 0.00 0.21
4964.70 0.00 0.00 0.00 0.00 0.00 0.22 0.00 0.23
4964.80 0.00 0.00 0.00 0.00 0.00 0.24 0.00 0.24 VOL 100+WQCV
4964.90 0.00 0.00 0.00 0.00 0.00 0.25 0.00 0.25
4965.00 0.00 0.00 0.00 0.00 0.00 0.26 0.00 0.26
4965.10 0.00 0.00 0.00 0.00 0.00 0.27 0.00 0.28
4965.20 0.00 0.00 0.00 0.00 0.00 0.28 0.00 0.29
4965.30 0.01 0.00 0.00 0.00 0.00 0.29 0.00 0.30
4965.40 0.01 0.00 0.00 0.00 0.00 0.30 0.00 0.31
4965.50 0.01 0.00 0.00 0.00 0.00 0.31 0.00 0.32
4965.60 0.01 0.00 0.00 0.00 0.00 0.32 0.00 0.33
4965.70 0.01 0.00 0.00 0.00 0.00 0.33 0.00 0.33
4965.80 0.01 0.00 0.00 0.00 0.00 0.34 0.00 0.34 TOP OF BERM
4965.90 0.01 0.00 0.00 0.00 0.00 0.35 0.00 0.35
4966.00 0.01 0.00 0.00 0.00 0.00 0.35 0.00 0.36
4966.10 0.01 0.00 0.00 0.00 0.00 0.36 0.00 0.37
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
Project:
Basin ID:
Status: Sheet Contains Warnings. See Culvert_ErrorList Range
Design Information (Input):
Circular Culvert: Barrel Diameter in Inches D = 8 in.
Circular Culvert: Inlet Edge Type (choose from pull-down list) Grooved End with Headwall
OR:
Box Culvert: Barrel Height (Rise) in Feet Height (Rise) = ft.
Box Culvert: Barrel Width (Span) in Feet Width (Span) = ft.
Box Culvert: Inlet Edge Type (choose from pull-down list) Square Edge w/ 90-15 deg. Flared Wingwall
Number of Barrels No = 1
Inlet Elevation at Culvert Invert Ielev = 4963.50 ft. elev.
Outlet Elevation at Culvert Invert Oelev = 4963.30 ft. elev.
Culvert Length in Feet L = 20.0 ft.
Manning's Roughness n = 0.0130
Bend Loss Coefficient Kb = 0.00
Exit Loss Coefficient Kx = 0.50
Design Information (calculated):
Entrance Loss Coefficient Ke = 0.20
Friction Loss Coefficient Kf = 1.07
Sum of All Loss Coefficients Ks = 1.77
Orifice Inlet Condition Coefficient Cd = 1.02
Minimum Energy Condition Coefficient KElow = -0.16
Calculations of Culvert Capacity (output):
Water Surface Tailwater Culvert Culvert Flowrate Controlling Inlet
Elevation Surface Inlet-Control Outlet-Control Into Culvert Culvert Equation
From Sheet Elevation Flowrate Flowrate From Sheet Flowrate Used
"Basin" ft cfs cfs "Outlet" cfs
(ft., linked) (input if known) (output) (output) (cfs, linked) (output) (output)
4963.50 0.00 0.00 0.00 0.00 0.00 No Flow (WS < inlet)
4963.60 0.00 0.10 0.54 0.00 0.00 Min. Energy. Eqn.
4963.70 0.00 0.20 0.54 0.00 0.00 Min. Energy. Eqn.
4963.80 0.00 0.30 0.54 0.00 0.00 Min. Energy. Eqn.
4963.90 0.00 0.40 0.60 0.00 0.00 Regression Eqn.
4964.00 0.00 0.60 0.66 0.00 0.00 Regression Eqn.
4964.10 0.00 0.80 0.73 0.00 0.00 Regression Eqn.
4964.20 0.00 1.00 0.85 0.00 0.00 Regression Eqn.
4964.30 0.00 1.20 1.03 0.00 0.00 Regression Eqn.
4964.40 0.00 1.40 1.15 0.00 0.00 Regression Eqn.
4964.50 0.00 1.50 1.27 0.00 0.00 Regression Eqn.
4964.60 0.00 1.70 1.39 0.00 0.00 Regression Eqn.
4964.70 0.00 1.80 1.45 0.00 0.00 Regression Eqn.
4964.80 0.00 1.90 1.57 0.00 0.00 Regression Eqn.
4964.90 0.00 2.00 1.63 0.00 0.00 Regression Eqn.
4965.00 0.00 2.10 1.75 0.00 0.00 Regression Eqn.
4965.10 0.00 2.20 1.81 0.00 0.00 Regression Eqn.
4965.20 0.00 2.30 1.87 0.00 0.00 Regression Eqn.
4965.30 0.00 2.40 1.99 0.01 0.01 Regression Eqn.
4965.40 0.00 2.50 2.05 0.01 0.01 Regression Eqn.
4965.50 0.00 2.60 2.11 0.01 0.01 Regression Eqn.
4965.60 0.00 2.70 2.18 0.01 0.01 Orifice Eqn.
4965.70 0.00 2.80 2.24 0.01 0.01 Orifice Eqn.
4965.80 0.00 2.90 2.30 0.01 0.01 Orifice Eqn.
4965.90 0.00 2.90 2.36 0.01 0.01 Orifice Eqn.
4966.00 0.00 3.00 2.42 0.01 0.01 Orifice Eqn.
4966.10 0.00 3.10 2.48 0.01 0.01 Orifice Eqn.
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
Project:
Basin ID:
Design Information (input):
Bottom Length of Weir L = 1.25 feet
Angle of Side Slope Weir Angle = 12.00 degrees
Elev. for Weir Crest EL. Crest = 4,964.80 feet
Coef. for Rectangular Weir Cw = 3.10
Coef. for Trapezoidal Weir Ct = 3.37
Calculation of Spillway Capacity (output):
Water Rect. Triangle Total Total
Surface Weir Weir Spillway Pond
Elevation Flowrate Flowrate Release Release
ft. cfs cfs cfs cfs
(linked) (output) (output) (output) (output)
4963.50 0.00 0.00 0.00 0.00
4963.60 0.00 0.00 0.00 0.01
4963.70 0.00 0.00 0.00 0.02
4963.80 0.00 0.00 0.00 0.04
4963.90 0.00 0.00 0.00 0.07
4964.00 0.00 0.00 0.00 0.09
4964.10 0.00 0.00 0.00 0.12
4964.20 0.00 0.00 0.00 0.15
4964.30 0.00 0.00 0.00 0.17
4964.40 0.00 0.00 0.00 0.18
4964.50 0.00 0.00 0.00 0.20
4964.60 0.00 0.00 0.00 0.21
4964.70 0.00 0.00 0.00 0.23
4964.80 0.00 0.00 0.00 0.24
4964.90 0.12 0.00 0.12 0.37
4965.00 0.35 0.01 0.36 0.62
4965.10 0.64 0.04 0.67 0.95
4965.20 0.98 0.07 1.05 1.34
4965.30 1.37 0.13 1.50 1.80
4965.40 1.80 0.20 2.00 2.31
4965.50 2.27 0.29 2.56 2.88
4965.60 2.77 0.41 3.18 3.51
4965.70 3.31 0.55 3.86 4.19
4965.80 3.88 0.72 4.59 4.93
4965.90 4.47 0.91 5.38 5.73
4966.00 5.09 1.13 6.22 6.58
4966.10 5.74 1.38 7.12 7.49
#N/A #N/A #N/A #N/A #N/A
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#N/A #N/A #N/A #N/A #N/A
STAGE-DISCHARGE SIZING OF THE SPILLWAY
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
STORMWATER DETENTION AND
INFILTRATION DESIGN DATA SHEET
Stormwater Facility Name:
Facility Location & Jurisdiction:
User (Input) Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope = 0.035 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length-to-Width Ratio = 3.20 L:W 0.00 0 0.00 0.00
Watershed Area = 2.03 acres 0.25 15 0.25 0.10
Watershed Imperviousness = 50.0% percent 0.50 35 0.50 0.15
Percentage Hydrologic Soil Group A = 0.0% percent 0.75 919 0.75 0.25
Percentage Hydrologic Soil Group B = 0.0% percent 1.00 4,162 1.00 0.55
Percentage Hydrologic Soil Groups C/D = 100.0% percent 1.25 4,532 1.25 0.85
1.50 4,905 1.50 1.06
User Input 17 1.75 5,281 1.75 1.06
2.00 5,662 2.00 1.06
2.25 6,656 2.25 1.06
User Input: Detention Basin Characteristics 2.50 7,681 2.50 1.06
WQCV Design Drain Time = 72.00 hours 2.75 8,212 2.75 2.72
3.00 9,190 3.00 4.38
3.25 11,320 3.25 6.04
3.50 13,450 3.50 7.71
3.75 15,580 3.75
4.00 17,710 4.00
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period = WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth = 0.36 0.82 1.12 1.40 2.27 2.86 in
Calculated Runoff Volume = 0.035 0.066 0.111 0.155 0.300 0.401 acre-ft
OPTIONAL Override Runoff Volume = 0.06 0.03 0.05 0.07 0.14 0.19 acre-ft
Inflow Hydrograph Volume = 0.054 0.030 0.050 0.072 0.139 0.189 acre-ft
Time to Drain 97% of Inflow Volume = 1.7 1.3 1.6 1.8 2.5 2.8 hours
Time to Drain 99% of Inflow Volume = 1.8 1.3 1.7 2.0 2.5 3.0 hours
Maximum Ponding Depth = 1.01 0.86 0.98 1.10 1.46 1.77 ft
Maximum Ponded Area = 0.096 0.054 0.090 0.099 0.111 0.122 acres
Maximum Volume Stored = 0.018 0.007 0.016 0.027 0.065 0.100 acre-ft
Location for 1-hr Rainfall Depths (use dropdown):
Workbook Protected Worksheet Protected
Stormwater Detention and Infiltration Design Data Sheet
WHITMAN STORAGE FACILITY II - BASIN 'A'
209 E. SKYWAY DR., FORT COLLINS, CO 80524
WHITMAN SDI, Design Data 8/30/2016, 10:59 AM
Doing_Clear_Formatting Yes =
CountA= 1
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 0
Area
Discharge
Stormwater Detention and Infiltration Design Data Sheet
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0.1 1 10
FLOW [cfs]
TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0.1 1 10 100
PONDING DEPTH [ft]
DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
WHITMAN SDI, Design Data 8/30/2016, 10:59 AM
Stormwater Facility Name:
Facility Location & Jurisdiction:
User (Input) Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope = 0.038 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs]
Watershed Length-to-Width Ratio = 1.89 L:W 0.00 0 0.00 0.00
Watershed Area = 0.51 acres 0.25 1,952 0.25 0.03
Watershed Imperviousness = 50.0% percent 0.50 1,961 0.50 0.10
Percentage Hydrologic Soil Group A = 0.0% percent 0.75 1,966 0.75 0.17
Percentage Hydrologic Soil Group B = 0.0% percent 1.00 1,972 1.00 0.21
Percentage Hydrologic Soil Groups C/D = 100.0% percent 1.25 1,977 1.25 0.25
1.50 1,983 1.50 0.27
User Input 17 1.75 1,988 1.75 0.36
2.00 1,994 2.00 1.05
2.25 1,999 2.25 2.26
User Input: Detention Basin Characteristics 2.50 2,005 2.50 3.86
WQCV Design Drain Time = 72.00 hours 2.75 2,010 2.75 4.59
3.00 2,015 3.00 8.36
After completing and printing this worksheet to a pdf, go to:
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create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period = WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth = 0.36 0.82 1.12 1.40 2.27 2.86 in
Calculated Runoff Volume = 0.009 0.016 0.028 0.039 0.075 0.101 acre-ft
OPTIONAL Override Runoff Volume = 0.06 0.03 0.05 0.07 0.14 0.19 acre-ft
Inflow Hydrograph Volume = 0.054 0.030 0.050 0.072 0.139 0.189 acre-ft
Time to Drain 97% of Inflow Volume = 7.5 6.8 7.3 7.9 7.9 7.3 hours
Time to Drain 99% of Inflow Volume = 8.5 7.6 8.4 9.1 9.5 9.2 hours
Maximum Ponding Depth = 1.00 0.60 0.92 1.30 2.04 2.28 ft
Maximum Ponded Area = 0.045 0.045 0.045 0.045 0.046 0.046 acres
Maximum Volume Stored = 0.039 0.021 0.036 0.053 0.087 0.098 acre-ft
Stormwater Detention and Infiltration Design Data Sheet
WHITMAN STORAGE FACILITY II - BASIN 'B'
209 E. SKYWAY DR., FORT COLLINS, CO 80524
Location for 1-hr Rainfall Depths (use dropdown):
Workbook Protected Worksheet Protected
WHITMAN SDI - B, Design Data 8/30/2016, 5:10 PM
Doing_Clear_Formatting Yes =
CountA= 1
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Stormwater Detention and Infiltration Design Data Sheet
Area
Discharge
0
1
2
3
4
5
6
0.1 1 10
FLOW [cfs]
TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
0.5
1
1.5
2
2.5
0.1 1 10 100
PONDING DEPTH [ft]
DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
WHITMAN SDI - B, Design Data 8/30/2016, 5:10 PM
ACCESS CULVERT
Project:
Pipe ID:
Design Information (Input)
Pipe Invert Slope So = 0.0400 ft/ft
Pipe Manning's n-value n = 0.0120
Pipe Diameter D = 30.00 inches
Design discharge Q = 87.00 cfs
Full-flow Capacity (Calculated)
Full-flow area Af = 4.91 sq ft
Full-flow wetted perimeter Pf = 7.85 ft
Half Central Angle Theta = 3.14 radians
Full-flow capacity Qf = 89.11 cfs
Calculation of Normal Flow Condition
Half Central Angle (0<Theta<3.14) Theta = 2.21 radians
Flow area An = 4.21 sq ft
Top width Tn = 2.00 ft
Wetted perimeter Pn = 5.53 ft
Flow depth Yn = 2.00 ft
Flow velocity Vn = 20.69 fps
Discharge Qn = 87.00 cfs
Percent Full Flow Flow = 97.6% of full flow
Normal Depth Froude Number Frn = 2.52 supercritical
Calculation of Critical Flow Condition
Half Central Angle (0<Theta-c<3.14) Theta-c = 2.94 radians
Critical flow area Ac = 4.90 sq ft
Critical top width Tc = 0.50 ft
Critical flow depth Yc = 2.47 ft
Critical flow velocity Vc = 17.75 fps
Critical Depth Froude Number Frc = 1.00
CIRCULAR CONDUIT FLOW (Normal & Critical Depth Computation)
WHITMAN STORAGE FACILITY II
ACCESS DRIVE CULVERT
Copy of UD-Culvert_v3.04, Pipe 10/25/2016, 5:10 PM
Project:
Basin ID:
Status:
47187.82
X
Design Information (Input):
Circular Culvert: Barrel Diameter in Inches D = 30 inches
Inlet Edge Type (choose from pull-down list) Grooved End with Headwall
OR:
Box Culvert: Barrel Height (Rise) in Feet Height (Rise) = ft.
Barrel Width (Span) in Feet Width (Span) = ft.
Inlet Edge Type (choose from pull-down list) Square Edge w/ 30-78 deg. Flared Wingwall
Number of Barrels No = 1
Inlet Elevation at Culvert Invert Inlet Elev = 4969.5 ft. elev.
Outlet Elevation at Culvert Invert OR Slope of Culvert (ft v./ft h.) Outlet Elev = 4968.86 ft. elev.
Culvert Length in Feet L = 16 ft.
Manning's Roughness n = 0.012
Bend Loss Coefficient Kb = 0
Exit Loss Coefficient Kx = 0.3
Design Information (calculated):
Entrance Loss Coefficient Ke = 0.20
Friction Loss Coefficient Kf = 0.13
Sum of All Loss Coefficients Ks = 0.63
Orifice Inlet Condition Coefficient Cd = 0.99
Minimum Energy Condition Coefficient KElow = -0.1363
Calculations of Culvert Capacity (output):
Water Surface Tailwater Culvert Culvert Controlling Inlet Flow
Elevation Surface Inlet-Control Outlet-Control Culvert Equation Control
Elevation Flowrate Flowrate Flowrate Used: Used
ft cfs cfs cfs
(ft., linked) (output)
4970.00 1.50 14.13 1.50 Min. Energy. Eqn. INLET
4970.25 3.10 14.75 3.10 Min. Energy. Eqn. INLET
4970.50 5.40 15.95 5.40 Min. Energy. Eqn. INLET
4970.75 8.10 18.09 8.10 Min. Energy. Eqn. INLET
4971.00 10.90 21.82 10.90 Regression Eqn. INLET
4971.25 14.10 26.75 14.10 Regression Eqn. INLET
4971.50 17.80 31.15 17.80 Regression Eqn. INLET
4971.75 21.60 35.77 21.60 Regression Eqn. INLET
4972.00 25.30 39.90 25.30 Regression Eqn. INLET
4972.25 28.80 47.01 28.80 Regression Eqn. INLET
4972.50 32.10 53.23 32.10 Regression Eqn. INLET
4972.75 35.10 58.79 35.10 Regression Eqn. INLET
4973.00 37.80 63.85 37.80 Regression Eqn. INLET
4973.25 40.40 68.52 40.40 Regression Eqn. INLET
4973.50 42.90 72.92 42.90 Regression Eqn. INLET
4973.75 45.20 77.05 45.20 Regression Eqn. INLET
4974.00 47.40 80.96 47.40 Regression Eqn. INLET
4974.25 49.50 84.74 49.50 Regression Eqn. INLET
4974.50 51.50 88.34 51.50 Regression Eqn. INLET
4974.75 53.50 91.76 53.50 Regression Eqn. INLET
4975.00 55.40 95.09 55.40 Regression Eqn. INLET
4975.25 57.20 98.29 57.20 Regression Eqn. INLET
4975.50 59.00 101.40 59.00 Regression Eqn. INLET
4975.75 60.80 104.42 60.80 Regression Eqn. INLET
4976.00 62.50 107.36 62.50 Regression Eqn. INLET
4976.25 64.20 110.20 64.20 Regression Eqn. INLET
4976.50 65.90 113.00 65.90 Regression Eqn. INLET
4976.75 67.50 115.71 67.50 Regression Eqn. INLET
4977.00 69.10 118.38 69.10 Regression Eqn. INLET
Project:
Basin ID:
CULVERT STAGE-DISCHARGE SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
WHITMAN STORAGE FACILITY II
ACCESS DRIVE CULVERT
4970
4971
4972
4973
4974
4975
4976
4977
4978
0 20 40 60 80 100 120 140
Stage (feet, elev)
Discharge (cfs)
STAGE-DISCHARGE CURVE FOR THE CULVERT
Stage-Discharge Inlet Control Outlet Control
Copy of UD-Culvert_v3.04, Culvert Rating 10/26/2016, 7:24 AM
APPENDIX II
CHARTS, GRAPHS, FIGURES & DETAILS
(11) Section 4.0 is amended to read as follows:
4.0 Intensitv-Duration-Frequencv Curves for Rational Method:
The one-hour rainfall Intensity-Duration-Frequency tables for use the Rational Method
of runoff analysis are provided in Table RA-7 and in Table RA-8.
Table RA-7 - City of Fort Collins
Rainfall Intensity-Duration-Frequency Table
for Use with the Rational Method
(5 minutes to 30 minutes)
2-Year 10-Year 100-Year
Duration
(min)
Intensity
(in/hr)
Intensity
(in/hr)
Intensity
(in/hr)
5 2.85 4.87 9.95
6 2.67 4.56 9.31
7 2.52 4.31 8.8
8 2.4 4.1 8.38
9 2.3 3.93 8.03
10 2.21 3.78 7.72
11 2.13 3.63 7.42
12 2.05 3.5 7.16
13 1.98 3.39 6.92
14 1.92 3.29 6.71
15 1.87 3.19 6.52
16 1.81 3.08 6.3
17 1.75 2.99 6.1
18 1.7 2.9 5.92
19 1.65 2.82 5.75
20 1.61 2.74 5.6
21 1.56 2.67 5.46
22 1.53 2.61 5.32
23 1.49 2.55 5.2
24 1.46 2.49 5.09
25 1.43 2.44 4.98
26 1.4 2.39 4.87
27 1.37 2.34 4.78
28 1.34 2.29 4.69
29 1.32 2.25 4.6
30 1.3 2.21 4.52
33
Table RA-8 - City of Fort Collins
Rainfall Intensity-Duration-Frequency Table
for Use with the Rational Method
(31 minutes to 60 minutes)
2-Year 10-Year 100-Year
Duration Intensity Intensity Intensity
(min) (in/hr) (in/hr) (in/hr)
31 1.27 2.16 4.42
32 1.24 2.12 4.33
33 1.22 2.08 4.24
34 1.19 2.04 4.16
35 1.17 2.0 4.08
36 1.15 1.96 4.01
37 1.16 1.93 3.93
38 1.11 1.89 3.87
39 1.09 1.86 3.8
40 1.07 1.83 3.74
41 1.05 1.8 3.68
42 1.04 1.77 3.62
43 1.02 1.74 3.56
44 1.01 1.72 3.51
45 0.99 1.69 3.46
46 0.98 1.67 3.41
47 0.96 1.64 3.36
48 0.95 1.62 3.31
49 0.94 1.6 3.27
50 0.92 1.58 3.23
51 0.91 1.56 3.18
52 0.9 1.54 3.14
53 0.89 1.52 3.1
54 0.88 1.5 3.07
55 0.87 1.48 3.03
56 0.86 1.47 2.99
57 0.85 1.45 2.96
58 0.84 1.43 2.92
59 0.83 1.42 2.89
60 0.82 1.4 2.86
34
Table RO-10
Rational Method Minor Storm Runoff Coefficients for Zoning Classifications
Description of Area or Zoning Coefficient |
R-F 0.3
U-E 0.3
L-M-In 0.55
R-L, N-C-L 0.6
M-M-N, N-C-M 0.65
N-C-B 0.7
Business:
C-C-N, C-C-R, C-N, N-C, C-S 0.95
R-D-R, C-C, C-L 0.95
D,C 0.95
H-C 0.95
C-S 0.95
Industrial:
E 0.85
I 0.95
Undeveloped:
R-C,T 0.2
P-O-L 0.25
For guidance regarding zoning districts and classifications of such districts please refer to
Article Four of the City Land Use Code, as amended.
40
Table RO-11
Rational Method RunofT Coefficients for Composite Analysis
Character of Surface Runoff Coefficient
Streets, Parking Lots,
Drives:
Asphalt 0.95
Concrete 0.95
Gravel 0.5
Roofs 0.95
Recycled Asphalt 0.8
Lavms, Sandy Soil:
Flat<2% 0.1
Average 2 to 7% 0.15
Steep >7% 0.2
Lawns, Heavy Soil:
Flat <2% 0.2
Average 2 to 7% 0.25
Steep >7% 0.35
(4) A new Section 2.9 is added, to read as follows:
2.9 Composite Runoff Coefficient
Drainage sub-basins are frequently composed of land that has multiple surfaces or zoning
classifications. In such cases a composite runoff coefficient must be calculated for any
given drainage sub-basin.
The composite nmoff coefficient is obtained using the following formula:
Tic.'A,)
C = — (RO-8)
Where: C = Composite Runoff Coefficient
Cj = Runoff Coefficient for Specific Area (Aj)
Ai = Area of Surface with Runoff Coefficient of Cj, acres or feet^
n = Number of different surfaces to be considered
At= Total Area over which C is applicable, acres or feet^
(5) A new Section 2.70 is added, to read as follows:
41
2.10 Runoff Coefticient Adjustment for Infrequent Storms
The ruiioff coefficients provided in tables RO-10 and RO-11 are appropriate for use with
the 2-year storm event. For storms with higher intensities, an adjustment of the runoff
coefficient is required due to the lessening amount of infiltration, depression retention,
evapo-transpiration and other losses that have a proportionally smaller effect on storm
runoff. This adjustment is appUed to the composite runoff coefficient.
These fi-equency adjustment factors are found in Table RO-12.
Table RO-12
Rational Method Runoff Coefficients for Composite Analysis
Storm Return Period Frequency Factor
(years) Cf
2 to 10 I.OO
11 to 25 1.10
26 to 50 1.20
51 to 100 1.25 1
Note: The product of C times Cf cannot exceed the value of 1, in the cases where it does a value of
1 must be used
(6) Section 3. J is deleted in its entirety.
(7) Section 3.2 is deleted in its entirety.
(8) Section 3.3 is deleted in its entu-ety.
(9) A new Section 4.3 is added, to read as follows:
4.3 Computer Modeling Practices
(a) For circumstances requiring computer modehng, the design storm hydrographs must
be determined using the Stormwater Management Model (SWMM). Basin and
conveyance element parameters must be computed based on the physical characteristics
of the site.
(b) Refer to the SWMM Users' Manual for appropriate modeling methodology, practices
and development The Users' Manual can be found on the Environmental Protection
Agency (EPA) website Qittp://v\'W'w^epa.pov/edimrnirl/modeJs/swiTim/index.htm).
(c) It is the responsibility of the design engineer to verify that all of the models used in
the design meet all current City criteria and regulations.
4.3.1 Surface Storage. Resistance Factors, and Infiltration
Table RO-13 provides values for surface storage for pervious and impervious surfaces
and the infiltration rates to be used with SWMM. Table RO-13 also lists the appropriate
infiltration decay rate, zero detention depth and resistance factors, or Manning's "n"
values, for pervious and impervious surfaces to be used for SWMM modeling in the city
of Fort Collins.
4977.25 70.50 120.95 70.50 Orifice Eqn. INLET
Processing Time: 00.90 Seconds
CULVERT STAGE-DISCHARGE SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
WHITMAN STORAGE FACILITY II
ACCESS DRIVE CULVERT
Copy of UD-Culvert_v3.04, Culvert Rating 10/26/2016, 7:24 AM
ONSITE AREA "B"
DET B 8-10-16, Spillway 8/11/2016, 3:52 PM
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
STAGE-DISCHARGE SIZING OF THE OUTLET CULVERT (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE BASIN "B"
DETENTION POND B 8-10-16, Culvert 9/6/2016, 10:44 AM
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
Routing 5: Water flows separately through WQCV plate, #1 horizontal opening, #2 horizontal opening, #1 vertical opening, and #2
vertical opening. The sum of all four will be applied to culvert sheet.
STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL)
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE AREA "B"
Current Routing Order is #5
W.S. EL. WQ
W.S. EL. Minor
W.S. EL. Major
WQ
H1
H2
V1 V2
Routing Order #1 (Standard)
V1
W.S. EL. WQ
W.S. EL. Design Storm
WQ
H1
Routing Order #3 (Single Stage) Routing Order #4
V2
V1
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ
W.S. EL. Emergency Spillway
Emergency Overflow into Pipe- H2
V2
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ V1
Routing Order #2
DET B 8-10-16, Outlet 8/11/2016, 3:44 PM
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
Override
Area
Row 1
Override
Area
Row 2
Override
Area
Row 3
Override
Area
Row 4
Override
Area
Row 5
Override
Area
Row 6
Override
Area
Row 7
Override
Area
Row 8
Override
Area
Row 9
Override
Area
Row 10
Override
Area
Row 11
Override
Area
Row 12
Override
Area
Row 13
Override
Area
Row 14
Override
Area
Row 15
Override
Area
Row 16
Override
Area
Row 17
Override
Area
Row 18
Override
Area
Row 19
Override
Area
Row 20
Override
Area
Row 21
Override
Area
Row 22
Override
Area
Row 23
Override
Area
Row 24
Central Elevations of Rows of Holes in feet
Collection Capacity for Each Row of Holes in cfs
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
WHITMAN STORAGE II
BASIN 'B'
DET B 8-10-16, WQCV 8/11/2016, 3:32 PM
#N/A #N/A
STAGE-STORAGE SIZING FOR DETENTION BASINS
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
Check Basin Shape
ONSITE AREA "B"
DET B 8-10-16, Basin 8/11/2016, 3:29 PM
ONSITE AREA "A"
VOID DETENTION A VOID, Spillway 8/11/2016, 4:15 PM
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
0.00 0.00 0.00 0.00 #N/A #N/A No Flow (WS < inlet)
STAGE-DISCHARGE SIZING OF THE OUTLET CULVERT (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)
VOID DETENTION A VOID, Culvert 8/11/2016, 4:16 PM
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
#N/A #N/A #N/A #N/A #N/A #N/A 0.00 #N/A
Routing 5: Water flows separately through WQCV plate, #1 horizontal opening, #2 horizontal opening, #1 vertical opening, and #2
vertical opening. The sum of all four will be applied to culvert sheet.
STAGE-DISCHARGE SIZING OF THE WEIRS AND ORIFICES (INLET CONTROL)
WHITMAN STORAGE II (LOT 3, BLOCK 1, LYNN ACRES)
ONSITE AREA "A"
Current Routing Order is #5
W.S. EL. WQ
W.S. EL. Minor
W.S. EL. Major
WQ
H1
H2
V1 V2
Routing Order #1 (Standard)
V1
W.S. EL. WQ
W.S. EL. Design Storm
WQ
H1
Routing Order #3 (Single Stage) Routing Order #4
V2
V1
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ
W.S. EL. Emergency Spillway
Emergency Overflow into Pipe- H2
V2
H1
WQ
W.S. EL. Major
W.S. EL. Minor
W.S. EL. WQ V1
Routing Order #2
VOID DETENTION A VOID, Outlet 8/11/2016, 4:17 PM
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
#N/A #N/A #N/A #N/A
Override
Area
Row 1
Override
Area
Row 2
Override
Area
Row 3
Override
Area
Row 4
Override
Area
Row 5
Override
Area
Row 6
Override
Area
Row 7
Override
Area
Row 8
Override
Area
Row 9
Override
Area
Row 10
Override
Area
Row 11
Override
Area
Row 12
Override
Area
Row 13
Override
Area
Row 14
Override
Area
Row 15
Override
Area
Row 16
Override
Area
Row 17
Override
Area
Row 18
Override
Area
Row 19
Override
Area
Row 20
Override
Area
Row 21
Override
Area
Row 22
Override
Area
Row 23
Override
Area
Row 24
Central Elevations of Rows of Holes in feet
Collection Capacity for Each Row of Holes in cfs
STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET
WHITMAN STORAGE II
BASIN 'A'
VOID DETENTION A VOID, WQCV 8/11/2016, 4:40 PM
#N/A #N/A
STAGE-STORAGE SIZING FOR DETENTION BASINS
WHITMAN STORAGE FACILITY II (LOT 3, BLOCK 1, LYNN ACRES)
Check Basin Shape
ONSITE AREA 'A'
VOID DETENTION A VOID, Basin 8/11/2016, 4:43 PM
Peak Flowrate, Qp = 0.94 cfs
Peak Flowrate, Qp = 0.85 cfs
Peak Flowrate, Qp = 0.85 cfs
PROP 'B'QIO, Tcand PeakQ 7/14/2016, 3:05 PM
Peak Flowrate, Qp = 0,50 cfs
PROP 'B' 02, Tc and PeakQ 7/14/2016, 3:02 PM
Peak Flov^rate, Qp = 7.99 cfs
Peak Flov^rate, Qp = 7,99 cfs
PROP 'AQ100, Tc and PeakQ 7/6/2016, 12:05 PM
13.39
Computed Tc =
Regional Tc =
User-Entered Tc = 13.39
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 3.03 inch/hr
Rainfall Intensity at Regional Tc, I = 3.35 inch/hr
Rainfall Intensity at User-Defined Tc, I = 3,35 inch/hr
Peak Flowrate, Qp = 2.83 cfs
Peak Flowrate, Qp = 3.13 cfs
Peak Flowrate, Qp= 3.13 cfs
PROP 'A' Q10, Tc and PeakQ 7/6/2016, 12:07 PM
Rainfall Intensity at Regional To, I = 1.96 inch/hr
Rainfall Intensity at User-Defined Tc, I = 1.96 inch/hr
Peak Flowrate, Qp = 1.66 cfs
Peak Flowrate, Qp = 1.83 cfs
Peak Flovi^rate, Qp = 1.83 cfs
PROP 'A' 02, Tc and PeakQ 7/6/2016, 12:09 PM
Peak Flowrate, Qp = 1.54 cfs
Peak Flowrate, Qp = 1.52 cfs
EXIST 'C QIOOxIs, Tc and PeakQ 07/08/2016, 14:02:38
input input output input output output
Overland 0.0510 50 0,25 N/A 0,13 6,34
1 0.0510 200 10.00 2,26 1.48
2
3
4
5
Sum 250 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = /,81
Regional Tc =
User-Entered Tc =
11.39
Computed Tc =
Regional Tc =
User-Entered Tc = 11.67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I = "
4.15 inch/hr
3.59 inch/hr
3.56 inch/hr
Peak Flowrate, Qp = 0.69 cfs
Peak Flowrate, Qp = 0.60 cfs
Peak Flowrate, Qp = 0.60 cfs
EXIST 'C Q10.xls, Tc and PeakQ 07/08/2016, 14:01:54
5
Sum 250 Computed To =
Regional Tc =
User-Entered Tc =
Computed To = /.81
Regional Tc =
User-Entered Tc =
11.39
Computed To =
Regional Tc =
User-Entered Tc = 11.67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 2.43 inch/hr
Rainfall Intensity at Regional Tc, I = 2.10 inch/hr
Rainfall Intensity at User-Defined Tc, I = 2.08 inch/hr
Peak Flowrate, Qp = 0.41 cfs
Peak Flowrate, Qp 0.35 cfs
Peak Flowrate, Qp = 0.35 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
EXIST 'C Q2.xls, Tc and PeakQ 07/08/2016, 14:01:00
2
3
4
5
Sum 237 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 1U.2U
Regional Tc =
User-Entered Tc =
11.32
Computed Tc =
Regional Tc =
User-Entered Tc = 10.74
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I = "
7.68 inch/hr
7.36 inch/hr
7.52 inch/hr
Peak Flowrate, Qp = 1,22 cfs
Peak Flowrate, Qp = 1.17 cfs
Peak Flowrate, Qp = 1.20 cfs
EXIST 'B' QIOOxIs, Tc and PeakQ 07/08/2016, 14:00:03
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I = '
Rainfall Intensity at User-Defined Tc, I =
3,66 inch/hr
3.60 inch/hr
3.68 inch/hr
Peak Flowrate, Qp = 0.47 cfs
Peak Flowrate, Qp = 0.46 cfs
Peak Flowrate, Qp = 0.47 cfs
EXIST 'B' Q10.xls, Tc and PeakQ 07/08/2016, 13:58:57
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I 2.14 inch/hr
Rainfall Intensity at Regional Tc, I = 2.11 inch/hr
Rainfall Intensity at User-Defined Tc, I = 2.16 inch/hr
Peak Flowrate, Qp = 0.27 cfs
Peak Flowrate, Qp = 0.27 cfs
Peak Flowrate, Qp = 0.27 cfs
EXIST 'B' Q2.xls, Tc and PeakQ 07/08/2016, 13:57:44
5
Sum 300 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 12.69
Regional Tc =
User-Entered Tc =
11.67
Computed Tc =
Regional Tc =
User-Entered Tc = 11.67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I = "
7,01 inch/hr
7.26 inch/hr
7.26 inch/hr
Peak Flowrate, Qp = 4.44 cfs
Peak Flowrate, Qp= 4.61 cfs
Peak Flowrate, Qp = 4,61 cfs
EXIST A' Q100.xls, Tc and PeakQ 07/08/2016, 13:56:53
2
3
4
5
Sum 300 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 13.59
Regional Tc =
User-Entered Tc =
11.67
Computed Tc =
Regional Tc =
User-Entered Tc = 11.67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I = "
3.33 inch/hr
3.56 inch/hr
3.56 inch/hr
Peak Flowrate, Qp = 1.69 cfs
Peak Flowrate, Qp = 1.80 cfs
Peak Flowrate, Qp = 1.80 cfs
EXIST 'A Q10.xls, Tc and PeakQ 07/08/2016, 13:55:47
4
5
Sum 300 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc = 13,69
Regional Tc =
User-Entered Tc =
11,67
Computed Tc =
Regional Tc =
User-Entered Tc = 11.67
IV. Peak Runoff Prediction
Rainfall Intensity at Computed To, I =
Rainfall Intensity at Regional Tc. I = "
Rainfall Intensity at User-Defined Tc, I =
1.95 Inch/hr
2.08 inch/hr
2.08 inch/hr
Peak Flowrate, Qp = 0.99 cfs
Peak Flovi/rate, Qp = 1.06 cfs
Peak Flowrate, Qp = 1.06 cfs
Calculated values for Tc & Qp are based on overide values entered for C & C-5.
EXIST A' Q2.xls, Tc and PeakQ 07/08/2016, 13:54:51
4
5
Sum 800 Computed Tc = 22. bU
Regional Tc = 14.44
User-Entered Tc = 14.44
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I =
4.80 inch/hr
6.01 inch/hr
6.01 inch/hr
Peak Flowrate, Qp = 6.66 cfs
Peak Flowrate, Qp 8.33 cfs
Peak Flowrate, Qp = 8.33 cfs
OFFSITE 2 EXIST 100YR.xls, To and PeakQ 07/06/2016, 16:59:42
4
5
Sum 800 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc =
Regional Tc =
User-Entered Tc =
14.44
Computed Tc =
Regional Tc =
User-Entered Tc = 14.44
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I = "
2.86 inch/hr
3.58 inch/hr
3.58 inch/hr
Peak Flowrate, Qp = 2.64 cfs
Peak Flowrate, Qp = 3.31 cfs
Peak Flowrate, Qp = 3.31 cfs
OFFSITE 2 EXIST 10YR.xls, Tc and PeakQ 07/06/2016, 16:58:50
3
4
5
Sum 800 Computed Tc =
Regional Tc =
User-Entered Tc =
Computed Tc =
Regional Tc =
User-Entered Tc =
14.44
Computed Tc =
Regional Tc =
User-Entered Tc = 14.44
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I = '
Rainfall Intensity at User-Defined Tc, I = "
1.75 inch/hr
2.20 inch/hr
2.20 inch/hr
Peak Flow/rate, Qp = 0.94 cfs
Peak Flov/rate, Qp = 1.18 cfs
Peak Flowrate, Qp = 1.18 cfs
OFFSITE 2 EXIST 2YR.xls, Tc and PeakQ 07/06/2016, 16:58:10
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I =
5.62 inch/hr
6.18 inch/hr
6.18 inch/hr
Peak Flowrate, Qp =
Peak Flowrate, Qp =
Peak Flowrate, Qp ='
12.53 cfs
13.78 cfs
13.78 cfs
OFFSITE 1 EXIST 100YR.xls, Tc and PeakQ 07/06/2016, 16:56:30
User-Entered Tc =
Computed Tc = 16.60
Regional Tc =
User-Entered Tc =
13.56
Computed Tc =
Regional Tc =
User-Entered Tc = 13.56
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I = 3.35 inch/hr
Rainfall Intensity at Regional Tc, I = 3.69 inch/hr
Rainfall Intensity at User-Defined Tc, I = 3.69 inch/hr
Peak Flowrate, Qp = 6.04 cfs
Peak Flowrate, Qp = 6.65 cfs
Peak Flowrate, Qp = 6.65 cfs
OFFSITE 1 EXIST 10YR.xls, Tcand PeakQ 07/06/2016, 16:54:49
5
Sum 640 Computed Tc = ib.yy
Regional Tc = 13.56
User-Entered Tc = 13.56
IV. Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =
Rainfall Intensity at Regional Tc, I =
Rainfall Intensity at User-Defined Tc, I ='
2.11 inch/hr
2.26 inch/hr
2.26 inch/hr
Peak Flowrate, Qp = 3.07 cfs
Peak Flowrate, Qp = 3.28 cfs
Peak Flowrate, Qp = 3.28 cfs
OFFSITE 1 EXIST 2YR.xls, Tc and PeakQ 07/06/2016, 16:52:24