HomeMy WebLinkAboutWATERFIELD THIRD FILING - FDP - FDP140006 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTApril 9, 2014
FINAL DRAINAGE AND
EROSION CONTROL REPORT FOR
WATERFIELD THIRD FILING
Fort Collins, Colorado
Prepared for:
Risheill Homes, LLC
Curly Risheill
PO Box 400
Castle Rock, CO 80104
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 889-001
This Drainage Report is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy is absolutely necessary, we recommend double-sided printing.
April 9, 2014
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Final Drainage and Erosion Control Report for
WATERFIELD THIRD FILING
Dear Staff:
Northern Engineering is pleased to submit this Final Drainage and Erosion Control Report for your
review. This report accompanies the Project Development Plan submittal for the proposed
Waterfield Third Filing development.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed project. We
understand that review by the City is to assure general compliance with standardized criteria
contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Aaron Cvar, PE
Project Engineer
Waterfield Third Filing
Final Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION .................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain ......................................................................................................................................... 4
II. DRAINAGE BASINS AND SUB-BASINS ........................................................................ 4
A. Major Basin Description .................................................................................................................... 4
III. DRAINAGE DESIGN CRITERIA .................................................................................... 5
A. Regulations ........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 6
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 6
G. Modifications of Criteria ................................................................................................................... 7
IV. DRAINAGE FACILITY DESIGN ..................................................................................... 7
A. General Concept ............................................................................................................................... 7
B. Specific Details .................................................................................................................................. 8
V. CONCLUSIONS ........................................................................................................ 10
A. Compliance with Standards ............................................................................................................ 10
B. Drainage Concept ............................................................................................................................ 10
References ......................................................................................................................... 10
APPENDICES:
APPENDIX A Hydrologic Computations
APPENDIX B Street Capacity Calculations
APPENDIX C Inlet Calculations
APPENDIX D Storm Line Calculations and Riprap Calculations
APPENDIX E Water Quality and LID Supporting Documentation
APPENDIX F Stormwater Management Model (SWMM)
APPENDIX G Emergency Overflow Calculations
APPENDIX H Erosion Control Report
Waterfield Third Filing
Final Drainage Report
LIST OF TABLES AND FIGURES:
Figure 1 – Aerial Photograph .................................................................................................. 2
Figure 2– Proposed Site Plan .................................................................................................. 3
Figure 3 – Existing Floodplains ............................................................................................... 4
MAP POCKET:
Proposed Drainage Exhibit
Waterfield Third Filing
Final Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the west half of Section 5, Township 7 North, Range 68
West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of
Colorado .
3. The project site is located on the north side of Vine Drive and is just northwest of the
intersection of Vine Drive and Timberline Road.
4. The project site lies within the Dry Creek Basin. Detention requirements are to detain
the difference between the 100-year developed inflow rate and the historic 2-year
release rate. The historic release rate for this basin is 0.20 cfs per acre.
5. The existing Waterfield P.U.D. First Filing residential development exists to the
southeast of the proposed Third Filing site. The Lake Canal crosses the southwest
corner of the property, and is within the property limits. The Larimer and Weld Canal
runs along the northern border of the property.
6. Any offsite flows that would enter the site on the north are intercepted by the Larimer
and Weld Canal.
Waterfield Third Filing
Final Drainage Report 2
B. Description of Property
1. The development area is roughly 117 net acres.
Figure 1 – Aerial Photograph
2. The subject property is currently leased for farming purposes. The ground cover
generally consists of row crops. Existing ground slopes are mild to moderate (i.e., 1 -
6±%) through the interior of the property. General topography slopes from north to
south. The existing wetland area within the interior of the site collects a significant
amount of storm drainage and excess irrigation flows.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey website:
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx,
the site consists of Paoli fine sandy loam and Table Mountain Loam, which fall into
Hydrologic Soil Group B.
Waterfield Third Filing
Final Drainage Report 3
4. The proposed project site plan is composed of residential and commercial
development. Associated roadways, water and sewer lines will be constructed with
the development. The existing wetland within the interior of the site be utilized for
stacked detention (detention over the permanent pool elevation of the wetland). The
existing detention pond constructed with Waterfield P.U.D. First Filing, located along
the south boundary of the site, will be expanded and utilized for detention and water
quality treatment.
Figure 2– Proposed Site Plan
5. The Lake Canal crosses the southwest corner of the property, and is within the
property limits. The Larimer and Weld Canal runs along the northern border of the
property.
6. The proposed land use is residential and commercial.
Waterfield Third Filing
Final Drainage Report 4
C. Floodplain
1. The project site is not encroached by any City or FEMA floodplain.
Figure 3 –Area Floodplain Mapping
2. No offsite improvements are proposed with the project.
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
3. The project site lies within the Dry Creek Basin. Detention requirements are to detain
the difference between the 100-year developed inflow rate and the historic 2-year
release rate. The historic release rate for this basin is 0.20 cfs per acre. The site
outfall is the existing outfall structure for the existing detention pond constructed with
Waterfield P.U.D., First Filing. The outfall for this pond is a siphon storm line
which conveys flows under the Lake Canal. This pond is to be modified with
the currently proposed development to incorporate detention and water quality
measures for the existing development, as well as the proposed Waterfield
Third Filing development. It is understood that the siphon outfall for this pond
is the responsibility of the development to maintain.
Waterfield Third Filing
Final Drainage Report 5
B. Sub-Basin Description
4. The subject property historically drains overland from north to south. Runoff from a
portion of the site has historically collected in the existing wetland located within the
interior of the site. The remainder of the site historically sheet flows to the existing
detention pond at the southern boundary of the site. This pond outfalls via a siphon
under the Lake Canal into the Vine Drive roadside ditch. The proposed site will
generally maintain these historic drainage patterns. A more detailed description of the
project drainage patterns follows in Section IV.A.4., below.
III. DRAINAGE DESIGN CRITERIA
A. Regulations
There are no optional provisions outside of the FCSCM proposed with the proposed
project.
B. Four Step Process
The overall stormwater management strategy employed with the proposed project utilizes
the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters.
The following is a description of how the proposed development has incorporated each
step.
Step 1 – Employ Runoff Reduction Practices
Several techniques have been utilized with the proposed development to facilitate the
reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the
current use by implementing multiple Low Impact Development (LID) strategies including:
Conserving existing amenities in the site including the existing vegetated areas.
Providing vegetated open areas throughout the site to reduce the overall impervious
area and to minimize directly connected impervious areas (MDCIA).
Routing flows, to the extent feasible, through vegetated swales to increase time of
concentration, promote infiltration and provide initial water quality.
Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with
Slow Release
The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban
development of this intensity will still generate stormwater runoff that will require
additional BMPs and water quality. The majority of stormwater runoff from the site will
ultimately be intercepted and treated using extended detention methods prior to exiting the
site.
Step 3 – Stabilize Drainageways
There are no major drainageways within the subject property. While this step may not
seem applicable to proposed development, the project indirectly helps achieve stabilized
drainageways nonetheless. By providing water quality where none previously existed,
sediment with erosion potential is removed from the downstream drainageway systems.
Furthermore, this project will pay one-time stormwater development fees, as well as
ongoing monthly stormwater utility fees, both of which help achieve City-wide drainageway
stability.
Waterfield Third Filing
Final Drainage Report 6
Step 4 – Implement Site Specific and Other Source Control BMPs.
The proposed project will improve upon site specific source controls compared to historic
conditions:
Trash, waste products, etc. that were previously left exposed with the historic trailer
park will no longer be allowed to exposure to runoff and transport to receiving
drainageways. The proposed development will eliminate these sources of potential
pollution.
C. Development Criteria Reference and Constraints
The subject property is surrounded by currently developed properties. Thus, several
constraints have been identified during the course of this analysis that will impact the
proposed drainage system including:
Existing elevations along the property lines will generally be maintained.
As previously mentioned, overall drainage patterns of the existing site will be
maintained.
Elevations of existing downstream facilities that the subject property will release to
will be maintained.
D. Hydrological Criteria
1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the proposed development. Tabulated data contained in Table RA-7
has been utilized for Rational Method runoff calculations.
2. The Rational Method has been employed to compute stormwater runoff utilizing
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3. Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80th percentile rain event, which has been
employed to design the project’s water quality features. The second event analyzed is
the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third
event considered is the “Major Storm,” which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
4. No other assumptions or calculation methods have been used with this development
that are not referenced by current City of Fort Collins criteria.
E. Hydraulic Criteria
1. As previously noted, the subject property maintains historic drainage patterns.
2. All drainage facilities proposed with the project are designed in accordance with
criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District
(UDFCD) Urban Storm Drainage Criteria Manual.
3. As stated above, the subject property is not located in a City or FEMA regulatory
floodplain.
4. The proposed project does not propose to modify any natural drainageways.
Waterfield Third Filing
Final Drainage Report 7
F. Modifications of Criteria
1. The proposed development is not requesting any modifications to criteria at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of the project drainage design are to maintain existing drainage
patterns, and to ensure no adverse impacts to any adjacent properties.
2. The existing wetland within the interior of the site be utilized for stacked detention
(detention over the permanent pool elevation of the wetland). The existing detention
pond constructed with Waterfield P.U.D. First Filing, located along the south
boundary of the site, will be expanded and utilized for detention and water quality
treatment.
3. A list of tables and figures used within this report can be found in the Table of
Contents at the front of the document. The tables and figures are located within the
sections to which the content best applies.
4. The drainage patterns anticipated for proposed drainage basins are described below.
Basins 1-4, 6-8
Basins 1 through 4 and Basins 6 through 8 consists of open space, residential and
commercial development. These basins will drain generally via street curb and gutter
to the existing wetland, noted as Pond 1, which will be utilized for stacked detention.
A PLD section with an underdrain is proposed within the center median of Gargeney
Drive. This street will have an inverted crown, sloping to the center median, and will
collect drainage from Basins 2 through 7. This PLD will serve as an onsite LID
feature, and will treat runoff prior to entry to Pond 1.
Basin 5
Basin 5 consists of open space and a portion of Vine Drive. This basin will drain via
street curb and gutter and via sheet flow to the proposed Pond 2.
Basins 9-12, 14
Basins 9 through 12, and Basin 14 consist of residential development. These basins
will drain generally via street curb and gutter to the existing detention pond
constructed with Waterfield P.U.D., First Filing which is noted as Pond 3 with the
current project. The outfall for this pond is a siphon storm line which conveys
flows under the Lake Canal. This pond is to be modified with the currently
proposed development to incorporate detention for the existing Waterfield
P.U.D. First Filing development, as well as the proposed Third Filing
Development.
It is noted that a portion of New Vine Drive will exceed allowable 2-year street
capacity from the intersection of New Vine Drive and Merganser Drive west
656 feet to the sump in New Vine Drive. Allowable 2-year street capacity is
8.9 cfs, and we have calculated 10.1 cfs at design point 9.
Waterfield Third Filing
Final Drainage Report 8
We seek a variance for this 1.2 cfs additional flow, as there will be minimal
impact to 2-year depth in the street. The additional 1.2 cfs will result in
allowable curb and gutter depth to be exceeded by 0.25 inch.
Basin 13
Basin 13 consists of backs of residential lots and will drain via sheetflow undetained
to offsite property to the southwest, and immediately into the Lake Canal, located at
the southwest corner of the site. Historically, a much larger area (9.60 acres) within
the development limits drained to this offsite property. The historic area would
generate roughly 16.0 cfs in a 100-year event. The currently proposed site plan and
grading shows Basin 13 with an area of 1.52 acres, generating 8.4 cfs in a 100-year
event. The proposed character of the flow is no different from historic, with sheet flow
being discharged overland into the same area southwest of the site as was the historic
path.
Basin 15
Basin 15 consists of Right of Way for Merganser Street. This basin will drain
undetained south into Vine Drive.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report.
B. Specific Details
1. Standard water quality treatment in the form of Extended Detention is being
provided for the proposed development in Pond 3.
2. Pond 1 will provide water quality treatment in the wet component of this
pond. As previously discussed, Pond 1 is an existing wetland with a
permanent water surface. The wetland vegetation and permanent pool will
greatly enhance water quality for runoff discharging from the site. Water
quality forebays will be provided for pre-treatment at all concentrated points of
entry to the existing wetland.
3. LID features will be incorporated in the design of the PLD running along
Garganey Drive at Final design. The following summary table outlines LID
features and proportion of the site draining to each feature.
Waterfield Third Filing
Final Drainage Report 9
Table 1 – LID Summary Table
LID Feature Drainage
Basin
Directly
Contributing
to LID
Total Drainage Basin Area (AC) Percent
of Site
Draining
into LID
Pond 1 (wetland) 1 40.88 35.0%
Pond 1 North Forebay 2,6‐8 21.98 18.8%
Pond 1 South Forebay 5 8.41 7.2%
Garganey Drive PLD (within
median) 3,4 18.84 16.1%
Pond 3 Extended Detention Basin 9‐12,14 26.26 22.5%
Total Area Passing Through an LID
Feature: 99.6%
4. Final design details, construction documentation, and Standard Operating
Procedures (SOP) Manual shall be provided to the City of Fort Collins for
review prior to Final Development Plan approval. A final copy of the approved
SOP manual shall be provided to City and must be maintained on-site by the
entity responsible for the facility maintenance. Annual reports must also be
prepared and submitted to the City discussing the results of the maintenance
program (i.e. inspection dates, inspection frequency, volume loss due to
sedimentation, corrective actions taken, etc.).
5. Table 2, below, summarizes preliminary detention and water quality volumes for
Ponds 1 through 3.
Table 2 – Pond Summary Table
Pond Detention Water Quality Total Required Detention
Volume Capture Volume Volume Release Rate
(AC‐FT) (AC‐FT) (FT) (CFS)
1
14.35
1.74
14.35
(wet pond‐not
additive)
1.25
2 0.58 N/A 0.58 2.26
3 10.71 0.44 11.15 7.64
6. Proper maintenance of the drainage facilities designed with the proposed
development is a critical component of their ongoing performance and effectiveness.
The water quality pond will be designed at Final to be easily accessed by
maintenance staff via gentle slopes provided to the bottom of the pond.
7. The drainage features associated with the proposed project are all private facilities,
located on private property.
Waterfield Third Filing
Final Drainage Report 10
V. CONCLUSIONS
A. Compliance with Standards
1. The drainage design proposed with the proposed project complies with the City of Fort
Collins’ Stormwater Criteria Manual.
2. The drainage design proposed with this project complies with requirements for the
Dry Creek Basin.
3. The drainage plan and stormwater management measures proposed with the
proposed development are compliant with all applicable State and Federal regulations
governing stormwater discharge.
4. A variance is sought a portion of New Vine Drive to be allowed to exceed 2-year street
capacity by a depth of 0.25 inch, as discussed in Section IV.A.4.
B. Drainage Concept
1. The drainage design proposed with this project will effectively limit any potential
damage associated with its stormwater runoff by providing detention and water
quality mitigation features.
2. The drainage concept for the proposed development is consistent with requirements
for the Dry Creek Basin.
Waterfield Third Filing
Final Drainage Report 11
References
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
APPENDIX A
HYDROLOGIC COMPUTATIONS
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 889-001
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC
Asphalt ……....……………...……….....…...……………….………………………………… 0.95 100% Date:
Concrete …….......……………….….……….………………..….……………………………… 0.95 90%
Gravel ……….…………………….….…………………………..……………………………… 0.50 40%
Roofs …….…….………………..……………….…………………………………………….. 0.95 90%
Pavers…………………………...………………..…………………………………………….. 0.40 22%
Lawns and Landscaping
Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0%
Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf
= 1.00 100-year Cf = 1.25
Basin ID
Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1 1780641 40.88 11.000 5.000 5.000 0.000 19.878 0.61 0.61 0.76 49%
2 233407 5.36 0.627 0.449 1.010 0.000 3.272 0.52 0.52 0.65 36%
3 519624 11.93 1.437 0.796 1.469 0.000 8.227 0.47 0.47 0.58 29%
4 301114 6.91 0.230 1.599 1.240 0.000 3.844 0.56 0.56 0.70 40%
5 260471 5.98 0.434 0.118 0.000 0.000 5.427 0.31 0.31 0.39 9%
6 114325 2.62 0.389 0.195 0.321 0.000 1.719 0.49 0.49 0.61 33%
7 243526 5.59 Assumed 80% imperviousness for future development area within 0.85 0.85 1.00 80%
8 366211 8.41 Basins 7 and 8 0.85 0.85 1.00 80%
9 51924 1.19 0.434 0.118 0.000 0.000 0.640 0.57 0.57 0.72 45%
10a 76097 1.75 0.297 0.157 0.275 0.000 1.018 0.54 0.54 0.68 39%
Overland Flow, Time of Concentration:
Project: 889-001
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = Ti + Tt (Equation RO-2)
Velocity (Gutter Flow), V = 20·S½
Velocity (Swale Flow), V = 15·S½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Is Length
>500' ?
C*Cf
(2-yr
Cf=1.00)
C*Cf
(10-yr
Cf=1.00)
C*Cf
(100-yr
Cf=1.25)
Length,
L
(ft)
Slope,
S
(%)
Ti
2-yr
(min)
Ti
10-yr
(min)
Ti
100-yr
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
Tt
(min)
2-yr
Tc
Rational Method Equation: Project: 889-001
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 40.88 36 36 33 0.61 0.61 0.76 1.16 1.98 4.24 28.9 49.3 132.1
2 2 5.36 12 12 9 0.52 0.52 0.65 2.09 3.57 8.03 5.9 10.0 28.1
3 3 11.93 20 20 17 0.47 0.47 0.58 1.63 2.78 6.10 9.1 15.5 42.5
4 4 6.91 14 14 11 0.56 0.56 0.70 1.95 3.34 7.42 7.6 12.9 36.0
5 5 5.98 21 21 19 0.31 0.31 0.39 1.56 2.67 5.75 2.9 5.0 13.5
6 6 2.62 12 12 10 0.49 0.49 0.61 2.05 3.50 7.72 2.6 4.5 12.4
7 7 5.59 22 22 21 0.85 0.85 1.00 1.53 2.61 5.46 7.3 12.4 30.5
8 8 8.41 26 26 24 0.85 0.85 1.00 1.42 2.42 5.09 10.1 17.3 42.8
9 9 1.19 10 10 8 0.57 0.57 0.72 2.26 3.86 8.59 1.5 2.6 7.4
10a 10a 1.75 12 12 9 0.54 0.54 0.68 2.09 3.57 8.03 2.0 3.4 9.5
10b 10b 1.72 12 12 10 0.58 0.58 0.72 2.05 3.50 7.88 2.0 3.5 9.8
11 11 9.07 15 15 12 0.58 0.58 0.73 1.87 3.19 7.16 9.8 16.8 47.1
12 12 738 15 15 13 055 055 069 187 319 704 76 12 9 35 6
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
DEVELOPED RUNOFF COMPUTATIONS
C100
Design
Point
Flow,
Q100
(cfs)
Flow,
Q2
(cfs)
10-yr
Tc
(min)
2-yr
Tc
(min)
C2
Flow,
Q10
(cfs)
Intensity,
i100
(in/hr)
Basin(s)
ATC
February 1, 2014
Q C f C i A
12 12 7.38 15 15 13 0.55 0.55 0.69 1.87 3.19 7.04 7.6 12.9 35.6
13 13 1.52 15 15 13 0.33 0.33 0.41 1.90 3.24 6.92 1.0 1.6 4.4
APPENDIX B
WATER WAWASTREET CAPACITY CALCULATIONS
Project: 889‐001
By: ATC
Date: 2/1/2014
Design Street Street Street 2‐Yr 2‐Yr Comment
Point Name Section Slope Flow Capacity
STREET CAPACITY SUMMARY
(CFS) (CFS)
2 Mandarin Dr. Half Street ‐15 ft 0.80% 5.90 6.30 Flow < Cap.
3 Rosybill Dr. Half Street ‐15 ft 1.10% 6.10 7.40 Flow < Cap.
4 Garganey Dr. Half Street ‐20 ft 1.20% 7.60 15.00 Flow < Cap.
6 Mandarin Dr. Half Street ‐15 ft 0.60% 2.60 5.40 Flow < Cap.
7 Garganey Dr. Half Street ‐20 ft 1.20% 7.30 15.00 Flow < Cap.
8 New Vine Dr. Half Street ‐32 ft 0.60% 10.10 8.90 Flow > Cap.
11 (*Portion) Shearwater Dr. Half Street ‐15 ft 0.50% 2.45 5.00 Flow < Cap.
12 (*Portion) Aleutian Dr. Half Street ‐15 ft 0.75% 5.26 6.30 Flow < Cap.
*Portion of basin evaluated for street capacity calculations
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.004 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 4.4 5.3 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:25 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.005 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 5.0 5.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:25 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.006 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 5.4 6.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:26 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.007 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 5.9 7.0 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:26 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.008 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 6.3 7.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:27 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.009 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 6.7 7.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:27 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.010 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 7.0 8.3 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:28 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.012 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 7.7 9.1 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:28 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.014 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 8.3 9.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:28 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.016 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 8.9 10.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:29 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.018 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 9.4 11.2 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:29 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.020 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 9.9 11.8 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:29 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.022 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 10.4 12.4 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:30 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.024 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 10.9 12.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:30 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.026 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 11.3 13.4 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:31 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.028 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 11.8 13.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:31 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 15.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.030 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.0 15.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 12.2 14.4 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 15-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:31 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.004 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 4.5 80.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:15 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.005 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 5.1 90.0 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:15 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.006 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 5.5 98.6 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:16 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.007 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 6.0 106.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:17 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.008 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 6.4 113.9 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:17 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.009 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 6.8 120.8 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:18 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.010 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 7.2 127.3 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:18 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.012 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 7.8 139.5 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:19 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.014 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 8.5 150.6 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:19 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.016 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 9.1 160.6 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:19 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.018 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 9.6 155.0 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:20 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.020 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 10.1 150.2 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:20 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.022 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 10.6 146.0 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:21 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.024 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 11.1 142.2 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:21 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.026 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 11.5 138.8 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:21 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.028 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 12.0 135.8 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:22 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 4.75 inches
Distance from Curb Face to Street Crown TCROWN = 18.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.030 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 14.1 18.0 ft
Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 5.6 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow = 12.4 133.0 cfs
Warning 02: Max Allowable Depth for Minor Storm is greater than the Curb Height.
Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Residential - 18-ft Half Street Section
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap, Q-Allow 2/19/2014, 1:22 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 6.00 inches
Distance from Curb Face to Street Crown TCROWN = 32.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.006 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 25.0 30.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.00 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 8.9 39.6 cfs
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Vine Drive Half Street
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap-vine dr, Q-Allow 2/19/2014, 2:54 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.020 ft/ft
Manning's Roughness Behind Curb nBACK = 0.016
Height of Curb at Gutter Flow Line HCURB = 6.25 inches
Distance from Curb Face to Street Crown TCROWN = 32.0 ft
Gutter Width W = 2.00 ft
Street Transverse Slope SX = 0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.098 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO = 0.006 ft/ft
Manning's Roughness for Street Section nSTREET = 0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX = 25.0 30.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.25 12.3 inches
Allow Flow Depth at Street Crown (leave blank for no) check = yes
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 10.2 38.9 cfs
WARNING: MAJOR STORM max. allowable capacity is less than flow given on sheet 'Q-Peak'
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
STREET CAPACITY
Vine Drive Half Street
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak'
UD Inlet 3.1-strt cap-vine dr, Q-Allow 2/19/2014, 2:54 PM
APPENDIX C
INLET CALCULATIONS
Project: 889‐001
By: ATC
Date: 4/1/2014
Inlet Inlet Inlet Design Design
ID Type Condition Storm Flow Inlet Capacity
(CFS) (CFS)
B3‐1W Double Combination Inlet Sump 10‐yr 1.70 6.20
B3‐1E Double Combination Inlet Sump 10‐yr 1.60 6.20
B5 Double Area Inlet Sump 10‐yr 2.70 4.97
C5 Double Combination Inlet Sump 10‐yr 6.10 6.20
C6 Double Combination Inlet Sump 10‐yr 6.00 6.20
E1 Double Combination Inlet Sump 2‐yr 9.80 6.20
E2 Single Area Inlet Sump 2‐yr 0.51 2.49
E3 Double Combination Inlet Sump 2‐yr 3.80 6.20
E4 Double Combination Inlet Sump 2‐yr 3.80 6.20
INLET CAPACITY SUMMARY
Area Inlet Performance Curve:
Double Area Inlet
Governing Equations:
At low flow depths, the inlet will act like a weir governed by the following equation:
* where P = 2(L + W)
* where H corresponds to the depth of water above the flowline
At higher flow depths, the inlet will act like an orifice governed by the following equation:
* where A equals the open area of the inlet grate
* where H corresponds to the depth of water above the centroid of the cross-sectional area (A)
The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown.
However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation
will cross at a certain flow depth. The two curves can be found below:
If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir.
Input Parameters:
Type of Grate: Area Inlet
Length of Grate (ft): 1.98
Width of Grate (ft): 2.71
Open Area of Grate (ft
2
): 3.75
Flowline Elevation (ft): 0.000
Allowable Capacity: 50%
Depth vs. Flow:
Depth Above Inlet (ft)
Elevation
(ft)
Shallow
Weir Flow
(cfs)
Orifice
Flow
(cfs)
Actual
Flow
(cfs)
0.00 0.00 0.00 0.00 0.00
0.10 0.10 0.44 3.19 0.44
0.20 0.20 1.26 4.51 1.26
0.30 0.30 2.31 5.53 2.31
0.40 0.40 3.56 6.38 3.56
0.50 0.500 4.97 7.13 4.97
0.60 0.60 6.54 7.81 6.54
0.70 0.70 8.24 8.44 8.24
0.80 0.80 10.07 9.02 9.02
0.90 0.90 12.01 9.57 9.57
1.00 1.000 14.07 10.09 10.09
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Discharge (cfs)
Stage (ft)
Stage - Discharge Curves
Weir Flow
Orifice Flow
Project =
Inlet ID =
Design Information (Input) MINOR MAJOR
Type of Inlet Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal
= 2.00 2.00 inches
Number of Unit Inlets (Grate or Curb Opening) No = 2 2
Water Depth at Flowline (outside of local depression) Flow Depth = 6.0 12.0 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo
(G) = 3.00 3.00 feet
Width of a Unit Grate Wo
= 2.00 2.00 feet
Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio
= 0.31 0.31
Warning 3 Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf
(G) = 0.50 0.50
Grate Weir Coefficient (typical value 2.15 - 3.60) Cw
(G) = 3.60 3.60
Grate Orifice Coefficient (typical value 0.60 - 0.80) Co
(G) = 0.60 0.60
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo
(C) = 3.00 3.00 feet
Height of Vertical Curb Opening in Inches Hvert
= 6.50 6.50 inches
Height of Curb Orifice Throat in Inches Hthroat
= 5.25 5.25 inches
Angle of Throat (see USDCM Figure ST-5) Theta = 0.00 0.00 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet) Wp
= 2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10) Cf
(C) = 0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.6) Cw
(C) = 3.70 3.70
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co
(C) = 0.66 0.66
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition) Qa
= 6.2 21.4 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q PEAK) Q
PEAK REQUIRED = 6.0 16.0 cfs
Warning 1: Dimension entered is not a typical dimension for inlet type specified.
Warning 3: Clogging factor is not in the recommended value for inlet type specified.
INLET IN A SUMP OR SAG LOCATION
889-001
Combo Inlet - Double
Denver No. 16 Combination
H-Vert
H-Curb
W
Lo (C)
Lo (G)
Wo
WP
UD Inlet 3.1-comboinlet-double, Inlet In Sump 2/18/2014, 4:40 PM
APPENDIX D
STORM LINE CALCULATIONS
Hydraflow Plan View
Project File: Storm A.stm No. Lines: 1 02-18-2014
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 ST Pipe A1 1.40 15 c 388.5 4949.54 4951.55 0.517 4949.99 4952.02 0.08 4952.02 End
Project File: Storm A.stm Number of lines: 1 Run Date: 02-18-2014
NOTES: c = cir; e = ellip; b = box; Return period = 2 Yrs.
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.Hydraflow com) Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 15 1.40 4949.54 4949.99 0.45 0.40 3.53 0.19 4950.18 0.431 388 4951.55 4952.02 0.47** 0.43 3.29 0.17 4952.19 0.431 0.431 n/a 0.50 0.08
Project File: Storm A.stm Number of lines: 1 Run Date: 02-18-2014
Notes: ; ** Critical depth.
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Hydraflow Plan View
Project File: Storm B.stm No. Lines: 7 02-18-2014
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 ST Pipe B1 8.30 30 c 81.0 4940.35 4943.46 3.838 4940.88 4944.42 0.33 4944.42 End
2 ST Pipe B2 8.30 24 c 265.8 4943.43 4944.76 0.500 4944.67 4945.78 n/a 4945.78 j 1
3 ST Pipe B3 5.00 24 c 121.7 4944.76 4945.37 0.502 4946.15 4946.20 0.18 4946.39 2
4 ST Pipe B4 5.00 24 c 179.7 4945.37 4946.27 0.501 4946.60 4947.06 n/a 4947.06 j 3
5 ST Pipe B5 2.30 15 c 233.4 4947.02 4948.42 0.600 4947.59 4949.03 n/a 4949.03 j 4
6 ST Pipe B3-1E 1.60 15 c 25.6 4944.76 4944.89 0.509 4946.17* 4946.18* 0.03 4946.21 2
7 ST Pipe B3-1W 1.70 15 c 6.4 4944.76 4944.79 0.475 4946.16* 4946.17* 0.03 4946.20 2
Project File: Storm B.stm Number of lines: 7 Run Date: 02-18-2014
NOTES: c = cir; e = ellip; b = box; Return period = 2 Yrs. ; *Surcharged (HGL above crown). ; j - Line contains hyd. jump.
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.Hydraflow com) Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 30 8.30 4940.35 4940.88 0.53 0.77 10.84 1.83 4942.71 0.353 81.0 4943.46 4944.42 0.96** 1.74 4.76 0.35 4944.78 0.353 0.353 n/a 0.93 0.33
2 24 8.30 4943.43 4944.67 1.24 2.04 4.07 0.26 4944.92 0.232 266 4944.76 4945.78 j 1.02** 1.61 5.15 0.41 4946.19 0.429 0.330 n/a 1.00 0.41
3 24 5.00 4944.76 4946.15 1.39 2.34 2.14 0.07 4946.23 0.060 122 4945.37 4946.20 0.83 1.23 4.05 0.25 4946.46 0.319 0.190 0.231 0.72 0.18
4 24 5.00 4945.37 4946.60 1.23 2.03 2.47 0.09 4946.70 0.086 180 4946.27 4947.06 j 0.79** 1.16 4.32 0.29 4947.35 0.381 0.233 n/a 0.99 0.29
5 15 2.30 4947.02 4947.59 0.57* 0.55 4.21 0.28 4947.87 0.590 233 4948.42 4949.03 j 0.61** 0.59 3.89 0.24 4949.26 0.478 0.534 n/a 1.00 n/a
6 15 1.60 4944.76 4946.17 1.25 1.23 1.30 0.03 4946.19 0.052 25.6 4944.89 4946.18 1.25 1.23 1.30 0.03 4946.21 0.052 0.052 0.013 1.00 0.03
7 15 1.70 4944.76 4946.16 1.25 1.23 1.39 0.03 4946.19 0.059 6.4 4944.79 4946.17 1.25 1.23 1.39 0.03 4946.20 0.059 0.059 0.004 1.00 0.03
Project File: Storm B.stm Number of lines: 7 Run Date: 02-18-2014
Notes: * Normal depth assumed.; ** Critical depth.; j-Line contains hyd. jump.
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Bottom Width B = 6.00 feet
Left Side Slope Z1 = 4.00 ft/ft
Right Side Slope Z2 = 4.00 ft/ft
Manning's n or SCS Retardance Curve n = 0.035
Longitudinal Slope S = 0.0100 ft/ft
Flow Manning's Flow Wetted Hydraulic Flow Flow Froude
Depth Roughness Area Perimeter Radius Velocity rate Number
YnA P R VQ Fr
(ft) (sq ft) (ft) (ft) (fps) (cfs)
0.00 0.0350 0.00 6.00 0.00 0.0 0.0 0.00
0.05 0.0350 0.31 6.41 0.05 0.6 0.2 0.45
0.10 0.0350 0.64 6.82 0.09 0.9 0.6 0.50
0.15 0.0350 0.99 7.24 0.14 1.1 1.1 0.54
020 0 0350 136 765 018 13 18 056
RATING CURVE FOR TRAPEZOIDAL CHANNEL
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0 5 10 15 20 25 30 35 40
Depth (ft)
Flow (cfs)
Depth vs. Flow
0.20 0.0350 1.36 7.65 0.18 1.3 1.8 0.56
0.25 0.0350 1.75 8.06 0.22 1.5 2.7 0.58
0.30 0.0350 2.16 8.47 0.25 1.7 3.7 0.59
0.35 0.0350 2.59 8.89 0.29 1.9 4.8 0.61
0.40 0.0350 3.04 9.30 0.33 2.0 6.1 0.62
0.45 0.0350 3.51 9.71 0.36 2.2 7.6 0.63
0.50 0.0350 4.00 10.12 0.40 2.3 9.1 0.64
0.55 0.0350 4.51 10.54 0.43 2.4 10.9 0.65
0.60 0.0350 5.04 10.95 0.46 2.5 12.8 0.65
0.65 0.0350 5.59 11.36 0.49 2.6 14.8 0.66
0.70 0.0350 6.16 11.77 0.52 2.8 17.0 0.67
0.75 0.0350 6.75 12.18 0.55 2.9 19.3 0.67
0.80 0.0350 7.36 12.60 0.58 3.0 21.8 0.68
0.85 0.0350 7.99 13.01 0.61 3.1 24.5 0.68
0.90 0.0350 8.64 13.42 0.64 3.2 27.3 0.69
0.95 0.0350 9.31 13.83 0.67 3.3 30.4 0.69
1.00 0.0350 10.00 14.25 0.70 3.4 33.5 0.70
UD-Channels_v1.04-inlet 100yr overflow, Rating 2/19/2014, 11:51 AM
VR Product
0
0.0272393
0.0821838
0.1542003
0 2386812
RATING CURVE FOR TRAPEZOIDAL CHANNEL
0 040
00.511.522.5
40
VR Product
Velocity, Flow Depth, Froude Number & Manning's n vs. Discharge
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
00.511.522.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.00 0.20 0.40 0.60 0.80 1.00 1.20
Mannin'g n
VR Product
Velocity (fps), Froude Number
Flow Depth (ft)
Velocity, Froude Number, & Manning's n vs. Flow Depth
Velocity (fps) Froude Number Manning's n
0.2386812
0.332902
0.4350821
0.5439918
0.6587487
0.778702
0.9033606
1.0323465
1.1653644
1.3021795
1.4426029
1.5864807
1.7336857
1.8841117
2.0376694
2.1942822
2.3538844
0.000
0.005
0.010
0.015
0.020
Hydraflow Plan View
Project File: Storm C.stm No. Lines: 2 02-18-2014
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 ST Pipe C3 12.10 15 c 36.3 4942.08 4943.20 3.084 4943.15 4944.42 n/a 4944.42 End
2 ST Pipe C4 6.10 15 c 32.0 4943.20 4943.36 0.499 4945.57* 4945.81* 0.38 4946.19 1
Project File: Storm C.stm Number of lines: 2 Run Date: 02-18-2014
NOTES: c = cir; e = ellip; b = box; Return period = 2 Yrs. ; *Surcharged (HGL above crown).
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.Hydraflow com) Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 15 12.10 4942.08 4943.15 1.07 1.12 10.85 1.83 4944.98 2.654 36.3 4943.20 4944.42 1.22** 1.22 9.93 1.53 4945.95 2.655 2.654 n/a 0.15 n/a
2 15 6.10 4943.20 4945.57 1.25 1.23 4.97 0.38 4945.95 0.761 32.0 4943.36 4945.81 1.25 1.23 4.97 0.38 4946.19 0.760 0.761 0.243 1.00 0.38
Project File: Storm C.stm Number of lines: 2 Run Date: 02-18-2014
Notes: ; ** Critical depth.
Hydraflow Storm Sewers 2005
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Hydraflow Plan View
Project File: Storm E.stm No. Lines: 4 04-08-2014
Hydraflow Storm Sewers 2005
Storm Sewer Summary Report Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor HGL Dns
No. rate size length EL Dn EL Up slope down up loss Junct line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) (ft) No.
1 ST Pipe E1 14.31 24 c 33.8 4943.99 4944.16 0.502 4945.33 4945.57 0.08 4945.66 End
2 ST Pipe E2 10.51 18 c 30.0 4944.16 4944.31 0.500 4945.67* 4945.93* 0.08 4946.01 1
3 ST Pipe E3 6.71 18 c 33.0 4944.31 4944.40 0.272 4946.34* 4946.45* 0.03 4946.49 2
4 ST Pipe E3 (1) 6.20 18 c 282.8 4944.40 4945.23 0.294 4946.52* 4947.36* 0.19 4947.55 3
Project File: Storm E.stm Number of lines: 4 Run Date: 04-08-2014
NOTES: c = cir; e = ellip; b = box; Return period = 2 Yrs. ; *Surcharged (HGL above crown).
Hydraflow Storm Sewers 2005
Hydraulic Grade Line Computations Page 1
Line Size Q Downstream Len Upstream Check JL Minor
coeff loss
Invert HGL Depth Area Vel Vel EGL Sf Invert HGL Depth Area Vel Vel EGL Sf Ave Enrgy
elev elev head elev elev elev head elev Sf loss
(in) (cfs) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (ft) (ft) (ft) (ft) (sqft) (ft/s) (ft) (ft) (%) (%) (ft) (K) (ft)
1 24 14.31 4943.99 4945.33 1.34 2.24 6.40 0.64 4945.97 0.548 33.8 4944.16 4945.57 1.41 2.37 6.03 0.56 4946.14 0.474 0.511 0.173 0.15 0.08
2 18 10.51 4944.16 4945.67 1.50 1.77 5.95 0.55 4946.22 0.854 30.0 4944.31 4945.93 1.50 1.77 5.95 0.55 4946.48 0.854 0.854 0.256 0.15 0.08
3 18 6.71 4944.31 4946.34 1.50 1.77 3.80 0.22 4946.56 0.348 33.0 4944.40 4946.45 1.50 1.77 3.80 0.22 4946.68 0.348 0.348 0.115 0.15 0.03
4 18 6.20 4944.40 4946.52 1.50 1.77 3.51 0.19 4946.71 0.297 283 4945.23 4947.36 1.50 1.77 3.51 0.19 4947.55 0.297 0.297 0.840 1.00 0.19
Project File: Storm E.stm Number of lines: 4 Run Date: 04-08-2014
Hydraflow Storm Sewers 2005
Circular
D or Da,
Pipe
Diameter
(ft)
H or Ha,
Culvert
Height
(ft)
W,
Culvert
Width
(ft)
Yt/D Q/D
1.5
Q/D
2.5 Y
t/H Q/WH
0.5
Storm Line A 1.40 1.25 0.50 0.40 1.00 0.80 N/A N/A 6.70 0.80 0.28 ‐4.62 Type M 5.00 7.00 1.5
Storm Line B 8.30 2.50 1.00 0.40 2.10 0.84 N/A N/A 6.70 0.84 1.66 ‐5.63 Type M 10.00 12.00 1.5
Storm Line C 12.10 1.25 0.50 0.40 8.66 6.93 N/A N/A 4.20 6.93 2.42 15.08 Type M 16.00 14.00 1.5
Storm Line E 14.30 2.00 0.80 0.40 5.06 2.53 N/A N/A 5.30 2.53 2.86 8.35 Type M 10.00 12.00 1.5
OUTPUT
Spec
Length
of
Riprap
(ft)
Box Culvert
CALCULATIONS FOR RIPRAP PROTECTION AT PIPE OUTLETS
Circular
Pipe
(Figure MD‐21)
Rectangular
Pipe
(Figure MD‐22) Spec
Width
of
Riprap
(ft)
2*d50,
Depth
of
Riprap
(ft)
for L/2
Froude
Parameter
Q/D
2.5
Max 6.0
or
Q/WH
1.5
Max 8.0
Riprap
Type
(From
Figure
APPENDIX E
WATER QUALITY AND LID SUPPORTING DOCUMENTATION
WATER QUALITY POND DESIGN CALCULATIONS
Pond 1 (Wet Pond)
Project: 889-001
By: ATC
Date: 4/1/14
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 87.680 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 47.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.4700 <-- CALCULATED
WQCV (watershed inches) = 0.198 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 1.738 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 0.210 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = N/A <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = N/A <-- INPUT from Figure 5
n = N/A <-- INPUT from Figure 5
t (in) = N/A <-- INPUT from Figure 5
number of rows = N/A <-- CALCULATED from WQ Depth and row spacing
WATER QUALITY POND DESIGN CALCULATIONS
Forebay #1 (North)
Project: 889-001
By: ATC
Date: 4/1/14
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 7.980 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 34.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.3400 <-- CALCULATED
WQCV (watershed inches) = 0.150 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.100 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
Volume Provided (ac-ft) = 0.240
WATER QUALITY POND DESIGN CALCULATIONS
Forebay #2 (South)
Project: 889-001
By: ATC
Date: 4/1/14
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 11.210 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 70.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.7000 <-- CALCULATED
WQCV (watershed inches) = 0.220 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.206 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
Volume Provided (ac-ft) = 0.270
WATER QUALITY POND DESIGN CALCULATIONS
Pond 3
Project: 889-001
By: ATC
Date: 2/1/14
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 26.260 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 36.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.3600 <-- CALCULATED
WQCV (watershed inches) = 0.169 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.444 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = 1.500 <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = 1.356 <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = 1 1/4 <-- INPUT from Figure 5
n = 5 <-- INPUT from Figure 5
t (in) = 1/4 <-- INPUT from Figure 5
number of rows = 1 <-- CALCULATED from WQ Depth and row spacing
Calculating the WQCV and Volume Reduction Chapter 3
3-6 Urban Drainage and Flood Control District August 2011
Urban Storm Drainage Criteria Manual Volume 3
Once the WQCV in watershed inches is found from Figure 3-2 or using Equation 3-1 and/or 3-2, the
required BMP storage volume in acre-feet can be calculated as follows:
𝑉 = �
WQCV
12
� 𝐴 Equation 3-3
Where:
V = required storage volume (acre-ft)
A = tributary catchment area upstream (acres)
WQCV = Water Quality Capture Volume (watershed inches)
Figure 3-2. Water Quality Capture Volume (WQCV) Based on BMP Drain Time
Garganey Street
LID Supporting Documentation
MODIFIED RESIDENTIAL STREET
GARGANEY DRIVE
PART 2 - SOIL MA
PART 3 - EXECUT
707 BIO-RETENTION SOIL LAYERING
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-1
Urban Storm Drainage Criteria Manual Volume 3
Terminology
The term bioretention refers to the
treatment process although it is also
frequently used to describe a BMP
that provides biological uptake and
retention of the pollutants found in
stormwater runoff. This BMP is
frequently referred to as a porous
landscape detention (PLD) area or
rain garden.
Photograph B-1. This recently constructed rain garden provides
bioretention of pollutants, as well as an attractive amenity for a
residential building. Treatment should improve as vegetation matures.
Description
A BMP that utilizes bioretention is an
engineered, depressed landscape area
designed to capture and filter or infiltrate
the water quality capture volume
(WQCV). BMPs that utilize bioretention
are frequently referred to as rain gardens
or porous landscape detention areas
(PLDs). The term PLD is common in the
Denver metropolitan area as this manual
first published the BMP by this name in
1999. In an effort to be consistent with
terms most prevalent in the stormwater
industry, this document generally refers to
the treatment process as bioretention and
to the BMP as a rain garden.
The design of a rain garden may provide
detention for events exceeding that of the WQCV. There are
generally two ways to achieve this. The design can provide the
flood control volume above the WQCV water surface elevation,
with flows bypassing the filter usually by overtopping into an
inlet designed to restrict the peak flow for a larger event (or
events). Alternatively, the design can provide and slowly release
the flood control volume in an area downstream of one or more
rain gardens.
This infiltrating BMP requires consultation with a
geotechnical engineer when proposed near a structure. A
geotechnical engineer can assist with evaluating the suitability of
soils, identifying potential impacts, and establishing minimum
distances between the BMP and structures.
Bioretention
(Rain Garden)
Functions
LID/Volume Red. Yes
WQCV Capture Yes
WQCV+Flood Control Yes
Fact Sheet Includes
EURV Guidance No
Typical Effectiveness for Targeted
Pollutants3
Sediment/Solids Very Good1
Nutrients Moderate
Total Metals Good
Bacteria Moderate
T-3 Bioretention
B-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Site Selection
Bioretention can be provided in a variety of areas within new
developments, or as a retrofit within an existing site. This
BMP allows the WQCV to be treated within areas
designated for landscape (see design step 7 for appropriate
vegetation). In this way, it is an excellent alternative to
extended detention basins for small sites. A typical rain
garden serves a tributary area of one impervious acre or less,
although they can be designed for larger tributary areas.
Multiple installations can be used within larger sites. Rain
gardens should not be used when a baseflow is anticipated.
They are typically small and installed in locations such as:
Parking lot islands
Street medians
Landscape areas between the road and a detached walk
Planter boxes that collect roof drains
Bioretention requires a stable watershed. Retrofit
applications are typically successful for this reason. When
the watershed includes phased construction, sparsely
vegetated areas, or steep slopes in sandy soils, consider
another BMP or provide pretreatment before runoff from
these areas reaches the rain garden. The surface of the rain
garden should be flat. For this reason, rain gardens can be
more difficult to incorporate into steeply sloping terrain;
however, terraced applications of these facilities have been
successful in other parts of the country.
When bioretention (and other BMPs used for infiltration) are
located adjacent to buildings or pavement areas, protective measures should be implemented to avoid
adverse impacts to these structures. Oversaturated subgrade soil underlying a structure can cause the
structure to settle or result in moisture-related problems. Wetting of expansive soils or bedrock can cause
swelling, resulting in structural movements. A geotechnical engineer should evaluate the potential impact
of the BMP on adjacent structures based on an evaluation of the subgrade soil, groundwater, and bedrock
conditions at the site. Additional minimum requirements include:
In locations where subgrade soils do not allow infiltration, the growing medium should be underlain
by an underdrain system.
Where infiltration can adversely impact adjacent structures, the filter layer should be underlain by an
underdrain system designed to divert water away from the structure.
In locations where potentially expansive soils or bedrock exist, placement of a rain garden adjacent to
structures and pavement should only be considered if the BMP includes an underdrain designed to
divert water away from the structure and is lined with an essentially impermeable geomembrane liner
designed to restrict seepage.
Benefits
Bioretention uses multiple
treatment processes to remove
pollutants, including
sedimentation, filtering,
adsorption, evapotranspiration,
and biological uptake of
constituents.
Volumetric stormwater treatment
is provided within portions of a
site that are already reserved for
landscaping.
There is a potential reduction of
irrigation requirements by taking
advantage of site runoff.
Limitations
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-3
Urban Storm Drainage Criteria Manual Volume 3
Designing for Maintenance
Recommended maintenance practices for all BMPs are in Chapter
6 of this manual. During design, the following should be
considered to ensure ease of maintenance over the long-term:
Do not put a filter sock on the underdrain. This is not
necessary and can cause the BMP to clog.
The best surface cover for a rain garden is full vegetation. Do
not use rock mulch within the rain garden because sediment
build-up on rock mulch tends to inhibit infiltration and require
frequent cleaning or removal and replacement. Wood mulch
handles sediment build-up better than rock mulch; however,
wood mulch floats and may clog the overflow depending on
the configuration of the outlet, settle unevenly, or be
transported downstream. Some municipalities may not allow wood mulch for this reason.
Consider all potential maintenance requirements such as mowing (if applicable) and replacement of
the growing medium. Consider the method and equipment for each task required. For example, in a
large rain garden where the use of hand tools is not feasible, does the shape and configuration of the
rain garden allow for removal of the growing medium using a backhoe?
Provide pre-treatment when it will reduce the extent and frequency of maintenance necessary to
maintain function over the life of the BMP. For example, if the site is larger than 2 impervious acres,
prone to debris or the use of sand for ice control, consider a small forebay.
Make the rain garden as shallow as possible. Increasing the depth unnecessarily can create erosive
side slopes and complicate maintenance. Shallow rain gardens are also more attractive.
Design and adjust the irrigation system (temporary or permanent) to provide appropriate water for the
establishment and maintenance of selected vegetation.
Design Procedure and Criteria
The following steps outline the design procedure and criteria, with Figure B-1 providing a corresponding
cross-section.
1. Basin Storage Volume: Provide a storage volume based on a 12-hour drain time.
Find the required WQCV (watershed inches of runoff). Using the imperviousness of the tributary
area (or effective imperviousness where LID elements are used upstream), use Figure 3-2 located
in Chapter 3 of this manual to determine the WQCV based on a 12-hour drain time.
Calculate the design volume as follows:
𝑉𝑉 = �
WQCV
12
� 𝐴𝐴 Equation B-1
Where:
V= design volume (ft3)
Is Pretreatment Needed
Designing the inflow gutter to
the rain garden at a minimal
slope of 0.5% can facilitate
sediment and debris deposition
prior to flows entering the BMP.
Be aware, this will reduce
maintenance of the BMP, but
may require more frequent
sweeping of the gutter to ensure
that the sediment does not
impede flow into the rain
garden.
T-3 Bioretention
B-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Benefits of Shredded Paper in Rain Garden Growing Media
Shredded paper, similar to other woody materials, captures nutrients from the compost and
slowly releases them as the paper decomposes. Compost alone will leach more nutrients than
desired.
As the paper decomposes, nutrients stored in the material are available to the vegetation.
Paper temporarily slows the infiltration rate of the media and retains moisture, providing
additional time for a young root system to benefit from moisture in the growing media.
A = area of watershed tributary to the rain garden (ft2)
2. Basin Geometry: A maximum WQCV ponding depth of 12 inches is recommended to maintain
vegetation properly. Provide an inlet or other means of overflow at this elevation. Depending on the
type of vegetation planted, a greater depth may be utilized to detain larger (more infrequent) events.
The bottom surface of the rain garden, also referred to here as the filter area, should be flat. Sediment
will reside on the filter area of the rain garden; therefore, if the filter area is too small, it may clog
prematurely. Increasing the filter area will reduce clogging and decrease the frequency of
maintenance. Equation B-2 provides a minimum filter area allowing for some of the volume to be
stored beyond the area of the filter (i.e., above the sideslopes of the rain garden).
Note that the total surcharge volume provided by the design must also equal or exceed the
design volume. Use vertical walls or slope the sides of the basin to achieve the required volume.
Use the rain garden growing medium described in design step 3 only on the filter area because this
material is more erosive than typical site soils. Sideslopes should be no steeper than 4:1
(horizontal:vertical).
𝐴𝐴 ≥ (2/3)
V
1 foot
Equation B-2
Where:
V= design volume (ft3)
A = minimum filter area (flat surface area) (ft2)
The one-foot dimension in this equation represents the maximum recommended WQCV depth in the
rain garden. The actual design depth may differ; however, it is still appropriate to use a value of one
foot when calculating the minimum filter area.
3. Growing Medium: For partial and no infiltration sections, provide a minimum of 18 inches of
growing medium to enable establishment of the roots of the vegetation (see Figure B-1). Previous
versions of this manual recommended a mix of 85% sand and 15% peat (by volume). Peat is a
material that typically requires import to Colorado and mining peat has detrimental impacts to the
environment (Mazerolle 2002). UDFCD partnered with the University of Colorado to perform a
study to find a sustainable material to replace peat. The study was successful in finding a
replacement that performed well for filtering ability, clogging characteristics, as well as seed
germination. This mixture consists of 85% coarse sand and a 15% compost/shredded paper mixture
(by volume). The study used thin (approximately 1/4 inch) strips of loosely packed shredded paper
mixed with an equal volume of compost. Based on conversations with local suppliers, compost
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-5
Urban Storm Drainage Criteria Manual Volume 3
containing shredded paper is not an uncommon request, although not typically provided in the
proportions recommended in this BMP Fact Sheet. Compost suppliers have access to shredded paper
through document destruction companies and can provide a mixture of Class 1 compost and shredded
paper. The supplier should provide the rain garden compost mixture premixed with coarse sand. On-
site mixing is not recommended.
Rain Garden Compost Mixture (by volume)
50% Class 1 STA registered compost (approximate bulk density 1000 lbs/CY)
50% loosely packed shredded paper (approximate bulk density 50 to 100 lbs/CY)
When using diamond cut shredded paper or tightly packed paper, use the bulk densities provided to
mix by weight.
The supplier should premix the rain garden compost mixture (above) with coarse sand, in the
following proportions, prior to delivery to the site:
Rain Garden Growing Medium
15% rain garden compost mixture described above (by volume)
85% coarse sand (either Class C Filter Material per Table B-2 or sand meeting ASTM C-33) (by
volume)
Table B-1 provides detailed information on Class 1 compost. Be aware, regular testing is not
required to allow a compost supplier to refer to a product as a specific STA class. However, regular
testing is required and performed through the United States Compost Council (USCC) Seal of Testing
Assurance (STA) Program to be a STA registered compost. To ensure Class 1 characteristics, look
for a Class 1 STA registered compost.
Other Rain Garden Growing Medium Amendments
The growing medium described above is designed for filtration ability, clogging characteristics, and
vegetative health. It is important to preserve the function provided by the rain garden growing
medium when considering additional materials for incorporation into the growing medium or into the
standard section shown in Figure B-1. When desired, amendments may be included to improve water
quality or to benefit vegetative health as long as they do not add nutrients, pollutants, or modify the
infiltration rate. For example, a number of products, including steel wool, capture and retain
dissolved phosphorus (Erickson 2009). When phosphorus is a target pollutant, proprietary materials
with similar characteristics may be considered. Do not include amendments such as top soil, sandy
loam, and additional compost.
Full Infiltration Sections
A full infiltration section retains the WQCV onsite. For this section, it is not necessary to use the
prescribed rain garden growing medium. Amend the soils to provide adequate nutrients to establish
vegetation. Typically, 3 to 5 cubic yards of soil amendment (compost) per 1,000 square feet, tilled 6
inches into the soil, is required for vegetation to thrive. Additionally, inexpensive soil tests can be
conducted to determine required soil amendments. (Some local governments may also require proof
of soil amendment in landscaped areas for water conservation reasons.)
T-3 Bioretention
B-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table B-1. Class 1 Compost
Characteristic Criteria
Minimum Stability Indicator (Respirometry) Stable to Very Stable
Maturity Indicator Expressed as
Ammonia N / Nitrate N Ratio < 4
Maturity Indicator Expressed as
Carbon to Nitrogen Ratio < 12
Maturity Indicator Expressed as
Percentage of Germination/Vigor 80+ / 80+
pH – Acceptable Range 6.0 – 8.4
Soluble Salts – Acceptable Range
(1:5 by weight) 0 – 5 mmhos/cm
Testing and Test Report Submittal Requirement
Seal of Testing Assurance (STA)/Test
Methods for the Examination of
Composting and Compost (TMECC)
Chemical Contaminants
Equal or better than US EPA Class A
Standard, 40 CFR 503.13, Tables 1 & 3
levels
Pathogens Meet or exceed US EPA Class A standard,
40 CFR 503.32(a) levels
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-7
Urban Storm Drainage Criteria Manual Volume 3
4. Underdrain System: Underdrains are often necessary
and should be provided if infiltration tests show
percolation drawdown rates slower than 2 times the rate
needed to drain the WQCV over 12 hours, or where
required to divert water away from structures as
determined by a professional engineer. Percolation tests
should be performed or supervised by a licensed
professional engineer and conducted at a minimum depth
equal to the bottom of the bioretention facility.
Additionally, underdrains are required where
impermeable membranes are used. Similar to the
terminology used for permeable pavement sections, there
are three basic sections for bioretention facilities:
No-Infiltration Section: This section includes an
underdrain and an impermeable liner that does not
allow for any infiltration of stormwater into the
subgrade soils. It is appropriate to use a no-
infiltration system when either of the following is
true:
o Land use or activities could contaminate
groundwater when stormwater is allowed to
infiltrate, or
o The BMP is located over potentially expansive
soils or bedrock and is adjacent (within 10 feet) to
structures.
Partial Infiltration Section: This section does not
include an impermeable liner and, therefore; allows
for some infiltration. Stormwater that does not
infiltrate will be collected and removed by an
underdrain system.
Full Infiltration Section: This section is designed to
infiltrate all of the water stored into the subgrade below.
Overflows are managed via perimeter drainage to a
downstream conveyance element. UDFCD recommends
a minimum infiltration rate of 2 times the rate needed to
drain the WQCV over 12 hours.
When using an underdrain system, provide a control orifice
sized to drain the design volume in 12 hours or more (see
Equation B-3). Use a minimum orifice size of 3/8 inch to
avoid clogging. This will provide detention and slow release
of the WQCV, providing water quality benefits and reducing
impacts to downstream channels. Space underdrain pipes a
maximum of 20 feet on center. Provide cleanouts to enable
maintenance of the underdrain. Cleanouts can also be used to
conduct an inspection (by camera) of the underdrain system to
Important Design Considerations
The potential for impacts to adjacent
buildings can be significantly reduced
by locating the bioretention area at
least 10 feet away from the building,
beyond the limits of backfill placed
against the building foundation walls,
and by providing positive surface
drainage away from the building.
The BMP should not restrict surface
water from flowing away from the
buildings. This can occur if the top of
T-3 Bioretention
B-8 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
ensure that the pipe was not crushed or disconnected during construction.
Calculate the diameter of the orifice for a 12-hour drain time using Equation B-3 (Use a minimum orifice
size of 3/8 inch to avoid clogging.):
𝐷𝐷12 hour drain time = �
𝑉𝑉
1414 𝑦𝑦0.41 Equation B-3
Where:
D = orifice diameter (in)
y = distance from the lowest elevation of the storage volume
(i.e., surface of the filter) to the center of the orifice (ft)
V = volume (WQCV or the portion of the WQCV in the rain garden)
to drain in 12 hours (ft3)
In previous versions of this manual, UDFCD recommended that the underdrain be placed in an
aggregate layer and that a geotextile (separator fabric) be placed between this aggregate and the
growing medium. This version of the manual replaces that section with materials that, when used
together, eliminate the need for a separator fabric.
The underdrain system should be placed within an 6-inch-thick section of CDOT Class C filter
material meeting the gradation in Table B-2. Use slotted pipe that meets the slot dimensions provided
in Table B-3.
Table B-2. Gradation Specifications for CDOT Class C Filter Material
(Source: CDOT Table 703-7)
Sieve Size Mass Percent Passing
Square Mesh Sieves
19.0 mm (3/4”) 100
4.75 mm (No. 4) 60 – 100
300 µm (No. 50) 10 – 30
150 µm (No. 100) 0 – 10
75 µm (No. 200) 0 - 3
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-9
Urban Storm Drainage Criteria Manual Volume 3
Table B-3. Dimensions for Slotted Pipe
Pipe Diameter Slot
Length1
Maximum Slot
Width
Slot
Centers1
Open Area1
(per foot)
4” 1-1/16” 0.032” 0.413” 1.90 in2
6” 1-3/8” 0.032” 0.516” 1.98 in2
1 Some variation in these values is acceptable and is expected from various pipe
manufacturers. Be aware that both increased slot length and decreased slot centers
will be beneficial to hydraulics but detrimental to the structure of the pipe.
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric: For no-infiltration sections,
install a 30 mil (minimum) PVC geomembrane liner, per Table B-5, on the bottom and sides of the
basin, extending up at least to the top of the underdrain layer. Provide at least 9 inches (12 inches if
possible) of cover over the membrane where it is attached to the wall to protect the membrane from
UV deterioration. The geomembrane should be field-seamed using a dual track welder, which allows
for non-destructive testing of almost all field seams. A small amount of single track and/or adhesive
seaming should be allowed in limited areas to seam around pipe perforations, to patch seams removed
for destructive seam testing, and for limited repairs. The liner should be installed with slack to
prevent tearing due to backfill, compaction, and settling. Place CDOT Class B geotextile separator
fabric above the geomembrane to protect it from being punctured during the placement of the filter
material above the liner. If the subgrade contains angular rocks or other material that could puncture
the geomembrane, smooth-roll the surface to create a suitable surface. If smooth-rolling the surface
does not provide a suitable surface, also place the separator fabric between the geomembrane and the
underlying subgrade. This should only be done when necessary because fabric placed under the
geomembrane can increase seepage losses through pinholes or other geomembrane defects. Connect
the geomembrane to perimeter concrete walls around the basin perimeter, creating a watertight seal
between the geomembrane and the walls using a continuous batten bar and anchor connection
(see Figure B-3). Where the need for the impermeable membrane is not as critical, the membrane can
be attached with a nitrile-based vinyl adhesive. Use watertight PVC boots for underdrain pipe
penetrations through the liner (see Figure B-2).
T-3 Bioretention
B-10 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table B-4. Physical Requirements for Separator Fabric1
Table B-5. Physical Requirements for Geomembrane
Property
Thickness
0.76 mm
(30 mil)
Test Method
Thickness, % Tolerance ±5 ASTM D 1593
Tensile Strength, kN/m (lbs/in) width 12.25 (70) ASTM D 882, Method B
Modulus at 100% Elongation, kN/m (lbs/in) 5.25 (30) ASTM D 882, Method B
Ultimate Elongation, % 350 ASTM D 882, Method A
Tear Resistance, N (lbs) 38 (8.5) ASTM D 1004
Low Temperature Impact, °C (°F) -29 (-20) ASTM D 1790
Volatile loss, % max. 0.7 ASTM D 1203, Method A
Pinholes, No. Per 8 m2 (No. per 10 sq. yds.) max. 1 N/A
Bonded Seam Strength, % of tensile strength 80 N/A
Property
Class B
Elongation Test Method
< 50%2
Elongation
> 50%2
Grab Strength, N (lbs) 800 (180) 510 (115) ASTM D 4632
Puncture Resistance, N (lbs) 310 (70) 180 (40) ASTM D 4833
Trapezoidal Tear Strength, N (lbs) 310 (70) 180 (40) ASTM D 4533
Apparent Opening Size, mm
(US Sieve Size)
AOS < 0.3mm (US Sieve Size No. 50) ASTM D 4751
Permittivity, sec-1 0.02 default value,
must also be greater than that of soil
ASTM D 4491
Permeability, cm/sec k fabric > k soil for all classes ASTM D 4491
Ultraviolet Degradation at 500
hours
50% strength retained for all classes ASTM D 4355
1 Strength values are in the weaker principle direction
2 As measured in accordance with ASTM D 4632
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-11
Urban Storm Drainage Criteria Manual Volume 3
Designing for Flood Protection
Provide the WQCV in rain gardens that direct excess flow into to a landscaped area providing the
flood control volume. Design the flood control outlet to meter the major event (100-year event) and
slowly release the difference in volume between the EURV and the WQCV. (This assumes that the
runoff treated by the rain gardens is routed directly into the outlet or infiltrates.) Providing
treatment in this manner will reduce inundation in the landscaped area to a few times per year,
resulting in an area better suited for multipurpose uses.
6. Inlet/Outlet Control: In order to
provide the proper drain time, the
bioretention area can be designed
without an underdrain (provided it
meets the requirements in step 4) or
the outlet can be controlled by an
orifice plate. Equation B-3 is a
simplified equation for sizing an
orifice plate for a 12-hour drain time.
7. How flow enters and exits the BMP
is a function of the overall drainage
concept for the site. Inlets at each
rain garden may or may not be
needed. Curb cuts can be designed
to both allow stormwater into the rain
garden as well as to provide release of
stormwater in excess of the WQCV.
Roadside rain gardens located on a
steep site might pool and overflow
into downstream cells with a single curb cut, level spreader, or outlet structure located at the most
downstream cell. When selecting the type and location of the outlet structure, ensure that the runoff
will not short-circuit the rain garden. This is a frequent problem when using a curb inlet located
outside the rain garden for overflow.
For rain gardens with concentrated points of inflow, provide for energy dissipation. When rock is
used, provide separator fabric between the rock and growing medium to minimize subsidence.
8. Vegetation: UDFCD recommends that the filter area be vegetated with drought tolerant species that
thrive in sandy soils. Table B-6 provides a suggested seed mix for sites that will not need to be
irrigated after the grass has been established.
All seed must be well mixed and broadcast, followed by hand raking to cover seed and then mulched.
Hydromulching can be effective for large areas. Do not place seed when standing water or snow is
present or if the ground is frozen. Weed control is critical in the first two to three years, especially
when starting with seed.
Do not use conventional sod. Conventional sod is grown in clay soil that will seal the filter area,
greatly reducing overall function of the BMP. Several successful local installations have started with
seed.
Photograph B-2. The curb cut shown allows flows to enter this
rain garden while excess flows bypass the facility. Note: trees are
not recommended inside a rain garden
T-3 Bioretention
B-12 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
When using an impermeable liner, select plants with diffuse (or fibrous) root systems, not taproots.
Taproots can damage the liner and/or underdrain pipe. Avoid trees and large shrubs that may
interfere with restorative maintenance. Trees and shrubs can be planted outside of the area of
growing medium. Use a cutoff wall to ensure that roots do not grow into the underdrain or place trees
and shrubs a conservative distance from the underdrain.
9. Irrigation: Provide spray irrigation at or above the WQCV elevation or place temporary irrigation
on top of the rain garden surface. Do not place sprinkler heads on the flat surface. Remove
temporary irrigation when vegetation is established. If left in place this will become buried over time
and will be damaged during maintenance operations.
Irrigation schedules should be adjusted during the growing season to provide the minimum water
necessary to maintain plant health and to maintain the available pore space for infiltration.
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-13
Urban Storm Drainage Criteria Manual Volume 3
Table B-6. Native Seed Mix for Rain Gardens 2
1 Wildflower seed (optional) for a more diverse and natural look.
2 PLS = Pure Live Seed.
Common Name Scientific Name Variety PLS2
lbs per
Acre
Ounces
per
Acre
Sand bluestem Andropogon hallii Garden 3.5
Sideoats grama Bouteloua curtipendula Butte 3
Prairie sandreed Calamovilfa longifolia Goshen 3
Indian ricegrass Oryzopsis hymenoides Paloma 3
Switchgrass Panicum virgatum Blackwell 4
Western wheatgrass Pascopyrum smithii Ariba 3
Little bluestem Schizachyrium scoparium Patura 3
Alkali sacaton Sporobolus airoides 3
Sand dropseed Sporobolus cryptandrus 3
Pasture sage1 Artemisia frigida 2
Blue aster1 Aster laevis 4
Blanket flower1 Gaillardia aristata 8
Prairie coneflower1 Ratibida columnifera 4
Purple prairieclover1 Dalea (Petalostemum) purpurea 4
Sub-Totals: 27.5 22
Total lbs per acre: 28.9
T-3 Bioretention
B-14 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Reflective Design
A reflective design borrows the
characteristics, shapes, colors,
materials, sizes and textures of
the built surroundings. The result
is a design that fits seamlessly
and unobtrusively in its
environment.
Aesthetic Design
In addition to providing effective stormwater quality treatment, rain gardens can be attractively
incorporated into a site within one or several landscape areas. Aesthetically designed rain gardens will
typically either reflect the character of their surroundings or become distinct features within their
surroundings. Guidelines for each approach are provided below.
Reflecting the Surrounding
Determine design characteristics of the surrounding. This becomes the context for the drainage
improvement. Use these characteristics in the structure.
Create a shape or shapes that "fix" the forms surrounding the improvement. Make the improvement
part of the existing surrounding.
The use of material is essential in making any new
improvement an integral part of the whole. Select materials
that are as similar as possible to the surrounding
architectural/engineering materials. Select materials from the
same source if possible. Apply materials in the same
quantity, manner, and method as original material.
Size is an important feature in seamlessly blending the
addition into its context. If possible, the overall size of the
improvement should look very similar to the overall sizes of
other similar objects in the improvement area.
The use of the word texture in terms of the structure applies predominantly to the selection of plant
material. The materials used should as closely as possible, blend with the size and texture of other
plant material used in the surrounding. The plants may or may not be the same, but should create a
similar feel, either individually or as a mass.
Creating a Distinct Feature
Designing the rain garden as a distinct feature is limited only by budget, functionality, and client
preference. There is far more latitude in designing a rain garden that serves as a distinct feature. If this is
the intent, the main consideration beyond functionality is that the improvement create an attractive
addition to its surroundings. The use of form, materials, color, and so forth focuses on the improvement
itself and does not necessarily reflect the surroundings, depending on the choice of the client or designer.
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-15
Urban Storm Drainage Criteria Manual Volume 3
Figure B-1 – Typical Rain Garden Plan and Sections
T-3 Bioretention
B-16 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-17
Urban Storm Drainage Criteria Manual Volume 3
T-3 Bioretention
B-18 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-19
Urban Storm Drainage Criteria Manual Volume 3
Figure B-2. Geomembrane Liner/Underdrain Penetration Detail
Figure B-3. Geomembrane Liner/Concrete Connection Detail
T-3 Bioretention
B-20 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph B-3. Inadequate construction staking may have
contributed to flows bypassing this rain garden.
Photograph B-4. Runoff passed the upradient rain garden, shown in
Photo B-3, and flooded this downstream rain garden.
Construction Considerations
Proper construction of rain gardens involves careful attention to material specifications, final grades, and
construction details. For a successful project, implement the following practices:
Protect area from excessive sediment
loading during construction. This is the
most common cause of clogging of rain
gardens. The portion of the site draining
to the rain garden must be stabilized
before allowing flow into the rain
garden. This includes completion of
paving operations.
Avoid over compaction of the area to
preserve infiltration rates (for partial and
full infiltration sections).
Provide construction observation to
ensure compliance with design
specifications. Improper installation,
particularly related to facility dimensions
and elevations and underdrain elevations,
is a common problem with rain gardens.
When using an impermeable liner, ensure
enough slack in the liner to allow for
backfill, compaction, and settling without
tearing the liner.
Provide necessary quality assurance and
quality control (QA/QC) when
constructing an impermeable
geomembrane liner system, including but
not limited to fabrication testing,
destructive and non-destructive testing of
field seams, observation of geomembrane
material for tears or other defects, and air
lace testing for leaks in all field seams and
penetrations. QA/QC should be overseen
by a professional engineer. Consider
requiring field reports or other
documentation from the engineer.
Provide adequate construction staking to
ensure that the site properly drains into the
facility, particularly with respect to surface drainage away from adjacent buildings. Photo B-3 and
Photo B-4 illustrate a construction error for an otherwise correctly designed series of rain gardens.
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-21
Urban Storm Drainage Criteria Manual Volume 3
Photograph B-5. Rain garden is staked out at the low
point of the parking area prior to excavation.
Construction Example
Photograph B-6. Curb and gutter is installed. Flush
curbs with wheel stops or a slotted curb could have been
used in lieu of the solid raised curb with concentrated
inflow.
T-3 Bioretention
B-22 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph B-7. The aggregate layer is covered
with a geotextile and growing media. This photo
shows installation of the geotextile to separate the
growing media from the aggregate layer below.
Cleanouts for the underdrain system are also
shown. Note: The current design section does not
require this geotextile.
Photograph B-8. Shrubs and trees are placed outside
of the ponding area and away from geotextiles.
Photograph B-9. This photo was taken during the first
growing season of this rain garden. Better weed control in the
first two to three years will help the desired vegetation to
become established.
Bioretention T-3
November 2010 Urban Drainage and Flood Control District B-23
Urban Storm Drainage Criteria Manual Volume 3
Design Example
The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at
www.udfcd.org. This section provides a completed design form from this workbook as an example.
APPENDIX F
STORMWATER MANAGEMENT MODEL (SWMM)
1
3
2
4
out1
out3
out2
outfall
pond1
pond3
pond2
FtCollins-100yr
11/21/2012 00:15:00
SWMM 5 Page 1
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022)
--------------------------------------------------------------
*********************************************************
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
*********************************************************
****************
Analysis Options
****************
Flow Units ............... CFS
Process Models:
Rainfall/Runoff ........ YES
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... YES
Ponding Allowed ........ NO
Water Quality .......... NO
Infiltration Method ...... HORTON
Flow Routing Method ...... KINWAVE
Starting Date ............ NOV-21-2012 00:00:00
Ending Date .............. NOV-21-2012 06:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 41.984 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 11.849 1.036
Surface Runoff ........... 29.896 2.613
Final Surface Storage .... 0.433 0.038
Continuity Error (%) ..... -0.462
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 29.896 9.742
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 3.245 1.058
Internal Outflow ......... 0.000 0.000
Storage Losses ........... 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 26.652 8.685
Continuity Error (%) ..... -0.002
********************************
Highest Flow Instability Indexes
********************************
All links are stable.
SWMM 5 Page 1
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 30.00 sec
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
***************************
Subcatchment Runoff Summary
***************************
--------------------------------------------------------------------------------------------------------
Total Total Total Total Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10^6 gal CFS
--------------------------------------------------------------------------------------------------------
1 3.67 0.00 0.00 1.12 2.53 5.61 386.19 0.690
3 3.67 0.00 0.00 0.87 2.77 2.14 173.17 0.756
2 3.67 0.00 0.00 1.31 2.35 0.38 23.82 0.640
4 3.67 0.00 0.00 0.86 2.79 1.60 132.25 0.759
******************
Node Depth Summary
******************
---------------------------------------------------------------------
Average Maximum Maximum Time of Max
Depth Depth HGL Occurrence
Node Type Feet Feet Feet days hr:min
---------------------------------------------------------------------
outfall OUTFALL 0.00 0.00 96.00 0 00:00
pond1 STORAGE 2.35 2.72 107.72 0 02:45
pond3 STORAGE 2.62 3.06 103.06 0 02:19
pond2 STORAGE 2.51 3.01 106.01 0 02:19
*******************
Node Inflow Summary
*******************
-------------------------------------------------------------------------------------
Maximum Maximum Lateral Total
Lateral Total Time of Max Inflow Inflow
Inflow Inflow Occurrence Volume Volume
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal
-------------------------------------------------------------------------------------
outfall OUTFALL 0.00 7.64 0 02:19 0.000 1.057
pond1 STORAGE 386.19 386.19 0 00:40 5.614 5.614
pond3 STORAGE 305.41 306.42 0 00:40 3.746 4.051
pond2 STORAGE 23.82 24.46 0 00:40 0.381 0.571
**********************
Node Surcharge Summary
**********************
Surcharging occurs when water rises above the top of the highest conduit.
---------------------------------------------------------------------
Max. Height Min. Depth
Hours Above Crown Below Rim
Node Type Surcharged Feet Feet
SWMM ------5 --------------------------------------------------------------- Page 2
pond1 STORAGE 6.01 2.720 7.280
pond3 STORAGE 6.01 3.055 6.945
pond2 STORAGE 6.01 3.014 6.986
*********************
Node Flooding Summary
*********************
No nodes were flooded.
**********************
Storage Volume Summary
**********************
--------------------------------------------------------------------------------------------
Average Avg E&I Maximum Max Time of Max Maximum
Volume Pcnt Pcnt Volume Pcnt Occurrence Outflow
Storage Unit 1000 ft3 Full Loss 1000 ft3 Full days hr:min CFS
--------------------------------------------------------------------------------------------
pond1 607.428 6 0 740.031 7 0 02:45 1.36
pond3 373.865 7 0 466.674 9 0 02:18 7.64
pond2 34.794 7 0 45.433 9 0 02:18 2.26
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg. Max. Total
Freq. Flow Flow Volume
Outfall Node Pcnt. CFS CFS 10^6 gal
-----------------------------------------------------------
outfall 97.23 6.73 7.64 1.057
-----------------------------------------------------------
System 97.23 6.73 7.64 1.057
********************
Link Flow Summary
********************
-----------------------------------------------------------------------------
Maximum Time of Max Maximum Max/ Max/
|Flow| Occurrence |Veloc| Full Full
Link Type CFS days hr:min ft/sec Flow Depth
-----------------------------------------------------------------------------
out1 DUMMY 1.36 0 02:45
out3 DUMMY 7.64 0 02:19
out2 DUMMY 2.26 0 02:19
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Tue Feb 18 16:51:57 2014
Analysis ended on: Tue Feb 18 16:51:57 2014
Total elapsed time: < 1 sec
SWMM 5 Page 3
APPENDIX G
EMBERGENCY OVERFLOW CALCULATIONS
POND 1 PEAK 100-YR INFLOW= 256.8 CFS
Bottom Width B = 4.00 feet
Left Side Slope Z1 = 6.50 ft/ft
Right Side Slope Z2 = 6.50 ft/ft
Manning's n or SCS Retardance Curve n = 0.035
Longitudinal Slope S = 0.0050 ft/ft
Flow Manning's Flow Wetted Hydraulic Flow Flow Froude
Depth Roughness Area Perimeter Radius Velocity rate Number
YnA P R VQ Fr
(ft) (sq ft) (ft) (ft) (fps) (cfs)
0.00 0.0350 0.00 4.00 0.00 0.0 0.0 0.00
0.20 0.0350 1.06 6.63 0.16 0.9 0.9 0.39
0.40 0.0350 2.64 9.26 0.29 1.3 3.4 0.43
0.60 0.0350 4.74 11.89 0.40 1.6 7.7 0.45
080 0 0350 736 14 52 051 19 14 0 047
RATING CURVE FOR TRAPEZOIDAL CHANNEL
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
0 100 200 300 400 500 600 700
Depth (ft)
Flow (cfs)
Depth vs. Flow
0.80 0.0350 7.36 14.52 0.51 1.9 14.0 0.47
1.00 0.0350 10.50 17.15 0.61 2.2 22.7 0.49
1.20 0.0350 14.16 19.78 0.72 2.4 34.0 0.50
1.40 0.0350 18.34 22.41 0.82 2.6 48.2 0.51
1.60 0.0350 23.04 25.04 0.92 2.8 65.4 0.52
1.80 0.0350 28.26 27.68 1.02 3.0 86.0 0.53
2.00 0.0350 34.00 30.31 1.12 3.2 110.2 0.54
2.20 0.0350 40.26 32.94 1.22 3.4 138.2 0.54
2.40 0.0350 47.04 35.57 1.32 3.6 170.2 0.55
2.60 0.0350 54.34 38.20 1.42 3.8 206.4 0.56
2.80 0.0350 62.16 40.83 1.52 4.0 247.0 0.56
3.00 0.0350 70.50 43.46 1.62 4.1 292.2 0.57
3.20 0.0350 79.36 46.09 1.72 4.3 342.3 0.58
3.40 0.0350 88.74 48.72 1.82 4.5 397.3 0.58
3.60 0.0350 98.64 51.35 1.92 4.6 457.6 0.59
3.80 0.0350 109.06 53.98 2.02 4.8 523.3 0.59
4.00 0.0350 120.00 56.61 2.12 5.0 594.5 0.60
UD-Channels_v1.04-pond 1 EM overflow, Rating 2/19/2014, 12:07 PM
VR Product
0
0.1413705
0.3706795
0.6481203
0 9671717
RATING CURVE FOR TRAPEZOIDAL CHANNEL
0 040
024681012
60
VR Product
Velocity, Flow Depth, Froude Number & Manning's n vs. Discharge
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
024681012
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50
Mannin'g n
VR Product
Velocity (fps), Froude Number
Flow Depth (ft)
Velocity, Froude Number, & Manning's n vs. Flow Depth
Velocity (fps) Froude Number Manning's n
0.9671717
1.324911
1.7193647
2.1489765
2.6124406
3.1086277
3.6365438
4.1953033
4.7841095
5.4022401
6.049036
6.7238924
7.4262516
8.1555967
8.9114471
9.6933541
10.500898
0.000
0.005
0.010
0.015
0.020
0.025
0.030
APPENDIX H
EROSION CONTROL REPORT
Waterfield Third Filing
Erosion Control Report
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) HAS BEEN
PROVIDED BY SEPARATE DOCUMENT. It should be noted, however, that any such Erosion and
Sediment Control Plan serves only as a general guide to the Contractor. Staging and/or phasing of
the BMPs depicted, and additional or different BMPs from those included may be necessary during
construction, or as required by the authorities having jurisdiction.
It shall be the responsibility of the Contractor to ensure erosion control measures are properly
maintained and followed. The Erosion and Sediment Control Plan is intended to be a living
document, constantly adapting to site conditions and needs. The Contractor shall update the
location of BMPs as they are installed, removed or modified in conjunction with construction
activities. It is imperative to appropriately reflect the current site conditions at all times.
The Erosion and Sediment Control Plan shall address both temporary measures to be implemented
during construction, as well as permanent erosion control protection. Best Management Practices
from the Volume 3, Chapter 7 – Construction BMPs will be utilized. Measures may include, but are
not limited to, silt fencing along the disturbed perimeter, gutter protection in the adjacent roadways
and inlet protection at existing and proposed storm inlets. Vehicle tracking control pads, spill
containment and clean-up procedures, designated concrete washout areas, dumpsters, and job site
restrooms shall also be provided by the Contractor.
Grading and Erosion Control Notes can be found on the Utility Plans. The Final Plans contain a
full-size Erosion Control sheet as well as a separate sheet dedicated to Erosion Control Details. In
addition to this report and the referenced plan sheets, the Contractor shall be aware of, and adhere
to, the applicable requirements outlined in the Development Agreement for the development. Also,
the Site Contractor for this project will be required to secure a Stormwater Construction General
Permit from the Colorado Department of Public Health and Environment (CDPHE), Water Quality
Control Division – Stormwater Program, prior to any earth disturbance activities. Prior to securing
said permit, the Site Contractor shall develop a comprehensive StormWater Management Plan
(SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will further describe and
document the ongoing activities, inspections, and maintenance of construction BMPs.
MAP POCKET
DRAINAGE EXHIBITS
0.035
0.040
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 100 200 300 400 500 600 700
Manning's n
Flow Depth (ft), Velocity (fps), Froude No.
Flow Rate in cfs
Flow Depth Velocity Froude No. Manning's n
UD-Channels_v1.04-pond 1 EM overflow, Rating 2/19/2014, 12:07 PM
the perimeter wall for the BMP
impedes flow away from the building.
Always adhere to the slope
recommendations provided in the
geotechnical report. In the absence
of a geotechnical report, the following
general recommendations should be
followed for the first 10 feet from a
building foundation.
1) Where feasible, provide a slope of
10% for a distance of 10 feet away
from a building foundation.
2) In locations where non-expansive
soil or bedrock conditions exist,
the slope for the surface within 10
feet of the building should be at
least 5% away from the building
for unpaved (landscaped) surfaces.
3) In locations where potentially
expansive soil or bedrock
conditions exist, the design slope
should be at least 10% away from
the building for unpaved
(landscaped) surfaces.
4) For paved surfaces, a slope of at
least 2% away from the building is
adequate. Where accessibility
requirements or other design
constraints do not apply, use an
increased minimum design slope
for paved areas (2.5% where non-
expansive soil or bedrock
conditions exist).
Additional design and
construction steps are required for
placement of any ponding or
infiltration area near or upgradient
from a building foundation and/or
when expansive (low to high
swell) soils exist. This is
discussed in the design procedure
section.
In developing or otherwise erosive
watersheds, high sediment loads
can clog the facility.
Other Considerations
Life-cycle Costs4 Moderate
1
Not recommended for watersheds with
high sediment yields (unless pretreatment is
provided).
3
Based primarily on data from the
International Stormwater BMP Database
(www.bmpdatabase.org).
4
Based primarily on BMP-REALCOST
available at www.udfcd.org. Analysis
based on a single installation (not based on
the maximum recommended watershed
tributary to each BMP).
MD‐21 or
MD‐22)
By: ATC
CALCULATE
Date: 4/1/14
Project: 889‐001
Urban Drainage
pg MD‐107
L=
1/(2tanq)*
[At/Yt)‐W]
(ft)
INPUT
Storm
Line/Culvert
Label
Design
Discharge
(cfs)
Expansion
Factor
1/(2tanq)
(From
Figure
MD‐23 or
MD‐24)
Yt,
Tailwater
Depth
(ft)
Culvert Parameters
At=Q/V (ft)
0.025
0.030
0.035
0.040
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 5 10 15 20 25 30 35 40
Manning's n
Flow Depth (ft), Velocity (fps), Froude No.
Flow Rate in cfs
Flow Depth Velocity Froude No. Manning's n
UD-Channels_v1.04-inlet 100yr overflow, Rating 2/19/2014, 11:51 AM
Q 3 . 0 P H 1 . 5
Q 0 . 67 A ( 2 gH ) 0 . 5
14 14 5.15 20 20 19 0.31 0.31 0.38 1.61 2.74 5.84 2.5 4.3 11.5
15 15 0.77 11 11 10 0.65 0.65 0.82 2.13 3.63 7.88 1.1 1.8 5.0
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
11No0.25 0.25 0.31 370 1.00% 30.6 30.6 28.3 614 1.00% 2.00 5.1 0 0.00% N/A N/A 36 36 33
22No0.52 0.52 0.65 120 2.00% 9.4 9.4 7.3 439 3.00% 3.46 2.1 0 0.00% N/A N/A 12 12 9
33No0.47 0.47 0.58 185 2.00% 12.8 12.8 10.4 905 1.20% 2.19 6.9 0 0.00% N/A N/A 20 20 17
44No0.56 0.56 0.70 122 2.00% 8.8 8.8 6.5 584 1.00% 2.00 4.9 0 0.00% N/A N/A 14 14 11
55No0.31 0.31 0.39 340 2.00% 21.5 21.5 19.3 0 0.00% N/A N/A 0 0.00% N/A N/A 21 21 19
66No0.49 0.49 0.61 98 2.00% 8.9 8.9 7.1 320 0.75% 1.73 3.1 0 0.00% N/A N/A 12 12 10
77No0.25 0.25 0.31 150 2.00% 15.5 15.5 14.4 832 1.00% 2.00 6.9 0 0.00% N/A N/A 22 22 21
88No0.25 0.25 0.31 150 2.00% 15.5 15.5 14.4 935 0.60% 1.55 10.1 0 0.00% N/A N/A 26 26 24
99No0.57 0.57 0.72 75 2.00% 6.8 6.8 4.9 243 0.50% 1.41 2.9 0 0.00% N/A N/A 10 10 8
10a 10a No 0.54 0.54 0.68 145 2.00% 10.0 10.0 7.5 247 1.40% 2.37 1.7 0 0.00% N/A N/A 12 12 9
10b 10b N 058 058 072 146 2 00% 94 94 68 248 0 50% 141 29 0 0 00% N/A N/A 12 12 10
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
February 1, 2014
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
Ti C Cf L
10b 10b No 0.58 0.58 0.72 146 2.00% 9.4 9.4 6.8 248 0.50% 1.41 2.9 0 0.00% N/A N/A 12 12 10
11 11 No 0.58 0.58 0.73 150 2.00% 9.4 9.4 6.8 474 0.50% 1.41 5.6 0 0.00% N/A N/A 15 15 12
12 12 No 0.55 0.55 0.69 105 2.00% 8.4 8.4 6.3 941 1.40% 2.37 6.6 0 0.00% N/A N/A 15 15 13
13 13 No 0.33 0.33 0.41 170 2.00% 14.9 14.9 13.3 0 0.00% N/A N/A 0 0.00% N/A N/A 15 15 13
14 14 No 0.31 0.31 0.38 165 2.00% 15.1 15.1 13.7 437 0.50% 1.41 5.2 0 0.00% N/A N/A 20 20 19
15 15 No 0.65 0.65 0.82 50 2.00% 4.7 4.7 3.0 622 0.60% 1.55 6.7 0 0.00% N/A N/A 11 11 10
10b 75020 1.72 0.264 0.173 0.367 0.000 0.918 0.58 0.58 0.72 44%
11 395073 9.07 2.353 0.920 1.010 0.000 4.787 0.58 0.58 0.73 45%
12 321304 7.38 1.138 0.676 1.331 0.000 4.230 0.55 0.55 0.69 40%
13 66265 1.52 0.000 0.038 0.138 0.000 1.346 0.33 0.33 0.41 10%
14 224433 5.15 0.000 0.088 0.321 0.000 4.742 0.31 0.31 0.38 7%
15 33680 0.77 0.446 0.000 0.000 0.000 0.327 0.65 0.65 0.82 58%
1-4,6-8 3558848 81.70 13.684 8.038 9.040 0.000 50.937 0.51 0.51 0.64 36%
9-12, 14 1143851 26.26 4.486 2.132 3.306 0.000 16.335 0.51 0.51 0.64 36%
DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS
Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I.
10-year Cf = 1.00
February 1, 2014