HomeMy WebLinkAboutWEST PLUM HOUSING - FDP - FDP160048 - REPORTS - DRAINAGE REPORTFebruary 22, 2017
FINAL DRAINAGE AND
EROSION CONTROL REPORT FOR
West Plum Housing
Fort Collins, Colorado
Prepared for:
Plum Owner Ft Collins CO LLC
999 South Shady Grove Road, Suite 600
Memphis, TN 38120
Prepared by:
301 N. Howes St., Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 1252-001
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.
February 22, 2017
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Final Drainage and Erosion Control Report for
West Plum Housing
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report
for your review. This report accompanies the Preliminary Plan submittal for the proposed West
Plum Housing 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, PhD, PE
Senior Project Engineer
West Plum Housing
Final Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 3
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 4
A. Major Basin Description .................................................................................................................... 4
B. Sub-Basin Description ....................................................................................................................... 4
III. DRAINAGE DESIGN CRITERIA ................................................................................... 5
A. Regulations........................................................................................................................................ 5
B. Four Step Process .............................................................................................................................. 5
C. Development Criteria Reference and Constraints ............................................................................ 5
D. Hydrological Criteria ......................................................................................................................... 6
E. Hydraulic Criteria .............................................................................................................................. 6
F. Modifications of Criteria ................................................................................................................... 6
IV. DRAINAGE FACILITY DESIGN .................................................................................... 6
A. General Concept ............................................................................................................................... 6
B. Specific Details .................................................................................................................................. 7
V. CONCLUSIONS ........................................................................................................ 8
A. Compliance with Standards .............................................................................................................. 8
B. Drainage Concept .............................................................................................................................. 8
APPENDICES:
APPENDIX A – Hydrologic Calculations, Historic Drainage Exhibit, Existing vs. Proposed
Imperviousness Exhibit
APPENDIX B – Detention and Outfall Pipe Calculations; Water Quality Calculations
APPENDIX C – Erosion Control Report
APPENDIX D – LID Design Information
APPENDIX E – USDA Soils Information
APPENDIX F – Flood Modeling Summary and Technical Appendix
West Plum Housing
Final Drainage Report
LIST OF FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 3
Figure 3 – Existing Floodplains ............................................................................................. 4
MAP POCKET:
Proposed Drainage Exhibit
West Plum Housing
Final Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the southwest quarter of Section 12, Township 7 North,
Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado.
3. The project site is located just southeast of the intersection of Plum Street and City
Park Avenue.
4. The District at Campus West (Reference 1) development exists just to the north of the
site, and the Scott Plaza development exists just to the east of the site. An existing
storm line within Plum Street begins roughly 500 feet east of the project site, and
runs within Plum Street Right of Way east to Shields Street. The storm line ties in
with an existing storm main in Shields Street. The existing Plum Street storm line
will receive all runoff from the proposed site. The proposed project will discharge into
the south flowline of Plum Street and surface flow within Plum Street Right of Way
east to the existing inlets and storm line in Plum Street.
Offsite flow does not enter the site. City Park Avenue intercepts any offsite flow that
would enter the site from the west, Plum Street intercepts any offsite flow that would
enter the site from the north. General drainage patterns direct historic sheet flow
along the site’s southern and eastern boundaries away from the site. The developed
West Plum Housing
Final Drainage Report 2
drainage plan will capture developed flows that would sheet flow off the site along
these boundaries, and direct runoff into proposed stormwater facilities.
B. Description of Property
1. The project area is roughly 1.3 net acres.
Figure 1 – Aerial Photograph
2. The existing property is currently single family residential, with ground conver
consisting of landscaping lawns, etc.. Existing ground slopes are mild to moderate
(i.e., 1 - 6±%) through the interior of the property. General topography slopes from
west to east.
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 Nunn
Clay Loam (Hydrologic Soil Group A), and Santana loam (Hydrologic Soil Group C).
4. The proposed project site plan is composed of apartment complexes and parking
areas. Associated landscaping, water and sewer lines, and other improvements will
be constructed with the development. Please see Figure 2, below, showing the
proposed site plan.
PROJECT
SITE
West Plum Housing
Final Drainage Report 3
Figure 2– Proposed Site Plan
5. There are no known irrigation laterals crossing the site.
6. The proposed land use is residential.
C. Floodplain
1. The project site is not encroached by any City or FEMA 100-year or 500-year
floodplain. However, floodplain modeling of Plum Street originally requested with
Northern Engineering designed with the District at Campus West (Reference 1)
development has been updated with current conditions and extended to cover the
extents of the currently proposed project. A copy of the original study is provided in
Appendix F.
2. The original study reach for the District at Campus West extended from Shields Street
to roughly 350 feet west of Bluebell Street. Floodplain modeling done with the
current project extends the study reach west to City Park Avenue. Additionally,
current floodplain modeling includes updated mapping of the Plum Street corridor, as
Plum Street was overlayed, and street elevations are now higher than that of the
original modeling. Recently constructed buildings encroaching into the floodplain
have also been reflected in current floodplain modeling.
3. Based on the flood study provided in Appendix F, BFE’s range from 5036.90 to
5039.04. Proposed building finished floor elevations range from 5039.30 to
5041.25. All proposed building finished floor elevations are elevated a minimum of
12-inches above 100-year flows in Plum Street.
West Plum Housing
Final Drainage Report 4
Figure 3 –Area Floodplain Mapping
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site is located in the City of Fort Collins Old Town Drainage Basin.
B. Sub-Basin Description
4. The subject property historically drains overland from west to east. Runoff from the
majority of the site has historically been collected in the adjacent Plum Street Right of
Way and conveyed via surface flow. An existing storm line within Plum Street begins
roughly 500 feet east of the project site, and runs within Plum Street Right of Way
east to Shields Street. The storm line ties in with an existing storm main in Shields
Street. The existing Plum Street storm line will receive all runoff from the proposed
site. The proposed project will discharge into the south flowline of Plum Street and
surface flow within Plum Street Right of Way east to the existing inlets and storm line
in Plum Street. A more detailed description of the project drainage patterns follows in
Section IV.A.4., below.
PROJECT
SITE
West Plum Housing
Final Drainage Report 5
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 filtration detention methods prior to exiting the
site.
Step 3 – Stabilize Drainageways
There are no regional 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.
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
West Plum Housing
Final Drainage Report 6
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.
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 site has been broken into 2 onsite sub-basins. Anticipated drainage patterns for
proposed drainage basins are described below.
West Plum Housing
Final Drainage Report 7
Basin 1
Basin 1 consist of apartment rooftop. This basin will generally drain via rooftop
drainage systems, and an internal storm piping system into the detention vault within
the parking garage. The final point of stormwater release will be at the northeast
corner of the site, and will tie to the existing curb and gutter within the south flowline
of the adjacent Plum Street Right of Way. As discussed above, release will be
conveyed within Plum Street Right of Way to the existing Plum Street storm system.
We note that the rooftop drainage system has been designed by the building
mechanical engineer to meet international plumbing code.
Basin 2
Basin 2 consist of an area of concrete and landscaping area that we are unable to be
bring into the proposed LID and detention system. The size of this area is 0.30 acre,
producing 2.14 cfs in a 100-year event, and we will compensate for this undetained
runoff as discussed below.
Basin 3
Basin 3 consist of a landscaping area that we are unable to be bring into the proposed
LID and detention system, and will be conveyed via swale to the historic concentration
point H2. The size of proposed Basin 3 is 0.13 acre, producing 0.21 cfs in a 100-
year event. This is below the historic runoff of 0.30 cfs generated by historic basin
H2 in a 100-year event.
Basin 4
Basin 4 consist of a landscaping area that we are unable to be bring into the proposed
LID and detention system, and will sheet flow to the historic concentration point H1.
The size of proposed Basin 4 is 0.03 acre, producing 0.06 cfs in a 100-year event.
This is below the historic runoff of 3.15 cfs generated by historic basin H1 in a 100-
year event.
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. The majority of developed runoff will be routed into the proposed detention
vault within the proposed parking garage structure. Site runoff will be
conveyed via surface flow, roof drain systems, and through an interior storm
drain system to the proposed detention vault. Release from the detention
vault will occur through a small pipe and a sidewalk chase within Plum Street
Right of Way.
1. Release rate from the detention vault is based on a combination of historic 2-
year discharge to Plum Street from the historic site as well as historic 100-
year discharge from existing impervious areas within the development site. A
composite historic 2-year discharge from the existing site has been calculated
at 3.88 cfs. The basis for this is evaluating the 2-year historic discharge from
the site draining to Plum Street (Basin H1) and calculating a cfs per acre
value of 0.65 cfs per acre. We then took the existing impervious area based
on the Existing vs. Proposed Impervious Area Exhibit provided in Appendix A,
and computed 100-year discharge from the impervious area totaling 0.34
acre, which was computed as 3.40 cfs. We then added a pro-rated 2-year
West Plum Housing
Final Drainage Report 8
historic discharge from the non-impervious portion of Historic Basin H1 (1.08
acres – 0.34 acre=0.74 acre) and used the 0.65 cfs per acre (0.74 ac *
0.65 cfs per ac = 0.48 cfs) to achieve an allowable site release rate of 3.40
cfs + 0.48 cfs = 3.88 cfs. However, we propose to allow Basin 2 to release
2.14 cfs in a 100-year event undetained from the site. This reduces our
allowable release rate to 3.88 cfs – 2.14 cfs = 1.74 cfs.
2. Onsite LID features have been incorporated in the design of the proposed site.
The majority of the site will be conveyed into the proposed PLD located within
the parking structure. A portion of the site will not be conveyed into the PLD
and will be treated in a proposed landscape buffer area in the southwest
corner of the site as shown in the LID Treatment Exhibit. Please see the LID
Treatment Exhibit and LID Design Information provided in Appendix D.
3. The detention vault will provide a minimum of 3067 cubic feet of detention
storage volume. The vault is also designed as a PLD, providing approximately
883 cubic feet of PLD water quality capture volume (WQCV). A total volume
of 3950 cubic feet will be provided in the vault. The vault will have an open
bottom design, which will allow infiltration into the subsurface. Runoff being
received by the PLD will not be from paved driving or parking surfaces; rather,
only rooftop drainage will be received by the PLD. Runoff from the rooftop will
be relatively free of particlates, and the PLD will allow full infiltration to the
subsurface. Therefore, we feel that placing the PLD within the bottom stage of
the detention vault meets the spirit of design practices. Please see detention
and PLD Volume calculations provided in Appendix B.
4. The drainage features associated with the proposed project are all private facilities,
located on private property, with the exception of the project site outfall, which will be
a sidewalk chase within Plum Street Right of Way.
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 Old
Town 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.
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 Old Town Basin.
West Plum Housing
Final Drainage Report 9
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.
6. The District at Campus West, March 27, 2013, Northern Engineering.
APPENDIX A
Historic and Developed Hydrologic Calculations
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 1252-001
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
Concrete 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
Concrete
Pavers
(ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
H1 46,838 1.08 0.00 0.07 0.19 0.00 0.00 0.82 0.34 0.34 0.43 21.8
H2 9,489 0.22 0.00 0.00 0.00 0.00 0.00 0.22 0.15 0.15 0.19 0.0
Exist-Impervious
Area 14,899 0.34 0.00 0.07 0.20 0.07 0.00 0.00 0.86 0.86 1.00 80.4
EXISTING 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
Overland Flow, Time of Concentration:
Project: 1252-001
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = T
i + Tt
(Equation RO-2)
Velocity (Gutter Flow), V = 20·S
½
Velocity (Swale Flow), V = 15·S
½
NOTE: C-value for overland flows over grassy surfaces; C = 0.25
Length>
500'
C*Cf
(2-yr
Cf=1.00)
C*Cf
(10-yr
Cf=1.00)
C*Cf
(100-yr
Cf=1.25)
0
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)
Rational Method Equation: Project: 1252-001
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
H1 H1 1.08 14.9 14.9 14.0 0.34 0.34 0.43 1.90 3.24 6.82 0.70 1.20 3.15
H2 H2 0.22 12.2 12.2 11.3 0.15 0.15 0.19 2.05 3.50 7.42 0.07 0.11 0.30
Exist-
Impervious
Area
Exist-Impervious
Area
0.34 5.0 5.0 5.0 0.86 0.86 1.00 2.85 4.87 9.95 0.84 1.44 3.40
Area, A
(acres)
Intensity,
i2
(in/hr)
100-yr
Tc
(min)
EXISTING 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
December 1, 2016
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Q C f C i A
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational Calcs_Existing.xlsx\Direct-Runoff
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 1252-001
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
Concrete 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
Concrete
Pavers
(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 33,243 0.76 0.00 0.00 0.76 0.00 0.00 0.00 0.95 0.95 1.00 90.0
2 15,899 0.36 0.00 0.22 0.00 0.00 0.00 0.14 0.63 0.63 0.79 54.2
3 5,749 0.13 0.00 0.00 0.00 0.00 0.00 0.13 0.15 0.15 0.19 0.0
4 1,435 0.03 0.00 0.00 0.00 0.00 0.00 0.03 0.15 0.15 0.19 0.0
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
Overland Flow, Time of Concentration:
Project: 1252-001
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
Tt = L / 60V
Tc = T
i + Tt
(Equation RO-2)
Velocity (Gutter Flow), V = 20·S
½
Velocity (Swale Flow), V = 15·S
½
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)
Rational Method Equation: Project: 1252-001
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 0.76 6.8 6.8 5.7 0.95 0.95 1.00 2.60 4.44 9.63 1.87 3.20 7.35
2 2 0.36 12.0 12.0 11.4 0.63 0.63 0.79 2.09 3.57 7.42 0.48 0.82 2.14
3 3 0.13 8.4 8.4 7.9 0.15 0.15 0.19 2.40 4.10 8.59 0.05 0.08 0.21
4 4 0.03 5.6 5.6 5.2 0.15 0.15 0.19 2.76 4.72 9.95 0.01 0.02 0.06
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
December 1, 2016
Intensity,
i10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C10
Q C f C i A
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational-Calcs_Proposed.xlsx\Direct-Runoff
S
S
D D
T
WV
H
Y
D
H
Y
D
WV
WV
X X
X X
X
X
X
T T T
G
G G
T
T
T
CTV
CTV
ST
ST
ST ST ST
ST
ST ST
SS SS
SS
SS SS
SS
SS
SS SS
SS
SS
SS SS
W W W
VAULT
ELEC
S
T FO
T
FO
ELEC
V.P.
CONTROL
VAULT
ELEC W
W
D
X
X
G
FO
VAULT
ELEC
D
T
M
X
X
X X
X
X
X
X
X
X
X
VAULT
ELEC
T FO
FO T
ELEC
VAULT
ELEC
D
X
X
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC FO
VAULT
ELEC
T FO
E
X
CITY PARK AVENUE
PLUM STREET
(ROW VARIES)
D
T
X
X
X
X
X
VAULT
ELEC
T FO
FO T
ELEC
VAULT
APPENDIX B
Detention and Outfall Pipe Calculations; Water Quality Calculations
1252-001
Fort Collins, Colorado
ATC Date: December 1, 2016
Pond No.:
1
100-yr
1.00 WQCV 0 ft
3
Area (A)= 0.76 acres Quantity Detention 3067 ft
3
Max Release Rate = 1.74 cfs Total Volume 3067 ft
3
Total Volume 0.070 ac-ft
Time Time
Ft.Collins
100-yr
Intensity
Q100
Inflow
(Runoff)
Volume
Outflow
(Release) Volume
Storage
Detention
Volume
(mins) (secs) (in/hr) (cfs) (ft
3
) (ft
3
) (ft
3
)
5 300 9.95 7.6 2269 522 1747
10 600 7.72 5.9 3520 1044 2476
15 900 6.52 5.0 4460 1566 2894
20 1200 5.60 4.3 5107 2088 3019
25 1500 4.98 3.8 5677 2610 3067
30 1800 4.52 3.4 6183 3132 3051
35 2100 4.08 3.1 6512 3654 2858
40 2400 3.74 2.8 6822 4176 2646
45 2700 3.46 2.6 7100 4698 2402
50 3000 3.23 2.5 7364 5220 2144
55 3300 3.03 2.3 7599 5742 1857
60 3600 2.86 2.2 7825 6264 1561
65 3900 2.72 2.1 8062 6786 1276
70 4200 2.59 2.0 8267 7308 959
75 4500 2.48 1.9 8482 7830 652
80 4800 2.38 1.8 8682 8352 330
85 5100 2.29 1.7 8876 8874 2
90 5400 2.21 1.7 9070 9396 -326
95 5700 2.13 1.6 9227 9918 -691
100 6000 2.06 1.6 9394 10440 -1046
105 6300 2.00 1.5 9576 10962 -1386
110 6600 1.94 1.5 9731 11484 -1753
115 6900 1.89 1.4 9911 12006 -2095
120 7200 1.84 1.4 10068 12528 -2460
125 7500 1.79 1.4 10203 13050 -2847
130 7800 1.75 1.3 10374 13572 -3198
135 8100 1.71 1.3 10527 14094 -3567
ORIFICE RATING CURVE
Detention Vault
100-yr Orifice
PROJECT: 1252-001
DATE: 12/1/16
BY: ATC
ORIFICE RATING
Orifice Dia (in) 6 1/4
Orifice Area (sf) 0.21
Orifice invert (ft) 0.00
Orifice Coefficient 0.65
Outlet
Stage release
(FT) (CFS)
0.00 0.00
0.25 0.00
0.50 0.00
0.75 0.76
1.00 0.94
1.25 1.09
1.50 1.21
1.75 1.33
2.00 1.44
2.25 1.54
2.50 1.63
2.75 1.72
**2.82 1.74
**Vault 100-yr depth
WATER QUALITY DESIGN CALCULATIONS
Water Quality Capture Volume (12-Hr. PLD)
Project: 1252-001
By: ATC
Date: 12/15/16
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA (ac) = 0.760 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 90.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.9000 <-- CALCULATED
WQCV (watershed inches) = 0.320 <-- CALCULATED from Figure EDB-2
WQCV (cu-ft) = 883 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
APPENDIX C
Erosion Control Report
West Plum Housing
Final Erosion Control Report
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) WILL BE
PROVIDED BY SEPARATE DOCUMENT with the final construction drawings. 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 will 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.
APPENDIX D
LID Design Information
X
X
X
X
X X
X
X
X X
T T
T
T
T T T
T
X X
X
X
X
P
LD BASIN
PLUM STREET LANDSCAPE BUFFER
CITY PARK AVENUE
LEGEND
PLD BASIN
PLD TREATMENT AREA
LANDSCAPE BUFFER
LANDSCAPE BUFFER
TREATMENT AREA
WEST PLUM HOUSING
SHEET NO:
D:\PROJECTS\1252-001\DWG\DRNG\1252-001_LID.DWG
301 N. Howes Street, Suite 100
Fort Collins, Colorado 80521
E NGINEER ING
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
DRAWING REFERNCE:
LID TREATMENT EXHIBIT A. Reese
1 in = 30 ft
December 28, 2016 LID-1
DRAWN BY:
SCALE:
ISSUED:
( IN FEET )
0
1 INCH = 30 FEET
30 30
On-Site LID Treatment
Project Summary
Total Impervious Area 40,612 sf
Target Treatment Percentage 75%
Minimum Area to be Treated by LID measures 30,459 sf
PLD Basin
Basin Size 1,400 sf
Total PLD Treatment Area 33,106 sf
Landscape Buffer
Landscape Buffer Area 540 sf
Run-on area for Landscape Buffer 284 sf
Overall Run-on Ratio for Rain Garden (50:1 Max) 0.5 :1
Total Treatment Area 33,390 sf
APPENDIX E
USDA Soils Information
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Larimer County
Natural Area, Colorado
Resources
Conservation
Service
September 12, 2016
Preface
Soil surveys contain information that affects land use planning in survey areas. They
highlight soil limitations that affect various land uses and provide information about
the properties of the soils in the survey areas. Soil surveys are designed for many
different users, including farmers, ranchers, foresters, agronomists, urban planners,
community officials, engineers, developers, builders, and home buyers. Also,
conservationists, teachers, students, and specialists in recreation, waste disposal,
and pollution control can use the surveys to help them understand, protect, or enhance
the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil properties
that are used in making various land use or land treatment decisions. The information
is intended to help the land users identify and reduce the effects of soil limitations on
various land uses. The landowner or user is responsible for identifying and complying
with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some cases.
Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/
nrcs/main/soils/health/) and certain conservation and engineering applications. For
more detailed information, contact your local USDA Service Center (http://
offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic
tank absorption fields. A high water table makes a soil poorly suited to basements or
underground installations.
The National Cooperative Soil Survey is a joint effort of the United States Department
of Agriculture and other Federal agencies, State agencies including the Agricultural
Experiment Stations, and local agencies. The Natural Resources Conservation
Service (NRCS) has leadership for the Federal part of the National Cooperative Soil
Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs
and activities on the basis of race, color, national origin, age, disability, and where
applicable, sex, marital status, familial status, parental status, religion, sexual
orientation, genetic information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not all prohibited
bases apply to all programs.) Persons with disabilities who require alternative means
2
for communication of program information (Braille, large print, audiotape, etc.) should
contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a
complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272
(voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and
employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................7
Soil Map................................................................................................................8
Legend..................................................................................................................9
Map Unit Legend................................................................................................10
Map Unit Descriptions........................................................................................10
Larimer County Area, Colorado......................................................................12
74—Nunn clay loam, 1 to 3 percent slopes.................................................12
References............................................................................................................14
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous areas
in a specific area. They include a description of the soils and miscellaneous areas and
their location on the landscape and tables that show soil properties and limitations
affecting various uses. Soil scientists observed the steepness, length, and shape of
the slopes; the general pattern of drainage; the kinds of crops and native plants; and
the kinds of bedrock. They observed and described many soil profiles. A soil profile is
the sequence of natural layers, or horizons, in a soil. The profile extends from the
surface down into the unconsolidated material in which the soil formed or from the
surface down to bedrock. The unconsolidated material is devoid of roots and other
living organisms and has not been changed by other biological activity.
Currently, soils are mapped according to the boundaries of major land resource areas
(MLRAs). MLRAs are geographically associated land resource units that share
common characteristics related to physiography, geology, climate, water resources,
soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically
consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that is
related to the geology, landforms, relief, climate, and natural vegetation of the area.
Each kind of soil and miscellaneous area is associated with a particular kind of
landform or with a segment of the landform. By observing the soils and miscellaneous
areas in the survey area and relating their position to specific segments of the
landform, a soil scientist develops a concept, or model, of how they were formed. Thus,
during mapping, this model enables the soil scientist to predict with a considerable
degree of accuracy the kind of soil or miscellaneous area at a specific location on the
landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented by
an understanding of the soil-vegetation-landscape relationship, are sufficient to verify
predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them to
identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character of
soil properties and the arrangement of horizons within the profile. After the soil
scientists classified and named the soils in the survey area, they compared the
5
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that have
similar use and management requirements. Each map unit is defined by a unique
combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components of
the map unit. The presence of minor components in a map unit in no way diminishes
the usefulness or accuracy of the data. The delineation of such landforms and
landform segments on the map provides sufficient information for the development of
resource plans. If intensive use of small areas is planned, onsite investigation is
needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape, and
experience of the soil scientist. Observations are made to test and refine the soil-
landscape model and predictions and to verify the classification of the soils at specific
locations. Once the soil-landscape model is refined, a significantly smaller number of
measurements of individual soil properties are made and recorded. These
measurements may include field measurements, such as those for color, depth to
bedrock, and texture, and laboratory measurements, such as those for content of
sand, silt, clay, salt, and other components. Properties of each soil typically vary from
one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists interpret
the data from these analyses and tests as well as the field-observed characteristics
and the soil properties to determine the expected behavior of the soils under different
uses. Interpretations for all of the soils are field tested through observation of the soils
in different uses and under different levels of management. Some interpretations are
modified to fit local conditions, and some new interpretations are developed to meet
local needs. Data are assembled from other sources, such as research information,
production records, and field experience of specialists. For example, data on crop
yields under defined levels of management are assembled from farm records and from
field or plot experiments on the same kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on such
variables as climate and biological activity. Soil conditions are predictable over long
periods of time, but they are not predictable from year to year. For example, soil
scientists can predict with a fairly high degree of accuracy that a given soil will have
a high water table within certain depths in most years, but they cannot predict that a
high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
identified each as a specific map unit. Aerial photographs show trees, buildings, fields,
roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
6
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of soil
map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
7
8
Custom Soil Resource Report
Soil Map
4491670 4491680 4491690 4491700 4491710 4491720 4491730 4491740 4491750 4491760
4491670 4491680 4491690 4491700 4491710 4491720 4491730 4491740 4491750 4491760
491470 491480 491490 491500 491510 491520 491530 491540 491550 491560 491570 491580 491590 491600 491610
491470 491480 491490 491500 491510 491520 491530 491540 491550 491560 491570 491580 491590 491600 491610
40° 34' 35'' N
105° 6' 2'' W
40° 34' 35'' N
105° 5' 56'' W
40° 34' 32'' N
105° 6' 2'' W
40° 34' 32'' N
105° 5' 56'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 30 60 120 180
Feet
0 10 20 40 60
Meters
Map Scale: 1:690 if printed on A landscape (11" x 8.5") sheet.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
74 Nunn clay loam, 1 to 3 percent
slopes
1.6 100.0%
Totals for Area of Interest 1.6 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the soils
or miscellaneous areas in the survey area. The map unit descriptions, along with the
maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the landscape,
however, the soils are natural phenomena, and they have the characteristic variability
of all natural phenomena. Thus, the range of some observed properties may extend
beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic
class rarely, if ever, can be mapped without including areas of other taxonomic
classes. Consequently, every map unit is made up of the soils or miscellaneous areas
for which it is named and some minor components that belong to taxonomic classes
other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They generally
are in small areas and could not be mapped separately because of the scale used.
Some small areas of strongly contrasting soils or miscellaneous areas are identified
by a special symbol on the maps. If included in the database for a given area, the
contrasting minor components are identified in the map unit descriptions along with
some characteristics of each. A few areas of minor components may not have been
observed, and consequently they are not mentioned in the descriptions, especially
where the pattern was so complex that it was impractical to make enough observations
to identify all the soils and miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the usefulness
or accuracy of the data. The objective of mapping is not to delineate pure taxonomic
classes but rather to separate the landscape into landforms or landform segments that
have similar use and management requirements. The delineation of such segments
on the map provides sufficient information for the development of resource plans. If
intensive use of small areas is planned, however, onsite investigation is needed to
define and locate the soils and miscellaneous areas.
Custom Soil Resource Report
10
An identifying symbol precedes the map unit name in the map unit descriptions. Each
description includes general facts about the unit and gives important soil properties
and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major horizons
that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity,
degree of erosion, and other characteristics that affect their use. On the basis of such
differences, a soil series is divided into soil phases. Most of the areas shown on the
detailed soil maps are phases of soil series. The name of a soil phase commonly
indicates a feature that affects use or management. For example, Alpha silt loam, 0
to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps. The
pattern and proportion of the soils or miscellaneous areas are somewhat similar in all
areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present or
anticipated uses of the map units in the survey area, it was not considered practical
or necessary to map the soils or miscellaneous areas separately. The pattern and
relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-
Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas that
could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion of
the soils or miscellaneous areas in a mapped area are not uniform. An area can be
made up of only one of the major soils or miscellaneous areas, or it can be made up
of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil material
and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
11
Larimer County Area, Colorado
74—Nunn clay loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpxn
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Nunn and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Nunn
Setting
Landform: Terraces, fans
Landform position (three-dimensional): Base slope, tread
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium
Typical profile
H1 - 0 to 10 inches: clay loam
H2 - 10 to 60 inches: clay loam, clay
H2 - 10 to 60 inches:
Properties and qualities
Slope: 1 to 3 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 15 percent
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water storage in profile: Very high (about 18.9 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Hydric soil rating: No
Minor Components
Ulm
Percent of map unit: 10 percent
Hydric soil rating: No
Custom Soil Resource Report
12
Satanta
Percent of map unit: 5 percent
Hydric soil rating: No
Custom Soil Resource Report
13
References
American Association of State Highway and Transportation Officials (AASHTO). 2004.
Standard specifications for transportation materials and methods of sampling and
testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service
FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils
in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S.
Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making
and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service,
U.S. Department of Agriculture Handbook 436. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/
portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
14
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States, the
Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
15
APPENDIX F
Flood Modeling Summary and Technical Appendix
1
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
September 14, 2016
RE: HEC-RAS summary
West Plum Housing
Dear Staff,
This Memo is to summarize HEC-RAS modeling that we have done for the proposed
development referred to as West Plum Housing, which is located on Plum Street between just
east of City Park Avenue. We have run existing and proposed conditions models to represent
100-year water surface elevations prior to the project and after completion of the project. The
proposed conditions model is based on preliminary grading plans for the project.
A study of the area was originally conducted by Northern Engineering in conjunction with the
project referred to at the time as “The District”, and was later renamed “The District at Campus
West” (Ref: Final Drainage and Erosion Control Report for The District at Campus West, March
27, 2013, by Northern Engineering) The original study reach for the District at Campus West
extended from Shields Street to roughly 350 feet west of Bluebell Street. Floodplain modeling
done with the current project extends the study reach west to City Park Avenue. Additionally,
current floodplain modeling includes updated mapping of the Plum Street corridor, as Plum
Street was overlayed, and street elevations are now higher than that of the original modeling.
Recently constructed buildings encroaching into the floodplain have also been reflected in
current floodplain modeling.
As shown on the attached HEC-RAS Exhibit, we have added cross-sections at key locations along
the length of Plum Street. The majority of our modeling is based on one-foot topography
generated from field shots. All topographic information is related to the NAVD-88 vertical
datum.
Table 1, below shows existing and proposed conditions modeling results. Please see the
attached HEC-RAS output for support of this data.
2
Table 1 - HEC-RAS Model Output Summary
Corrected Proposed
Effective Condition Difference
River Sta Q Total Min Ch El W.S. Elev W.S. Elev W.S. Elev
(cfs) (ft) (ft) (ft) (ft)
100 232 5031.56 5032.9 5032.9 0
102 232 5030.92 5033.32 5033.32 0
103 232 5030.59 5033.48 5033.48 0
103.5 232 5030.83 5033.45 5033.45 0
104 232 5031.33 5033.47 5033.47 0
104.5 232 5031.62 5033.52 5033.52 0
105 232 5031.99 5033.66 5033.66 0
105.5 232 5032.18 5033.72 5033.72 0
106 232 5032.71 5034.29 5034.29 0
106.5 232 5033.22 5034.76 5034.76 0
107 232 5033.59 5035.17 5035.17 0
108 232 5034.48 5035.91 5035.91 0
109 232 5035.36 5036.91 5036.9 -0.01
110 232 5036.16 5037.69 5037.69 0
111 232 5036.86 5038.38 5038.37 -0.01
112 232 5037.43 5039.05 5039.04 -0.01
Please feel free to contact me with any questions you may have.
Sincerely,
Northern Engineering Services, Inc.
Aaron Cvar, PhD, PE
ATTACHMENT 1
HEC-RAS Modeling Workmap
D
D
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X
X
X X
X X
T
T T
T
T
ST ST ST ST
ST
ST ST
ST
ST
VAULT
ELEC
T FO
FO T
ELEC
V.P.
V.P.
CONTROL
IRR CONTROL
IRR
CONTROL
IRR CONTROL
IRR CONTROL
IRR
CONTROL
IRR
VAULT
F.O.
VAULT
F.O.
CONTROL
IRR CONTROL
IRR CONTROL
IRRCONTROL
IRR
D D
D D
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ATTACHMENT 2
HEC-RAS Output
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 1 of 17
HEC-RAS HEC-RAS 5.0.1 April 2016
U.S. Army Corps of Engineers
Hydrologic Engineering Center
609 Second Street
Davis, California
X X XXXXXX XXXX XXXX XX XXXX
X X X X X X X X X X
X X X X X X X X X
XXXXXXX XXXX X XXX XXXX XXXXXX XXXX
X X X X X X X X X
X X X X X X X X X X
X X XXXXXX XXXX X X X X XXXXX
PROJECT DATA
Project Title: 1252-001-BFE
Project File : 1252-001-BFE.prj
Run Date and Time: 9/13/2016 3:54:28 PM
Project in English units
PLAN DATA
Plan Title: CorrectedEff
Plan File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.p11
Geometry Title: Corrected Eff
Geometry File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.g01
Flow Title : Effective Flow
Flow File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.f02
Plan Summary Information:
Number of: Cross Sections = 16 Multiple Openings = 0
Culverts = 0 Inline Structures = 0
Bridges = 0 Lateral Structures = 0
Computational Information
Water surface calculation tolerance = 0.01
Critical depth calculation tolerance = 0.01
Maximum number of iterations = 20
Maximum difference tolerance = 0.3
Flow tolerance factor = 0.001
Computation Options
Critical depth computed only where necessary
Conveyance Calculation Method: At breaks in n values only
Friction Slope Method: Average Conveyance
Computational Flow Regime: Subcritical Flow
FLOW DATA
Flow Title: Effective Flow
Flow File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.f02
Flow Data (cfs)
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 2 of 17
River Reach RS PF 1
1 1 112 232
Boundary Conditions
River Reach Profile Upstream
Downstream
1 1 PF 1
Critical
GEOMETRY DATA
Geometry Title: Corrected Eff
Geometry File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.g01
CROSS SECTION
RIVER: 1
REACH: 1 RS: 112
INPUT
Description:
Station Elevation Data num= 25
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5040 -10 5038.13 0 5037.93 .1 5037.43 .55 5037.46
1.01 5037.47 2.22 5037.56 2.44 5037.56 8.58 5038 19 5038.32
21.2 5038.44 21.41 5038.45 22.2 5038.44 23.36 5038.45 23.72 5038.45
25.12 5038.44 26.71 5038.46 39.32 5038.38 39.52 5038.37 40.52 5038.31
40.67 5038.31 40.67 5038.25 41.24 5038.61 51.24 5038.81 84.27 5039.7
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41.24 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.24 84 84 84 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5039.45 Element Left OB Channel Right OB
Vel Head (ft) 0.40 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5039.05 Reach Len. (ft) 84.00 84.00 84.00
Crit W.S. (ft) 5039.05 Flow Area (sq ft) 10.19 34.77 4.41
E.G. Slope (ft/ft) 0.004314 Area (sq ft) 10.19 34.77 4.41
Q Total (cfs) 232.00 Flow (cfs) 37.99 187.46 6.55
Top Width (ft) 70.08 Top Width (ft) 10.05 41.24 18.79
Vel Total (ft/s) 4.70 Avg. Vel. (ft/s) 3.73 5.39 1.49
Max Chl Dpth (ft) 1.62 Hydr. Depth (ft) 1.01 0.84 0.23
Conv. Total (cfs) 3532.0 Conv. (cfs) 578.4 2853.9 99.7
Length Wtd. (ft) 84.00 Wetted Per. (ft) 10.92 41.85 18.79
Min Ch El (ft) 5037.43 Shear (lb/sq ft) 0.25 0.22 0.06
Alpha 1.17 Stream Power (lb/ft s) 0.94 1.21 0.09
Frctn Loss (ft) 0.37 Cum Volume (acre-ft) 0.45 1.23 0.05
C & E Loss (ft) 0.00 Cum SA (acres) 0.43 1.15 0.17
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 3 of 17
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 111
INPUT
Description:
Station Elevation Data num= 32
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5039.5 -10 5037.5 0 5037.3 .02 5037.3 .03 5037.29
.09 5037.29 .3 5037.07 .55 5036.86 .62 5036.87 .95 5036.89
2.48 5036.98 2.51 5036.94 2.57 5036.87 5.23 5037.01 15.37 5037.56
18.26 5037.75 21.09 5037.86 21.11 5037.85 21.78 5037.86 21.89 5037.87
23.37 5037.85 23.53 5037.85 23.9 5037.94 31.5 5037.85 37.98 5037.56
39.33 5037.54 39.56 5037.52 40.45 5037.45 40.95 5037.78 41 5037.81
51 5038.01 82.47 5039.9
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41 103 103 103 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5038.77 Element Left OB Channel Right OB
Vel Head (ft) 0.40 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5038.38 Reach Len. (ft) 103.00 103.00 103.00
Crit W.S. (ft) 5038.38 Flow Area (sq ft) 9.77 34.11 5.75
E.G. Slope (ft/ft) 0.004400 Area (sq ft) 9.77 34.11 5.75
Q Total (cfs) 232.00 Flow (cfs) 35.83 184.74 11.43
Top Width (ft) 67.12 Top Width (ft) 10.04 41.00 16.07
Vel Total (ft/s) 4.67 Avg. Vel. (ft/s) 3.67 5.42 1.99
Max Chl Dpth (ft) 1.51 Hydr. Depth (ft) 0.97 0.83 0.36
Conv. Total (cfs) 3497.6 Conv. (cfs) 540.1 2785.2 172.3
Length Wtd. (ft) 103.00 Wetted Per. (ft) 10.88 41.39 16.09
Min Ch El (ft) 5036.86 Shear (lb/sq ft) 0.25 0.23 0.10
Alpha 1.17 Stream Power (lb/ft s) 0.90 1.23 0.20
Frctn Loss (ft) 0.45 Cum Volume (acre-ft) 0.43 1.16 0.05
C & E Loss (ft) 0.00 Cum SA (acres) 0.41 1.07 0.14
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 4 of 17
RIVER: 1
REACH: 1 RS: 110
INPUT
Description:
Station Elevation Data num= 30
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5039 -10 5036.84 0 5036.64 .13 5036.64 .18 5036.63
.31 5036.49 .69 5036.16 1.86 5036.21 2.48 5036.24 2.51 5036.28
2.58 5036.31 2.66 5036.27 7.02 5036.6 13.77 5036.79 15.57 5036.96
21.32 5037.16 23.09 5037.13 29.64 5037.05 30.12 5037.06 31.74 5037.06
34.52 5036.96 39.23 5036.86 39.59 5036.83 39.62 5036.83 40.35 5036.76
40.37 5036.76 40.59 5036.89 40.92 5037.11 50.92 5037.31 80.31 5038.9
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.92 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.92 95 95 95 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5038.09 Element Left OB Channel Right OB
Vel Head (ft) 0.40 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5037.69 Reach Len. (ft) 95.00 95.00 95.00
Crit W.S. (ft) 5037.69 Flow Area (sq ft) 9.49 34.14 6.08
E.G. Slope (ft/ft) 0.004416 Area (sq ft) 9.49 34.14 6.08
Q Total (cfs) 232.00 Flow (cfs) 34.26 185.61 12.12
Top Width (ft) 67.93 Top Width (ft) 10.04 40.92 16.97
Vel Total (ft/s) 4.67 Avg. Vel. (ft/s) 3.61 5.44 1.99
Max Chl Dpth (ft) 1.53 Hydr. Depth (ft) 0.94 0.83 0.36
Conv. Total (cfs) 3491.0 Conv. (cfs) 515.6 2793.0 182.4
Length Wtd. (ft) 95.00 Wetted Per. (ft) 10.85 41.28 16.98
Min Ch El (ft) 5036.16 Shear (lb/sq ft) 0.24 0.23 0.10
Alpha 1.18 Stream Power (lb/ft s) 0.87 1.24 0.20
Frctn Loss (ft) 0.42 Cum Volume (acre-ft) 0.40 1.08 0.03
C & E Loss (ft) 0.00 Cum SA (acres) 0.38 0.98 0.10
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 109
INPUT
Description:
Station Elevation Data num= 19
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5038 -10 5035.89 0 5035.69 .14 5035.54 .32 5035.36
1.61 5035.47 2.32 5035.53 13 5035.96 20.63 5036.35 22.68 5036.33
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 5 of 17
28.54 5036.3 39.16 5036.31 39.93 5036.17 40.26 5036.18 40.69 5036.44
40.94 5036.53 40.96 5036.53 50.96 5036.73 78.98 5037.2
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.96 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.96 93 93 93 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5037.31 Element Left OB Channel Right OB
Vel Head (ft) 0.40 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5036.91 Reach Len. (ft) 93.00 93.00 93.00
Crit W.S. (ft) 5036.91 Flow Area (sq ft) 11.23 33.82 3.78
E.G. Slope (ft/ft) 0.004394 Area (sq ft) 11.23 33.82 3.78
Q Total (cfs) 232.00 Flow (cfs) 44.80 182.42 4.78
Top Width (ft) 71.77 Top Width (ft) 10.05 40.96 20.77
Vel Total (ft/s) 4.75 Avg. Vel. (ft/s) 3.99 5.39 1.27
Max Chl Dpth (ft) 1.55 Hydr. Depth (ft) 1.12 0.83 0.18
Conv. Total (cfs) 3499.8 Conv. (cfs) 675.9 2751.8 72.2
Length Wtd. (ft) 93.00 Wetted Per. (ft) 11.02 41.23 20.77
Min Ch El (ft) 5035.36 Shear (lb/sq ft) 0.28 0.23 0.05
Alpha 1.15 Stream Power (lb/ft s) 1.11 1.21 0.06
Frctn Loss (ft) 0.43 Cum Volume (acre-ft) 0.38 1.01 0.02
C & E Loss (ft) 0.00 Cum SA (acres) 0.36 0.89 0.06
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 108
INPUT
Description:
Station Elevation Data num= 19
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5037 -10 5035.05 0 5034.85 .1 5034.75 .37 5034.48
1.31 5034.57 2.37 5034.65 6.75 5034.91 13.64 5035.1 21.08 5035.32
28.1 5035.32 34.83 5035.19 39.14 5035.07 39.4 5035.09 40.02 5035.09
40.32 5035.12 40.39 5035.13 41.46 5035.3 51.46 5035.5
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41.46 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.46 94 94 94 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5036.32 Element Left OB Channel Right OB
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 6 of 17
Vel Head (ft) 0.41 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5035.91 Reach Len. (ft) 94.00 94.00 94.00
Crit W.S. (ft) 5035.91 Flow Area (sq ft) 9.59 33.10 5.07
E.G. Slope (ft/ft) 0.004801 Area (sq ft) 9.59 33.10 5.07
Q Total (cfs) 232.00 Flow (cfs) 36.36 182.70 12.94
Top Width (ft) 61.50 Top Width (ft) 10.04 41.46 10.00
Vel Total (ft/s) 4.86 Avg. Vel. (ft/s) 3.79 5.52 2.55
Max Chl Dpth (ft) 1.43 Hydr. Depth (ft) 0.95 0.80 0.51
Conv. Total (cfs) 3348.4 Conv. (cfs) 524.8 2636.8 186.7
Length Wtd. (ft) 94.00 Wetted Per. (ft) 10.86 41.65 10.41
Min Ch El (ft) 5034.48 Shear (lb/sq ft) 0.26 0.24 0.15
Alpha 1.13 Stream Power (lb/ft s) 1.00 1.31 0.37
Frctn Loss (ft) 0.27 Cum Volume (acre-ft) 0.36 0.94 0.01
C & E Loss (ft) 0.07 Cum SA (acres) 0.34 0.80 0.03
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 107
INPUT
Description:
Station Elevation Data num= 22
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5033.99 0 5033.59 2.22 5033.6 2.33 5033.6 3.89 5033.68
20.83 5034.51 22.73 5034.55 23.69 5034.58 25.15 5034.58 38.46 5034.42
38.48 5034.41 38.52 5034.38 39.4 5034.3 39.91 5034.28 40.27 5034.3
40.35 5034.35 40.36 5034.47 40.38 5034.34 40.57 5034.53 40.77 5034.65
40.9 5034.73 50.9 5034.93
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 40.9 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.9 46 46 46 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5035.36 Element Left OB Channel Right OB
Vel Head (ft) 0.19 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5035.17 Reach Len. (ft) 46.00 46.00 46.00
Crit W.S. (ft) Flow Area (sq ft) 27.67 37.93 3.43
E.G. Slope (ft/ft) 0.001852 Area (sq ft) 27.67 37.93 3.43
Q Total (cfs) 232.00 Flow (cfs) 84.55 143.22 4.24
Top Width (ft) 70.90 Top Width (ft) 20.00 40.90 10.00
Vel Total (ft/s) 3.36 Avg. Vel. (ft/s) 3.06 3.78 1.23
Max Chl Dpth (ft) 1.58 Hydr. Depth (ft) 1.38 0.93 0.34
Conv. Total (cfs) 5390.6 Conv. (cfs) 1964.5 3327.6 98.4
Length Wtd. (ft) 46.00 Wetted Per. (ft) 21.19 41.31 10.25
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 7 of 17
Min Ch El (ft) 5033.59 Shear (lb/sq ft) 0.15 0.11 0.04
Alpha 1.08 Stream Power (lb/ft s) 0.46 0.40 0.05
Frctn Loss (ft) 0.13 Cum Volume (acre-ft) 0.32 0.86 0.00
C & E Loss (ft) 0.03 Cum SA (acres) 0.31 0.71 0.01
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 106.5
INPUT
Description:
Station Elevation Data num= 27
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5036 -10 5033.91 0 5033.71 .49 5033.22 1.89 5033.26
1.93 5033.27 2.33 5033.28 20.49 5034.13 22.64 5034.16 24.79 5034.19
25.02 5034.19 25.55 5034.18 38.13 5034.11 38.14 5034.11 38.26 5034.05
38.44 5034.04 40.14 5034.09 40.19 5034.09 40.21 5034.12 40.21 5034.11
40.3 5034.2 40.33 5034.11 40.69 5034.48 40.7 5034.6 40.71 5034.62
40.71 5034.48 40.76 5034.48
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.76 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.76 67 67 67 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5035.21 Element Left OB Channel Right OB
Vel Head (ft) 0.45 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5034.76 Reach Len. (ft) 67.00 67.00 67.00
Crit W.S. (ft) 5034.76 Flow Area (sq ft) 9.47 34.82
E.G. Slope (ft/ft) 0.004722 Area (sq ft) 9.47 34.82
Q Total (cfs) 232.00 Flow (cfs) 35.30 196.70
Top Width (ft) 50.80 Top Width (ft) 10.04 40.76
Vel Total (ft/s) 5.24 Avg. Vel. (ft/s) 3.73 5.65
Max Chl Dpth (ft) 1.53 Hydr. Depth (ft) 0.94 0.85
Conv. Total (cfs) 3376.1 Conv. (cfs) 513.7 2862.4
Length Wtd. (ft) 67.00 Wetted Per. (ft) 10.85 41.82
Min Ch El (ft) 5033.22 Shear (lb/sq ft) 0.26 0.25
Alpha 1.06 Stream Power (lb/ft s) 0.96 1.39
Frctn Loss (ft) 0.32 Cum Volume (acre-ft) 0.30 0.82
C & E Loss (ft) 0.00 Cum SA (acres) 0.29 0.67
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
WEST PLUM HOUSING
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Page 8 of 17
CROSS SECTION
RIVER: 1
REACH: 1 RS: 106
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5035 -10 5033.4 0 5033.2 .36 5032.84 .49 5032.71
1.83 5032.83 2.28 5032.84 6.91 5033.07 20.36 5033.7 21.53 5033.69
22.97 5033.72 25.51 5033.76 25.63 5033.8 32.67 5033.67 38.26 5033.57
38.34 5033.57 38.82 5033.54 40.22 5033.54 40.25 5033.4 40.27 5033.42
40.72 5034.04 40.73 5033.95 40.78 5033.86
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.78 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.78 99 99 99 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5034.75 Element Left OB Channel Right OB
Vel Head (ft) 0.46 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5034.29 Reach Len. (ft) 99.00 99.00 99.00
Crit W.S. (ft) 5034.29 Flow Area (sq ft) 9.91 34.07
E.G. Slope (ft/ft) 0.004930 Area (sq ft) 9.91 34.07
Q Total (cfs) 232.00 Flow (cfs) 38.83 193.17
Top Width (ft) 50.84 Top Width (ft) 10.06 40.78
Vel Total (ft/s) 5.28 Avg. Vel. (ft/s) 3.92 5.67
Max Chl Dpth (ft) 1.58 Hydr. Depth (ft) 0.99 0.84
Conv. Total (cfs) 3304.2 Conv. (cfs) 553.0 2751.1
Length Wtd. (ft) 99.00 Wetted Per. (ft) 10.89 42.02
Min Ch El (ft) 5032.71 Shear (lb/sq ft) 0.28 0.25
Alpha 1.05 Stream Power (lb/ft s) 1.10 1.41
Frctn Loss (ft) 0.49 Cum Volume (acre-ft) 0.28 0.77
C & E Loss (ft) 0.01 Cum SA (acres) 0.28 0.60
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 105.5
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5035 -10 5032.89 0 5032.69 .01 5032.68 .4 5032.29
.51 5032.18 .89 5032.18 2.24 5032.21 5.32 5032.34 20.09 5033.03
21.15 5033.09 21.54 5033.09 22.8 5033.13 29.05 5033.32 30.84 5033.29
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Page 9 of 17
42.28 5033.21 45.01 5033.21 45.09 5033.06 46.33 5033.06 46.68 5033.05
46.69 5032.92 46.71 5032.92 47.2 5033.55
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 47.2 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 47.2 42 42 42 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5034.13 Element Left OB Channel Right OB
Vel Head (ft) 0.42 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.72 Reach Len. (ft) 42.00 42.00 42.00
Crit W.S. (ft) 5033.72 Flow Area (sq ft) 9.28 36.55
E.G. Slope (ft/ft) 0.004875 Area (sq ft) 9.28 36.55
Q Total (cfs) 232.00 Flow (cfs) 34.74 197.26
Top Width (ft) 57.24 Top Width (ft) 10.04 47.20
Vel Total (ft/s) 5.06 Avg. Vel. (ft/s) 3.74 5.40
Max Chl Dpth (ft) 1.54 Hydr. Depth (ft) 0.92 0.77
Conv. Total (cfs) 3322.7 Conv. (cfs) 497.5 2825.2
Length Wtd. (ft) 42.00 Wetted Per. (ft) 10.83 48.12
Min Ch El (ft) 5032.18 Shear (lb/sq ft) 0.26 0.23
Alpha 1.05 Stream Power (lb/ft s) 0.98 1.25
Frctn Loss (ft) 0.10 Cum Volume (acre-ft) 0.26 0.69
C & E Loss (ft) 0.08 Cum SA (acres) 0.25 0.50
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 105
INPUT
Description:
Station Elevation Data num= 26
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5032.47 0 5032.07 .56 5032.02 2.64 5031.99 3.02 5032.01
7.57 5032.21 19.74 5032.79 21.53 5032.89 21.58 5032.9 22.18 5032.91
30.98 5032.98 31.52 5032.92 35.32 5032.9 39.36 5032.82 43.83 5032.79
43.84 5032.81 43.9 5032.72 45.08 5032.68 45.79 5032.78 45.8 5032.64
45.87 5032.66 45.95 5032.66 46.14 5032.84 46.29 5033.06 46.43 5033.13
46.44 5033.13
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 46.44 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 46.44 42 42 42 .1 .3
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Page 10 of 17
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.82 Element Left OB Channel Right OB
Vel Head (ft) 0.16 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.66 Reach Len. (ft) 42.00 42.00 42.00
Crit W.S. (ft) Flow Area (sq ft) 27.81 47.10
E.G. Slope (ft/ft) 0.001341 Area (sq ft) 27.81 47.10
Q Total (cfs) 232.00 Flow (cfs) 72.55 159.45
Top Width (ft) 66.44 Top Width (ft) 20.00 46.44
Vel Total (ft/s) 3.10 Avg. Vel. (ft/s) 2.61 3.39
Max Chl Dpth (ft) 1.67 Hydr. Depth (ft) 1.39 1.01
Conv. Total (cfs) 6336.1 Conv. (cfs) 1981.4 4354.7
Length Wtd. (ft) 42.00 Wetted Per. (ft) 21.19 47.41
Min Ch El (ft) 5031.99 Shear (lb/sq ft) 0.11 0.08
Alpha 1.04 Stream Power (lb/ft s) 0.29 0.28
Frctn Loss (ft) 0.07 Cum Volume (acre-ft) 0.24 0.65
C & E Loss (ft) 0.01 Cum SA (acres) 0.24 0.46
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 104.5
INPUT
Description:
Station Elevation Data num= 32
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5034 -16 5032.52 0 5032.12 .1 5031.62 2.09 5031.71
2.25 5031.72 5.44 5031.88 16.82 5032.54 18.64 5032.66 18.91 5032.68
19.52 5032.72 25.21 5032.82 25.79 5032.84 28.52 5032.86 36.21 5032.84
37.6 5032.77 39.8 5032.62 40.2 5032.6 40.32 5032.53 40.35 5032.57
40.36 5032.57 42 5032.42 42.11 5032.43 42.15 5032.48 42.16 5032.47
42.23 5032.46 42.33 5032.45 42.44 5032.56 42.59 5032.9 42.65 5032.98
42.66 5032.97 42.7 5032.96
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 42.7 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 42.7 73 73 73 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.74 Element Left OB Channel Right OB
Vel Head (ft) 0.22 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.52 Reach Len. (ft) 73.00 73.00 73.00
Crit W.S. (ft) Flow Area (sq ft) 19.26 44.31
E.G. Slope (ft/ft) 0.001865 Area (sq ft) 19.26 44.31
Q Total (cfs) 232.00 Flow (cfs) 53.70 178.30
Top Width (ft) 58.77 Top Width (ft) 16.07 42.70
Vel Total (ft/s) 3.65 Avg. Vel. (ft/s) 2.79 4.02
Max Chl Dpth (ft) 1.90 Hydr. Depth (ft) 1.20 1.04
Conv. Total (cfs) 5371.7 Conv. (cfs) 1243.3 4128.4
Length Wtd. (ft) 73.00 Wetted Per. (ft) 17.01 44.10
Min Ch El (ft) 5031.62 Shear (lb/sq ft) 0.13 0.12
Alpha 1.07 Stream Power (lb/ft s) 0.37 0.47
Frctn Loss (ft) 0.09 Cum Volume (acre-ft) 0.22 0.61
C & E Loss (ft) 0.02 Cum SA (acres) 0.22 0.42
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 11 of 17
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 104
INPUT
Description:
Station Elevation Data num= 24
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5034 -16 5032.26 0 5031.86 .1 5031.36 .32 5031.33
1.57 5031.42 2.05 5031.44 6.12 5031.65 18.13 5032.3 18.97 5032.35
23.72 5032.47 25.53 5032.52 34.82 5032.49 36.25 5032.44 38.69 5032.35
38.91 5032.17 38.92 5032.16 39.99 5032.18 40.7 5032.15 40.76 5032.1
40.78 5032.05 40.96 5032.3 41.2 5032.65 41.24 5032.65
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 41.24 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.24 89 89 89 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.63 Element Left OB Channel Right OB
Vel Head (ft) 0.15 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.47 Reach Len. (ft) 89.00 89.00 89.00
Crit W.S. (ft) Flow Area (sq ft) 22.66 54.19
E.G. Slope (ft/ft) 0.000958 Area (sq ft) 22.66 54.19
Q Total (cfs) 232.00 Flow (cfs) 50.08 181.92
Top Width (ft) 57.31 Top Width (ft) 16.07 41.24
Vel Total (ft/s) 3.02 Avg. Vel. (ft/s) 2.21 3.36
Max Chl Dpth (ft) 2.14 Hydr. Depth (ft) 1.41 1.31
Conv. Total (cfs) 7494.1 Conv. (cfs) 1617.7 5876.4
Length Wtd. (ft) 89.00 Wetted Per. (ft) 17.22 42.94
Min Ch El (ft) 5031.33 Shear (lb/sq ft) 0.08 0.08
Alpha 1.09 Stream Power (lb/ft s) 0.17 0.25
Frctn Loss (ft) 0.06 Cum Volume (acre-ft) 0.19 0.52
C & E Loss (ft) 0.01 Cum SA (acres) 0.20 0.35
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 103.5
INPUT
Description:
Station Elevation Data num= 31
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5036 -16 5034.18 -6 5031.83 0 5031.02 .39 5031.03
.46 5030.85 .6 5030.83 1.68 5030.86 2.4 5030.94 2.53 5030.93
12.52 5031.49 19.02 5031.87 19.86 5031.92 20.34 5031.93 22.96 5031.96
24.64 5032.01 27.55 5032.02 34.95 5032.04 37.07 5031.93 38.28 5031.83
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CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
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Page 12 of 17
38.29 5031.82 39.11 5031.61 40.09 5031.43 40.14 5031.53 40.2 5031.5
40.29 5031.71 40.59 5031.98 40.67 5032.12 40.7 5032.14 40.71 5032.14
40.89 5032.15
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 40.89 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.89 46 46 46 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.56 Element Left OB Channel Right OB
Vel Head (ft) 0.11 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.45 Reach Len. (ft) 46.00 46.00 46.00
Crit W.S. (ft) Flow Area (sq ft) 17.68 72.91
E.G. Slope (ft/ft) 0.000450 Area (sq ft) 17.68 72.91
Q Total (cfs) 232.00 Flow (cfs) 27.20 204.80
Top Width (ft) 53.77 Top Width (ft) 12.88 40.89
Vel Total (ft/s) 2.56 Avg. Vel. (ft/s) 1.54 2.81
Max Chl Dpth (ft) 2.62 Hydr. Depth (ft) 1.37 1.78
Conv. Total (cfs) 10942.2 Conv. (cfs) 1282.7 9659.5
Length Wtd. (ft) 46.00 Wetted Per. (ft) 13.12 42.80
Min Ch El (ft) 5030.83 Shear (lb/sq ft) 0.04 0.05
Alpha 1.10 Stream Power (lb/ft s) 0.06 0.13
Frctn Loss (ft) 0.01 Cum Volume (acre-ft) 0.14 0.39
C & E Loss (ft) 0.02 Cum SA (acres) 0.17 0.26
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 103
INPUT
Description:
Station Elevation Data num= 33
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5031 0 5030.6 .38 5030.59 .47 5030.61 .6 5030.64
.61 5030.6 .73 5030.61 1.28 5030.67 3.18 5030.73 3.19 5030.76
8.01 5031.06 21.84 5031.82 22.39 5031.85 28.83 5031.84 29.8 5031.86
30.66 5031.86 34.02 5031.78 40.38 5031.71 40.41 5031.87 40.43 5031.83
41.76 5031.66 42.05 5031.65 42.08 5031.66 42.15 5031.7 42.16 5031.72
42.25 5031.71 42.34 5031.79 42.6 5031.78 42.63 5032.18 42.66 5032.22
42.67 5032.01 42.7 5032.04 42.71 5032.04
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 42.71 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 42.71 79 79 79 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.53 Element Left OB Channel Right OB
Vel Head (ft) 0.05 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.48 Reach Len. (ft) 79.00 79.00 79.00
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Page 13 of 17
Crit W.S. (ft) Flow Area (sq ft) 53.62 84.67
E.G. Slope (ft/ft) 0.000173 Area (sq ft) 53.62 84.67
Q Total (cfs) 232.00 Flow (cfs) 74.73 157.27
Top Width (ft) 62.71 Top Width (ft) 20.00 42.71
Vel Total (ft/s) 1.68 Avg. Vel. (ft/s) 1.39 1.86
Max Chl Dpth (ft) 2.89 Hydr. Depth (ft) 2.68 1.98
Conv. Total (cfs) 17658.2 Conv. (cfs) 5688.3 11969.9
Length Wtd. (ft) 79.00 Wetted Per. (ft) 22.48 45.08
Min Ch El (ft) 5030.59 Shear (lb/sq ft) 0.03 0.02
Alpha 1.05 Stream Power (lb/ft s) 0.04 0.04
Frctn Loss (ft) 0.03 Cum Volume (acre-ft) 0.11 0.31
C & E Loss (ft) 0.01 Cum SA (acres) 0.15 0.22
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 102
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-5.7 5033 -5.6 5031.68 -4.5 5031.63 0 5031.43 .1 5030.93
.35 5030.94 .44 5030.93 .54 5030.95 .71 5030.92 .77 5030.93
2.2 5030.97 2.21 5030.97 16.44 5031.72 21.02 5031.96 28.63 5032.18
39.01 5032.47 39.06 5032.47 39.07 5032.46 39.1 5032.46 41 5032.35
41.01 5032.36 41.5 5032.85 41.69 5032.85
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-5.7 .025 0 .016 41.69 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.69 150 150 150 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.49 Element Left OB Channel Right OB
Vel Head (ft) 0.17 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.32 Reach Len. (ft) 150.00 150.00 150.00
Crit W.S. (ft) Flow Area (sq ft) 9.98 62.20
E.G. Slope (ft/ft) 0.000812 Area (sq ft) 9.98 62.20
Q Total (cfs) 232.00 Flow (cfs) 20.93 211.07
Top Width (ft) 47.39 Top Width (ft) 5.70 41.69
Vel Total (ft/s) 3.21 Avg. Vel. (ft/s) 2.10 3.39
Max Chl Dpth (ft) 2.40 Hydr. Depth (ft) 1.75 1.49
Conv. Total (cfs) 8142.8 Conv. (cfs) 734.5 7408.3
Length Wtd. (ft) 150.00 Wetted Per. (ft) 7.25 42.82
Min Ch El (ft) 5030.92 Shear (lb/sq ft) 0.07 0.07
Alpha 1.05 Stream Power (lb/ft s) 0.15 0.25
Frctn Loss (ft) 0.21 Cum Volume (acre-ft) 0.05 0.18
C & E Loss (ft) 0.02 Cum SA (acres) 0.12 0.14
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
WEST PLUM HOUSING
CORRECTED EFFECTIVE HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 14 of 17
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 100
INPUT
Description:
Station Elevation Data num= 18
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-115.5 5033.18 -27.5 5032.68 -4.5 5032.18 0 5032.06 .1 5031.56
.84 5031.56 2.01 5031.63 2.78 5031.69 12.91 5031.76 19.06 5031.88
20.92 5031.92 28.05 5032.03 37.99 5032.12 38.6 5032.09 39.68 5032.1
39.88 5032.3 40.18 5032.6 40.51 5032.58
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-115.5 .025 0 .016 40.51 .025
Bank Sta: Left Right Coeff Contr. Expan.
0 40.51 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
46.2 40.51 5041.18
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.26 Element Left OB Channel Right OB
Vel Head (ft) 0.36 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5032.90 Reach Len. (ft)
Crit W.S. (ft) 5032.90 Flow Area (sq ft) 18.79 40.65
E.G. Slope (ft/ft) 0.003043 Area (sq ft) 18.79 40.65
Q Total (cfs) 232.00 Flow (cfs) 26.45 205.55
Top Width (ft) 107.28 Top Width (ft) 66.77 40.51
Vel Total (ft/s) 3.90 Avg. Vel. (ft/s) 1.41 5.06
Max Chl Dpth (ft) 1.34 Hydr. Depth (ft) 0.28 1.00
Conv. Total (cfs) 4205.9 Conv. (cfs) 479.5 3726.4
Length Wtd. (ft) Wetted Per. (ft) 66.78 41.46
Min Ch El (ft) 5031.56 Shear (lb/sq ft) 0.05 0.19
Alpha 1.50 Stream Power (lb/ft s) 0.08 0.94
Frctn Loss (ft) Cum Volume (acre-ft)
C & E Loss (ft) Cum SA (acres)
SUMMARY OF MANNING'S N VALUES
River:1
Reach River Sta. n1 n2 n3
1 112 .025 .016 .025
1 111 .025 .016 .025
1 110 .025 .016 .025
1 109 .025 .016 .025
1 108 .025 .016 .025
1 107 .025 .016 .025
1 106.5 .025 .016 .025
1 106 .025 .016 .025
1 105.5 .025 .016 .025
1 105 .025 .016 .025
1 104.5 .025 .016 .025
1 104 .025 .016 .025
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Page 15 of 17
1 103.5 .025 .016 .025
1 103 .025 .016 .025
1 102 .025 .016 .025
1 100 .025 .016 .025
SUMMARY OF REACH LENGTHS
River: 1
Reach River Sta. Left Channel Right
1 112 84 84 84
1 111 103 103 103
1 110 95 95 95
1 109 93 93 93
1 108 94 94 94
1 107 46 46 46
1 106.5 67 67 67
1 106 99 99 99
1 105.5 42 42 42
1 105 42 42 42
1 104.5 73 73 73
1 104 89 89 89
1 103.5 46 46 46
1 103 79 79 79
1 102 150 150 150
1 100
SUMMARY OF CONTRACTION AND EXPANSION COEFFICIENTS
River: 1
Reach River Sta. Contr. Expan.
1 112 .1 .3
1 111 .1 .3
1 110 .1 .3
1 109 .1 .3
1 108 .1 .3
1 107 .1 .3
1 106.5 .1 .3
1 106 .1 .3
1 105.5 .1 .3
1 105 .1 .3
1 104.5 .1 .3
1 104 .1 .3
1 103.5 .1 .3
1 103 .1 .3
1 102 .1 .3
1 100 .1 .3
Profile Output Table - Standard Table 1
Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev
E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl
(cfs) (ft) (ft) (ft) (ft)
(ft/ft) (ft/s) (sq ft) (ft)
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1 100 PF 1 232.00 5031.56 5032.90 5032.90 5033.26
0.003043 5.06 59.44 107.28 0.89
1 102 PF 1 232.00 5030.92 5033.32 5033.49
0.000812 3.39 72.18 47.39 0.49
1 103 PF 1 232.00 5030.59 5033.48 5033.53
0.000173 1.86 138.28 62.71 0.23
1 103.5 PF 1 232.00 5030.83 5033.45 5033.56
0.000450 2.81 90.60 53.77 0.37
1 104 PF 1 232.00 5031.33 5033.47 5033.63
0.000958 3.36 76.85 57.31 0.52
1 104.5 PF 1 232.00 5031.62 5033.52 5033.74
0.001865 4.02 63.57 58.77 0.70
1 105 PF 1 232.00 5031.99 5033.66 5033.82
0.001341 3.39 74.91 66.44 0.59
1 105.5 PF 1 232.00 5032.18 5033.72 5033.72 5034.13
0.004875 5.40 45.82 57.24 1.08
1 106 PF 1 232.00 5032.71 5034.29 5034.29 5034.75
0.004930 5.67 43.98 50.84 1.09
1 106.5 PF 1 232.00 5033.22 5034.76 5034.76 5035.21
0.004722 5.65 44.29 50.80 1.08
1 107 PF 1 232.00 5033.59 5035.17 5035.36
0.001852 3.78 69.03 70.90 0.69
1 108 PF 1 232.00 5034.48 5035.91 5035.91 5036.32
0.004801 5.52 47.76 61.50 1.09
1 109 PF 1 232.00 5035.36 5036.91 5036.91 5037.31
0.004394 5.39 48.83 71.77 1.05
1 110 PF 1 232.00 5036.16 5037.69 5037.69 5038.09
0.004416 5.44 49.71 67.93 1.05
1 111 PF 1 232.00 5036.86 5038.38 5038.38 5038.77
0.004400 5.42 49.63 67.12 1.05
1 112 PF 1 232.00 5037.43 5039.05 5039.05 5039.45
0.004314 5.39 49.37 70.08 1.04
Profile Output Table - Standard Table 2
Reach River Sta Profile E.G. Elev W.S. Elev Vel Head Frctn Loss C & E
Loss Q Left Q Channel Q Right Top Width
(ft) (ft) (ft) (ft)
(ft) (cfs) (cfs) (cfs) (ft)
1 100 PF 1 5033.26 5032.90 0.36
26.45 205.55 107.28
1 102 PF 1 5033.49 5033.32 0.17 0.21
0.02 20.93 211.07 47.39
1 103 PF 1 5033.53 5033.48 0.05 0.03
0.01 74.73 157.27 62.71
1 103.5 PF 1 5033.56 5033.45 0.11 0.01
0.02 27.20 204.80 53.77
1 104 PF 1 5033.63 5033.47 0.15 0.06
0.01 50.08 181.92 57.31
1 104.5 PF 1 5033.74 5033.52 0.22 0.09
0.02 53.70 178.30 58.77
1 105 PF 1 5033.82 5033.66 0.16 0.07
0.01 72.55 159.45 66.44
1 105.5 PF 1 5034.13 5033.72 0.42 0.10
0.08 34.74 197.26 57.24
1 106 PF 1 5034.75 5034.29 0.46 0.49
0.01 38.83 193.17 50.84
1 106.5 PF 1 5035.21 5034.76 0.45 0.32
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Page 17 of 17
1 109 PF 1 5037.31 5036.91 0.40 0.43
0.00 44.80 182.42 4.78 71.77
1 110 PF 1 5038.09 5037.69 0.40 0.42
0.00 34.26 185.61 12.12 67.93
1 111 PF 1 5038.77 5038.38 0.40 0.45
0.00 35.83 184.74 11.43 67.12
1 112 PF 1 5039.45 5039.05 0.40 0.37
0.00 37.99 187.46 6.55 70.08
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NORTHERN ENGINEERING; SEPTEMBER 2016
Page 1 of 17
HEC-RAS HEC-RAS 5.0.1 April 2016
U.S. Army Corps of Engineers
Hydrologic Engineering Center
609 Second Street
Davis, California
X X XXXXXX XXXX XXXX XX XXXX
X X X X X X X X X X
X X X X X X X X X
XXXXXXX XXXX X XXX XXXX XXXXXX XXXX
X X X X X X X X X
X X X X X X X X X X
X X XXXXXX XXXX X X X X XXXXX
PROJECT DATA
Project Title: 1252-001-BFE
Project File : 1252-001-BFE.prj
Run Date and Time: 9/13/2016 3:44:55 PM
Project in English units
PLAN DATA
Plan Title: ProposedCond
Plan File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.p10
Geometry Title: Proposed Cond
Geometry File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.g02
Flow Title : Effective Flow
Flow File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.f02
Plan Summary Information:
Number of: Cross Sections = 16 Multiple Openings = 0
Culverts = 0 Inline Structures = 0
Bridges = 0 Lateral Structures = 0
Computational Information
Water surface calculation tolerance = 0.01
Critical depth calculation tolerance = 0.01
Maximum number of iterations = 20
Maximum difference tolerance = 0.3
Flow tolerance factor = 0.001
Computation Options
Critical depth computed only where necessary
Conveyance Calculation Method: At breaks in n values only
Friction Slope Method: Average Conveyance
Computational Flow Regime: Subcritical Flow
FLOW DATA
Flow Title: Effective Flow
Flow File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.f02
Flow Data (cfs)
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Page 2 of 17
River Reach RS PF 1
1 1 112 232
Boundary Conditions
River Reach Profile Upstream
Downstream
1 1 PF 1
Critical
GEOMETRY DATA
Geometry Title: Proposed Cond
Geometry File : d:\Projects\1252-001\Drainage\Modeling\HEC-RAS\1252-001-BFE.g02
CROSS SECTION
RIVER: 1
REACH: 1 RS: 112
INPUT
Description:
Station Elevation Data num= 24
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5040 -10 5038.13 0 5037.93 .1 5037.43 .55 5037.46
1.01 5037.47 2.22 5037.56 2.44 5037.56 8.58 5038 19 5038.32
21.2 5038.44 21.41 5038.45 22.2 5038.44 23.36 5038.45 23.72 5038.45
25.12 5038.44 26.71 5038.46 39.32 5038.38 39.52 5038.37 40.52 5038.31
40.67 5038.31 40.67 5038.25 41.24 5038.61 51.24 5038.81
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41.24 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.24 84 84 84 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5039.45 Element Left OB Channel Right OB
Vel Head (ft) 0.42 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5039.04 Reach Len. (ft) 84.00 84.00 84.00
Crit W.S. (ft) 5039.04 Flow Area (sq ft) 10.07 34.27 3.25
E.G. Slope (ft/ft) 0.004542 Area (sq ft) 10.07 34.27 3.25
Q Total (cfs) 232.00 Flow (cfs) 38.23 187.71 6.05
Top Width (ft) 61.29 Top Width (ft) 10.05 41.24 10.00
Vel Total (ft/s) 4.88 Avg. Vel. (ft/s) 3.80 5.48 1.86
Max Chl Dpth (ft) 1.60 Hydr. Depth (ft) 1.00 0.83 0.32
Conv. Total (cfs) 3442.5 Conv. (cfs) 567.3 2785.3 89.8
Length Wtd. (ft) 84.00 Wetted Per. (ft) 10.91 41.85 10.23
Min Ch El (ft) 5037.43 Shear (lb/sq ft) 0.26 0.23 0.09
Alpha 1.13 Stream Power (lb/ft s) 0.99 1.27 0.17
Frctn Loss (ft) 0.38 Cum Volume (acre-ft) 0.44 1.23 0.05
C & E Loss (ft) 0.00 Cum SA (acres) 0.43 1.15 0.11
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NORTHERN ENGINEERING; SEPTEMBER 2016
Page 3 of 17
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 111
INPUT
Description:
Station Elevation Data num= 31
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5039.5 -10 5037.5 0 5037.3 .02 5037.3 .03 5037.29
.09 5037.29 .3 5037.07 .55 5036.86 .62 5036.87 .95 5036.89
2.48 5036.98 2.51 5036.94 2.57 5036.87 5.23 5037.01 15.37 5037.56
18.26 5037.75 21.09 5037.86 21.11 5037.85 21.78 5037.86 21.89 5037.87
23.37 5037.85 23.53 5037.85 23.9 5037.94 31.5 5037.85 37.98 5037.56
39.33 5037.54 39.56 5037.52 40.45 5037.45 40.95 5037.78 41 5037.81
51 5038.01
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41 103 103 103 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5038.78 Element Left OB Channel Right OB
Vel Head (ft) 0.41 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5038.37 Reach Len. (ft) 103.00 103.00 103.00
Crit W.S. (ft) 5038.37 Flow Area (sq ft) 9.71 33.89 4.59
E.G. Slope (ft/ft) 0.004524 Area (sq ft) 9.71 33.89 4.59
Q Total (cfs) 232.00 Flow (cfs) 36.01 185.32 10.67
Top Width (ft) 61.04 Top Width (ft) 10.04 41.00 10.00
Vel Total (ft/s) 4.81 Avg. Vel. (ft/s) 3.71 5.47 2.32
Max Chl Dpth (ft) 1.51 Hydr. Depth (ft) 0.97 0.83 0.46
Conv. Total (cfs) 3449.3 Conv. (cfs) 535.3 2755.3 158.7
Length Wtd. (ft) 103.00 Wetted Per. (ft) 10.87 41.39 10.36
Min Ch El (ft) 5036.86 Shear (lb/sq ft) 0.25 0.23 0.13
Alpha 1.13 Stream Power (lb/ft s) 0.94 1.26 0.29
Frctn Loss (ft) 0.46 Cum Volume (acre-ft) 0.43 1.16 0.04
C & E Loss (ft) 0.00 Cum SA (acres) 0.41 1.07 0.09
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 4 of 17
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 110
INPUT
Description:
Station Elevation Data num= 29
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5039 -10 5036.84 0 5036.64 .13 5036.64 .18 5036.63
.31 5036.49 .69 5036.16 1.86 5036.21 2.48 5036.24 2.51 5036.28
2.58 5036.31 2.66 5036.27 7.02 5036.6 13.77 5036.79 15.57 5036.96
21.32 5037.16 23.09 5037.13 29.64 5037.05 30.12 5037.06 31.74 5037.06
34.52 5036.96 39.23 5036.86 39.59 5036.83 39.62 5036.83 40.35 5036.76
40.37 5036.76 40.59 5036.89 40.92 5037.11 50.92 5037.31
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.92 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.92 95 95 95 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34.5
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5038.09 Element Left OB Channel Right OB
Vel Head (ft) 0.40 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5037.69 Reach Len. (ft) 95.00 95.00 95.00
Crit W.S. (ft) 5037.69 Flow Area (sq ft) 9.50 34.20 4.79
E.G. Slope (ft/ft) 0.004425 Area (sq ft) 9.50 34.20 4.79
Q Total (cfs) 232.00 Flow (cfs) 34.38 186.33 11.29
Top Width (ft) 60.96 Top Width (ft) 10.04 40.92 10.00
Vel Total (ft/s) 4.79 Avg. Vel. (ft/s) 3.62 5.45 2.36
Max Chl Dpth (ft) 1.53 Hydr. Depth (ft) 0.95 0.84 0.48
Conv. Total (cfs) 3487.8 Conv. (cfs) 516.9 2801.2 169.7
Length Wtd. (ft) 95.00 Wetted Per. (ft) 10.85 41.28 10.38
Min Ch El (ft) 5036.16 Shear (lb/sq ft) 0.24 0.23 0.13
Alpha 1.14 Stream Power (lb/ft s) 0.88 1.25 0.30
Frctn Loss (ft) 0.43 Cum Volume (acre-ft) 0.40 1.08 0.03
C & E Loss (ft) 0.00 Cum SA (acres) 0.38 0.98 0.07
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 109
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 5 of 17
INPUT
Description:
Station Elevation Data num= 18
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5038 -10 5035.89 0 5035.69 .14 5035.54 .32 5035.36
1.61 5035.47 2.32 5035.53 13 5035.96 20.63 5036.35 22.68 5036.33
28.54 5036.3 39.16 5036.31 39.93 5036.17 40.26 5036.18 40.69 5036.44
40.94 5036.53 40.96 5036.53 50.96 5036.73
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.96 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.96 93 93 93 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
-10.1 18.6 34
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5037.32 Element Left OB Channel Right OB
Vel Head (ft) 0.42 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5036.90 Reach Len. (ft) 93.00 93.00 93.00
Crit W.S. (ft) 5036.90 Flow Area (sq ft) 11.10 33.30 2.68
E.G. Slope (ft/ft) 0.004627 Area (sq ft) 11.10 33.30 2.68
Q Total (cfs) 232.00 Flow (cfs) 45.14 182.41 4.46
Top Width (ft) 61.01 Top Width (ft) 10.05 40.96 10.00
Vel Total (ft/s) 4.93 Avg. Vel. (ft/s) 4.07 5.48 1.66
Max Chl Dpth (ft) 1.54 Hydr. Depth (ft) 1.11 0.81 0.27
Conv. Total (cfs) 3410.8 Conv. (cfs) 663.6 2681.6 65.5
Length Wtd. (ft) 93.00 Wetted Per. (ft) 11.01 41.23 10.17
Min Ch El (ft) 5035.36 Shear (lb/sq ft) 0.29 0.23 0.08
Alpha 1.11 Stream Power (lb/ft s) 1.18 1.28 0.13
Frctn Loss (ft) 0.44 Cum Volume (acre-ft) 0.38 1.01 0.02
C & E Loss (ft) 0.00 Cum SA (acres) 0.36 0.89 0.05
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 108
INPUT
Description:
Station Elevation Data num= 19
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5037 -10 5035.05 0 5034.85 .1 5034.75 .37 5034.48
1.31 5034.57 2.37 5034.65 6.75 5034.91 13.64 5035.1 21.08 5035.32
28.1 5035.32 34.83 5035.19 39.14 5035.07 39.4 5035.09 40.02 5035.09
40.32 5035.12 40.39 5035.13 41.46 5035.3 51.46 5035.5
Manning's n Values num= 3
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Page 6 of 17
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 41.46 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.46 94 94 94 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5036.32 Element Left OB Channel Right OB
Vel Head (ft) 0.41 Wt. n-Val. 0.025 0.016 0.025
W.S. Elev (ft) 5035.91 Reach Len. (ft) 94.00 94.00 94.00
Crit W.S. (ft) 5035.91 Flow Area (sq ft) 9.59 33.10 5.07
E.G. Slope (ft/ft) 0.004801 Area (sq ft) 9.59 33.10 5.07
Q Total (cfs) 232.00 Flow (cfs) 36.36 182.70 12.94
Top Width (ft) 61.50 Top Width (ft) 10.04 41.46 10.00
Vel Total (ft/s) 4.86 Avg. Vel. (ft/s) 3.79 5.52 2.55
Max Chl Dpth (ft) 1.43 Hydr. Depth (ft) 0.95 0.80 0.51
Conv. Total (cfs) 3348.4 Conv. (cfs) 524.8 2636.8 186.7
Length Wtd. (ft) 94.00 Wetted Per. (ft) 10.86 41.65 10.41
Min Ch El (ft) 5034.48 Shear (lb/sq ft) 0.26 0.24 0.15
Alpha 1.13 Stream Power (lb/ft s) 1.00 1.31 0.37
Frctn Loss (ft) 0.27 Cum Volume (acre-ft) 0.36 0.94 0.01
C & E Loss (ft) 0.07 Cum SA (acres) 0.34 0.80 0.03
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 107
INPUT
Description:
Station Elevation Data num= 22
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5033.99 0 5033.59 2.22 5033.6 2.33 5033.6 3.89 5033.68
20.83 5034.51 22.73 5034.55 23.69 5034.58 25.15 5034.58 38.46 5034.42
38.48 5034.41 38.52 5034.38 39.4 5034.3 39.91 5034.28 40.27 5034.3
40.35 5034.35 40.36 5034.47 40.38 5034.34 40.57 5034.53 40.77 5034.65
40.9 5034.73 50.9 5034.93
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 40.9 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.9 46 46 46 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5035.36 Element Left OB Channel Right OB
Vel Head (ft) 0.19 Wt. n-Val. 0.025 0.016 0.025
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PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 7 of 17
W.S. Elev (ft) 5035.17 Reach Len. (ft) 46.00 46.00 46.00
Crit W.S. (ft) Flow Area (sq ft) 27.67 37.93 3.43
E.G. Slope (ft/ft) 0.001852 Area (sq ft) 27.67 37.93 3.43
Q Total (cfs) 232.00 Flow (cfs) 84.55 143.22 4.24
Top Width (ft) 70.90 Top Width (ft) 20.00 40.90 10.00
Vel Total (ft/s) 3.36 Avg. Vel. (ft/s) 3.06 3.78 1.23
Max Chl Dpth (ft) 1.58 Hydr. Depth (ft) 1.38 0.93 0.34
Conv. Total (cfs) 5390.6 Conv. (cfs) 1964.5 3327.6 98.4
Length Wtd. (ft) 46.00 Wetted Per. (ft) 21.19 41.31 10.25
Min Ch El (ft) 5033.59 Shear (lb/sq ft) 0.15 0.11 0.04
Alpha 1.08 Stream Power (lb/ft s) 0.46 0.40 0.05
Frctn Loss (ft) 0.13 Cum Volume (acre-ft) 0.32 0.86 0.00
C & E Loss (ft) 0.03 Cum SA (acres) 0.31 0.71 0.01
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 106.5
INPUT
Description:
Station Elevation Data num= 27
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5036 -10 5033.91 0 5033.71 .49 5033.22 1.89 5033.26
1.93 5033.27 2.33 5033.28 20.49 5034.13 22.64 5034.16 24.79 5034.19
25.02 5034.19 25.55 5034.18 38.13 5034.11 38.14 5034.11 38.26 5034.05
38.44 5034.04 40.14 5034.09 40.19 5034.09 40.21 5034.12 40.21 5034.11
40.3 5034.2 40.33 5034.11 40.69 5034.48 40.7 5034.6 40.71 5034.62
40.71 5034.48 40.76 5034.48
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.76 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.76 67 67 67 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5035.21 Element Left OB Channel Right OB
Vel Head (ft) 0.45 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5034.76 Reach Len. (ft) 67.00 67.00 67.00
Crit W.S. (ft) 5034.76 Flow Area (sq ft) 9.47 34.82
E.G. Slope (ft/ft) 0.004722 Area (sq ft) 9.47 34.82
Q Total (cfs) 232.00 Flow (cfs) 35.30 196.70
Top Width (ft) 50.80 Top Width (ft) 10.04 40.76
Vel Total (ft/s) 5.24 Avg. Vel. (ft/s) 3.73 5.65
Max Chl Dpth (ft) 1.53 Hydr. Depth (ft) 0.94 0.85
Conv. Total (cfs) 3376.1 Conv. (cfs) 513.7 2862.4
Length Wtd. (ft) 67.00 Wetted Per. (ft) 10.85 41.82
Min Ch El (ft) 5033.22 Shear (lb/sq ft) 0.26 0.25
Alpha 1.06 Stream Power (lb/ft s) 0.96 1.39
Frctn Loss (ft) 0.32 Cum Volume (acre-ft) 0.30 0.82
C & E Loss (ft) 0.00 Cum SA (acres) 0.29 0.67
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 8 of 17
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 106
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5035 -10 5033.4 0 5033.2 .36 5032.84 .49 5032.71
1.83 5032.83 2.28 5032.84 6.91 5033.07 20.36 5033.7 21.53 5033.69
22.97 5033.72 25.51 5033.76 25.63 5033.8 32.67 5033.67 38.26 5033.57
38.34 5033.57 38.82 5033.54 40.22 5033.54 40.25 5033.4 40.27 5033.42
40.72 5034.04 40.73 5033.95 40.78 5033.86
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 40.78 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.78 99 99 99 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5034.75 Element Left OB Channel Right OB
Vel Head (ft) 0.46 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5034.29 Reach Len. (ft) 99.00 99.00 99.00
Crit W.S. (ft) 5034.29 Flow Area (sq ft) 9.91 34.07
E.G. Slope (ft/ft) 0.004930 Area (sq ft) 9.91 34.07
Q Total (cfs) 232.00 Flow (cfs) 38.83 193.17
Top Width (ft) 50.84 Top Width (ft) 10.06 40.78
Vel Total (ft/s) 5.28 Avg. Vel. (ft/s) 3.92 5.67
Max Chl Dpth (ft) 1.58 Hydr. Depth (ft) 0.99 0.84
Conv. Total (cfs) 3304.2 Conv. (cfs) 553.0 2751.1
Length Wtd. (ft) 99.00 Wetted Per. (ft) 10.89 42.02
Min Ch El (ft) 5032.71 Shear (lb/sq ft) 0.28 0.25
Alpha 1.05 Stream Power (lb/ft s) 1.10 1.41
Frctn Loss (ft) 0.49 Cum Volume (acre-ft) 0.28 0.77
C & E Loss (ft) 0.01 Cum SA (acres) 0.28 0.60
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 9 of 17
REACH: 1 RS: 105.5
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-10.1 5035 -10 5032.89 0 5032.69 .01 5032.68 .4 5032.29
.51 5032.18 .89 5032.18 2.24 5032.21 5.32 5032.34 20.09 5033.03
21.15 5033.09 21.54 5033.09 22.8 5033.13 29.05 5033.32 30.84 5033.29
42.28 5033.21 45.01 5033.21 45.09 5033.06 46.33 5033.06 46.68 5033.05
46.69 5032.92 46.71 5032.92 47.2 5033.55
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-10.1 .025 0 .016 47.2 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 47.2 42 42 42 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5034.13 Element Left OB Channel Right OB
Vel Head (ft) 0.42 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.72 Reach Len. (ft) 42.00 42.00 42.00
Crit W.S. (ft) 5033.72 Flow Area (sq ft) 9.28 36.55
E.G. Slope (ft/ft) 0.004875 Area (sq ft) 9.28 36.55
Q Total (cfs) 232.00 Flow (cfs) 34.74 197.26
Top Width (ft) 57.24 Top Width (ft) 10.04 47.20
Vel Total (ft/s) 5.06 Avg. Vel. (ft/s) 3.74 5.40
Max Chl Dpth (ft) 1.54 Hydr. Depth (ft) 0.92 0.77
Conv. Total (cfs) 3322.7 Conv. (cfs) 497.5 2825.2
Length Wtd. (ft) 42.00 Wetted Per. (ft) 10.83 48.12
Min Ch El (ft) 5032.18 Shear (lb/sq ft) 0.26 0.23
Alpha 1.05 Stream Power (lb/ft s) 0.98 1.25
Frctn Loss (ft) 0.10 Cum Volume (acre-ft) 0.26 0.69
C & E Loss (ft) 0.08 Cum SA (acres) 0.25 0.50
Warning: The energy equation could not be balanced within the specified number of iterations.
The program used critical
depth for the water surface and continued on with the calculations.
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
Warning: During the standard step iterations, when the assumed water surface was set equal to
critical depth, the calculated
water surface came back below critical depth. This indicates that there is not a valid
subcritical answer. The
program defaulted to critical depth.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 105
INPUT
Description:
Station Elevation Data num= 26
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5032.47 0 5032.07 .56 5032.02 2.64 5031.99 3.02 5032.01
7.57 5032.21 19.74 5032.79 21.53 5032.89 21.58 5032.9 22.18 5032.91
30.98 5032.98 31.52 5032.92 35.32 5032.9 39.36 5032.82 43.83 5032.79
43.84 5032.81 43.9 5032.72 45.08 5032.68 45.79 5032.78 45.8 5032.64
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 10 of 17
45.87 5032.66 45.95 5032.66 46.14 5032.84 46.29 5033.06 46.43 5033.13
46.44 5033.13
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 46.44 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 46.44 42 42 42 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.82 Element Left OB Channel Right OB
Vel Head (ft) 0.16 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.66 Reach Len. (ft) 42.00 42.00 42.00
Crit W.S. (ft) Flow Area (sq ft) 27.81 47.10
E.G. Slope (ft/ft) 0.001341 Area (sq ft) 27.81 47.10
Q Total (cfs) 232.00 Flow (cfs) 72.55 159.45
Top Width (ft) 66.44 Top Width (ft) 20.00 46.44
Vel Total (ft/s) 3.10 Avg. Vel. (ft/s) 2.61 3.39
Max Chl Dpth (ft) 1.67 Hydr. Depth (ft) 1.39 1.01
Conv. Total (cfs) 6336.1 Conv. (cfs) 1981.4 4354.7
Length Wtd. (ft) 42.00 Wetted Per. (ft) 21.19 47.41
Min Ch El (ft) 5031.99 Shear (lb/sq ft) 0.11 0.08
Alpha 1.04 Stream Power (lb/ft s) 0.29 0.28
Frctn Loss (ft) 0.07 Cum Volume (acre-ft) 0.24 0.65
C & E Loss (ft) 0.01 Cum SA (acres) 0.24 0.46
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 104.5
INPUT
Description:
Station Elevation Data num= 32
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5034 -16 5032.52 0 5032.12 .1 5031.62 2.09 5031.71
2.25 5031.72 5.44 5031.88 16.82 5032.54 18.64 5032.66 18.91 5032.68
19.52 5032.72 25.21 5032.82 25.79 5032.84 28.52 5032.86 36.21 5032.84
37.6 5032.77 39.8 5032.62 40.2 5032.6 40.32 5032.53 40.35 5032.57
40.36 5032.57 42 5032.42 42.11 5032.43 42.15 5032.48 42.16 5032.47
42.23 5032.46 42.33 5032.45 42.44 5032.56 42.59 5032.9 42.65 5032.98
42.66 5032.97 42.7 5032.96
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 42.7 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 42.7 73 73 73 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.74 Element Left OB Channel Right OB
Vel Head (ft) 0.22 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.52 Reach Len. (ft) 73.00 73.00 73.00
Crit W.S. (ft) Flow Area (sq ft) 19.26 44.31
E.G. Slope (ft/ft) 0.001865 Area (sq ft) 19.26 44.31
Q Total (cfs) 232.00 Flow (cfs) 53.70 178.30
Top Width (ft) 58.77 Top Width (ft) 16.07 42.70
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PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 11 of 17
Vel Total (ft/s) 3.65 Avg. Vel. (ft/s) 2.79 4.02
Max Chl Dpth (ft) 1.90 Hydr. Depth (ft) 1.20 1.04
Conv. Total (cfs) 5371.7 Conv. (cfs) 1243.3 4128.4
Length Wtd. (ft) 73.00 Wetted Per. (ft) 17.01 44.10
Min Ch El (ft) 5031.62 Shear (lb/sq ft) 0.13 0.12
Alpha 1.07 Stream Power (lb/ft s) 0.37 0.47
Frctn Loss (ft) 0.09 Cum Volume (acre-ft) 0.22 0.61
C & E Loss (ft) 0.02 Cum SA (acres) 0.22 0.42
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 104
INPUT
Description:
Station Elevation Data num= 24
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5034 -16 5032.26 0 5031.86 .1 5031.36 .32 5031.33
1.57 5031.42 2.05 5031.44 6.12 5031.65 18.13 5032.3 18.97 5032.35
23.72 5032.47 25.53 5032.52 34.82 5032.49 36.25 5032.44 38.69 5032.35
38.91 5032.17 38.92 5032.16 39.99 5032.18 40.7 5032.15 40.76 5032.1
40.78 5032.05 40.96 5032.3 41.2 5032.65 41.24 5032.65
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 41.24 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.24 89 89 89 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.63 Element Left OB Channel Right OB
Vel Head (ft) 0.15 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.47 Reach Len. (ft) 89.00 89.00 89.00
Crit W.S. (ft) Flow Area (sq ft) 22.66 54.19
E.G. Slope (ft/ft) 0.000958 Area (sq ft) 22.66 54.19
Q Total (cfs) 232.00 Flow (cfs) 50.08 181.92
Top Width (ft) 57.31 Top Width (ft) 16.07 41.24
Vel Total (ft/s) 3.02 Avg. Vel. (ft/s) 2.21 3.36
Max Chl Dpth (ft) 2.14 Hydr. Depth (ft) 1.41 1.31
Conv. Total (cfs) 7494.1 Conv. (cfs) 1617.7 5876.4
Length Wtd. (ft) 89.00 Wetted Per. (ft) 17.22 42.94
Min Ch El (ft) 5031.33 Shear (lb/sq ft) 0.08 0.08
Alpha 1.09 Stream Power (lb/ft s) 0.17 0.25
Frctn Loss (ft) 0.06 Cum Volume (acre-ft) 0.19 0.52
C & E Loss (ft) 0.01 Cum SA (acres) 0.20 0.35
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 103.5
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 12 of 17
INPUT
Description:
Station Elevation Data num= 31
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-16.1 5036 -16 5034.18 -6 5031.83 0 5031.02 .39 5031.03
.46 5030.85 .6 5030.83 1.68 5030.86 2.4 5030.94 2.53 5030.93
12.52 5031.49 19.02 5031.87 19.86 5031.92 20.34 5031.93 22.96 5031.96
24.64 5032.01 27.55 5032.02 34.95 5032.04 37.07 5031.93 38.28 5031.83
38.29 5031.82 39.11 5031.61 40.09 5031.43 40.14 5031.53 40.2 5031.5
40.29 5031.71 40.59 5031.98 40.67 5032.12 40.7 5032.14 40.71 5032.14
40.89 5032.15
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-16.1 .025 0 .016 40.89 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 40.89 46 46 46 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.56 Element Left OB Channel Right OB
Vel Head (ft) 0.11 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.45 Reach Len. (ft) 46.00 46.00 46.00
Crit W.S. (ft) Flow Area (sq ft) 17.68 72.91
E.G. Slope (ft/ft) 0.000450 Area (sq ft) 17.68 72.91
Q Total (cfs) 232.00 Flow (cfs) 27.20 204.80
Top Width (ft) 53.77 Top Width (ft) 12.88 40.89
Vel Total (ft/s) 2.56 Avg. Vel. (ft/s) 1.54 2.81
Max Chl Dpth (ft) 2.62 Hydr. Depth (ft) 1.37 1.78
Conv. Total (cfs) 10942.2 Conv. (cfs) 1282.7 9659.5
Length Wtd. (ft) 46.00 Wetted Per. (ft) 13.12 42.80
Min Ch El (ft) 5030.83 Shear (lb/sq ft) 0.04 0.05
Alpha 1.10 Stream Power (lb/ft s) 0.06 0.13
Frctn Loss (ft) 0.01 Cum Volume (acre-ft) 0.14 0.39
C & E Loss (ft) 0.02 Cum SA (acres) 0.17 0.26
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 103
INPUT
Description:
Station Elevation Data num= 33
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-20 5031 0 5030.6 .38 5030.59 .47 5030.61 .6 5030.64
.61 5030.6 .73 5030.61 1.28 5030.67 3.18 5030.73 3.19 5030.76
8.01 5031.06 21.84 5031.82 22.39 5031.85 28.83 5031.84 29.8 5031.86
30.66 5031.86 34.02 5031.78 40.38 5031.71 40.41 5031.87 40.43 5031.83
41.76 5031.66 42.05 5031.65 42.08 5031.66 42.15 5031.7 42.16 5031.72
42.25 5031.71 42.34 5031.79 42.6 5031.78 42.63 5032.18 42.66 5032.22
42.67 5032.01 42.7 5032.04 42.71 5032.04
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-20 .025 0 .016 42.71 .025
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PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 13 of 17
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 42.71 79 79 79 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.53 Element Left OB Channel Right OB
Vel Head (ft) 0.05 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.48 Reach Len. (ft) 79.00 79.00 79.00
Crit W.S. (ft) Flow Area (sq ft) 53.62 84.67
E.G. Slope (ft/ft) 0.000173 Area (sq ft) 53.62 84.67
Q Total (cfs) 232.00 Flow (cfs) 74.73 157.27
Top Width (ft) 62.71 Top Width (ft) 20.00 42.71
Vel Total (ft/s) 1.68 Avg. Vel. (ft/s) 1.39 1.86
Max Chl Dpth (ft) 2.89 Hydr. Depth (ft) 2.68 1.98
Conv. Total (cfs) 17658.2 Conv. (cfs) 5688.3 11969.9
Length Wtd. (ft) 79.00 Wetted Per. (ft) 22.48 45.08
Min Ch El (ft) 5030.59 Shear (lb/sq ft) 0.03 0.02
Alpha 1.05 Stream Power (lb/ft s) 0.04 0.04
Frctn Loss (ft) 0.03 Cum Volume (acre-ft) 0.11 0.31
C & E Loss (ft) 0.01 Cum SA (acres) 0.15 0.22
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 102
INPUT
Description:
Station Elevation Data num= 23
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-5.7 5033 -5.6 5031.68 -4.5 5031.63 0 5031.43 .1 5030.93
.35 5030.94 .44 5030.93 .54 5030.95 .71 5030.92 .77 5030.93
2.2 5030.97 2.21 5030.97 16.44 5031.72 21.02 5031.96 28.63 5032.18
39.01 5032.47 39.06 5032.47 39.07 5032.46 39.1 5032.46 41 5032.35
41.01 5032.36 41.5 5032.85 41.69 5032.85
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-5.7 .025 0 .016 41.69 .025
Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan.
0 41.69 150 150 150 .1 .3
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.49 Element Left OB Channel Right OB
Vel Head (ft) 0.17 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5033.32 Reach Len. (ft) 150.00 150.00 150.00
Crit W.S. (ft) Flow Area (sq ft) 9.98 62.20
E.G. Slope (ft/ft) 0.000812 Area (sq ft) 9.98 62.20
Q Total (cfs) 232.00 Flow (cfs) 20.93 211.07
Top Width (ft) 47.39 Top Width (ft) 5.70 41.69
Vel Total (ft/s) 3.21 Avg. Vel. (ft/s) 2.10 3.39
Max Chl Dpth (ft) 2.40 Hydr. Depth (ft) 1.75 1.49
Conv. Total (cfs) 8142.8 Conv. (cfs) 734.5 7408.3
Length Wtd. (ft) 150.00 Wetted Per. (ft) 7.25 42.82
Min Ch El (ft) 5030.92 Shear (lb/sq ft) 0.07 0.07
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 14 of 17
Alpha 1.05 Stream Power (lb/ft s) 0.15 0.25
Frctn Loss (ft) 0.21 Cum Volume (acre-ft) 0.05 0.18
C & E Loss (ft) 0.02 Cum SA (acres) 0.12 0.14
Warning: The cross-section end points had to be extended vertically for the computed water
surface.
Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less
than 0.7 or greater than
1.4. This may indicate the need for additional cross sections.
CROSS SECTION
RIVER: 1
REACH: 1 RS: 100
INPUT
Description:
Station Elevation Data num= 18
Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev
-115.5 5033.18 -27.5 5032.68 -4.5 5032.18 0 5032.06 .1 5031.56
.84 5031.56 2.01 5031.63 2.78 5031.69 12.91 5031.76 19.06 5031.88
20.92 5031.92 28.05 5032.03 37.99 5032.12 38.6 5032.09 39.68 5032.1
39.88 5032.3 40.18 5032.6 40.51 5032.58
Manning's n Values num= 3
Sta n Val Sta n Val Sta n Val
-115.5 .025 0 .016 40.51 .025
Bank Sta: Left Right Coeff Contr. Expan.
0 40.51 .1 .3
Blocked Obstructions num= 1
Sta L Sta R Elev
46.2 40.51 5041.18
CROSS SECTION OUTPUT Profile #PF 1
E.G. Elev (ft) 5033.26 Element Left OB Channel Right OB
Vel Head (ft) 0.36 Wt. n-Val. 0.025 0.016
W.S. Elev (ft) 5032.90 Reach Len. (ft)
Crit W.S. (ft) 5032.90 Flow Area (sq ft) 18.79 40.65
E.G. Slope (ft/ft) 0.003043 Area (sq ft) 18.79 40.65
Q Total (cfs) 232.00 Flow (cfs) 26.45 205.55
Top Width (ft) 107.28 Top Width (ft) 66.77 40.51
Vel Total (ft/s) 3.90 Avg. Vel. (ft/s) 1.41 5.06
Max Chl Dpth (ft) 1.34 Hydr. Depth (ft) 0.28 1.00
Conv. Total (cfs) 4205.9 Conv. (cfs) 479.5 3726.4
Length Wtd. (ft) Wetted Per. (ft) 66.78 41.46
Min Ch El (ft) 5031.56 Shear (lb/sq ft) 0.05 0.19
Alpha 1.50 Stream Power (lb/ft s) 0.08 0.94
Frctn Loss (ft) Cum Volume (acre-ft)
C & E Loss (ft) Cum SA (acres)
SUMMARY OF MANNING'S N VALUES
River:1
Reach River Sta. n1 n2 n3
1 112 .025 .016 .025
1 111 .025 .016 .025
1 110 .025 .016 .025
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NORTHERN ENGINEERING; SEPTEMBER 2016
Page 15 of 17
1 109 .025 .016 .025
1 108 .025 .016 .025
1 107 .025 .016 .025
1 106.5 .025 .016 .025
1 106 .025 .016 .025
1 105.5 .025 .016 .025
1 105 .025 .016 .025
1 104.5 .025 .016 .025
1 104 .025 .016 .025
1 103.5 .025 .016 .025
1 103 .025 .016 .025
1 102 .025 .016 .025
1 100 .025 .016 .025
SUMMARY OF REACH LENGTHS
River: 1
Reach River Sta. Left Channel Right
1 112 84 84 84
1 111 103 103 103
1 110 95 95 95
1 109 93 93 93
1 108 94 94 94
1 107 46 46 46
1 106.5 67 67 67
1 106 99 99 99
1 105.5 42 42 42
1 105 42 42 42
1 104.5 73 73 73
1 104 89 89 89
1 103.5 46 46 46
1 103 79 79 79
1 102 150 150 150
1 100
SUMMARY OF CONTRACTION AND EXPANSION COEFFICIENTS
River: 1
Reach River Sta. Contr. Expan.
1 112 .1 .3
1 111 .1 .3
1 110 .1 .3
1 109 .1 .3
1 108 .1 .3
1 107 .1 .3
1 106.5 .1 .3
1 106 .1 .3
1 105.5 .1 .3
1 105 .1 .3
1 104.5 .1 .3
1 104 .1 .3
1 103.5 .1 .3
1 103 .1 .3
1 102 .1 .3
1 100 .1 .3
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 16 of 17
Profile Output Table - Standard Table 1
Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev
E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl
(cfs) (ft) (ft) (ft) (ft)
(ft/ft) (ft/s) (sq ft) (ft)
1 100 PF 1 232.00 5031.56 5032.90 5032.90 5033.26
0.003043 5.06 59.44 107.28 0.89
1 102 PF 1 232.00 5030.92 5033.32 5033.49
0.000812 3.39 72.18 47.39 0.49
1 103 PF 1 232.00 5030.59 5033.48 5033.53
0.000173 1.86 138.28 62.71 0.23
1 103.5 PF 1 232.00 5030.83 5033.45 5033.56
0.000450 2.81 90.60 53.77 0.37
1 104 PF 1 232.00 5031.33 5033.47 5033.63
0.000958 3.36 76.85 57.31 0.52
1 104.5 PF 1 232.00 5031.62 5033.52 5033.74
0.001865 4.02 63.57 58.77 0.70
1 105 PF 1 232.00 5031.99 5033.66 5033.82
0.001341 3.39 74.91 66.44 0.59
1 105.5 PF 1 232.00 5032.18 5033.72 5033.72 5034.13
0.004875 5.40 45.82 57.24 1.08
1 106 PF 1 232.00 5032.71 5034.29 5034.29 5034.75
0.004930 5.67 43.98 50.84 1.09
1 106.5 PF 1 232.00 5033.22 5034.76 5034.76 5035.21
0.004722 5.65 44.29 50.80 1.08
1 107 PF 1 232.00 5033.59 5035.17 5035.36
0.001852 3.78 69.03 70.90 0.69
1 108 PF 1 232.00 5034.48 5035.91 5035.91 5036.32
0.004801 5.52 47.76 61.50 1.09
1 109 PF 1 232.00 5035.36 5036.90 5036.90 5037.32
0.004627 5.48 47.08 61.01 1.07
1 110 PF 1 232.00 5036.16 5037.69 5037.69 5038.09
0.004425 5.45 48.48 60.96 1.05
1 111 PF 1 232.00 5036.86 5038.37 5038.37 5038.78
0.004524 5.47 48.20 61.04 1.06
1 112 PF 1 232.00 5037.43 5039.04 5039.04 5039.45
0.004542 5.48 47.58 61.29 1.06
Profile Output Table - Standard Table 2
Reach River Sta Profile E.G. Elev W.S. Elev Vel Head Frctn Loss C & E
Loss Q Left Q Channel Q Right Top Width
(ft) (ft) (ft) (ft)
(ft) (cfs) (cfs) (cfs) (ft)
1 100 PF 1 5033.26 5032.90 0.36
26.45 205.55 107.28
1 102 PF 1 5033.49 5033.32 0.17 0.21
0.02 20.93 211.07 47.39
1 103 PF 1 5033.53 5033.48 0.05 0.03
0.01 74.73 157.27 62.71
1 103.5 PF 1 5033.56 5033.45 0.11 0.01
0.02 27.20 204.80 53.77
1 104 PF 1 5033.63 5033.47 0.15 0.06
0.01 50.08 181.92 57.31
1 104.5 PF 1 5033.74 5033.52 0.22 0.09
0.02 53.70 178.30 58.77
1 105 PF 1 5033.82 5033.66 0.16 0.07
0.01 72.55 159.45 66.44
WEST PLUM HOUSING
PROPOSED CONDITION HEC-RAS MODEL OUTPUT
NORTHERN ENGINEERING; SEPTEMBER 2016
Page 17 of 17
1 106 PF 1 5034.75 5034.29 0.46 0.49
0.01 38.83 193.17 50.84
1 106.5 PF 1 5035.21 5034.76 0.45 0.32
0.00 35.30 196.70 50.80
1 107 PF 1 5035.36 5035.17 0.19 0.13
0.03 84.55 143.22 4.24 70.90
1 108 PF 1 5036.32 5035.91 0.41 0.27
0.07 36.36 182.70 12.94 61.50
1 109 PF 1 5037.32 5036.90 0.42 0.44
0.00 45.14 182.41 4.46 61.01
1 110 PF 1 5038.09 5037.69 0.40 0.43
0.00 34.38 186.33 11.29 60.96
1 111 PF 1 5038.78 5038.37 0.41 0.46
0.00 36.01 185.32 10.67 61.04
1 112 PF 1 5039.45 5039.04 0.42 0.38
0.00 38.23 187.71 6.05 61.29
ATTACHMENT 3
Previous Flood Modeling Summary (Northern Engineering, January 2012)
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, CO 80521
January 17, 2012
RE: HEC-RAS summary
The District
Dear Staff,
This Memo is to summarize HEC-RAS modeling that we have done for the proposed development
referred to as The District, which is located on Plum Street between Shields St. and City Park Ave. We
have run existing and proposed conditions models to represent 100-year water surface elevations prior to
the project and after completion of the project. The proposed conditions model is based on preliminary
grading plans for the project.
As shown on the attached Existing Conditions HEC-RAS Exhibit and Proposed Conditions HEC-RAS
Exhibit, we have placed cross-sections at key locations along the length of Plum Street. The majority of
our modeling is based on one-foot topography generated from field shots. However some augmentation
of data has been supplied by City two-foot aerial topography. All topographic information is related to City
of Fort Collins Vertical Datum (unadjusted NGVD-29).
The following table shows existing and proposed conditions modeling results. Please see the attached
HEC-RAS output for support of this data.
Existing
Cond. Proposed
100-yr Cond. Cond. Difference
Section Discharge Min Ch El W.S. Elev W.S. Elev W.S. Elev
(cfs) (ft) (ft) (ft) (ft)
114 232 34.22 35.73 35.8 0.07
112 232 33.62 35 35.04 0.04
110 232 32.73 33.79 34.03 0.24
108 232 31.24 32.54 32.79 0.25
107 232 30.38 31.87 31.89 0.02
106.5 232 30 31.61 31.48 -0.13
106 232 29.7 31.23 31.16 -0.07
105.5 232 28.85 30.41 30.52 0.11
105 232 28.55 30.48 30.43 -0.05
104 232 28.36 30.14 30.26 0.12
103.5 232 27.7 30.29 30.25 -0.04
103 232 27.45 30.3 30.3 0
102 232 27.7 30.14 30.14 0
100 232 28.49 29.75 29.75 0
‐ 1 ‐
The attached Finished Floor Elevation Exhibit 1 shows finished floor elevations at locations upstream of
cross-section 104. The apartment complex at Section 104 maintains 9-inches of freeboard from the
proposed condition water surface elevation. All other residences maintain12-inches or more of freeboard
from the proposed conditions 100-year water surface elevations.
The attached Finished Floor Elevation Exhibit 2 shows finished floor elevations at locations upstream of
cross-section 108. As shown in this exhibit, all residences maintain 12-inches or more of freeboard from
the proposed conditions 100-year water surface elevations.
Please feel free to contact me with any questions you may have.
Sincerely,
Northern Engineering Services, Inc.
Aaron Cvar, PE
‐ 2 ‐
T
T
T T T T T
T T
T T T
T T
T
T T
CTV
CTV
CTV
CTV CTV
CTV
TTT
X
X
X
X X
X
OHE OHE OHE
OHE OHE OHE
OHE
OHE
OHE
OHE
OHE
OHE
X X
X X
8" SS 8" SS 8" SS 8" SS
8" SS 8" SS 8" SS
8" SS
8" SS 8" SS 8" SS
8" SS 8" SS
8" SS 8" SS 8" SS
X
ST ST
ST
ST
ST
ST
X
X
CTV
CTV CTV
CTV
X X
X
8" SS
8" SS 8" SS 8" SS
8" SS
8" SS
8" SS
8" SS 8" SS 8" SS
CTV
CTV
CTV
CTV
G G
G
T
T
T T T T T
T T
T T T
T T
T
T T
CTV
CTV
CTV
CTV CTV
CTV
TTT
X
X
X
X X
X
OHE OHE OHE
OHE OHE OHE
OHE
OHE
OHE
OHE
OHE
OHE
X X
X X
8" SS 8" SS 8" SS 8" SS
8" SS 8" SS 8" SS
8" SS
8" SS 8" SS 8" SS
8" SS 8" SS
8" SS 8" SS 8" SS
X
ST ST
ST
ST
ST
ST
X
X
CTV
CTV CTV
CTV
X X
X
8" SS
8" SS 8" SS 8" SS
8" SS
8" SS
8" SS
8" SS 8" SS 8" SS
CTV
CTV
CTV
CTV
G G
G
107 106.5 106
105.5
105 104
DRAWN BY:ATC
SCALE:1"=40'
ISSUED:1/16/12
SHEET NO:
FINISHED FLOOR ELEVATION
EXHIBIT 1
1-STORY
WOOD 1-STORY
WOOD
FF=5037.48
FF=5037.35
1-STORY
WOOD
FF=5037.44
FF=5036.43
2-STORY
WOOD 1-STORY
WOOD
CARPORT
FF=5036.36
1-STORY
STUCCO w/
BASEMENT
FF=5035.82
1-STORY
WOOD
GARAGE
FF=5033.94
"NO PARKING"
"NO PARKING"
"NO PARKING"
"CAMPUS WEST
CONDOMINIUMS"
BRIDGE
3" ADS
ELEV=5034.74 FENCE ON
CONCRETE PAD
FENCE ON
CONCRETE
PAD
FENCE ON
CONCRETE
PAD
MOE=5033.57
MOE=5033.59
114 112 110
108
DRAWN BY:ATC
SCALE:1"=40'
ISSUED:1/16/12
SHEET NO:
FINISHED FLOOR ELEVATION
EXHIBIT 2
MAP POCKET
UD UD UD
UD UD UD
FDC
FDC
T
X
X
X X X
X
X X X
X X
X X X
X
T T T T
T
T
T
T T
T
T
T
T
VAULT
ELEC
T FO
T
FO
ELEC
VAULT
ELEC
ST
X X
X
VAULT
ELEC
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC FO
VAULT
ELEC
T FO
E
X X X X
X
X
D
D
D
TF
PLUM STREET
(ROW VARIES)
9' UTILITY EASEMENT
PROPOSED CONCRETE
COLLAR & CHASE
PROPOSED 2'
SIDEWALK CHASE
PROPOSED 2'
SIDEWALK CHASE
PROPOSED 2'
SIDEWALK CHASE
PROPOSED 5'
WALK w/ PAN
PROPOSED 1'
SIDEWALK CHASE PROPOSED 1'
SIDEWALK CHASE
PROPOSED 1'
SIDEWALK CHASE
9' UTILITY EASEMENT
5' UTILITY EASEMENT
UTILITY EASEMENT
THE LOFTS AT CAMPUS WEST
TOWN SQUARE
CONDOMINIUMS
CITY PARK CONDOMINIUMS
(BOOK 1291, PAGE 862)
THE DISTRICT AT CAMPUS WEST
(REC. NO. 20130032356)
5' UTILITY EASEMENT
PROPOSED
STORM DRAIN
OPEN BOTTOM
DETENTION VAULT
3
2
1
4
PROPOSED
OUTLET STRUCTURE
PROPOSED
TRENCH DRAIN
PROPOSED
TRENCH DRAIN
1
2
4
3
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE, OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
Call before you dig.
R
C800
DRAINAGE EXHIBIT
Sheet
of 17 Sheets
WEST PLUM HOUSING These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.
NOT FOR CONSTRUCTION
REVIEW SET
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
ENGINEER ING
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
NORTH
( IN FEET )
1 inch = ft.
20 0 20 Feet
20
40 60
LEGEND:
PROPOSED CONTOUR
PROPOSED STORM SEWER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
A
DESIGN POINT
FLOW ARROW
DRAINAGE BASIN LABEL
DRAINAGE BASIN BOUNDARY
PROPOSED SWALE SECTION
1 1
NOTES:
1. REFER TO THE FINAL DRAINAGE REPORT FOR WEST PLUM HOUSING, DATED
FEBRUARY 22, 2017 FOR ADDITIONAL INFORMATION.
BENCHMARK
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
C
PROJECT DATUM: NAVD88
CITY OF FORT COLLINS BENCHMARK 19-97
AT THE SOUTHEAST CORNER OF WEST ELIZABETH AND SHIELDS ST., ON A CONCRETE
TRAFFIC SIGNAL BASE.
ELEV.=5025.74
CITY OF FORT COLLINS BENCHMARK 3-08
SOUTHWEST CORNER OF MULBERRY ST. AND SHIELDS ST. ON A CONCRETE TRAFFIC
SIGNAL BASE.
ELEV.=5030.29
PLEASE NOTE: THIS PLAN SET IS USING NAVD88 FOR A VERTICAL DATUM.
SURROUNDING DEVELOPMENTS HAVE USED NGVD29 UNADJUSTED FOR THEIR VERTICAL
DATUMS.
IF NGVD29 UNADJUSTED DATUM IS REQUIRED FOR ANY PURPOSE, THE FOLLOWING
EQUATION SHOULD BE USED:
NGVD29 UNADJUSTED = NAVD88 - 3.17'
BASIS OF BEARINGS
THE BASIS OF BEARINGS IS THE SOUTH LINE OF THE NORTHEAST QUARTER OF SECTION
15, AS BEARING SOUTH 89°04'20" EAST.
DEVELOPED RUNOFF SUMMARY TABLE
BASIN
ID
TOTAL
AREA
(acres)
C2 C10 C100 2-yr Tc
(min)
10-yr Tc
(min)
100-yr Tc
(min)
Q2
(cfs)
Q10
(cfs)
Q100
(cfs)
1 0.76 0.95 0.95 1.00 6.8 6.8 5.7 1.87 3.20 7.35
2 0.36 0.63 0.63 0.79 12.0 12.0 11.4 0.48 0.82 2.14
3 0.13 0.15 0.15 0.19 8.4 8.4 7.9 0.05 0.08 0.21
4 0.03 0.15 0.15 0.19 5.6 5.6 5.2 0.01 0.02 0.06
On-Site LID Treatment
Project Summary
Total Impervious Area 40,612 sf
Target Treatment Percentage 75%
Minimum Area to be Treated by LID measures 30,459 sf
PLD Basin
Basin Size 1,400 sf
Total PLD Treatment Area 33,106 sf
Landscape Buffer
Landscape Buffer Area 540 sf
Run-on area for Landscape Buffer 284 sf
Overall Run-on Ratio for Rain Garden (50:1 Max) 0.5 :1
Total Treatment Area 33,390 sf
Percent Total Project Area Treated 82.2%
G G
G
G
G G G
G
G
G
G
G
G G
G G G
G
G
G
G G
G
G G G G G
G
G
G G
E
E
E
E
E
E E
E
E E E
20" W 20" W
20" W 20" W 20" W
20" W
20" W
20" W 20" W
20" W 20" W
20" W
20" W 20" W 20" W 20" W
6" W 6" W 6" W
6" W 6" W 6" W
FO FO
FO
FO FO
FO
FO
FO FO
FO FO
FO
FO FO FO FO FO FO
FO FO
FO
FO
FO
FO
FO
FO FO FO FO
FO
T T T
T
T T
T
T T T T T
T T T
T
T
T T T
ST ST
ST
ST
ST
ST
ST
ST
ST
6" SS
6" SS
6" SS
W W W
W
W
W
W
W
X
X
X
X
OHE
SHIELDS STREET
ASTER STREET
BLUEBELL STREET
W. PLUM STREET
COLUMBINE STREET
CITY PARK AVE.
114 112 110
108
107 106.5 106
105.5
105 104
103.5 103
102 100
DRAWN BY:ATC
SCALE:1"=150'
ISSUED:1/16/12
SHEET NO:
PROPOSED CONDITIONS
HEC-RAS EXHIBIT
G G
G
G
G G G
G
G
G
G
G
G G
G G G
G
G
G
G G
G
G G G G G
G
G
G G
E
E
E
E
E
E E
E
E E E
20" W 20" W
20" W 20" W 20" W
20" W
20" W
20" W 20" W
20" W 20" W
20" W
20" W 20" W 20" W 20" W
6" W 6" W 6" W
6" W 6" W 6" W
FO FO
FO
FO FO
FO
FO
FO FO
FO FO
FO
FO FO FO FO FO FO
FO FO
FO
FO
FO
FO
FO
FO FO FO FO
FO
T T T
T
T T
T
T T T T T
T T T
T
T
T T T
ST ST
ST
ST
ST
ST
ST
ST
ST
6" SS
6" SS
6" SS
W W W
W
W
W
W
W
X
X
X
X
OHE
SHIELDS STREET
ASTER STREET
BLUEBELL STREET
W. PLUM STREET
COLUMBINE STREET
CITY PARK AVE.
114 112 110
108
107 106.5 106
105.5
105 104
103.5 103
102 100
DRAWN BY:ATC
SCALE:1"=150'
ISSUED:1/16/12
SHEET NO:
EXISTING CONDITIONS
HEC-RAS EXHIBIT
1 105.5 PF 1 5034.13 5033.72 0.42 0.10
0.08 34.74 197.26 57.24
0.00 35.30 196.70 50.80
1 107 PF 1 5035.36 5035.17 0.19 0.13
0.03 84.55 143.22 4.24 70.90
1 108 PF 1 5036.32 5035.91 0.41 0.27
0.07 36.36 182.70 12.94 61.50
T
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC FO
VAULT
ELEC
FO T
E
X
W
W
F S
X
X
X X X
U
P
UP
T/TV T/TV
T/TV
T/TV
T/TV
T/TV
T/TV
T/TV
T/TV
T/TV
T/TV T/TV T/TV
T/TV
T/TV T/TV
T/TV
C
O
CO
CO
CO
TF TF
TF
TF
UD UD UD UD
UD
ASTER STREET
W. PLUM STREET
106 104
100
108 102
107
105
103
103.5
104.5
105.5
106.5
BLUEBELL STREET
112 111 110 109
CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU
DIG, GRADE, OR EXCAVATE FOR THE MARKING OF
UNDERGROUND MEMBER UTILITIES.
CALL UTILITY NOTIFICATION CENTER OF
COLORADO
Know what'sbelow.
Call before you dig.
R
HCRS1
HEC-RAS MODELING WORKMAP
Sheet
of 7 Sheets
WEST PLUM HOUSING These drawings are
instruments of service
provided by Northern
Engineering Services, Inc.
and are not to be used for
any type of construction
unless signed and sealed by
a Professional Engineer in
the employ of Northern
Engineering Services, Inc.
NOT FOR CONSTRUCTION
REVIEW SET
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
ENGINEER ING
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
NORTH
( IN FEET )
1 inch = ft.
50 0 50 Feet
50
100 150
LEGEND:
PROPOSED CONTOUR
PROPOSED STORM SEWER
PROPOSED SWALE
EXISTING CONTOUR
PROPOSED CURB & GUTTER
PROPERTY BOUNDARY
PROPOSED INLET
NOTES:
1. REFER TO THE PRELIMINARY DRAINAGE REPORT FOR WEST PLUM HOUSING,
DATED SEPTEMBER 14, 2016 FOR ADDITIONAL INFORMATION.
PROPOSED SUBDRAIN SD
BENCHMARK
FOR DRAINAGE REVIEW ONLY
NOT FOR CONSTRUCTION
PROJECT DATUM: NAVD88
CITY OF FORT COLLINS BENCHMARK 19-97
AT THE SOUTHEAST CORNER OF WEST ELIZABETH AND SHIELDS ST., ON A CONCRETE
TRAFFIC SIGNAL BASE.
ELEV.= 5025.74
CITY OF FORT COLLINS BENCHMARK 3-08
SOUTHWEST CORNER OF MULBERRY ST. AND SHIELDS ST. ON A CONCRETE TRAFFIC
SIGNAL BASE.
ELEV.= 5030.29
PLEASE NOTE: THIS PLAN SET IS USING NAVD88 FOR A VERTICAL DATUM.
SURROUNDING DEVELOPMENTS HAVE USED NGVD29 UNADJUSTED FOR THEIR VERTICAL
DATUMS.
IF NGVD29 UNADJUSTED DATUM IS REQUIRED FOR ANY PURPOSE, THE FOLLOWING
EQUATION SHOULD BE USED:
NGVD29 UNADJUSTED = NAVD88 - 3.17'
BASIS OF BEARINGS
BASIS OF BEARINGS IS THE THE SOUTH RIGHT OF WAY LINE OF WEST PLUM STREET AS
BEARING 89°34'04" EAST.
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 10, Sep 22, 2015
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Apr 28,
2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Custom Soil Resource Report
9
Percent Total Project Area Treated 82.2%
140 8400 1.67 1.3 10661 14616 -3955
145 8700 1.63 1.2 10778 15138 -4360
150 9000 1.60 1.2 10944 15660 -4716
155 9300 1.57 1.2 11097 16182 -5085
160 9600 1.54 1.2 11236 16704 -5468
165 9900 1.51 1.1 11361 17226 -5865
170 10200 1.48 1.1 11473 17748 -6275
175 10500 1.45 1.1 11571 18270 -6699
180 10800 1.42 1.1 11655 18792 -7137
185 11100 1.40 1.1 11810 19314 -7504
190 11400 1.38 1.0 11956 19836 -7880
195 11700 1.36 1.0 12093 20358 -8265
200 12000 1.34 1.0 12221 20880 -8659
205 12300 1.32 1.0 12339 21402 -9063
210 12600 1.30 1.0 12449 21924 -9475
215 12900 1.28 1.0 12549 22446 -9897
220 13200 1.26 1.0 12640 22968 -10328
225 13500 1.24 0.9 12722 23490 -10768
230 13800 1.22 0.9 12795 24012 -11217
235 14100 1.21 0.9 12966 24534 -11568
240 14400 1.20 0.9 13133 25056 -11923
Input Variables Results
Design Point
Design Storm Required Detention Volume
Developed "C" =
Detention Pond Calculation | FAA Method
Project:
Project Location:
Calculations By:
D:\Projects\1252-001\Drainage\Detention\1252-001_FAA Detention.xlsm\
ELEC
D
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC FO
VAULT
ELEC
T FO
E
CITY PARK AVENUE
PLUM STREET
(ROW VARIES)
ROOFTOP
CONCRETE
LANDSCAPE
SURFACE
AREA (SF) % IMPERV.
IMPERV.
AREA (SF)
8,859
3,098
37,016
100%
100%
0% 0
TOTALS 56,327 TOTAL= 14,899
ROOFTOP
CONCRETE
GRAVEL
SURFACE
AREA (SF) % IMPERV.
IMPERV.
AREA (SF)
33,244
9,972
0
100%
100%
40%
TOTALS 56,327 TOTAL= 43,216
EXISTING PROPOSED
33,244
0
8,859
3,098 9,972
D:\PROJECTS\1252-001\DWG\DRNG\1252-001_IMPERVIOUS.DWG
WEST PLUM HOUSING
FORT COLLINS
COLORADO
301 N. Howes Street, Suite 100
Fort Collins, Colorado 80521
E NGINEER ING
N O R T H E RN
PHONE: 970.221.4158
www.northernengineering.com
DESCRIPTION
EXISTING VS. PROPOSED
IMPERVIOUS AREA
DRAWN BY
B. RUCH
DATE
SEPTEMBER 14, 2016
PROJECT
1252-001 SK-C1
SCALE DRAWING
1"=60'
GRAVEL 7,354 40% 2,942
LANDSCAPE 13,111 0% 0
S
S
WV
WV
VAULT
ELEC
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
CONTROL
IRR
VAULT
ELEC FO
VAULT
ELEC
T FO
E
X
X
CTV
CTV
FO FO
FO
FO
E
E
E E E E
E
E
E
E
CTV
CTV
CTV
CTV
CTV
CTV
FO FO FO FO FO
FO
W
W W W W W
W
W
W
G
G
G
G
G G G G
E E
SS
SS
SS
SS SS
SS
SS
SS
S SS SS
W
W W
H2
H1
H1
H2
HISTORIC DRAINAGE EXHIBIT
FORT COLLINS, CO
WEST PLUM HOUSING
ENGINEER ING
N O R T H E RN
09.01.16
D:\PROJECTS\1252-001\DWG\ENGINEER\AARON\1252-001-HISTORIC DRNG-2016-08-09.DWG
NORTH
( IN FEET )
1 inch = ft.
40 0 40 Feet
40
Tt
(min)
2-yr
Tc
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
1 1 No 0.95 0.95 1.00 80 0.50% 3.2 3.2 2.1 334 0.60 1.55 3.6 0 N/A 0.00 0.0 6.8 6.8 5.7
2 2 No 0.25 0.25 0.31 32 2.00% 7.1 7.1 6.6 485 0.70 1.67 4.8 0 0.00 0.00 0.0 12.0 12.0 11.4
3 3 No 0.25 0.25 0.31 28 2.00% 6.7 6.7 6.2 0 0.60 0.00 0.0 174 1.20 1.64 1.8 8.4 8.4 7.9
4 4 No 0.25 0.25 0.31 20 2.00% 5.6 5.6 5.2 0 0.00 0.00 0.0 0 0.00 0.00 0.0 5.6 5.6 5.2
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Design
Point
Basin
Overland Flow
ATC
December 1, 2016
Gutter Flow Swale Flow Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational-Calcs_Proposed.xlsx\Tc-2-yr_&_100-yr
December 1, 2016
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational-Calcs_Proposed.xlsx\C-Values
2-yr
Tc
(min)
10-yr
Tc
(min)
100-yr
Tc
(min)
H1 H1 No 0.25 0.25 0.31 96 2.1 12.2 12.2 11.3 252 0.6 1.55 2.7 0 0.0 0.00 0.0 14.9 14.9 14.0
H2 H2 No 0.25 0.25 0.31 74 1.4 12.2 12.2 11.3 0 0.0 0.00 0.0 0 0.0 0.00 0.0 12.2 12.2 11.3
Exist-
Impervious
Area
Exist-
Impervious
Area N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 5.00 5.00 5.00
EXISTING TIME OF CONCENTRATION COMPUTATIONS
Design
Point
Basin
Overland Flow
ATC
December 1, 2016
Gutter Flow Swale Flow Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational Calcs_Existing.xlsx\Tc-2-yr_&_100-yr
December 1, 2016
D:\Projects\1252-001\Drainage\Hydrology\1252-001_Rational Calcs_Existing.xlsx\C-Values