HomeMy WebLinkAboutBANNER HEALTH MEDICAL CAMPUS - PDP - PDP130003 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTJanuary 23, 2013
PRELIMINARY DRAINAGE AND
EROSION CONTROL REPORT
BANNER HEALTH MEDICAL CAMPUS
Fort Collins, Colorado
Prepared for:
Banner Health
1801 16th Street
Greeley, CO 80631
Prepared by:
200 South College Avenue, Suite 10
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 306-003
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.
January 23, 2013
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report for
BANNER HEALTH MEDICAL CAMPUS
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report
for your review. This report accompanies the Project Development Plan submittal for the
proposed Banner Health Medical Campus development.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed project. We
understand that review by the City is to assure general compliance with standardized criteria
contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Aaron Cvar, PE
Project Engineer
Banner Health Medical Campus
Preliminary Drainage Report
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1
A. Location ............................................................................................................................................. 1
B. Description of Property ..................................................................................................................... 2
C. Floodplain.......................................................................................................................................... 4
II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 4
A. Major Basin Description .................................................................................................................... 4
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. Floodplain Regulations Compliance .................................................................................................. 6
G. Modifications of Criteria ................................................................................................................... 6
IV. DRAINAGE FACILITY DESIGN .................................................................................... 6
A. General Concept ............................................................................................................................... 6
B. Master Drainage Concepts ................................................................................................................ 8
C. Specific Details .................................................................................................................................. 9
V. CONCLUSIONS ...................................................................................................... 10
A. Compliance with Standards ............................................................................................................ 10
B. Drainage Concept ............................................................................................................................ 10
References ....................................................................................................................... 11
EROSION CONTROL REPORT ............................................................................................ 19
APPENDICES:
APPENDIX A – Hydrologic Computations
APPENDIX B – Hydraulic Computations
B.1 – Storm Sewers (reserved for future use)
B.2 – Inlets (reserved for future use)
APPENDIX C – Water Quality Design Computations
APPENDIX D – SWMM Analysis
APPENDIX F –Erosion Control Report
Banner Health Medical Campus
Preliminary Drainage Report
LIST OF TABLES AND FIGURES:
Figure 1 – Aerial Photograph ................................................................................................ 2
Figure 2– Proposed Site Plan ................................................................................................ 3
Figure 3 – Existing Floodplains ............................................................................................. 4
Table 1 - SWMM Pond Modeling Summary; Interim Conditions………………………………………8
Table 2 - SWMM Pond Modeling Summary; Full Build-Out Conditions.……………………….…..…9
Table 3 - Water Quality Pond Summary…………………………………………………………………9
MAP POCKET:
Drainage Exhibits
Banner Health Medical Campus
Preliminary Drainage Report 1
I. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
2. The project site is located in the northwest quarter of Section 4, Township 6 South,
Range 68 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 East Harmony Road
and Lady Moon Drive.
4. The project site lies within the East Harmony portion of the McClellands Creek Master
Drainage Basin. Per the “East Harmony Portion of the McClellands Creek Master
Drainage Plan Update”, by Icon Engineering, August 1999 (Ref. 6), onsite detention
is required with a release rate of 0.5 cfs per acre in the 100-year storm event.
5. Areas directly adjacent to the project site on the west, south and east are currently
undeveloped. The existing Hewlett Packard campus is located just north of the
project site on the north side of Harmony Road.
Banner Health Medical Campus
Preliminary Drainage Report 2
B. Description of Property
1. The subject property is approximately 33 net acres.
Figure 1 – Aerial Photograph
2. The subject property currently consists of vacant ground. The ground cover generally
consists of open pasture and some native seeding. Existing ground slopes are
generally mild (i.e., 1 to 5±%) through the interior of the property. General
topography slopes from west to east towards the Fossil Creek Reservoir Inlet Ditch.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey, the site consists of Paoli fine sandy loam,
which falls into Hydrologic Soil Group B.
4. The proposed project will develop the majority of the existing site, constructing a
medical campus. Parking areas and associated utilities will be constructed.
Detention/water quality ponds will be constructed at the northeast and southeast
corners of the site.
Banner Health Medical Campus
Preliminary Drainage Report 3
Figure 2– Proposed Site Plan
5. The Fossil Creek Reservoir Inlet Ditch is located roughly 1400 feet east of the project
site, and runs parallel to the site from north to south. There are no other major
irrigation ditches or related facilities in the vicinity of the project site.
6. The proposed land use is comprised entirely of a medical campus.
Banner Health Medical Campus
Preliminary Drainage Report 4
C. Floodplain
1. The Cache La Poudre River 100-year floodplain lies approximately 2000 feet offsite
to the east. No portion of the subject property is encroached by any City or FEMA
jurisdictional floodplain.
Figure 3 – Existing Floodplains
2. It is noted that the vertical datum utilized for site survey work is the City of Fort
Collins Benchmark #7-01 (Elevation=4911.33, Ft. Collins NGVD 29).
II. DRAINAGE BASINS AND SUB-BASINS
A. Major Basin Description
1. The project site is located within the East Harmony portion of the McClellands Creek
Master Drainage Basin.
B. Sub-Basin Description
2. The subject property historically drains overland towards the Fossil Creek Reservior
Inlet Ditch, located roughly 1400 feet east of the project site. A more detailed
description of the project drainage patterns follows in Section IV.A.4., below.
3. Areas to the east of the site drain into an existing storm line within Lady Moon Drive
and are conveyed south in the existing storm system. Drainage from East Harmony
Road to the north of the site is conveyed east via the roadside ditch running along the
south side of East Harmony Road. There is an existing storm line that begins just
west of Cinquefoil Lane and runs roughly 500 feet east which conveys drainage from
the roadside ditch.
PROJECT
SITE
Banner Health Medical Campus
Preliminary 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 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 treatment. All stormwater runoff from the site will
ultimately be routed to onsite water quality ponds, where it will be treated prior to exiting
the site and entering the storm collection system.
Step 3 – Stabilize Drainageways
There are no major drainageways within the subject property. While this step may not
seem applicable to proposed development, the project indirectly helps achieve stabilized
drainageways nonetheless. By providing water quality where none previously existed,
sediment with erosion potential is removed from the downstream drainageway systems
and receiving Fossil Creek Reservoir Inlet Ditch. 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 require the need for site specific source controls including:
Localized trash enclosures throughout the site for the disposal of waste products.
C. Development Criteria Reference and Constraints
The subject property is bounded on several sides by currently developed properties
and existing public streets. As such, several constraints have been identified during
the course of this analysis that will impact the proposed drainage system including:
Banner Health Medical Campus
Preliminary Drainage Report 6
Existing elevations along property lines will generally be maintained.
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 FEMA regulatory floodplain.
4. The proposed project does not propose to modify any natural drainageways.
F. Floodplain Regulations Compliance
1. As previously mentioned, all structures are located outside of any FEMA100-year
floodplain, and thus the structures are not subject to any floodplain regulations.
G. 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, ensure no adverse impacts to any adjacent properties, and to maintain the
detention concepts as outlined in the “Harmony Portion of the McClellands Creek
Master Drainage Plan Update”, by Icon Engineering, August 1999 (Ref. 6).
2. Areas to the west of the site are intercepted by a storm line system within Lady Moon
Banner Health Medical Campus
Preliminary Drainage Report 7
Drive and do not flow through the site. East Harmony Road and areas to the north of
the site drain into a roadside swale along the south side of East Harmony Road and
do not drain through the site.
3. A list of tables and figures used within this report can be found in the Table of
Contents at the front of the document. The tables and figures are located within the
sections to which the content best applies.
4. The drainage patterns anticipated for proposed drainage basins are described below.
Basin 1
Basin 1 consists of landscaped and paved parking areas, and drains into the proposed
Pond 1.
Basin 2
Basin 2 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 1.
Basin 3
Basin 2 consists of landscaped, paved parking areas and drives, and a proposed
helipad. This basin drains into the proposed Pond 1.
Basin 4
Basin 4 consists of landscaped areas, paved drives, and public street. This basin
drains offsite into the roadside ditch running along the south side of East Harmony
Road. Due to grading constraints this 0.50 acres of area (0.24 acres of public
R.O.W. - Cinquefoil Lane, 0.26 acres of the project site) must drain north into East
Harmony Road R.O.W.
Basin 5
Basin 5 consists of rooftop area, and drains into the proposed Pond 1.
Basin 6
Basin 6 consists of rooftop area, and drains into the proposed Pond 2.
Basin 7
Basin 7 consists of landscaped, paved parking areas and drives, and drains into the
proposed Pond 2.
Basin 8
Basin 8 consists of landscaped area, and drains into the proposed Pond 2.
Basin 9
Basin 9 consists of landscaped areas, paved drives, and public street. This basin
drains offsite into Regional Pond 3. Due to grading constraints, this area must drain
into Cinquefoil Lane. Drainage will be collected in a storm collection system with
Cinquefoil Lane, and directed east into Regional Pond 3.
Basin 10
Basin 10 consists of the proposed Pond 2.
Banner Health Medical Campus
Preliminary Drainage Report 8
Basin 11
Basin 11 consists of 0.21 acres of LeFever Drive R.O.W. and drains into the existing
storm collection system within Lady Moon Drive.
Basin 12
Basin 12 consists of 0.76 acres of LeFever Drive R.O.W. Drainage will be collected in
a storm collection system with Cinquefoil Lane, and directed east into Regional Pond
3.
A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of
this report.
B. Master Drainage Concepts
1. The intent of the master drainage plan done with this PDP submittal was to
demonstrate overall drainage concepts for the sites adjacent to the current project
site. The currently proposed detention ponds must work in conjunction with future
ponds to the south (Ponds 4 and 5), and both the currently proposed Interim Regional
Pond 3 as well as the future (full build-out) Pond 3.
The computer model EPA SWMM 5 has been utilized to model the overall drainage
system.Tables 1 and 2, below summarize master drainage SWMM modeling results.
SWMM output is provided in the Appendix of this report.
A full-size copy of the Master Drainage Exhibit can be found in the Map Pocket at the
end of this report.
Table 1 – SWMM Pond Modeling Summary; Interim Conditions
Pond ID Detention Water Quality Total Volume Peak
Volume
Capture
Volume
Release Rate
(AC-FT) (AC-FT) (AC-FT) (CFS)
1 2.92 0.43 3.35 5.80
2 0.91 0.40 1.31 52.80
3
(Interim) 3.56 0.11 3.67 14.00
Banner Health Medical Campus
Preliminary Drainage Report 9
Table 2 – SWMM Pond Modeling Summary; Full Build-Out Conditions
Pond ID Detention Water Quality Total Volume Peak
Volume
Capture
Volume
Release Rate
(AC-FT) (AC-FT) (AC-FT) (CFS)
1 2.92 0.43 3.35 5.80
2 0.91 0.40 1.31 52.80
3 7.70 0.80 8.50 29.30
4 1.26 0.15 1.41 1.20
5 1.47 0.20 1.67 1.40
C. Specific Details
1. Water quality treatment is being provided for the proposed development in the form of
extended detention as previously described. Further documentation of treatment
volumes and removal rates of stormwater BMPs will be documented with the Final
Drainage Report prepared during the City FCP process.
Final design details, construction documentation, and Standard Operating
Procedures (SOP) Manual shall be provided to the City of Fort Collins for
review prior to Final Development Plan approval. A final copy of the approved
SOP manual shall be provided to City and must be maintained on-site by the
entity responsible for the facility maintenance. Annual reports must also be
prepared and submitted to the City discussing the results of the maintenance
program (i.e. inspection dates, inspection frequency, volume loss due to
sedimentation, corrective actions taken, etc.).
2. Table 1, below, summarizes the water quality information for the proposed water
quality ponds.
Table 3 – Water Quality Pond Summary
Pond ID Water Quality Water Quality
Pond
Spillway Top of Pond
Capture Volume WSEL Elevation Elevation
(AC-FT) (FT) (FT) (FT)
1 0.43 4900.20 4905.10 4905.60
2 0.40 4902.60 4905.00 4905.80
3
(Interim) 0.11 4887.20 4893.00 4894.00
3. Proper maintenance of the drainage facilities designed with the proposed
development is a critical component of their ongoing performance and effectiveness.
The water quality pond may be easily accessed by maintenance staff via the gentle
slope provided at the southwest corners of Ponds 1 and 2 to the bottom of the pond.
Banner Health Medical Campus
Preliminary Drainage Report 10
Current grading shown for Regional Pond 3 represents an interim grading plan. At
full-build out for the pond, a gentle slope should be designed for ease of access.
4. The drainage features associated with the proposed project are all private facilities,
located on private property, with the exception of the pond outfalls. Pond outfalls for
Ponds 1 and 2 will be within Cinquefoil Land R.O.W. The outfall for Regional Pond 3
will be within the R.O.W. of Fossil Creek Reservoir Inlet Ditch.
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 the “East Harmony
Portion of the McClellands Creek Master Drainage Plan Update”, by Icon Engineering,
August 1999 (Ref. 6)
3. There are no regulatory floodplains within the proposed development.
4. 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 an extended detention
water quality pond.
2. The drainage concept for the proposed development is consistent with the “East
Harmony Portion of the McClellands Creek Master Drainage Plan Update”, by Icon
Engineering, August 1999 (Ref. 6)
Banner Health Medical Campus
Preliminary Drainage Report 11
References
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation
Service, United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008.
6. East Harmony Portion of the McClellands Creek Master Drainage Plan Update, Icon
Engineering, August 1999.
7. Final Drainage and Erosion Control Report for Presidio Apartments, Northern Engineering,
December 2009.
APPENDIX A
HYDROLOGIC COMPUTATIONS
CHARACTER OF SURFACE:
Runoff
Coefficient
Percentage
Impervious Project: 306-003
Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC
Asphalt ……....……………...……….....…...……………….…………………………………..0.95 100% Date:
Concrete …….......……………….….……….………………..….………………………………0….95 90%
Gravel ……….…………………….….…………………………..………………………………..0.50 40%
Roofs …….…….………………..……………….…………………………………………….. 0.95 90%
Pavers…………………………...………………..…………………………………………….. 0.40 22%
Lawns and Landscaping
Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0%
Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year C
f
= 1.00 100-year C
f
= 1.25
Basin ID
Basin Area
(s.f.)
Basin Area
(ac)
Area of
Asphalt
(ac)
Area of
Concrete
(ac)
Area of
Roofs
(ac)
Area of
Gravel
(ac)
Area of
Lawns and
Landscaping
(ac)
2-year
Composite
Runoff
Coefficient
10-year
Composite
Runoff
Coefficient
100-year
Composite
Runoff
Coefficient
Composite
% Imperv.
1 145337 3.34 Note: Assumed 90% imperviousness for all basins 0.000 0.88 0.88 1.00 90%
2 261080 5.99 for preliminary calculations. 0.254 0.88 0.88 1.00 90%
3 91205 2.09 0.254 0.88 0.88 1.00 90%
4 21710 0.50 0.254 0.88 0.88 1.00 90%
5 66666 1.53 0.254 0.88 0.88 1.00 90%
6 126012 2.89 0.254 0.88 0.88 1.00 90%
7 328111 7.53 0.254 0.88 0.88 1.00 90%
Overland Flow, Time of Concentration:
Project: 306-003
Calculations By:
Date:
Gutter/Swale Flow, Time of Concentration:
T
t
= L / 60V
T
c
= T
i
+ T
t
(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*C
f
(2-yr
C
f
=1.00)
C*C
f
(10-yr
C
f
=1.00)
C*C
f
(100-yr
C
f
=1.25)
Length,
L
(ft)
Slope,
S
(%)
T
i
2-yr
(min)
T
i
10-yr
(min)
T
i
100-yr
(min)
Length,
L
Rational Method Equation: Project: 306-003
Calculations By:
Date:
From Section 3.2.1 of the CFCSDDC
Rainfall Intensity:
1 1 3.34 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 8.4 14.4 33.2
2 2 5.99 8 8 7 0.88 0.88 1.00 2.40 4.10 8.80 12.7 21.7 52.7
3 3 2.09 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 5.3 9.0 20.8
4 4 0.50 6 6 5 0.88 0.88 1.00 2.67 4.56 9.95 1.2 2.0 5.0
5 5 1.53 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 3.9 6.6 15.2
6 6 2.89 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 7.3 12.5 28.8
7 7 7.53 10 10 9 0.88 0.88 1.00 2.21 3.78 8.03 14.7 25.2 60.5
8 8 1.23 17 17 16 0.88 0.88 1.00 1.78 3.04 6.41 1.9 3.3 7.9
9 9 2.60 8 8 7 0.88 0.88 1.00 2.46 4.21 8.80 5.7 9.7 22.9
DEVELOPED RUNOFF COMPUTATIONS
C
100
Design
Point
Flow,
Q
100
(cfs)
Flow,
Q
2
(cfs)
10-yr
T
c
(min)
2-yr
T
c
(min)
C
2
Flow,
Q
10
(cfs)
Intensity,
i
100
(in/hr)
Basin(s)
ATC
January 21, 2013
Intensity,
i
10
(in/hr)
Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1
C
10
Area, A
(acres)
Intensity,
i
2
APPENDIX B
HYDRAULIC COMPUTATIONS
B.1 – Storm Sewers (reserved for future use)
B.2 – Inlets (reserved for future use)
APPENDIX B.1
STORM SEWERS (reserved for future use)
APPENDIX B.2
INLETS (reserved for future use)
APPENDIX C
WATER QUALITY DESIGN COMPUTATIONS
WATER QUALITY POND DESIGN CALCULATIONS
POND 1
Project: 306-003
By: ATC
Date: 1.21.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 12.950 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 90.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.9000 <-- CALCULATED
WQCV (watershed inches) = 0.401 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.433 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = ** <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = ** <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = ** <-- INPUT from Figure 5
n = ** <-- INPUT from Figure 5
t (in) = ** <-- INPUT from Figure 5
number of rows = ** <-- CALCULATED from WQ Depth and row spacing
**To be completed at final design
WATER QUALITY POND DESIGN CALCULATIONS
POND 2
Project: 306-003
By: ATC
Date: 1.21.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 12.790 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 90.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.9000 <-- CALCULATED
WQCV (watershed inches) = 0.401 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.428 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = ** <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = ** <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = ** <-- INPUT from Figure 5
n = ** <-- INPUT from Figure 5
t (in) = ** <-- INPUT from Figure 5
number of rows = ** <-- CALCULATED from WQ Depth and row spacing
**To be completed at final design
WATER QUALITY POND DESIGN CALCULATIONS
POND 3
Project: 306-003
By: ATC
Date: 1.21.13
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 3.360 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 90.00 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = 0.9000 <-- CALCULATED
WQCV (watershed inches) = 0.401 <-- CALCULATED from Figure EDB-2
WQCV (ac-ft) = 0.112 <-- CALCULATED from UDFCD DCM V.3 Section 6.5
WQ Depth (ft) = ** <-- INPUT from stage-storage table
AREA REQUIRED PER ROW, a (in
2
) = ** <-- CALCULATED from Figure EDB-3
CIRCULAR PERFORATION SIZING:
dia (in) = ** <-- INPUT from Figure 5
n = ** <-- INPUT from Figure 5
t (in) = ** <-- INPUT from Figure 5
number of rows = ** <-- CALCULATED from WQ Depth and row spacing
**To be completed at final design
APPENDIX D
SWMM ANALYSIS
1
2
3
5
6
out1
out2
out3
mh2
mh3
FCRID
pond1
pond2 pond3
FtCollins-100-yr
11/21/2012 00:15:00
SWMM 5 Page 1
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022)
--------------------------------------------------------------
*********************************************************
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
*********************************************************
****************
Analysis Options
****************
Flow Units ............... CFS
Process Models:
Rainfall/Runoff ........ YES
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... YES
Ponding Allowed ........ NO
Water Quality .......... NO
Infiltration Method ...... HORTON
Flow Routing Method ...... KINWAVE
Starting Date ............ NOV-21-2012 00:00:00
Ending Date .............. NOV-21-2012 06:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 8.898 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 0.331 0.136
Surface Runoff ........... 8.414 3.470
Final Surface Storage .... 0.221 0.091
Continuity Error (%) ..... -0.769
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 8.414 2.742
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 5.565 1.813
Internal Outflow ......... 0.000 0.000
Storage Losses ........... 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 2.845 0.927
Continuity Error (%) ..... 0.051
********************************
Highest Flow Instability Indexes
********************************
Link out2 (37)
Link 6 (28)
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 30.00 sec
SWMM 5 Page 1
Average Time Step : 30.00 sec
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
***************************
Subcatchment Runoff Summary
***************************
--------------------------------------------------------------------------------------------------------
Total Total Total Total Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10^6 gal CFS
--------------------------------------------------------------------------------------------------------
1 3.67 0.00 0.00 0.14 3.47 1.22 121.50 0.946
2 3.67 0.00 0.00 0.14 3.47 1.21 120.63 0.946
3 3.67 0.00 0.00 0.13 3.47 0.32 33.16 0.946
******************
Node Depth Summary
******************
---------------------------------------------------------------------
Average Maximum Maximum Time of Max
Depth Depth HGL Occurrence
Node Type Feet Feet Feet days hr:min
---------------------------------------------------------------------
mh2 JUNCTION 0.29 0.32 101.32 0 02:08
mh3 JUNCTION 0.41 0.98 99.98 0 00:47
FCRID OUTFALL 0.00 0.00 96.00 0 00:00
pond1 STORAGE 1.91 2.38 107.38 0 02:08
pond2 STORAGE 0.34 2.54 107.54 0 00:47
pond3 STORAGE 1.93 2.50 99.50 0 02:09
*******************
Node Inflow Summary
*******************
-------------------------------------------------------------------------------------
Maximum Maximum Lateral Total
Lateral Total Time of Max Inflow Inflow
Inflow Inflow Occurrence Volume Volume
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal
-------------------------------------------------------------------------------------
mh2 JUNCTION 0.00 5.77 0 02:08 0.000 0.761
mh3 JUNCTION 0.00 57.95 0 00:47 0.000 1.965
FCRID OUTFALL 0.00 13.99 0 02:09 0.000 1.813
pond1 STORAGE 121.50 121.50 0 00:40 1.220 1.220
pond2 STORAGE 120.63 120.63 0 00:40 1.205 1.205
pond3 STORAGE 33.16 83.61 0 00:40 0.317 2.281
**********************
Node Surcharge Summary
**********************
Surcharging occurs when water rises above the top of the highest conduit.
---------------------------------------------------------------------
Max. Height Min. Depth
Hours Above Crown Below Rim
Node Type Surcharged Feet Feet
---------------------------------------------------------------------
pond1 STORAGE 6.01 2.384 7.616
pond2 STORAGE 6.01 2.535 7.465
*********************
Node Flooding Summary
SWMM 5 Page 2
*********************
No nodes were flooded.
**********************
Storage Volume Summary
**********************
--------------------------------------------------------------------------------------------
Average Avg E&I Maximum Max Time of Max Maximum
Volume Pcnt Pcnt Volume Pcnt Occurrence Outflow
Storage Unit 1000 ft3 Full Loss 1000 ft3 Full days hr:min CFS
--------------------------------------------------------------------------------------------
pond1 89.442 4 0 127.940 6 0 02:08 5.77
pond2 3.254 1 0 40.205 6 0 00:46 53.03
pond3 102.171 4 0 156.012 6 0 02:08 13.99
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg. Max. Total
Freq. Flow Flow Volume
Outfall Node Pcnt. CFS CFS 10^6 gal
-----------------------------------------------------------
FCRID 97.23 11.53 13.99 1.813
-----------------------------------------------------------
System 97.23 11.53 13.99 1.813
********************
Link Flow Summary
********************
-----------------------------------------------------------------------------
Maximum Time of Max Maximum Max/ Max/
|Flow| Occurrence |Veloc| Full Full
Link Type CFS days hr:min ft/sec Flow Depth
-----------------------------------------------------------------------------
5 CONDUIT 5.77 0 02:08 7.48 0.00 0.03
6 CONDUIT 57.95 0 00:47 14.96 0.02 0.10
out1 DUMMY 5.77 0 02:08
out2 DUMMY 53.03 0 00:47
out3 DUMMY 13.99 0 02:09
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Mon Jan 21 13:01:14 2013
Analysis ended on: Mon Jan 21 13:01:14 2013
Total elapsed time: < 1 sec
SWMM 5 Page 3
1
2
3
4
5
5
6
out1
out2
out3
out4 out5
mh2
mh3
FCRID
pond1
pond2 pond3
pond4
pond5
FtCollins-100yr
11/21/2012 00:15:00
SWMM 5 Page 1
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022)
--------------------------------------------------------------
*********************************************************
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
*********************************************************
****************
Analysis Options
****************
Flow Units ............... CFS
Process Models:
Rainfall/Runoff ........ YES
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... YES
Ponding Allowed ........ NO
Water Quality .......... NO
Infiltration Method ...... HORTON
Flow Routing Method ...... KINWAVE
Starting Date ............ NOV-21-2012 00:00:00
Ending Date .............. NOV-21-2012 06:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 00:15:00
Wet Time Step ............ 00:05:00
Dry Time Step ............ 01:00:00
Routing Time Step ........ 30.00 sec
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 18.508 3.669
Evaporation Loss ......... 0.000 0.000
Infiltration Loss ........ 0.758 0.150
Surface Runoff ........... 17.435 3.457
Final Surface Storage .... 0.457 0.091
Continuity Error (%) ..... -0.772
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 17.435 5.681
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 11.247 3.665
Internal Outflow ......... 0.000 0.000
Storage Losses ........... 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 6.183 2.015
Continuity Error (%) ..... 0.026
********************************
Highest Flow Instability Indexes
********************************
Link out2 (37)
Link 6 (26)
*************************
Routing Time Step Summary
*************************
Minimum Time Step : 30.00 sec
Average Time Step : 30.00 sec
Total Total Total Total Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10^6 gal CFS
--------------------------------------------------------------------------------------------------------
1 3.67 0.00 0.00 0.14 3.47 1.22 121.50 0.946
2 3.67 0.00 0.00 0.14 3.47 1.21 120.63 0.946
3 3.67 0.00 0.00 0.14 3.47 2.24 216.06 0.945
4 3.67 0.00 0.00 0.21 3.40 0.47 47.21 0.928
5 3.67 0.00 0.00 0.21 3.40 0.55 54.75 0.928
******************
Node Depth Summary
******************
---------------------------------------------------------------------
Average Maximum Maximum Time of Max
Depth Depth HGL Occurrence
Node Type Feet Feet Feet days hr:min
---------------------------------------------------------------------
mh2 JUNCTION 0.29 0.32 101.32 0 02:08
mh3 JUNCTION 0.46 1.00 100.00 0 00:47
FCRID OUTFALL 0.00 0.00 96.00 0 00:00
pond1 STORAGE 1.91 2.38 107.38 0 02:08
pond2 STORAGE 0.34 2.54 107.54 0 00:47
pond3 STORAGE 1.62 2.12 99.12 0 02:07
pond4 STORAGE 2.50 2.96 107.96 0 02:12
pond5 STORAGE 2.93 3.43 108.43 0 02:12
*******************
Node Inflow Summary
*******************
-------------------------------------------------------------------------------------
Maximum Maximum Lateral Total
Lateral Total Time of Max Inflow Inflow
Inflow Inflow Occurrence Volume Volume
Node Type CFS CFS days hr:min 10^6 gal 10^6 gal
-------------------------------------------------------------------------------------
mh2 JUNCTION 0.00 5.77 0 02:08 0.000 0.761
mh3 JUNCTION 0.00 60.24 0 00:47 0.000 2.334
FCRID OUTFALL 0.00 29.31 0 02:07 0.000 3.665
pond1 STORAGE 121.50 121.50 0 00:40 1.220 1.220
pond2 STORAGE 120.63 120.63 0 00:40 1.205 1.205
pond3 STORAGE 216.06 268.29 0 00:40 2.240 4.573
pond4 STORAGE 47.21 47.21 0 00:40 0.471 0.471
pond5 STORAGE 54.75 54.75 0 00:40 0.545 0.545
**********************
Node Surcharge Summary
**********************
Surcharging occurs when water rises above the top of the highest conduit.
---------------------------------------------------------------------
Max. Height Min. Depth
Hours Above Crown Below Rim
Node Type Surcharged Feet Feet
---------------------------------------------------------------------
pond1 STORAGE 6.01 2.384 7.616
pond2 STORAGE 6.01 2.535 7.465
pond4 STORAGE 6.01 2.965 7.035
pond5 STORAGE 6.01 3.430 6.570
*********************
Node Flooding Summary
*********************
No nodes were flooded.
**********************
pond1 89.442 4 0 127.940 6 0 02:08 5.77
pond2 3.254 1 0 40.205 6 0 00:46 53.03
pond3 217.800 3 0 336.791 4 0 02:06 29.31
pond4 42.519 7 0 54.939 9 0 02:11 1.24
pond5 49.801 8 0 63.953 10 0 02:12 1.36
***********************
Outfall Loading Summary
***********************
-----------------------------------------------------------
Flow Avg. Max. Total
Freq. Flow Flow Volume
Outfall Node Pcnt. CFS CFS 10^6 gal
-----------------------------------------------------------
FCRID 97.23 23.31 29.31 3.665
-----------------------------------------------------------
System 97.23 23.31 29.31 3.665
********************
Link Flow Summary
********************
-----------------------------------------------------------------------------
Maximum Time of Max Maximum Max/ Max/
|Flow| Occurrence |Veloc| Full Full
Link Type CFS days hr:min ft/sec Flow Depth
-----------------------------------------------------------------------------
5 CONDUIT 5.77 0 02:08 7.48 0.00 0.03
6 CONDUIT 60.24 0 00:48 15.10 0.02 0.10
out1 DUMMY 5.77 0 02:08
out2 DUMMY 53.03 0 00:47
out3 DUMMY 29.31 0 02:07
out4 DUMMY 1.24 0 02:12
out5 DUMMY 1.36 0 02:12
*************************
Conduit Surcharge Summary
*************************
No conduits were surcharged.
Analysis begun on: Mon Jan 21 12:54:22 2013
Analysis ended on: Mon Jan 21 12:54:22 2013
Total elapsed time: < 1 sec
SWMM 5 Page 3
APPENDIX E
EROSION CONTROL REPORT
River District Block One Mixed Use
Preliminary Erosion Control Report
EROSION CONTROL REPORT
A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included
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.
River District Block One Mixed Use
Preliminary Erosion Control Report
MAP POCKET
DRAINAGE EXHIBITS
Storage Volume Summary
**********************
--------------------------------------------------------------------------------------------
Average Avg E&I Maximum Max Time of Max Maximum
Volume Pcnt Pcnt Volume Pcnt Occurrence Outflow
Storage Unit 1000 ft3 Full Loss 1000 ft3 Full days hr:min CFS
--------------------------------------------------------------------------------------------
SWMM 5 Page 2
Maximum Time Step : 30.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
***************************
Subcatchment Runoff Summary
***************************
--------------------------------------------------------------------------------------------------------
SWMM 5 Page 1
(in/hr)
100-yr
T
c
(min)
Q C f C i A
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
T
t
(min)
Length,
L
(ft)
Slope,
S
(%)
Velocity,
V
(ft/s)
T
t
(min)
2-yr
T
c
(min)
10-yr
T
c
(min)
100-yr
T
c
(min)
1 1 No 0.95 0.95 1.00 50 2.00% 1.6 1.6 1.0 0 0.50% N/A N/A 287 1.50% 1.84 2.6 5 5 5
2 2 No 0.95 0.95 1.00 130 2.00% 2.5 2.5 1.7 469 0.50% 1.41 5.5 0 N/A N/A N/A 8 8 7
3 3 No 0.95 0.95 1.00 122 2.00% 2.5 2.5 1.6 177 0.50% 1.41 2.1 0 N/A N/A N/A 5 5 5
4 4 No 0.95 0.95 1.00 53 2.00% 1.6 1.6 1.1 372 0.50% 1.41 4.4 0 N/A N/A N/A 6 6 5
5 5 No 0.95 0.95 1.00 197 1.00% 3.9 3.9 2.6 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
6 6 No 0.95 0.95 1.00 156 1.00% 3.5 3.5 2.3 0 0.50% N/A N/A 0 N/A N/A N/A 5 5 5
7 7 No 0.95 0.95 1.00 193 2.00% 3.1 3.1 2.1 605 0.50% 1.41 7.1 0 N/A N/A N/A 10 10 9
8 8 No 0.25 0.25 0.31 141 2.00% 15.0 15.0 13.9 135 0.50% 1.41 1.6 0 N/A N/A N/A 17 17 16
9 9 No 0.95 0.95 1.00 91 5.00% 1.6 1.6 1.0 514 0.50% 1.41 6.1 0 N/A N/A N/A 8 8 7
10 10 No 0.95 0.95 1.00 154 2.00% 2.8 2.8 1.8 0 0.50% N/A N/A 175 1.00% 1.50 1.9 5 5 5
11 11 No 0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 148 0.50% 1.41 1.7 0 N/A N/A N/A 5 5 5
12 12 No 0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 781 0.50% 1.41 9.2 0 N/A N/A N/A 10 10 10
DEVELOPED TIME OF CONCENTRATION COMPUTATIONS
Gutter Flow Swale Flow
Design
Point
Basin
Overland Flow
ATC
January 21, 2013
Time of Concentration
(Equation RO-4)
3
1
1 . 87 1 . 1 *
S
C Cf L
Ti
8 53517 1.23 0.254 0.88 0.88 1.00 90%
9 113315 2.60 0.254 0.88 0.88 1.00 90%
10 49256 1.13 0.254 0.88 0.88 1.00 90%
11 9177 0.21 0.254 0.88 0.88 1.00 90%
12 33063 0.76 0.254 0.88 0.88 1.00 90%
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 C
f
= 1.00
January 21, 2013