HomeMy WebLinkAboutMULBERRY CONNECTION - FDP200030 - - DRAINAGE REPORT (3)kimley-horn.com 4582 South Ulster Street, Suite 1500, Denver, CO 80237 303 228 2300
DRAINAGE REPORT COVER LETTER
To:
City of Fort Collins
Matt Simpson, P.E., CFM
Development Review Engineer
From:Dan Skeehan, P.E.
Kimley-Horn and Associates, Inc
Date:January 21, 2021
Subject:Mulberry Connection, PDP190015
Drainage Report Cover Letter
Kimley-Horn and Associates, Inc. (Kimley-Horn) is submitting this Drainage Report Cover Letter for the above
referenced project. The purpose of this letter is to serve as an outline for the proposed development and associated
drainage.
PROJECT DESCRIPTION
The proposed Mulberry Connection Project is located within the Northeast Quarter of Section 9, Township 7 North,
Range 68 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer, Colorado. A vicinity map is
provided below.
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kimley-horn.com 4582 South Ulster Street, Suite 1500, Denver, Colorado, 80237 303 228 2300
The site is approximately 13 acres and is existing farm land. The proposed site includes two industrial buildings
with associated parking and landscape improvements. Drainage improvements include two proposed rain
gardens, proposed underground water quality treatment, and a proposed detention pond. A variance is being
requested to allow for an inflow infiltration basin at the inflow into the detention pond due to existing grades
within the project site and along the adjacent boundaries.
“I hereby attest that this report for the final drainage design for the Mulberry Connection was prepared by me or
under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria Manual. I
understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by
others.”
SIGNATURE: _________________________________
Dan Skeehan, P.E.
Registered Professional Engineer
State of Colorado No. 46391
ATTACHMENTS
Final Drainage Report
City of Fort Collins
Mulberry Connection
(Redman Drive and I-25 Frontage Road)
Final Drainage Report
JANURARY 2021 | VERSION 1
Prepared By:
4582 South Ulster Street, Suite 1500
Denver, CO 80237
Dan Skeehan
Registered Professional Engineer
State of Colorado No. 46391
2
INTRODUCTION
The proposed Mulberry Connection Project is located within the Northeast Quarter of Section 9, Township
7 North, Range 68 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer, Colorado.
The site is bound by:
· North: Existing Farmland
· East: Interstate 25 (“I-25”) Frontage Road
· South: Redman Drive
· West: Existing Farmland
A vicinity map is provided below.
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
3
PROPOSED DEVELOPMENT
The site is approximately 13.05 acres and is existing farmland. The proposed site includes two industrial
buildings with associated parking and landscape improvements.
EXISTING SITE INFORMATION
The Site is located within the Boxelder Creek and Cooper Slough Basins. The Master Plan for these basins
is currently being updated, according to the City of Fort Collins website. According to the Problem
Identification Map provided on the City of Fort Collins website for the Boxelder and Cooper Slough Basin,
the Site is not within a high or moderate risk floodplain. The Flooding Solutions Map indicates that upgrades
to pipes and open channels are recommended south of the Site along E. Mulberry Street. No flooding,
water quality, nor Master Plan improvements are recommended within the vicinity of the Site.
The soil on the site is primarily Nunn loam and Garrett loam, which are classified as Hydrologic Soil Group
C and B, respectively. The soil Classification Map can be found in Appendix A. This Site is a part of the
Boxelder Creek & Cooper Slough Master Drainage Plan, which is currently under revision and has not been
referenced in this design. The existing site is utilized as agricultural land with ground cover primarily made
up of crop.
According to the Geotechnical Evaluation performed by Ninyo & Moore on July 2, 2019, groundwater was
encountered at depths ranging between approximately 8.5 to 12 feet below ground surface.
HISTORIC DRAINAGE
The existing Site is relativity flat with slopes ranging from 0.5% to 3%. There are currently no existing on-
site water quality or detention improvements. The majority of the site currently slopes to the southwest,
conveying water into an existing roadside ditch adjacent to Redman Drive, which discharges into Cooper
Slough approximately 600 feet west of the Site. The property directly north of the Site is collected by an
existing drainage ditch along the northern property line, routing all discharges around the Site. I-25 Frontage
Road is adjacent to the Site to the east. The width of the Frontage Road drains west into an existing
drainage ditch adjacent to the Site in the existing condition.
The site is located within City of Fort Collins Federal Emergency Management Agency (FEMA) Flood
Insurance Rate Map Number 08069C0984H and the property being developed is designated as an area
outside of the 100-year floodplain. The updated FEMA maps is included in Appendix A.
Per the FEMA Flood Insurance Rate Map and City of Fort Collins Problem Identification Map, the Site is
not within a 100-year floodplain and therefore additional analysis and permitting will not be required.
DESIGN CRITERIA
The City of Fort Collins “Stormwater Criteria Manual, December 2018 Edition,” (Criteria Manual) and the
“Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual” Volumes 1, 2, and 3
(Drainage Manual), with latest revisions, were used to prepare the storm calculations. Weighted impervious
values were calculated and used for the site area in accordance with the Criteria Manual and Drainage
Manual.
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This Site is a part of the Boxelder Creek & Cooper Slough Master Drainage Plan, which is currently under
revision. Existing storm sewer infrastructure is not present on the Site. An existing drainage ditch is present
on both sides (north and south) of Redman Drive, in addition to the existing concrete irrigation ditch on the
adjacent property to the north. An existing drainage ditch adjacent to the Site to the east collects the
Frontage Road runoff.
Hydrologic Criteria
The 2-year and 100-year storm event were evaluated for this Site. Rainfall intensity values provided in the
Criteria Manual were utilized for the analysis. Impervious values for pavement, roof, and landscape area
were taken from the Criteria Manual. Runoff coefficients were calculated per the Criteria Manual. The
Rational Method was utilized to calculate the peak runoff values for the minor and major storm event.
Peak runoff values were calculated for the existing conditions of the Site, which the 2-year existing peak
runoff informed the allowable release from the Site in the proposed conditions in the 100-year storm event.
Topographic survey of the Site was utilized to delineate existing sub-basins for the Site. An Existing
Drainage Map is provided in Appendix B and all hydrologic calculations are provided in Appendix C.
The proposed site layout and grading was utilized to delineate sub-basins for the proposed condition, as
shown in the Proposed Drainage Map included in Appendix B. Peak runoff values for the proposed sub-
basins were calculated using the Rational Method. Hydrologic calculations are provided in Appendix C.
Hydraulic Criteria
Water Quality Capture Volumes for sub-basins A, B, C, and D were calculated per the methods described
in the Criteria Manual. The Modified FAA Method, as described in the Criteria Manual, was utilized to
calculate the required detention volume for the Site in the proposed conditions. Water quality and detention
calculations are provided in Appendix D.
This Final Drainage Report includes the following hydraulic calculations: inlet calculations; pipe capacity
calculations utilizing Bentley StormCAD. Sizing of the overflow spillways have been done per the methods
described in the Criteria Manual. All hydraulic calculations are included in Appendix D.
DRAINAGE PLAN
GENERAL CONCEPT
The Site in the proposed conditions was divided into four major onsite sub-basins which are described in
greater detail in the following section. BMPs were selected utilizing the four-step process outlined in Volume
3, Chapter 1, Section 4 of the Drainage Manual:
1. Employ runoff reduction practices (Minimize Directly Connected Impervious Area) - The
redevelopment of an urban site provides limited opportunities to employ runoff reduction practices.
The Site has been developed to install landscaping wherever pavement (or building) is not required.
Additionally, impervious areas have been disconnected from storm sewer infrastructure at all
feasible locations, and are routed into the proposed rain gardens within basins A and C.
2. Implement BMPs that provide a water quality capture volume with a slow release – 12.01 acres will
be treated for the water quality capture volume (WQCV). The total on-site proposed impervious
surface area is 8.92 acres (including pavement and roofs), 8.85 acre of which will be treated by
bioretention or underground proprietary system. D sub-basins are directly tributary to the inflow
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
5
infiltration basin within the detention pond. WQCV for the D sub-basins will be treated via infiltration.
Drainage basins O1, O2, O3, O4, OS1, and OS2 will not be treated for water quality, a total of 0.76
acres on-site and 1.92 acres off-site. A rain garden is proposed to treat the WQCV from sub-basin
C, an underground treatment system is proposed to treat the WQCV from sub-basin B, a rain
garden is proposed to treat the WQCV from sub-basin A, and the WQCV from sub-basin D will be
infiltrated via the inflow infiltration basin in the detention pond, as detailed in Table 1 below.
Table 1. Summary of Impervious Area Treated
On-Site Sub-
Basin
Total
Area
(ac)
Impervious
Area (ac)
Impervious
Area Treated
(ac)
Percent
Impervious
Treated
Water Quality
Feature
A 5.39 3.65 3.65 100%Rain Garden A
B1 1.72 1.52 1.52 100%
Underground
B2 1.27 1.13 1.13 100%
C 3.63 2.55 2.55 100%Rain Garden C
Total to LID 12.01 8.85 8.85 100%--
D1 0.16 0.04 0.04 100%Inflow Infiltration
Basin within
Detention PondD20.14 0.02 0.02 100%
Total to
Infiltration
0.30 0.06 0.06 100%--
O1 0.52 0.00 0.00 0%
Flows Off-SiteO20.07 0.03 0.00 0%
O3 0.03 0.02 0.00 0%
O4 0.14 0.00 0.00 0%
Total Not
Treated
0.76 0.05 0.00 0%--
Total On-Site 13.07 8.96 8.91 98% (percent impervious treated)
92% (percent total Site to LID)
The three proposed water quality treatment areas are shown on the Proposed Drainage Map in
Appendix B and calculations are provided in Appendix D.
6
3. Stabilize streams – Not applicable.
4. Implement site specific and other source control BMPs – During construction, the site will include
silt fence to reduce potential for contamination discharges at the perimeter. Site access will be
provided through an area of vehicle tracking control to reduce tracking of contamination offsite
which will be further controlled with street sweeping and rock socks along Redman Drive. Proposed
storm sewer will have inlet protection. Additionally, diversion ditches routing water to a sediment
basin will be installed at the beginning of construction.
SPECIFIC DETAILS
Runoff generated by three of the on-site basins (sub-basins A B, and C - 12.01 acres of the total 13.07
acres – 92% of the Site) will be routed to LID features and the WQCV treated. Runoff generated by storm
events greater than the WQCV will be routed through the LID features to a proposed detention pond via
proposed storm sewer infrastructure. Runoff generated by one on-site basin (sub-basin D – 0.30 acres of
the total 13.07 acres – 2% of the Site) will be routed to the inflow infiltration basin within the proposed
detention pond. The proposed detention pond will outfall to an existing drainage swale directly upstream of
Cooper Slough and adjacent to the Site. Four on-site basins (0.76 acres – 6% of the Site) will surface flow
off-site and not be treated for water quality or be detained. The 100-year release rate from the proposed
detention pond was calculated to take into account the undetained flows from these basins that are not fully
pervious (sub-basins O1 and O4 are fully pervious, while sub-basins O2 and O3 are accounted for in the
100-year release rate). Two offsite sub-basins are included in the drainage analysis to properly size all
proposed drainage features. The Proposed Drainage Map included in Appendix B shows the onsite and
offsite sub-basins and each basin is described in further detail below. Table 2 summarizes the tributary
areas, impervious areas, imperviousness, and peak flows from each sub-basin. Full calculations are
included in Appendix C.
Sub-basin A
Sub-basin A is 5.39 acres and consists of on-site parking, sidewalk, one of the buildings, and landscape
areas that surface flow to proposed Rain Garden A. Water quality treatment for runoff from this sub-basin
will occur within Rain Garden A. Flows above the WQCV will flow to the detention pond via two overflow
spillways between Rain Garden A and the detention pond.
Sub-basin B1
Sub-basin B1 is 1.72 acres and consists of on-site parking, sidewalk, loading dock, and landscaped areas.
Runoff within this sub-basin surface flows to a proposed double CDOT Type 13 inlet within a proposed
valley gutter.
Sub-basin B2
Sub-basin B2 is 1.27 acres and consists of loading dock. Runoff within this sub-basin surface flows to a
proposed double CDOT Type 13 inlet within a proposed valley gutter.
Both inlets within sub-basin B will connect to the ADS Inflow Manhole. This manhole has been designed
with a low-flow outlet pipe at the bottom of the structure, connected to an underground water quality facility,
which will convey the WQCV. Flows over the WQCV will pond within the manhole structure to the “overflow
outlet pipe”, which will convey flows to the detention pond. The invert of the overflow outlet pipe has been
set at the maximum storage elevation within the underground water quality facility to store the required
WQCV. The stage storage table for the ADS underground system is included in Appendix D.
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
7
Sub-basin C
Sub-basin C is 3.63 acres and consists of on-site parking, sidewalk, one of the buildings, and landscaped
areas. Runoff within this sub-basin will surface flow east into Rain Garden C, which will provide water quality
treatment. Storm events greater than the WQCV will be routed through Rain Garden C, into the proposed
outlet structure and conveyed via storm pipe to the detention pond.
Sub-basin D1
Sub-basin D1 is 0.16 acres and consists of on-site landscaped area and a portion of sidewalk. Runoff within
this sub-basin will surface flow to a proposed CDOT Type D inlet. Flows will be routed to the proposed
inflow infiltration basin within the detention pond via proposed storm sewer.
Sub-basin D2
Sub-basin D2 is 0.14 acres and consists of on-site landscaped area and a portion of sidewalk. Runoff within
this sub-basin will surface flow to a proposed CDOT Type D inlet. Flows will be routed to the proposed
inflow infiltration basin within the detention pond via proposed storm sewer.
Sub-basin O1
Sub-basin O1 is 0.52 acres and consists of on-site landscaped area. Runoff within this sub-basin will
surface flow offsite and water quality treatment nor detention will be provided for this sub-basin.
Sub-basin O2
Sub-basin O2 is 0.07 acres and consists of on-site landscaped area and a portion of the west access drive.
Runoff within this sub-basin will surface flow offsite to Redman Drive. Water quality treatment nor detention
will be provided for this sub-basin.
Sub-basin O3
Sub-basin O3 is 0.03 acres and consists of on-site landscaped area and a portion of the east access drive.
Runoff within this sub-basin will surface flow offsite to Redman Drive. Water quality treatment nor detention
will be provided for this sub-basin.
Sub-basin O4
Sub-basin O4 is 0.14 acres and consists of on-site landscaped area. Runoff within this sub-basin will
surface flow offsite to the I-25 Frontage Road. Runoff will be collected in the proposed curb and gutter and
will be routed south across Redman Drive via a proposed valley gutter. Runoff will enter an existing drainage
swale south of the intersection via a 2-foot curb cut. Water quality treatment nor detention will be provided
for this sub-basin.
Sub-basin OS1
Sub-basin OS1 is 0.96 acres and consists of off-site landscaped area, sidewalk, and I-25 Frontage Road.
Runoff within this sub-basin will flow to the proposed curb and gutter, following historic drainage patterns.
Flows will be routed across Redman Drive via a proposed valley gutter. Runoff will enter an existing
8
drainage swale south of the intersection via a 2-foot curb cut. Water continues flowing south via an existing
grass swale that is proposed to be modified with the adjacent roadway improvements.
The proposed improvements to I-25 Frontage Road increase the impervious area from 0.50 acres to 0.55
acres, which results in an increase in the 100-year flow rate from 5.28 CFS to 7.21 CFS, an increase of
1.93 CFS. The proposed 100-year flows from sub-basins O4 and OS1 were combined and the hydraulic
capacity of the proposed grass swale evaluated. The Bentley FlowMaster calculations are included in
Appendix D and indicate that the grass swale has capacity for the increased flows in the proposed condition.
Water quality treatment nor detention will be provided for this sub-basin on the proposed site. Additionally,
this basin is not included as a part of the total Site improvement area, as proposed off-site improvements
will improve existing conditions and maintain historic drainage patterns.
Sub-basin OS2
Sub-basin OS2 is 0.55 acres and consists of a portion of Redman Drive and offsite landscape area. Runoff
within this sub-basin will surface flow to proposed curb and gutter adjacent to the Site and the existing
drainage ditch on the north side of Redman Drive. Water quality treatment nor detention will be provided
for this sub-basin. Additionally, this basin is not included as a part of the total Site improvement area, as
proposed off-site improvements will improve existing conditions and maintain historic drainage patterns.
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
9
Table 2. Summary of proposed drainage sub-basins.
Basin ID Total
Tributary
Area (acres)
Impervious
Area (acres)1
Imperviousness 2-Year Peak
Flow (CFS)
100-Year
Peak Flow
(CFS)
A 5.39 3.65 64%7.95 41.06
B1 1.72 1.52 89%4.20 17.08
B2 1.27 1.13 90%2.93 11.79
C 3.63 2.55 66%6.20 32.11
D1 0.16 0.04 27%0.12 0.54
D2 0.14 0.02 19%0.09 0.37
O1 0.52 0.00 2%0.22 0.97
O2 0.07 0.03 44%0.10 0.45
O3 0.03 0.02 55%0.05 0.22
O4 0.14 0.00 2%0.06 0.26
Total On-Site2 13.07 8.96 66%21.91 104.86
Total On-Site
to Detention3
12.31 8.92 70%21.48 102.95
Total On-Site
to Offsite4
0.76 0.05 7.9%0.43 1.90
OS-1 0.96 0.88 92%2.42 9.58
OS-2 0.96 0.55 58%1.46 7.21
Total Off-Site5 1.92 1.43 75%3.89 16.79
1. Includes pavement and roof areas.
2. Does not include O1 – O5
3. Includes A, B, C, and D
4. Includes O1 – O5
5. Includes OS1 and OS2
10
Rain Garden A
Rain Garden A is proposed to treat runoff from, sub-basin A. Unconcentrated sheet flow runoff will surface
flow from the parking lot, down the rain garden slope (maximum 4:1) and into a sediment forebay proposed
along the length of the bottom of the rain garden. Rain Garden A is designed with an 8-foot width bottom
and 4:1 side slopes to the berm between the rain garden and detention pond. An underdrain is proposed
along the length of the rain garden. The northern underdrain will discharge directly to the proposed dry well
within the inflow infiltration basin. The southern underdrain will connect to the underdrain from the ADS
system that discharges directly into the drywell. Two CDOT Type D inlets will convey flows greater than the
WQCV to the detention pond. Inlet calculations for these inlets indicate that water will pond 0.39 feet above
the WQCV surface in order for the inlets to convey the 100-year storm event. An equalizer pipe is proposed
between the north and south portions of the rain garden to ensure the full volume is utilized. Final design
details of the rain garden are provided in the Construction Documents and summarized in Table 3 below.
Table 3. Rain Garden A design data.
Calculated WQCV 4,702 cubic feet
Required Flat Surface Area 3,005 square feet
Provided Flat Surface Area 3,030 square feet
Provided Volume 4,831 cubic feet
Top of Media Elevation 4952.00
WQCV Ponding Depth 12 inches
WQCV Ponding Elevation (Rim of Inlets)4953.00
100-Year Ponding Depth 0.39 feet
Top of Berm (between rain garden and pond)4953.50
Maintenance: Maintenance access of Rain Garden A is provided via the adjacent parking lot along the east
side of the rain garden. Several cleanouts are provided for the underdrains. A drainage easement has been
provided around the Rain Garden.
Overflow: In the case in which the Rain Garden becomes clogged and ponds to the top of berm height of
4953.50, water will spill over the berm west into the detention pond.
Underground Facility
An ADS SC-740 underground chamber system is proposed to treat the WQCV from sub-basin B. Runoff
from sub-basin B will be collected by two double CDOT Type 13 inlets. These inlets connect to the ADS
Inflow Manhole. The “low-flow” outlet pipe at the bottom of the manhole will convey the WQCV to the
underground facility. Flows greater than the WQCV will pond within the manhole structure to the maximum
elevation of WQCV storage in the underground facility and then enter the 24” outlet pipe, conveying flows
to the detention pond. The underground facility will be designed per ADS recommendations, including an
underdrain. The underdrain will outfall to the proposed dry well within the inflow infiltration basin proposed
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
11
within the detention pond. The ADS detail sheets and detail of the ADS Inflow Manhole are included in the
Construction Documents. Table 4 below summarizes the ADS system design.
Table 4. Summary of ADS system design.
Required WQCV 4,096 cubic feet
Number of Chambers 55
Bottom of Stone/Invert of Underdrain 4944.59 feet
Ponding Depth within System 3 feet
Invert of 100-year Pipe in “ADS Inflow Manhole”4947.59 feet
Maintenance: Maintenance access of the underground facility will be provided by access ports at one end
of each of the chamber rows, per manufacturer recommendations. A drainage easement has been provided
around the underground facility.
Overflow: In the case in which the underground facility becomes plugged, water will pond within the storm
sewer system, surcharging the inlets within the loading court and ponding within this area. Water will pond
to an elevation of 4952.2 (3.9 feet below FFE of 4956.10) within the loading court before overtopping the
highpoint in the access drive and flowing into Redman Drive.
Rain Garden C
Rain Garden C is proposed to treat the WQCV from sub-basin C. Unconcentrated sheet flow runoff will
surface flow off the parking lot and down the rain garden slope (maximum 4:1) to a sediment forebay
proposed along the length of the bottom of the Rain Garden. Rain Garden C is designed with maximum 4:1
side slopes to the berm between the rain garden and I-25 Frontage Road. An underdrain is proposed along
the length of the rain garden. The underdrain will connect to the overflow inlet. A proposed CDOT Type D
inlet will convey flows greater than the WQCV to the proposed storm system and ultimately the detention
pond. Inlet calculations indicate that water will pond 0.6 feet in order to capture the 100-year flow rate in
the Type D inlet. Final design details of the rain garden are provided in the Construction Documents and
summarized in Table 5 below.
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Table 5. Rain Garden C design data.
Calculated WQCV 3,264 cubic feet
Required Flat Surface Area 2,087 square feet
Provided Flat Surface Area 5,731 square feet
Provided Volume 7,732 cubic feet
Top of Media Elevation 4952.00
WQCV Ponding Depth 12 inches
WQCV Ponding Elevation (Rim of Inlets)4953.00
100-Year Ponding Depth 0.60 feet
Top of Berm (between rain garden and ROW)4957.00
Maintenance: Maintenance access of Rain Garden C is provided via the adjacent parking lot along the west
side of the rain garden. Two cleanouts are provided for the underdrain. A drainage easement has been
provided around the Rain Garden.
Overflow: In the case in which the outlet inlet become clogged water will pond within the Rain Garden to an
elevation of 4953.70 (2.4 feet below FFE) before spilling over the sidewalk at the south side of the Rain
Garden and flowing south into Redman Drive and the I-25 Frontage Road.
Detention Pond
A detention pond is proposed to detain site flows from the 100-year storm event to the 2-year historic
release rate. Due to Site constraints, the inflow pipe to the pond is proposed with an “inflow infiltration
basin”. The bottom elevation of the inflow basin will be approximately 4.5-feet below the bottom of the pond.
In addition to the “inflow infiltration basin” being sized to drain it’s volume in 40 hours via infiltration, and 36”
diameter dry well is proposed within the “inflow infiltration basin”. Table 6 summarizes the pond bottom
elevation, “inflow infiltration basin” elevation, dry well elevations, and groundwater elevation in the
approximate location of the pond (boring B-17) as shown in the Draft Geotechnical Evaluation prepared by
Ninyo & Moore, dated July 2, 2019, included in Appendix E for reference.
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
13
Table 6. Comparison of pond elevations and groundwater elevation.
Finished Floor Elevation 4956.10
Pond Crest of Spillway Elevation 4952.00
100-Year Water Surface Elevation 4952.00
Pond Bottom Elevation at Outlet Structure 4949.00
“Inflow Infiltration Basin” Bottom Elevation 4944.50
“Inflow Infiltration Basin” Flat Bottom Area 353 FT2
Depth of Infiltration Rock 1-FT
Percolation Rate of Native Soil 30 min/in (2 in/hr)
“Inflow Infiltration Basin” Volume 5,082 FT3
Top of Gravel in Dry Well 4943.50
Invert of Underdrains into Dry Well 4943.00
Top of Perforated Dry Well Pipe 4942.50
Approximate Groundwater Elevation 4942.001
Bottom of Dry Well Structure 4941.00
Elevation of SW Soil in Boring B-17 4938.00
Bottom of Perforated Dry Well Pipe 4936.00
1. Existing ground elevation at approximate location of boring B-17 is 4951.00. Groundwater was encountered
approximately 8-feet below existing ground surface.
The elevation of the bottom of the pond is set to allow positive drainage from the pond outlet to the existing
drainage ditch adjacent to the Site. The inflow infiltration basin has a total volume of 0.12 ac-ft (5,082 cubic
feet). The percolation rate, as measured by Ninyo & Moore in October 2019, within the detention pond area
is 30 mins/inch (2 in/hr). The flat area of the basin is 353 square feet, therefore, a basin volume of 2,353
cubic feet would be required to drain that surface area within 40 hours. As designed, the inflow infiltration
basin has a total volume of 5,082 cubic feet, which provides an extra volume of 2,729 cubic feet above the
required volume to infiltrate the surface area in 40 hours. The volume of the inflow infiltration basin is not
included in the total detention pond volume calculations.
Flows greater than the volume of the inflow infiltration basin will overtop the basin at the outflow trickle
channel and enter the detention pond, discharging via the outlet structure. The 2-foot wide concrete V trickle
channel conveys flows at 0.5% slope from the inflow infiltration basin to the outlet structure. One concrete
forebay is proposed where the Rain Garden A 100-year flow enters the pond. A concrete V trickle channel
14
conveys these flows to the inflow infiltration basin. The detention pond also includes a maintenance path
the length of the pond.
A modified CDOT Type D inlet is proposed to serve as the outlet structure for the detention pond. The
trickle channel is proposed to flow up to the base of the inlet. A 0.5-foot wide by 0.9-foot high square orifice
is proposed at the trickle channel flowline/bottom of structure on the outside face of the structure. A trash
rack is proposed over the orifice plate. The orifice is sized to release 3.40 CFS, which is the required 100-
year release rate. The top of the inlet is set at an elevation of 4951.00, allowing any ponded water into the
inlet. A second orifice plate over the outlet pipe with the same orifice dimensions is required to ensure the
100-year release rate is met. A 15-inch RCP storm pipe will convey flows from the outlet structure to the
existing roadside swale. The crest of the emergency overflow spillway is set at the 100-year water surface
elevation and 1.5-foot below the top of berm elevation. Spillway calculations provided in Appendix D
indicate that the undetained 100-year flow rate flowing over the spillway will pond 0.5 feet above the crest.
Maintenance of the detention pond is provided via a 12-foot gravel maintenance path accessible north of
the pond via mountable curb in the parking lot. A 10-foot grass maintenance path along the bottom of the
pond to allows access to the inflow infiltration basin and outlet structure. A drainage easement has been
provided around the detention pond.
Table 7. Detention Pond Summary Table
Approx. Bottom of Pond Elevation 4949.00
100-Year Orifice Open Area 0.45 SF
Top of Outlet Structure 4951.00
100-Year Water Surface Elevation 4952.00
Crest of Spillway Elevation 4952.00
Top of Berm Elevation 4953.50
Storm Sewer Conveyance
Storm sewer pipe is proposed to connect sub-basins A, B, C, and D to the detention pond. The main
stormline (rain garden C to detention pond) has been designed so that there is minimal ponding in the 100-
year storm event. The tailwater condition into the pond was set at an elevation of 4949.66, which is the
maximum ponding elevation with the inflow infiltration basin. This tailwater elevation causes minimal
surcharging to occur at the Rain Garden C inlet and Inlet D4, just downstream of Rain Garden C in the 100-
year storm event. Ponded water within Rain Garden C will pond to an elevation of 4953.70 (2.4 feet below
FFE) before overtopping the south sidewalk and flowing into Redman Drive and the I-25 Frontage Road. A
ponding depth above the inlet rim of 0.60 feet will occur. Ponded water at Inlet D4 will pond to an elevation
of 4955.42 (0.68 feet below FFE) before spilling over the berm at the southern property line and flow into
Redman Drive. A ponding depth of 2.42 feet above the rim of the inlet will occur before the berm if
overtopped.
Due to the required elevations within the loading dock area, ponding will occur within this area during the
100-year storm event. In addition to the HGL surcharging at all these locations, when the detention pond is
at the 100-year water surface elevation (4952.00), the water surface will equalize into this area. The
Preliminary Drainage Report
Mulberry Connection – Fort Collins, Colorado
15
maximum ponding depth in this area is 12-inches. Because of this ponding in the 100-year storm event,
only the 2-year storm event was modeled for the length of pipe within the truck court.
Inlet Capacity
The capacity of each proposed inlet was evaluated to determine the maximum ponding depth to convey
the 100-year storm event. The results of the capacity analysis indicate that the CDOT Type D inlets have
the capacity to collect contributing runoff with minimal ponding during the 100-year storm event.
Street Capacity
Two streets within the project limits were evaluated, private Redman Drive and public I-25 Frontage Road.
Redman Drive is an existing private street with a total width of 40 feet and a crown approximately 20-ft from
the proposed northern curb line. Redman Drive currently has no curb and gutter, with an existing swale
conveying runoff west to Cooper Slough. Curb and gutter and driveway valley gutters are proposed along
the north property frontage. Flows from Redman Drive (sub-basin OS-2) and a small portion of on-site
runoff (sub-basins O2 and O3) will be conveyed west via the proposed curb and gutter until the curb is
transitioned back to the existing roadside swale. The total flows to the north curb and gutter along Redman
Drive are 1.6 CFS and 7.9 CFS in the 2-year and 100-year storm events, respectively. These flows are a
sum of calculated flows from sub-basins OS-2, O2, and O3. The street capacity was evaluated using the
MHFD UD-Inlet spreadsheet. The results of the analysis indicate that water will spread 11-feet into Redman
Drive in the 2-year storm event, with 6-inches of ponding at the curb flowline. In the 100-year storm event
the north side of the street will not have capacity to convey the entire 100-year flows, therefore, the runoff
will overtop the crown and utilize both sides of the street. A ponding depth of 6.5-inches at the curb flowline
will result in a spread of 20.8 feet
The I-25 Frontage Road is a public roadway owned and maintained by CDOT. The below typical section
shows the ultimate cross-section of the roadway.
As shown in the figure above, the proposed condition will maintain the existing super-elevated condition of
the roadway, with runoff flowing east to west across the roadway. Sub-Basin OS-1 was delineated to
capture the entire portion of the I-25 Frontage Road adjacent to the on-site improvements. Approximately
16
2.4 CFS and 9.6 CFS of runoff is generated from sub-basin OS-1 in the 2-year and 100-year storm events,
respectively. On-site sub-basin O4 also flows to the I-25 Frontage Road. The total flows in the roadway are
2.5 CFS and 9.8 CFS in the 2-year and 100-year storm events, respectively. The UD-Inlet street capacity
analysis indicates that in the 2-year storm event flows will spread 8.5 feet from the flowline into the roadway,
which will occupy 0.5-feet into the travel lane. This spread results in 5-inches of ponding at the curb flowline.
In the 100-year storm event flows will spread 16-feet from the flowline into the roadway, which will occupy
8-feet of the travel lane. This spread results in 6-inches of ponding at the curb flowline.
VARIANCE REQUESTS
A variance is requested to allow the inflow infiltration basin within the detention pond. A separate variance
request will be submitted.
EROSION CONTROL
A separate Erosion Control Report will be provided in addition to this Final Drainage Report.
CONCLUSIONS
COMPLIANCE WITH STANDARDS
The Mulberry Connection project is in compliance with City of Fort Collins criteria for storm drainage design.
The “Fort Collins Stormwater Criteria Manual, December 2018 Edition,” and the Urban Drainage Flood
Control District “Urban Storm Drainage Criteria Manual Volumes 1, 2, and 3 have been utilized for
reference.
SUMMARY OF CONCEPT
The proposed drainage concept is to surface flow runoff from impervious areas to pervious area to the
extent practicable. Two rain gardens and one underground facility are proposed to treat the WQCV from as
much of the Site as possible. A detention pond is proposed to detain the on-site 100-year runoff volume to
the 2-year historic on-site flow. Downstream impacts due to the development of this Site are not anticipated.
REFERENCES
Fort Collins Stormwater Criteria Manual, December 2018 Edition, City of Fort Collins.
Urban Storm Drainage Criteria Manual, Volume 1-3, Urban Drainage and Flood Control District, Denver,
CO; January 2016, with latest revisions.
APPENDICES
A. NRCS Data and FEMA Map
B. Existing and Proposed Drainage Map
C. Hydrologic Calculations
D. Hydraulic Calculations
E. Reference Materials
17
APPENDIX A
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
Area, ColoradoNatural
Resources
Conservation
Service
August 15, 2019
6
Custom Soil Resource Report
Soil Map
44932804493330449338044934304493480449353044935804493280449333044933804493430449348044935304493580499430 499480 499530 499580 499630 499680 499730 499780 499830 499880
499430 499480 499530 499580 499630 499680 499730 499780 499830 499880
40° 35' 35'' N 105° 0' 25'' W40° 35' 35'' N105° 0' 4'' W40° 35' 24'' N
105° 0' 25'' W40° 35' 24'' N
105° 0' 4'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 100 200 400 600
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,260 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
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:
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 the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 13, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
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
7
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
40 Garrett loam, 0 to 1 percent
slopes
5.6 27.8%
53 Kim loam, 1 to 3 percent slopes 0.0 0.0%
63 Longmont clay, 0 to 3 percent
slopes
0.6 2.8%
73 Nunn clay loam, 0 to 1 percent
slopes
13.9 69.4%
76 Nunn clay loam, wet, 1 to 3
percent slopes
0.0 0.1%
Totals for Area of Interest 20.0 100.0%
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.
Custom Soil Resource Report
8
19
Custom Soil Resource Report
Map—Hydrologic Soil Group
44932804493330449338044934304493480449353044935804493280449333044933804493430449348044935304493580499430 499480 499530 499580 499630 499680 499730 499780 499830 499880
499430 499480 499530 499580 499630 499680 499730 499780 499830 499880
40° 35' 35'' N 105° 0' 25'' W40° 35' 35'' N105° 0' 4'' W40° 35' 24'' N
105° 0' 25'' W40° 35' 24'' N
105° 0' 4'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 100 200 400 600
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,260 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
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:
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 the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 13, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
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
20
Table—Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
40 Garrett loam, 0 to 1
percent slopes
B 5.6 27.8%
53 Kim loam, 1 to 3 percent
slopes
B 0.0 0.0%
63 Longmont clay, 0 to 3
percent slopes
D 0.6 2.8%
73 Nunn clay loam, 0 to 1
percent slopes
C 13.9 69.4%
76 Nunn clay loam, wet, 1 to
3 percent slopes
C 0.0 0.1%
Totals for Area of Interest 20.0 100.0%
Rating Options—Hydrologic Soil Group
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
21
PROJECT LOCATION
18
APPENDIX B
19
APPENDIX C
POUDRE VALLEY DEVELOPMENT DATE:1/18/2021
096501004
HMO
DLS
TYPE B/C SOIL
ASPHALT/
CONCRETE ROOFTOP
LAWNS, SANDY SOIL,
AVG SLOPE
LAND USE:AREA AREA AREA
2-YR RUNOFF COEFFICIENT 0.95 0.95 0.15
5-YR RUNOFF COEFFICIENT 0.95 0.95 0.15
100-YR RUNOFF COEFFICIENT 1.19 1.19 0.19
IMPERVIOUS %100%90%2%
ASPHALT/
CONCRETE ROOFTOP
LAWNS, SANDY SOIL,
AVG SLOPE TOTAL
DESIGN DESIGN AREA AREA AREA AREA
BASIN POINT (AC)(AC)(AC)(AC)Cc(2)Cc(5)Cc(100)Imp %
EX1 EX1 0.00 0.00 13.23 13.23 0.15 0.15 0.19 2%
EX2 EX2 0.23 0.00 0.32 0.55 0.48 0.48 0.60 42%
EX3 EX3 0.50 0.00 0.46 0.96 0.57 0.57 0.71 53%
A A 1.50 2.15 1.76 5.39 0.69 0.69 0.87 64%
B1 B1 1.52 0.00 0.20 1.72 0.86 0.86 1.00 89%
B2 B2 1.13 0.00 0.13 1.27 0.87 0.87 1.00 90%
C C 0.91 1.63 1.09 3.63 0.71 0.71 0.89 66%
D1 D1 0.04 0.00 0.12 0.16 0.35 0.35 0.44 27%
D2 D2 0.02 0.00 0.11 0.14 0.29 0.29 0.36 19%
O1 O1 0.00 0.00 0.52 0.52 0.15 0.15 0.19 2%
O2 O2 0.03 0.00 0.04 0.07 0.50 0.50 0.62 44%
O3 O3 0.02 0.00 0.01 0.03 0.58 0.58 0.72 55%
O4 O4 0.00 0.00 0.14 0.14 0.15 0.15 0.19 2%
TOTAL ON-SITE 13.07 0.70 0.70 0.86 66%
TOTAL TO DETENTION (A+B+C+D)12.31 0.73 0.73 0.89 70%
TOTAL TO LID BMP (A+B+C)12.01 0.74 0.74 0.91 71%
TOTAL TO WQ IN POND (D)0.30 0.32 0.32 0.40 23%
TOTAL OFFSITE NON-LANDSCAPE (O2+O3)0.10 0.52 0.52 0.65 47%
TOTAL OFFSITE LANDSCAPE ONLY (O1+O4)0.66 0.15 0.15 0.19 2%
OS1 OS1 0.88 0.00 0.08 0.96 0.88 0.88 1.00 92%
OS2 OS2 0.55 0.00 0.41 0.96 0.60 0.60 0.76 58%
* NOTE: O1-O4 DO NOT CONTRIBUTE TO THE PROPOSED WATER QUALITY TREATMENT AND DETENTION POND.
CHECKED BY:
PROJECT NUMBER:
CALCULATED BY:
NOTE: C2-YR*1.00 PER FCSCM TABLE 3-2-3
OFF-SITE BASINS
ON-SITE BASINS
RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION
PROJECT NAME:
COMPOSITE RUNOFF
COEFFICIENT
NOTE: C2-YR*1.25 PER FCSCM TABLE 3-2-3
EXISTING BASINS
POUDRE VALLEY DEVELOPMENT DATE: 1/18/2021
096501004
HMO
DLS
FINAL
Tc
DESIGN AREA C2 LENGTH SLOPE Ti LENGTH SLOPE n R VEL Tt MAX Tc MIN Tc
BASIN Ac Ft %Min.Ft.%fps Min.Min.Min.Min.Min.
EX1 13.23 0.15 500 0.6%46.1 600 0.6%0.032 0.654 2.8 3.6 49.7 12.8 5.0 12.8
EX2 0.55 0.48 62 0.4%12.2 560 1.0%0.032 0.654 3.5 2.7 14.9 10.3 5.0 10.3
EX3 0.96 0.57 75 3.0%6.0 465 0.6%0.032 0.654 2.8 2.8 8.8 10.4 5.0 8.8
A 5.39 0.69 215 1.0%11.2 185 2.0%0.013 0.195 5.5 0.6 11.2 11.2 5.0 11.2
B1 1.72 0.86 200 2.0%5.1 239 0.6%0.013 0.195 3.0 1.3 5.1 11.1 5.0 5.1
B2 1.27 0.87 117 1.0%4.7 0.013 0.195 --4.7 10.7 6.0 6.0
C 3.63 0.71 240 2.5%8.3 430 0.5%0.013 0.195 2.7 2.6 8.3 11.3 5.0 8.3
D1 0.16 0.35 80 0.7%14.1 0.013 0.195 --14.1 10.4 5.0 10.4
D2 0.14 0.29 78 1.0%13.4 0.013 0.195 --13.4 10.4 5.0 10.4
O1 0.52 0.15 15 25.0%2.4 0.013 0.195 --2.4 10.1 5.0 5.0
O2 0.07 0.50 40 5.0%4.2 0.013 0.195 --4.2 10.2 5.0 5.0
O3 0.03 0.58 58 2.0%5.9 0.013 0.195 --5.9 10.3 5.0 5.9
O4 0.14 0.15 12 20.0%2.3 0.013 0.195 --2.3 10.1 5.0 5.0
OS1 0.963 0.88 30 1.0%2.2 490 1.0%0.032 0.654 3.5 2.3 4.6 10.2 5.0 5.0
OS2 0.959 0.60 30 2.0%4.0 990 0.5%0.013 0.654 6.1 2.7 6.7 10.2 5.0 6.7
TIME OF CONCENTRATION
MAXIMUM & MINIMUM
TIME OF CONCENTRATION
PROJECT NAME:
PROJECT NUMBER:
DATA
INITIAL/OVERLAND
TIME (Ti)
CHANNELIZED TIME
(Tt)
SUB-BASIN
CALCULATED BY:
ON-SITE BASINS
CHECKED BY:
Tc
2-YEAR
OFF-SITE BASINS
EXISTING BASINS
ܶ =1.87(1.1 − ܥݔܥ )ܮܵయ ܶ =ܶ +ܶ௧ܸ=1.49݊ ܴ ଶ/ଷ ܵ ଵ/ଶ ܶ,௫ =ܮ180 +10
POUDRE VALLEY DEVELOPMENT DATE: 1/18/2021
096501004
HMO
DLS
FINAL
Tc
DESIGN AREA C100 LENGTH SLOPE Ti LENGTH SLOPE n R VEL Tt MAX Tc MIN Tc
BASIN Ac Ft %Min.Ft.%fps Min.Min.Min.Min.Min.
EX1 13.23 0.19 500 0.6%44.3 600 0.6%0.032 0.654 6.9 1.4 45.7 12.8 5.0 12.8
EX2 0.55 0.60 62 0.4%9.8 560 1.0%0.032 0.654 8.6 1.1 10.9 10.3 5.0 10.3
EX3 0.96 0.71 75 3.0%4.4 465 0.6%0.032 0.654 6.8 1.1 5.5 10.4 5.0 5.5
A 5.39 0.87 215 1.0%6.4 185 2.0%0.013 0.654 12.2 0.3 6.4 11.2 5.0 6.4
B1 1.72 1.00 200 2.0%2.1 239 0.6%0.013 0.654 6.7 0.6 2.1 11.1 5.0 5.0
B2 1.27 1.00 117 1.0%2.0 0.013 0.654 ######2.0 10.7 6.0 6.0
C 3.63 0.89 240 2.5%4.5 430 0.5%0.013 0.654 6.1 1.2 4.5 11.3 5.0 5.0
D1 0.16 0.44 80 0.7%12.5 0.013 0.654 ###### 12.5 10.4 5.0 10.4
D2 0.14 0.36 78 1.0%12.2 0.013 0.654 ###### 12.2 10.4 5.0 10.4
O1 0.52 0.19 15 25.0%2.3 0.013 0.654 ######2.3 10.1 5.0 5.0
O2 0.07 0.62 40 5.0%3.3 0.013 0.654 ######3.3 10.2 5.0 5.0
O3 0.03 0.72 58 2.0%4.2 0.013 0.654 ######4.2 10.3 5.0 5.0
O4 0.14 0.19 12 20.0%2.2 0.013 0.654 ######2.2 10.1 5.0 5.0
OS1 0.963 1.00 30 1.0%1.0 490 1.0%0.032 0.654 8.6 0.9 2.0 10.2 5.0 5.0
OS2 0.959 0.76 30 2.0%2.8 990 0.5%0.013 0.654 6.1 2.7 5.5 10.2 5.0 5.5
CHECKED BY:
TIME OF CONCENTRATION
100-YEAR
PROJECT NAME:
PROJECT NUMBER:
CALCULATED BY:
EXISTING BASINS
ON-SITE BASINS
OFF-SITE BASINS
SUB-BASIN INITIAL/OVERLAND CHANNELIZED TIME
Tc
MAXIMUM & MINIMUM
DATA TIME (Ti)(Tt)TIME OF CONCENTRATION
ܶ =1.87(1.1 − ܥݔܥ )ܮܵయ ܶ =ܶ +ܶ௧ܸ=1.49݊ ܴ ଶ/ଷ ܵ ଵ/ଶ ܶ,௫ =ܮ180 +10
PROJECT NAME:POUDRE VALLEY DEVELOPMENT DATE:
PROJECT NUMBER:096501004
CALCULATED BY:HMO
CHECKED BY:DLS
REMARKS
DESIGNPOINTDESIGNBASINAREA(AC)RUNOFFCOEFFC2tc(min)C*A(ac)I(in/hr)Q(cfs)tc(max)S(C*A)(ac)I(in/hr)Q(cfs)SLOPE(%)STREETFLOW(cfsDESIGNFLOW(cfs)SLOPE(%)PIPESIZE(in)LENGTH(ft)VELOCITYtt(min)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)
EX1 EX1 13.23 0.15 12.78 1.98 2.05 4.07
EX2 EX2 0.55 0.48 10.34 0.26 2.13 0.56
EX3 EX3 0.96 0.57 8.78 0.55 2.13 1.16
A A 5.39 0.69 11.18 3.73 2.13 7.95
B1 B1 1.72 0.86 5.07 1.47 2.85 4.20
B2 B2 1.27 0.87 6.00 1.10 2.67 2.93
C C 3.63 0.71 8.31 2.58 2.40 6.20
D1 D1 0.16 0.35 10.44 0.06 2.13 0.12
D2 D2 0.14 0.29 10.43 0.04 2.13 0.09
O1 O1 0.52 0.15 5.00 0.08 2.85 0.22
O2 O2 0.07 0.50 5.00 0.04 2.85 0.10
O3 O3 0.03 0.58 5.88 0.02 2.67 0.05
O4 O4 0.14 0.15 5.00 0.02 2.85 0.06
OS1 OS1 0.96 0.88 5.00 0.85 2.85 2.42
OS2 OS2 0.96 0.60 6.73 0.58 2.52 1.46
Note: Rainfall intensities are taken from Table 3.4-1 in the FCSCM. Time of concentration values have been rounded to the nearest minute.
ON-SITE BASINS
OFF-SITE BASINS
EXISTING BASINSSTORMLINE(1)
STANDARD FORM SF-3
STORM DRAINAGE DESIGN - RATIONAL METHOD 2 YEAR EVENT
1/18/2021
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME
PROJECT NAME:POUDRE VALLEY DEVELOPMENT DATE:
PROJECT NUMBER:096501004
CALCULATED BY:HMO
CHECKED BY:DLS
REMARKS
DESIGNPOINTDESIGNBASINAREA(AC)RUNOFFCOEFFC100tc(min)C*A(ac)I(in/hr)Q(cfs)tc(max)S(C*A)(ac)I(in/hr)Q(cfs)SLOPE(%)STREETFLOW(cfs)DESIGNFLOW(cfs)SLOPE(%)PIPESIZE(in)LENGTH(ft)VELOCITY(fps)tt(min)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)
EX1 EX1 13.23 0.19 12.78 2.48 6.92 17.17
EX2 EX2 0.55 0.60 10.34 0.33 7.72 2.55
EX3 EX3 0.96 0.71 5.52 0.68 7.72 5.28
A A 5.39 0.87 6.43 4.67 8.80 41.06
B1 B1 1.72 1.00 5.00 1.72 9.95 17.08
B2 B2 1.27 1.00 6.00 1.27 9.31 11.79
C C 3.63 0.89 5.00 3.23 9.95 32.11
D1 D1 0.16 0.44 10.44 0.07 7.72 0.54
D2 D2 0.14 0.36 10.43 0.05 7.42 0.37
O1 O1 0.52 0.19 5.00 0.10 9.95 0.97
O2 O2 0.07 0.62 5.00 0.05 9.95 0.45
O3 O3 0.03 0.72 5.00 0.02 9.95 0.22
O4 O4 0.14 0.19 5.00 0.03 9.95 0.26
OS1 OS1 0.96 1.00 5.00 0.96 9.95 9.58
OS2 OS2 0.96 0.76 5.50 0.72 9.95 7.21
Note: Rainfall intensities are taken from Table 3.4-1 in the FCSCM. Time of concentration values have been rounded to the nearest minute.
STANDARD FORM SF-3
STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT
1/18/2021
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME
STORMLINE(1)
EXISTING BASINS
ON-SITE BASINS
OFF-SITE BASINS
PROJECT NAME:POUDRE VALLEY DEVELOPMENT DATE: 1/18/2021
PROJECT NUMBER:096635000
CALCULATED BY:HMO
CHECKED BY:DLS
TOTAL
IMPERVIOUS AREA
IMPERVIOUS
AREA TREATED
(AC)(AC)Q2 Q100
EX1 EX1 13.23 0.00 0.00 4.07 17.17
EX2 EX2 0.55 0.00 0.00 0.56 2.55
EX3 EX3 0.96 0.00 0.00 1.16 5.28
14.74 0.00 0.00 5.80 24.99
A A 5.39 3.65 3.65 7.95 41.06
B1 B1 1.72 1.52 1.52 4.20 17.08
B2 B2 1.27 1.13 1.13 2.93 11.79
C C 3.63 2.55 2.55 6.20 32.11
D1 D1 0.16 0.04 0.04 0.12 0.54
D2 D2 0.14 0.02 0.02 0.09 0.37
O1 O1 0.52 0.00 0.00 0.22 0.97
O2 O2 0.07 0.03 0.00 0.10 0.45
O3 O3 0.03 0.02 0.00 0.05 0.22
O4 O4 0.14 0.00 0.00 0.06 0.26
13.07 8.96 --21.91 104.86
12.01 8.85 8.85 ----
0.30 0.06 0.06 ----
12.31 8.92 --21.48 102.95
OS1 OS1 0.96 0.88 0.00 2.42 9.58
OS2 OS2 0.96 0.55 0.00 1.46 7.21
1.92 1.43 0.00 3.89 16.79
ON-SITE BASINS
OFF-SITE BASINS
TOTAL
TOTAL
TOTAL
TOTAL ON-SITE TO DETENTION
TOTAL ON-SITE TO WQ TREATMENT (LID)
TOTAL ON-SITE TO WQ TREATMENT (POND)
EXISTING BASINS
DESIGN POINT
RATIONAL CALCULATIONS SUMMARY
TRIBUTARY BASINS TRIBUTARY AREA
(AC)
PEAK FLOWS (CFS)
20
APPENDIX D
Mulberry Connection
CM-D2
CM-B1
CM-D4
CM-C
CM-B2
CM-D3CM-D1
PIPE-04PIPE -08PIPE-17
PIPE -03 (1)
PIPE -03PIPE-17(1)
PIPE -30POND INFLOW FES
POND OUTFALL FES
DETENTION POND OUTLET STUCTURE
INLET D1
INLET B1
INLET B2
INLET D2 INLET D3 INLET D4 RAIN GARDEN C OUTLET STRUCTUREMH-1
ADS INLET MH
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11/20/2020
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Catch Basin Table
Mulberry Connection
Flow (Total Out)
(cfs)
Headloss
(ft)
Hydraulic Grade
Line (Out)
(ft)
Hydraulic Grade
Line (In)
(ft)
Elevation
(Invert)
(ft)
Elevation (Rim)
(ft)
Label
6.280.144,950.094,950.234,949.304,953.00RAIN GARDEN C
OUTLET STRUCTURE
5.830.134,949.174,949.304,948.414,953.25INLET D4
6.870.394,949.174,949.564,947.754,950.97INLET B2
5.170.144,951.104,951.244,948.954,951.88INLET B1
11.160.194,947.154,947.354,946.104,953.77INLET D1
3.400.004,949.764,949.764,949.004,951.00DETENTION POND
OUTLET STUCTURE
41.060.554,952.114,952.664,949.674,953.00RG A OUTLET
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StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Catchment Table
Mulberry Connection
Flow (Total Out)
(cfs)
Outflow ElementLabel
5.17INLET B1CM-B1
2.04INLET B2CM-B2
6.28
RAIN GARDEN C
OUTLET
STRUCTURE
CM-C
0.09INLET D4CM-D2
0.11INLET D1CM-D1
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StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Conduit Table
Mulberry Connection
Hydraulic
Grade Line
(Out)
(ft)
Hydraulic
Grade Line
(In)
(ft)
Capacity
(Full
Flow)
(cfs)
Velocit
y
(ft/s)
Flow
(cfs)
Manning's
n
Diameter
(in)
Slope
(Calculat
ed)
(ft/ft)
Length
(User
Defined)
(ft)
Invert
(Stop)
(ft)
Stop NodeInvert
(Start)
(ft)
Start NodeLabel
4,945.494,946.4947.055.4310.990.01336.00.005188.94,944.50
POND
INFLOW
FES
4,945.44MH-1PIPE -05
4,946.724,947.1547.345.4711.160.01336.00.005130.24,945.44MH-14,946.10INLET D1PIPE -17
(1)
4,947.354,947.9547.155.4711.260.01336.00.005158.94,946.10INLET D14,946.89MH-D2PIPE -17
4,949.304,950.0947.284.646.280.01336.00.005177.14,948.41INLET D44,949.30
RAIN
GARDEN C
OUTLET
STRUCTURE
PIPE -08
4,948.234,948.5216.004.896.830.01324.00.005140.44,946.89MH-D24,947.59ADS INLET
MHPIPE -27
4,949.524,949.764.914.323.400.01315.00.00638.04,948.78
POND
OUTFALL
FES
4,949.00
DETENTION
POND
OUTLET
STUCTURE
PIPE -04
4,949.564,951.104.584.225.170.01315.00.005239.04,947.75INLET B24,948.95INLET B1PIPE -31
4,948.804,949.174.545.606.870.01315.00.00532.44,947.59ADS INLET
MH4,947.75INLET B2PIPE -30
4,948.234,949.1749.104.675.830.01336.00.005203.04,947.31MH-D24,948.41INLET D4PIPE-09
4,951.704,952.1129.008.3641.060.01330.00.00524.04,949.55RG POND
INFLOW4,949.67RG A
OUTLETCO-3
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StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Manhole Table
Mulberry Connection
Headloss
(ft)
Hydraulic Grade
Line (In)
(ft)
Hydraulic Grade
Line (Out)
(ft)
Flow (Total Out)
(cfs)
Elevation
(Invert)
(ft)
Elevation (Rim)
(ft)
Label
0.234,946.724,946.4910.994,945.444,953.88MH-1
0.294,948.804,948.526.834,947.594,951.36ADS INLET MH
0.274,948.234,947.9511.264,946.894,953.42MH-D2
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Outfall Table
Mulberry Connection
System Rational
Flow
(cfs)
System
Additional Flow
(cfs)
Boundary Condition TypeHydraulic Grade
(ft)
Elevation
(Invert)
(ft)
Elevation
(Ground)
(ft)
Label
0.003.40Free Outfall4,949.524,948.784,948.78POND OUTFALL
FES
10.770.00Free Outfall4,945.494,944.504,948.33POND INFLOW
FES
0.0041.06Free Outfall4,951.704,949.554,949.55RG POND
INFLOW
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/19/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
Profile Report
Engineering Profile - Mainline (Mulberry.stsw)
Mulberry Connection
4,940.00
4,945.00
4,950.00
4,955.00
-0+50 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+50 5+00 5+50 6+00 6+50 7+00 7+50 8+00 8+50 9+00
Station (ft)Elevation(ft)MH-1
Rim: 4,953.88 ft
Invert: 4,945.44 ft
HGL: 4,946.72 ft
MH-D2
Rim: 4,953.42 ft
Invert: 4,946.89 ft
HGL: 4,948.23 ft
INLET D1
Rim: 4,953.77 ft
Invert: 4,946.10 ft
HGL: 4,947.35 ft
INLET D4
Rim: 4,953.25 ft
Invert: 4,948.41 ft
HGL: 4,949.30 ft
RAIN GARDEN C OUTLET STRUCTURE
Rim: 4,953.00 ft
Invert: 4,949.30 ft
HGL: 4,950.23 ft
POND INFLOW FES
Rim: 4,948.33 ft
Invert: 4,944.50 ft
HGL: 4,945.49 ft
177.1 ft of 36.0in RCP@0.005 ft/ftFlow=6.28 cfsVelocity=4.64 ft/s 158.9 ft of 36.0in RCP@0.005 ft/ftFlow=11.26 cfsVelocity=5.47 ft/s
130.2 ft of 36.0in RCP@0.005 ft/ftFlow=11.16 cfsVelocity=5.47 ft/s
188.9 ft of 36.0in RCP@0.005 ft/ftFlow=10.99 cfsVelocity=5.43 ft/s
203.0 ft of 36.0in RCP@0.005 ft/ftFlow=5.83 cfsVelocity=4.67 ft/s
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
FlexTable: Outfall Table
Mulberry Connection
System Rational
Flow
(cfs)
System
Additional Flow
(cfs)
Boundary Condition TypeHydraulic Grade
(ft)
Elevation
(Invert)
(ft)
Elevation
(Ground)
(ft)
Label
0.003.40Free Outfall4,949.524,948.784,948.78POND OUTFALL
FES
10.770.00Free Outfall4,945.494,944.504,948.33POND INFLOW
FES
0.0041.06Free Outfall4,951.704,949.554,949.55RG POND
INFLOW
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 2-YR
Profile Report
Engineering Profile - Truck court to Mainline (Mulberry.stsw)
Mulberry Connection
4,945.00
4,950.00
4,955.00
-0+50 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+50
Station (ft)Elevation(ft)ADS INLET MH
Rim: 4,951.36 ft
Invert: 4,947.59 ft
HGL: 4,948.80 ft
MH-D2
Rim: 4,953.42 ft
Invert: 4,946.89 ft
HGL: 4,948.23 ft
INLET B1
Rim: 4,951.88 ft
Invert: 4,948.95 ft
HGL: 4,951.24 ft
INLET B2
Rim: 4,950.97 ft
Invert: 4,947.75 ft
HGL: 4,949.56 ft
239.0 ft of 15.0in RCP@0.005 ft/ftFlow=5.17 cfsVelocity=4.22 ft/s
140.4 ft of 24.0in RCP@0.005 ft/ftFlow=6.83 cfsVelocity=4.89 ft/s
32.4 ft of 15.0in RCP@0.005 ft/ftFlow=6.87 cfsVelocity=5.60 ft/s
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 100-YR
FlexTable: Catch Basin Table
Mulberry Connection
Flow (Total Out)
(cfs)
Headloss
(ft)
Hydraulic Grade
Line (Out)
(ft)
Hydraulic Grade
Line (In)
(ft)
Elevation
(Invert)
(ft)
Elevation (Rim)
(ft)
Label
32.400.164,953.004,953.164,949.304,953.00RAIN GARDEN C
OUTLET STRUCTURE
25.140.104,953.254,953.354,948.414,953.25INLET D4
28.066.504,950.974,957.474,947.754,950.97INLET B2
17.251.544,951.884,953.424,948.954,951.88INLET B1
46.170.334,951.564,951.894,946.104,953.77INLET D1
3.400.004,949.764,949.764,949.004,951.00DETENTION POND
OUTLET STUCTURE
41.060.544,952.244,952.794,949.674,953.00RG A OUTLET
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755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 100-YR
FlexTable: Catchment Table
Mulberry Connection
Flow (Total Out)
(cfs)
Outflow ElementLabel
17.25INLET B1CM-B1
11.92INLET B2CM-B2
32.40
RAIN GARDEN C
OUTLET
STRUCTURE
CM-C
0.39INLET D4CM-D2
0.54INLET D1CM-D1
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755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 100-YR
FlexTable: Conduit Table
Mulberry Connection
Hydraulic
Grade Line
(Out)
(ft)
Hydraulic
Grade Line
(In)
(ft)
Capacity
(Full
Flow)
(cfs)
Velocit
y
(ft/s)
Flow
(cfs)
Manning's
n
Diameter
(in)
Slope
(Calculat
ed)
(ft/ft)
Length
(User
Defined)
(ft)
Invert
(Stop)
(ft)
Stop NodeInvert
(Start)
(ft)
Start NodeLabel
4,949.664,950.5447.056.4645.630.01336.00.005188.94,944.50
POND
INFLOW
FES
4,945.44MH-1PIPE -05
4,950.934,951.5647.346.5346.170.01336.00.005130.24,945.44MH-14,946.10INLET D1PIPE -17
(1)
4,951.894,952.6647.156.5546.330.01336.00.005158.94,946.10INLET D14,946.89MH-D2PIPE -17
4,953.254,953.6747.284.5832.400.01336.00.005177.14,948.41INLET D44,949.30
RAIN
GARDEN C
OUTLET
STRUCTURE
PIPE -08
4,953.124,955.2816.008.9228.020.01324.00.005140.44,946.89MH-D24,947.59ADS INLET
MHPIPE -27
4,949.524,949.764.914.323.400.01315.00.00638.04,948.78
POND
OUTFALL
FES
4,949.00
DETENTION
POND
OUTLET
STUCTURE
PIPE -04
4,950.974,968.024.5814.0617.250.01315.00.005239.04,947.75INLET B24,948.95INLET B1PIPE -31
4,951.364,957.474.5422.8728.060.01315.00.00532.44,947.59ADS INLET
MH4,947.75INLET B2PIPE -30
4,953.124,953.4149.103.5625.140.01336.00.005203.04,947.31MH-D24,948.41INLET D4PIPE-09
4,952.004,952.2429.008.3641.060.01330.00.00524.04,949.55RG POND
INFLOW4,949.67RG A
OUTLETCO-3
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[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Note: this pipe is along the
truck court lateral. The design
storm event for this lateral is
the 2-year storm event.
Ponding in the truck court will
occur in the 100-year storm
event, therefore this velocity
does not accurately represent
the 100-year conditions.
Active Scenario: 100-YR
FlexTable: Manhole Table
Mulberry Connection
Headloss
(ft)
Hydraulic Grade
Line (In)
(ft)
Hydraulic Grade
Line (Out)
(ft)
Flow (Total Out)
(cfs)
Elevation
(Invert)
(ft)
Elevation (Rim)
(ft)
Label
0.394,950.934,950.5445.634,945.444,953.88MH-1
0.994,952.354,951.3628.024,947.594,951.36ADS INLET MH
0.474,953.124,952.6646.334,946.894,953.42MH-D2
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[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 100-YR
FlexTable: Outfall Table
Mulberry Connection
System Rational
Flow
(cfs)
System
Additional Flow
(cfs)
Elevation (User
Defined
Tailwater)
(ft)
Boundary Condition TypeHydraulic Grade
(ft)
Elevation
(Invert)
(ft)
Elevation
(Ground)
(ft)
Label
0.003.40Free Outfall4,949.524,948.784,948.78POND OUTFALL
FES
44.890.004,949.66User Defined Tailwater4,949.664,944.504,948.33POND INFLOW
FES
0.0041.064,952.00User Defined Tailwater4,952.004,949.554,949.55RG POND
INFLOW
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755-1666
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StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Elevation of top of
inflow infiltration basin
100-year WSEL in pond
Active Scenario: 100-YR
Profile Report
Engineering Profile - Mainline (Mulberry.stsw)
Mulberry Connection
4,940.00
4,945.00
4,950.00
4,955.00
-0+50 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+50 5+00 5+50 6+00 6+50 7+00 7+50 8+00 8+50 9+00
Station (ft)Elevation(ft)MH-1
Rim: 4,953.88 ft
Invert: 4,945.44 ft
HGL: 4,950.93 ft
MH-D2
Rim: 4,953.42 ft
Invert: 4,946.89 ft
HGL: 4,953.12 ft
INLET D1
Rim: 4,953.77 ft
Invert: 4,946.10 ft
HGL: 4,951.89 ft
INLET D4
Rim: 4,953.25 ft
Invert: 4,948.41 ft
HGL: 4,953.35 ft
RAIN GARDEN C OUTLET STRUCTURE
Rim: 4,953.00 ft
Invert: 4,949.30 ft
HGL: 4,953.16 ft
POND INFLOW FES
Rim: 4,948.33 ft
Invert: 4,944.50 ft
HGL: 4,949.66 ft
177.1 ft of 36.0in RCP@0.005 ft/ftFlow=32.40 cfsVelocity=4.58 ft/s 158.9 ft of 36.0in RCP@0.005 ft/ftFlow=46.33 cfsVelocity=6.55 ft/s
130.2 ft of 3 6.0in RCP@0.005 ft/ftFlow=46 .17 cfsVelocity=6.53 ft/s
188.9 ft of 36.0in RCP@0.005 ft/ftFlow=45.63 cfsVelocity=6.46 ft/s
203.0 ft of 36.0in RCP@0.005 ft/ftFlow=25.14 cfsVelocity=3.56 ft/s
Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-
755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Note: 100-year profile of truck
court storm line not provided as
design storm event for truck court
storm line is 2-year storm event.
Active Scenario: 100-YR
Profile Report
Engineering Profile - Outfall (Mulberry.stsw)
Mulberry Connection
4,945.00
4,950.00
4,955.00
-0+50 0+00 0+50
Station (ft)Elevation(ft)DETENTION POND OUTLET STUCTURE
Rim: 4,951.00 ft
Invert: 4,949.00 ft
HGL: 4,949.76 ft
POND OUTFALL FES
Rim: 4,948.78 ft
Invert: 4,948.78 ft
HGL: 4,949.52 ft
38.0 ft of 15.0in RCP@0.006 ft/ftFlow=3.40 cfsVelocity=4.32 ft/s
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755-1666
1/18/2021
StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Active Scenario: 100-YR
Profile Report
Engineering Profile - Rain Garden A (Mulberry.stsw)
Mulberry Connection
4,945.00
4,950.00
4,955.00
-0+50 0+00 0+50
Station (ft)Elevation(ft)RG A OUTLET
Rim: 4,953.00 ft
Invert: 4,949.67 ft
HGL: 4,952.79 ft
RG POND INFLOW
Rim: 4,949.55 ft
Invert: 4,949.55 ft
HGL: 4,952.00 ft
2 4 .0 f t o f 3 0 .0 i n R C P
@ 0 .0 0 5 f t /f t
F lo w =4 1 .0 6 c f s
V e l o c it y=8 .3 6 f t /s
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StormCAD
[10.02.03.03]Bentley Systems, Inc. Haestad Methods Solution CenterMulberry.stsw
Mulberry Connection
Fort Collins, CO
1/19/2021
Rain Garden A
CDOT Double Type D Close Mesh Grate
3.44' x 2.79'per grate
Area of Grate (sq ft)19.1952
Apply 70% for Grate Open Area 13.44
100-Yr Flow, Q =41.06 cfs
Area of Opening, A (Grate Area x Opening Ratio) =13.44 sf
Ponding, h =0.39 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =67.34 x h ^ 1/2
For h =0.39
Q intercepted, Qi =42.05 cfs
Q intercepted, Qi =42.05 > Q =41.06 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
Mulberry Connection
Fort Collins, CO
1/19/2021
Rain Garden C
CDOT Type D Close Mesh Grate
3.44' x 2.79'
Area of Grate (sq ft)9.5976
Apply 70% for Grate Open Area 6.72
100-Yr Flow, Q =32.11 cfs
Area of Opening, A (Grate Area x Opening Ratio) =6.72 sf
Ponding, h =0.60 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =41.76 x h ^ 1/2
For h =0.60
Q intercepted, Qi =32.35 cfs
Q intercepted, Qi =32.35 > Q =32.11 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
Mulberry Connection
Fort Collins, CO
1/19/2021
Inlet D1
CDOT Type D Close Mesh Grate
3.44' x 2.79'
Area of Grate (sq ft)9.5976
Apply 70% for Grate Open Area 6.72
100-Yr Flow, Q =0.54 cfs
Area of Opening, A (Grate Area x Opening Ratio) =6.72 sf
Ponding, h =0.02 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =7.62 x h ^ 1/2
For h =0.02
Q intercepted, Qi =1.08 cfs
Q intercepted, Qi =1.08 > Q =0.54 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
Mulberry Connection
Fort Collins, CO
1/19/2021
Inlet D4
CDOT Type D Close Mesh Grate
3.44' x 2.79'
Area of Grate (sq ft)9.5976
Apply 70% for Grate Open Area 6.72
100-Yr Flow, Q =0.37 cfs
Area of Opening, A (Grate Area x Opening Ratio) =6.72 sf
Ponding, h =0.02 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =7.62 x h ^ 1/2
For h =0.02
Q intercepted, Qi =1.08 cfs
Q intercepted, Qi =1.08 > Q =0.37 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
Mulberry Connection
Fort Collins, CO
1/19/2021
Inlet B1
CDOT Type 13 Inlet
3.27' x 1.88'
Area of Grate (sq ft)6.0912
Apply 70% for Grate Open Area 4.26
100-Yr Flow, Q =17.08 cfs
Area of Opening, A (Grate Area x Opening Ratio) =4.26 sf
Ponding, h =0.50 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =24.20 x h ^ 1/2
For h =0.50
Q intercepted, Qi =17.11 cfs
Q intercepted, Qi =17.11 > Q =17.08 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
Mulberry Connection
Fort Collins, CO
1/19/2021
Inlet B2
CDOT Type 13 Inlet
3.27' x 1.88'
Area of Grate (sq ft)6.0912
Apply 70% for Grate Open Area 4.26
100-Yr Flow, Q =11.79 cfs
Area of Opening, A (Grate Area x Opening Ratio) =4.26 sf
Ponding, h =0.35 ft
Q = CA ( 2gh ) ^ 1/2 =0.60 x A ( 2 x 32.2 ) ^ 1/2 x h ^1/2
Q =20.24 x h ^ 1/2
For h =0.35
Q intercepted, Qi =11.98 cfs
Q intercepted, Qi =11.98 > Q =11.79 cfs
GRATE CALCULATIONS
Pond
Grate Description:
Dimensions:
4582 S. Ulster Street - Suite 1500
Denver, Colorado 80237
Project:Mulberry Connection Prepared By:HMO
Project Number:096501004 Checked By:DLS
Date:18-Jan-21
Water Quality Capture Volume - Basin A
Contributing Basin Characteristics
Site Area =5.39 64%--
Hydrologic Soil Group A =
Hydrologic Soil Group B =
Hydrologic Soil Group C =
Hydrologic Soil Group D =
Water Quality Capture Volume
FCSCM Equation 7-1 WQ Watershed Inches = a*(0.91i3-1.19i2+.078i)
a12 = 0.8 (12-Hr Drain Time)
a40 = 1.0 (40-Hr Drain Time)
FCSCM Equation 7-2 WQCV = (WQCV/12)*(Area)*1.2
WQCV Impervious (Site) =64%
a =0.8
WQ Watershed Inches (Site) =0.200
WQCV Area (Site) =5.39
WQ Capture Volume (Site) =0.108 AC-FT
0.108 AC-FT
4,702 CU-FT
Area
(AC)
Impervious
(%)
Watershed Flow
Length (ft)
Watershed Flow
Slope (ft/ft)
Site WQ Volume
WQCV A (12hr) - 1/19/2021
4582 S. Ulster Street - Suite 1500
Denver, Colorado 80237
Project:Mulberry Connection Prepared By:HMO
Project Number:096501004 Checked By:DLS
Date:18-Jan-21
Water Quality Capture Volume - Basin B1 & B2
Contributing Basin Characteristics
Site Area =2.99 89%--
Hydrologic Soil Group A =
Hydrologic Soil Group B =
Hydrologic Soil Group C =
Hydrologic Soil Group D =
Water Quality Capture Volume
FCSCM Equation 7-1 WQ Watershed Inches = a*(0.91i3-1.19i2+.078i)
a12 = 0.8 (12-Hr Drain Time)
a40 = 1.0 (40-Hr Drain Time)
FCSCM Equation 7-2 WQCV = (WQCV/12)*(Area)*1.2
WQCV Impervious (Site) =89%
a =0.8
WQ Watershed Inches (Site) =0.314
WQCV Area (Site) =2.99
WQ Capture Volume (Site) =0.094 AC-FT
0.094 AC-FT
4,096 CU-FT
Site WQ Volume
Area
(AC)
Impervious
(%)
Watershed Flow
Length (ft)
Watershed Flow
Slope (ft/ft)
WQCV B (12hr) - 1/19/2021
4582 S. Ulster Street - Suite 1500
Denver, Colorado 80237
Project:Mulberry Connection Prepared By:HMO
Project Number:096501004 Checked By:DLS
Date:18-Jan-21
Water Quality Capture Volume - Basin C
Contributing Basin Characteristics
Site Area =3.63 66%--
Hydrologic Soil Group A =
Hydrologic Soil Group B =
Hydrologic Soil Group C =
Hydrologic Soil Group D =
Water Quality Capture Volume
FCSCM Equation 7-1 WQ Watershed Inches = a*(0.91i3-1.19i2+.078i)
a12 = 0.8 (12-Hr Drain Time)
a40 = 1.0 (40-Hr Drain Time)
FCSCM Equation 7-2 WQCV = (WQCV/12)*(Area)*1.2
WQCV Impervious (Site) =66%
a =0.8
WQ Watershed Inches (Site) =0.206
WQCV Area (Site) =3.63
WQ Capture Volume (Site) =0.075 AC-FT
0.075 AC-FT
3,264 CU-FT
Site WQ Volume
Area
(AC)
Impervious
(%)
Watershed Flow
Length (ft)
Watershed Flow
Slope (ft/ft)
WQCV C (12hr) - 1/19/2021
PROJECT NAME:Mulberry Connection
PROJECT NUMBER:096501004
CALCULATED BY:HMO
CHECKED BY:DLS 2-yr Historic Flow (EX1)4.07 CFS
DATE:1/18/2021 O2 100-yr Flow 0.45 CFS
O3 100-yr Flow 0.22 CFS
Allowed Release Rate 3.40 CFS
12.40
3.40
0.89
Duration, Td Rainfall Intensity, I Inflow Volume, Vi Outflow Volume, Vo Storage Volume, Vs Storage Volume, Vs
(min)(in/hr)(CF)(CF)(CF)(AC-FT)
5 9.95 32942 1020 31922 0.73
10 7.72 51119 2040 49079 1.13
15 6.52 64759 3060 61699 1.42
20 5.60 74162 4080 70082 1.61
25 4.98 82439 5100 77339 1.78
30 4.52 89789 6120 83669 1.92
35 4.08 94556 7140 87416 2.01
40 3.74 99059 8160 90899 2.09
45 3.46 103098 9180 93918 2.16
50 3.23 106939 10200 96739 2.22
55 3.03 110349 11220 99129 2.28
60 2.86 113627 12240 101387 2.33
65 2.71 116639 13260 103379 2.37
70 2.59 120050 14280 105770 2.43
75 2.48 123162 15300 107862 2.48
80 2.38 126075 16320 109755 2.52
85 2.29 128889 17340 111549 2.56
90 2.21 131704 18360 113344 2.60
95 2.13 133988 19380 114608 2.63
100 2.06 136405 20400 116005 2.66
105 2.00 139054 21420 117634 2.70
110 1.94 141305 22440 118865 2.73
115 1.88 143159 23460 119699 2.75
120 1.84 146205 24480 121725 2.79
ALLOWED RELEASE RATE CALCULATION
Release Rate (R)'
100-Year Runoff Coefficient (C)'
CALCULATIONS
cfs (Historic 2-yr flow)
Composite of entire proposed area
MODIFIED FAA DETENTION SIZING
DETENTION BASIN
Area (A)
DETENTION VOLUME BY MODIFIED FAA METHOD - 100 YEAR
acres (Basins A, B, C, & D)
PROJECT NAME:
PROJECT NUMBER:096755001
CALCULATED BY:HMO
CHECKED BY:DLS
DATE:1/18/2021
Volume = (D/3)(A + B + (AB)^(1/2))D=depth between two contours, ft
A=area of bottom contour, SF; B=area of top contour, SF
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.)(CU FT)(CU FT)(AC-FT)
4949.1 747 0 0 0.00
4949.2 4,793 248 248 0.01
4949.3 8,422 652 900 0.02
4949.4 11,741 1,004 1,904 0.04
4949.5 14,816 1,325 3,229 0.07
4949.6 17,737 1,625 4,854 0.11
4949.7 23,738 2,066 6,920 0.16
4949.8 26,581 2,515 9,435 0.22
4949.9 29,289 2,792 12,227 0.28
4950 32,975 3,111 15,339 0.35
4950.1 35,432 3,420 18,758 0.43
4950.2 38,080 3,675 22,433 0.51
4950.3 40,387 3,923 26,356 0.61
4950.4 42,406 4,139 30,495 0.70
4950.5 43,663 8,403 34,759 0.80
4950.6 44,662 8,706 39,201 0.90
4950.7 45,492 8,915 43,674 1.00
4950.8 46,174 9,083 48,284 1.11
4950.9 46,777 9,227 52,900 1.21
4951 47,293 9,347 57,631 1.32
4951.1 47,739 9,451 62,352 1.43
4951.2 48,160 9,545 67,176 1.54
4951.3 48,572 9,631 71,983 1.65
4951.4 48,985 9,714 76,891 1.77
4951.5 49,400 9,797 81,780 1.88
4951.6 49,816 9,880 86,771 1.99
4951.7 50,235 9,963 91,743 2.11
4951.8 50,655 10,047 96,818 2.22
4951.9 51,077 10,131 101,874 2.34
4952 51,739 10,239 107,057 2.46
STAGE-STORAGE ANALYSIS
Detention Pond
DETENTION BASIN
PROJECT NAME:Detention Pond
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.)(CU FT)(CU FT)(AC-FT)
4951 26 0 0 0.00
4951.1 499 21 21 0.00
4951.2 1,636 101 123 0.00
4951.3 3,565 254 376 0.01
4951.4 6,407 492 868 0.02
4951.5 10,145 820 1,689 0.04
4951.6 14,959 1,247 2,936 0.07
4951.7 21,150 1,797 4,733 0.11
4951.8 29,024 2,498 7,231 0.17
4951.9 38,735 3,376 10,607 0.24
4952 49,359 4,394 15,001 0.34
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.)(CU FT)(CU FT)(AC-FT)
4949.1 747 0 0 0.00
4949.2 4,793 248 248 0.01
4949.3 8,422 652 900 0.02
4949.4 11,741 1,004 1,904 0.04
4949.5 14,816 1,325 3,229 0.07
4949.6 17,737 1,625 4,854 0.11
4949.7 23,738 2,066 6,920 0.16
4949.8 26,581 2,515 9,435 0.22
4949.9 29,289 2,792 12,227 0.28
4950 32,975 3,111 15,339 0.35
4950.1 35,432 3,420 18,758 0.43
4950.2 38,080 3,675 22,433 0.51
4950.3 40,387 3,923 26,356 0.61
4950.4 42,406 4,139 30,495 0.70
4950.5 43,663 4,303 34,799 0.80
4950.6 44,662 4,416 39,215 0.90
4950.7 45,492 4,508 43,722 1.00
4950.8 46,174 4,583 48,306 1.11
4950.9 46,777 4,648 52,953 1.22
4951 47,319 4,705 57,658 1.32
4951.1 48,238 4,778 62,436 1.43
4951.2 49,796 4,902 67,337 1.55
4951.3 52,137 5,096 72,434 1.66
4951.4 55,392 5,376 77,809 1.79
4951.5 59,545 5,746 83,555 1.92
4951.6 64,775 6,214 89,769 2.06
4951.7 71,385 6,805 96,574 2.22
4951.8 79,679 7,549 104,124 2.39
4951.9 89,812 8,470 112,593 2.58
4952 101,098 9,540 122,133 2.80 100-YR (2.79 AC-FT) = 4952.00
PARKING LOT PONDING
COMBINED VOLUMES
PROJECT NAME:
PROJECT NUMBER:096755001
CALCULATED BY:HMO
CHECKED BY:DLS
DATE:1/18/2021
Volume = (D/3)(A + B + (AB)^(1/2))D=depth between two contours, ft
A=area of bottom contour, SF; B=area of top contour, SF
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.) (CU FT)(CU FT)(AC-FT)
4952 522 0 0 0.00 TOP OF MEDIA = 4952
4952.2 929 143 143 0.00
4952.4 1,132 206 349 0.01
4952.6 1,341 247 596 0.01
4952.8 1,558 290 886 0.02
4953 1,783 334 1,220 0.03 RIM OF INLET = 4953
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.) (CU FT)(CU FT)(AC-FT)
4952 2,508 0 0 0.00 TOP OF MEDIA = 4952
4952.2 3,409 589 589 0.01
4952.4 3,797 720 1,310 0.03
4952.6 4,160 795 2,105 0.05
4952.8 4,508 867 2,972 0.07
4953 4,849 935 3,907 0.09 RIM OF INLET = 4953
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.) (CU FT)(CU FT)(AC-FT)
4952 3,030 0 0 0.00
4952.2 4,339 733 733 0.02
4952.4 4,929 926 1,659 0.04
4952.6 5,502 1,043 2,702 0.06
4952.8 6,066 1,156 3,858 0.09
4953 6,632 1,269 5,127 0.12 REQUIRED WQCV = 4,702 cubic foot
RAIN GARDEN A - SOUTH
RAIN GARDEN A - COMBINED
STAGE-STORAGE ANALYSIS
BASIN A
RAIN GARDEN A - NORTH
PROJECT NAME:
PROJECT NUMBER:096755001
CALCULATED BY:HMO
CHECKED BY:DLS
DATE:1/18/2021
Volume = (D/3)(A + B + (AB)^(1/2))D=depth between two contours, ft
A=area of bottom contour, SF; B=area of top contour, SF
ELEV.AREA VOLUME ACCUM. VOL.ACCUM. VOL.
(FT)(SQ FT.) (CU FT)(CU FT)(AC-FT)
4952 5,731 0 0 0.00
4952.2 6,411 1,214 1,214 0.03
4952.4 7,117 1,352 2,566 0.06
4952.6 7,892 1,500 4,066 0.09
4952.8 8,769 1,665 5,731 0.13
4953 9,733 1,849 7,581 0.17 RIM OF INLET = 4953; REQUIRED WQCV = 3,264 CF
STAGE-STORAGE ANALYSIS
Rain Garden C
RAINGARDEN C
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =64.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.640
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV =0.20 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area)Area = 234,788 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region,VWQCV OTHER =cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =4,702 cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical)Z =4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =3005 sq ft
D) Actual Flat Surface Area AActual =3030 sq ft
E) Area at Design Depth (Top Surface Area)ATop =6632 sq ft
F) Rain Garden Total Volume VT=4,831 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =2.3 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =4,702 cu ft
iii) Orifice Diameter, 3/8" Minimum DO =1 9/16 in
Design Procedure Form: Rain Garden (RG)
HMO
Kimley-Horn
January 20, 2021
Mulberry Connection - Basin A
Fort Collins, CO
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.07 A.xlsm, RG 1/20/2021, 12:04 PM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
NO SPRINKLER HEADS ON FLAT SURFACE
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
HMO
Kimley-Horn
January 20, 2021
Mulberry Connection - Basin A
Fort Collins, CO
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.07 A.xlsm, RG 1/20/2021, 12:04 PM
Sheet 1 of 2
Designer:
Company:
Date:
Project:
Location:
1. Basin Storage Volume
A) Effective Imperviousness of Tributary Area, Ia Ia =66.0 %
(100% if all paved and roofed areas upstream of rain garden)
B) Tributary Area's Imperviousness Ratio (i = Ia/100)i =0.660
C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV =0.21 watershed inches
(WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i)
D) Contributing Watershed Area (including rain garden area)Area = 158,123 sq ft
E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft
Vol = (WQCV / 12) * Area
F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in
Average Runoff Producing Storm
G) For Watersheds Outside of the Denver Region,VWQCV OTHER =cu ft
Water Quality Capture Volume (WQCV) Design Volume
H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =3,264 cu ft
(Only if a different WQCV Design Volume is desired)
2. Basin Geometry
A) WQCV Depth (12-inch maximum)DWQCV =12 in
B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical)Z =4.00 ft / ft
(Use "0" if rain garden has vertical walls)
C) Mimimum Flat Surface Area AMin =2087 sq ft
D) Actual Flat Surface Area AActual =5731 sq ft
E) Area at Design Depth (Top Surface Area)ATop =9733 sq ft
F) Rain Garden Total Volume VT=7,732 cu ft
(VT= ((ATop + AActual) / 2) * Depth)
3. Growing Media
4. Underdrain System
A) Are underdrains provided?1
B) Underdrain system orifice diameter for 12 hour drain time
i) Distance From Lowest Elevation of the Storage y =2.3 ft
Volume to the Center of the Orifice
ii) Volume to Drain in 12 Hours Vol12 =3,264 cu ft
iii) Orifice Diameter, 3/8" Minimum DO =1 1/4 in
Design Procedure Form: Rain Garden (RG)
HMO
Kimley-Horn
January 18, 2021
Mulberry Connection - Basin C
Fort Collins, CO
UD-BMP (Version 3.07, March 2018)
Choose One
Choose One
18" Rain Garden Growing Media
Other (Explain):
YES
NO
UD-BMP_v3.07 C.xlsm, RG 1/18/2021, 9:42 PM
Sheet 2 of 2
Designer:
Company:
Date:
Project:
Location:
5. Impermeable Geomembrane Liner and Geotextile Separator Fabric
A) Is an impermeable liner provided due to proximity
of structures or groundwater contamination?
6. Inlet / Outlet Control
A) Inlet Control
7. Vegetation
8. Irrigation
NO SPRINKLER HEADS ON FLAT SURFACE
A) Will the rain garden be irrigated?
Notes:
Design Procedure Form: Rain Garden (RG)
HMO
Kimley-Horn
January 18, 2021
Mulberry Connection - Basin C
Fort Collins, CO
Choose One
Choose One
Choose One
Sheet Flow- No Energy Dissipation Required
Concentrated Flow- Energy Dissipation Provided
Plantings
Seed (Plan for frequent weed control)
Sand Grown or Other High Infiltration Sod
Choose One
YES
NO
YES
NO
UD-BMP_v3.07 C.xlsm, RG 1/18/2021, 9:42 PM
Project:
Chamber Model -SC-740
Units -Imperial
Number of chambers -55
Voids in the stone (porosity) -40 %
Base of Stone Elevation -0.00 ft
Amount of Stone Above Chambers -6 in
Amount of Stone Below Chambers -6 in
Area of system -2197 sf Min. Area -
Height of
System
Incremental Single
Chamber
Incremental
Total Chamber
Incremental
Stone
Incremental Ch
& St
Cumulative
Chamber Elevation
(inches)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(feet)
42 0.00 0.00 73.23 73.23 4592.18 3.50
41 0.00 0.00 73.23 73.23 4518.94 3.42
40 0.00 0.00 73.23 73.23 4445.71 3.33
39 0.00 0.00 73.23 73.23 4372.48 3.25
38 0.00 0.00 73.23 73.23 4299.24 3.17
37 0.00 0.00 73.23 73.23 4226.01 3.08
36 0.05 3.02 72.02 75.05 4152.78 3.00
35 0.16 8.96 69.65 78.61 4077.73 2.92
34 0.28 15.51 67.03 82.54 3999.12 2.83
33 0.60 33.22 59.95 93.16 3916.58 2.75
32 0.80 44.09 55.60 99.69 3823.42 2.67
31 0.95 52.29 52.32 104.61 3723.73 2.58
30 1.07 59.10 49.59 108.69 3619.12 2.50
29 1.18 64.93 47.26 112.19 3510.43 2.42
28 1.27 69.61 45.39 115.00 3398.24 2.33
27 1.36 74.53 43.42 117.95 3283.24 2.25
26 1.45 79.98 41.24 121.22 3165.29 2.17
25 1.52 83.86 39.69 123.55 3044.07 2.08
24 1.58 87.03 38.42 125.45 2920.52 2.00
23 1.64 90.33 37.10 127.43 2795.07 1.92
22 1.70 93.47 35.84 129.32 2667.65 1.83
21 1.75 96.41 34.67 131.08 2538.33 1.75
20 1.80 99.15 33.57 132.73 2407.25 1.67
19 1.85 102.02 32.42 134.45 2274.52 1.58
18 1.89 104.12 31.59 135.71 2140.07 1.50
17 1.93 106.37 30.69 137.06 2004.37 1.42
16 1.97 108.62 29.78 138.41 1867.31 1.33
15 2.01 110.55 29.02 139.56 1728.90 1.25
14 2.04 112.47 28.24 140.72 1589.34 1.17
13 2.07 114.12 27.58 141.71 1448.63 1.08
12 2.10 115.77 26.93 142.70 1306.92 1.00
11 2.13 117.25 26.33 143.58 1164.22 0.92
10 2.15 118.46 25.85 144.31 1020.64 0.83
9 2.18 119.74 25.34 145.08 876.33 0.75
8 2.20 120.91 24.87 145.78 731.25 0.67
7 2.21 121.40 24.67 146.08 585.48 0.58
6 0.00 0.00 73.23 73.23 439.40 0.50
5 0.00 0.00 73.23 73.23 366.17 0.42
4 0.00 0.00 73.23 73.23 292.93 0.33
3 0.00 0.00 73.23 73.23 219.70 0.25
2 0.00 0.00 73.23 73.23 146.47 0.17
1 0.00 0.00 73.23 73.23 73.23 0.08
StormTech SC-740 Cumulative Storage Volumes
1859 sf min. area
Include Perimeter Stone in Calculations
Click Here for Metric
Vault ID
Total Required
WQ Volume (cf)
Flow, WQ
(cfs)i Chamber Type
Chamber Release
Ratea (cfs)
Chamber
Volumeb (cf)
Installed Chamber w/
Aggregatec (cf)
Minimum No. of
Chambersd
Total Release
Ratee (cfs)
Required Storage Volume by
FAA Method (cf)j
Minimum No. of
Chambersf
Storage Provided within
the Chambersg (cf)
Total Installed System
Volumeh (cf)
1 4071 3.57 SC-740 0.023586 45.9 74.9 55 1.30 1004 22 2524.50 4119.50
a. Release rate per chamber, limited by flow through geotextile with accumulated sediment.
b. Volume within chamber only, not accounting for void spaces in surrounding aggregate.
c. Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit.
d. Number of chambers required to provide full WQCV within total installed system, including aggregate rounded up to nearest whole number
e. Release rate per chamber times number of chambers.
f. Number of chambers required to provide required FAA storage volume stored within the chamber only (no aggregate storage).
g. Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume.
h. System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required WQCV.
i. Assumed 1/2 of the 2-year storm event to calculate water quality flow.
j. Assumed the 2-year storm event for intesity values in calculating storage volume by FAA method.
Chamber Configuration Summary
PROJECT NAME:Mulberry Connection
PROJECT NUMBER:096501004
CALCULATED BY:HMO
CHECKED BY:DLS
DATE:12/11/2020
3
1.297
0.86
Duration, Td Rainfall Intensity, I Inflow Volume, Vi Outflow Volume, Vo Storage Volume, Vs Storage Volume, Vs
(min)(in/hr)(CF)(CF)(CF)(AC-FT)
5 1.43 1103 389 714 0.02
6 1.34 1240 467 773 0.02
7 1.26 1365 545 820 0.02
8 1.20 1486 623 863 0.02
9 1.15 1602 701 902 0.02
10 1.11 1711 778 932 0.02
11 1.07 1813 856 957 0.02
12 1.03 1904 934 970 0.02
13 0.99 1992 1012 980 0.02
14 0.96 2081 1090 991 0.02
15 0.94 2171 1168 1004 0.02
16 0.91 2242 1245 996 0.02
17 0.88 2303 1323 979 0.02
18 0.85 2368 1401 967 0.02
19 0.83 2426 1479 948 0.02
20 0.81 2492 1557 936 0.02
21 0.78 2536 1635 901 0.02
22 0.77 2605 1712 893 0.02
23 0.75 2652 1790 862 0.02
24 0.73 2712 1868 844 0.02
25 0.72 2767 1946 821 0.02
26 0.70 2817 2024 794 0.02
27 0.69 2863 2102 762 0.02
28 0.67 2904 2179 725 0.02
Area (A)acres (Basins B1 & B2)
MODIFIED FAA DETENTION SIZING
BASIN B WQCV
WATER QUALITY CONTROL VOLUME BY MODIFIED FAA METHOD
Release Rate (R)'cfs (Total Release Rate From Chamber)
2-Year Runoff Coefficient (C)'Composite of B1 & B2
CALCULATIONS
PROJECT NAME:MULBERRY CONNECTION
PROJECT NUMBER:096635000
CALCULATED BY:HMO
CHECKED BY:DLS
DATE:1/18/2021
102.95
2.75
115
0.48
105.17
143.10
0.5
0.50
105.67
TRAPEZOIDAL WEIR SIZING - SPILLWAY
Required 100-year Flow CFS
Rectangular Portion of Weir
V-Notch Portion of Weir
Provided Flow Over Rectangular Weir (Qw)CFS
Headwater Depth above Apex of Notch FT
Provided Flow Over V-Notch Weir (Qw)CFS
Total Provided Flow Over Trapezoidal Weir CFS
Angle of V-Notch Degrees
Weir Coefficient (Cw)
Horizontal Weir Length (L)FT
Headwater Depth above Weir Crest (Hw)FT
Detention Pond
SPILLWAY SIZING
Rating Table for Pond Outlet Orifice
Project Description
DischargeSolve For
Input Data
ft3.00Headwater Elevation
ft0.45Centroid Elevation
ft0.00Tailwater Elevation
0.600Discharge Coefficient
ft0.50Opening Width
ft0.9Opening Height
Velocity
(ft/s)
Discharge
(cfs)
Headwater Elevation
(ft)
(N/A)0.00
3.571.581.00
5.992.652.00
7.693.403.00
Page 1 of 127 Siemon Company Drive Suite 200 W
Watertown, CT 06795 USA +1-203-755-1666
1/19/2021
FlowMaster
[10.03.00.03]
Bentley Systems, Inc. Haestad Methods Solution
CenterMulberry Connection.fm8
Worksheet for Pond Outlet Orifice
Project Description
DischargeSolve For
Input Data
ft3.00Headwater Elevation
ft0.45Centroid Elevation
ft0.00Tailwater Elevation
0.600Discharge Coefficient
ft0.50Opening Width
ft0.9Opening Height
Results
cfs3.40Discharge
ft2.55Headwater Height Above
Centroid
ft-0.45Tailwater Height Above
Centroid
ft²0.4Flow Area
ft/s7.69Velocity
Page 1 of 127 Siemon Company Drive Suite 200 W
Watertown, CT 06795 USA +1-203-755-1666
1/19/2021
FlowMaster
[10.03.00.03]
Bentley Systems, Inc. Haestad Methods Solution
CenterMulberry Connection.fm8
.
Applicable Equations:
Lp = (1/2tanΘ)(At/Yt-W)
At = Q/V
Θ = tan-1(1/(2*ExpansionFactor))
T = 2(LptanΘ)+W
d50 = (0.023Q)/(Yt
1.2Dc
0.3)
Assumptions
Major event velocity is 5fps for non-cohesive soils and 7fps for erosion resistant soils.
Input parameters:
Description Variable Input Unit
Width of the conduit (use diameter for circular conduits),W (Dc):1.25 ft
HGL Elevation (assumed at centerline of pipe)4949.445 ft
Invert Elevation 4948.82 ft
Tailwater depth (ft),Yt:0.63 ft
Expansion angle of the culvert flow Θ:0.08 radians
Design discharge (cfs)Q:2.67 cfs
Froude Number F r 0.48 Subcritical
Unitless Variables for Tables:
For Figure 7.2-2 Q/D2.5 1.53
For Figure 9-35 Yt/D 0.50
For Figure 9-38 Q/WH1.5 1.91
For Figure 9-38 Yt/D 0.50
Allowable non-eroding velocity in the downstream channel (ft/sec)V:5 ft/sec
Expansion Factor (Figure 9-35), 1/(2tan(θ))6.5
Solve for:
Description Variable Output Unit
1. Required area of flow at allowable velocity (ft2)At:0.53 ft2
2. Length of Protection Lp:-2.57 ft
Lp < 3D?Yes
Lpmin:3.75 ft
3. Width of downstream riprap protection T:2.00 ft
Rip Rap Size
Mean Particle Size Intermediate Dimension (for subcritical flow only)d50 0.10 inches
Type from Figure 7.3-1 Type:L
Fort Collins Requirements:
d50 Minimum:12.00 inches
Type:M
Equation 9-14 per FCSCM
Rip-Rap Apron Calculation
Detention Pond 100-Year Outflow
Equation 9-10 per FCSCM
Equation 9-11 per FCSCM
Equation 9-12 per FCSCM
Equation 9-13 per FCSCM
Stormwater Facility Name:
Facility Location & Jurisdiction:
User Input: Watershed Characteristics User Defined User Defined User Defined User Defined
Watershed Slope =0.010 ft/ft Stage [ft]Area [ft^2]Stage [ft]Discharge [cfs]
Watershed Length =1000 ft 0.00 503 0.00 0.02
Watershed Area =12.31 acres 1.00 862 1.00 0.02
Watershed Imperviousness =70.0%percent 2.00 1,322 2.00 0.02
Percentage Hydrologic Soil Group A =0.0%percent 3.00 1,894 3.00 0.02
Percentage Hydrologic Soil Group B =100.0%percent 4.00 2,619 4.00 0.02
Percentage Hydrologic Soil Groups C/D =0.0%percent 5.00 31,274 5.00 1.58
6.00 47,292 6.00 2.65
User Input 17 7.00 51,508 7.00 3.40
8.00 55,516 8.00 104.86
WQCV Treatment Method =hours
After completing and printing this worksheet to a pdf, go to:
https://maperture.digitaldataservices.com/gvh/?viewer=cswdif
create a new stormwater facility, and
attach the pdf of this worksheet to that record.
Routed Hydrograph Results
Design Storm Return Period =WQCV 2 Year 5 Year 10 Year 50 Year 100 Year
One-Hour Rainfall Depth =0.53 0.86 1.14 1.44 2.40 2.93 in
Calculated Runoff Volume =0.572 0.797 1.094 2.062 2.640 acre-ft
OPTIONAL Override Runoff Volume =acre-ft
Inflow Hydrograph Volume =0.571 0.797 1.093 2.061 2.640 acre-ft
Time to Drain 97% of Inflow Volume =76.1 73.4 69.7 56.4 48.0 hours
Time to Drain 99% of Inflow Volume =83.0 83.1 83.0 81.3 80.0 hours
Maximum Ponding Depth =4.88 5.13 5.43 6.25 6.71 ft
Maximum Ponded Area =0.63 0.76 0.87 1.11 1.15 acres
Maximum Volume Stored =0.432 0.611 0.857 1.688 2.206 acre-ft
Location for 1-hr Rainfall Depths (use dropdown):
Workbook Protected Worksheet Protected
Stormwater Detention and Infiltration Design Data Sheet
Mulberry Connection Detention Pond
Fort Collins, CO
SDI_Design_Data_v1.08_Detention Pond.xlsm, Design Data 1/19/2021, 1:31 PM
WQCV_Trigger =1
RunOnce=1
CountA=1
Draintime Coeff=1.0
0 1 2 3
#N/A
#N/A
0 1 2 3
#N/A
#N/A
Check Data Set 1 Check Data Set 1
Area
Discharge
Stormwater Detention and Infiltration Design Data Sheet
0
5
10
15
20
25
30
35
40
45
0.1 1 10FLOW[cfs]TIME [hr]
100YR IN
100YR OUT
50YR IN
50YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
WQCV IN
WQCV OUT
0
1
2
3
4
5
6
7
8
0.1 1 10 100PONDINGDEPTH[ft]DRAIN TIME [hr]
100YR
50YR
10YR
5YR
2YR
WQCV
SDI_Design_Data_v1.08_Detention Pond.xlsm, Design Data 1/19/2021, 1:31 PM
Chapter 12 Storage
September 2017 Urban Drainage and Flood Control District 12-33
Urban Storm Drainage Criteria Manual Volume 2
Figure 12-21. Embankment protection details and rock sizing chart (adapted from Arapahoe County)
105 CFS/115 FT = 0.91 CFS/FT
Use Type L to be conservative
Detention Pond Spillway
Worksheet for OFFSITE CURB CUT
Project Description
Manning
FormulaFriction Method
DischargeSolve For
Input Data
0.013Roughness Coefficient
ft/ft0.050Channel Slope
in6.0Normal Depth
ft2.00Bottom Width
Results
cfs12.29Discharge
ft²1.0Flow Area
ft3.0Wetted Perimeter
in4.0Hydraulic Radius
ft2.00Top Width
in12.7Critical Depth
ft/ft0.006Critical Slope
ft/s12.29Velocity
ft2.35Velocity Head
ft2.85Specific Energy
3.064Froude Number
SupercriticalFlow Type
GVF Input Data
in0.0Downstream Depth
ft0.0Length
0Number Of Steps
GVF Output Data
in0.0Upstream Depth
N/AProfile Description
ft0.00Profile Headloss
ft/sInfinityDownstream Velocity
ft/sInfinityUpstream Velocity
in6.0Normal Depth
in12.7Critical Depth
ft/ft0.050Channel Slope
ft/ft0.006Critical Slope
Page 1 of 127 Siemon Company Drive Suite 200 W
Watertown, CT 06795 USA +1-203-755-1666
1/19/2021
FlowMaster
[10.03.00.03]
Bentley Systems, Inc. Haestad Methods Solution
CenterMulberry Connection.fm8
Version 4.06 Released August 2018
Worksheet Protected
INLET NAME I-25 Fornatge Rd (OS1, O4)Redman Dr (OS2,O2,O3)User-Defined
URBAN URBAN
STREET STREET
On Grade On Grade
USER-DEFINED INPUT
User-Defined Design Flows
2.5 1.6
9.8 7.9
No Bypass Flow Received No Bypass Flow Received
0.0 0.0
0.0 0.0
Watershed Characteristics
Watershed Profile
Minor Storm Rainfall Input
Major Storm Rainfall Input
CALCULATED OUTPUT
2.5 1.6
9.8 7.9
Minor Storm (Calculated) Analysis of Flow Time
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
Major Storm (Calculated) Analysis of Flow Time
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
Overland Length (ft)
INLET MANAGEMENT
Inlet Application (Street or Area)
Hydraulic Condition
Minor QKnown (cfs)
Major QKnown (cfs)
Receive Bypass Flow from:
Minor Bypass Flow Received, Qb (cfs)
Major Bypass Flow Received, Qb (cfs)
Subcatchment Area (acres)
Percent Impervious
NRCS Soil Type
Overland Slope (ft/ft)
Inlet Type
Bypass (Carry-Over) Flow from Upstream
Channel Slope (ft/ft)
Channel Length (ft)
Design Storm Return Period, Tr (years)
One-Hour Precipitation, P1 (inches)
Design Storm Return Period, Tr (years)
One-Hour Precipitation, P1 (inches)
Recommended Tc
Tc selected by User
Design Rainfall Intensity, I
Minor Flow Bypassed Downstream, Qb (cfs)
Major Flow Bypassed Downstream, Qb (cfs)
Channel Flow Velocity, Vt
Overland Flow Time, Ti
Channel Travel Time, Tt
Calculated Time of Concentration, Tc
Regional Tc
Minor Total Design Peak Flow, Q (cfs)
Major Total Design Peak Flow, Q (cfs)
C
C5
Overland Flow Velocity, Vi
Site Type (Urban or Rural)
Calculated Local Peak Flow, Qp
Overland Flow Velocity, Vi
Channel Flow Velocity, Vt
Overland Flow Time, Ti
Channel Travel Time, Tt
Calculated Time of Concentration, Tc
Regional Tc
Calculated Local Peak Flow, Qp
C
Recommended Tc
Tc selected by User
Design Rainfall Intensity, I
C5
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK =0.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.000 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.013
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =48.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.015 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =8.5 16.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =5.0 6.0 inches
Allow Flow Depth at Street Crown (leave blank for no)check = yes
Maximum Capacity for 1/2 Street based On Allowable Spread Minor Storm Major Storm
Water Depth without Gutter Depression (Eq. ST-2)y =2.04 3.84 inches
Vertical Depth between Gutter Lip and Gutter Flowline (usually 2")dC =2.0 2.0 inches
Gutter Depression (dC - (W * Sx * 12))a =1.51 1.51 inches
Water Depth at Gutter Flowline d =3.55 5.35 inches
Allowable Spread for Discharge outside the Gutter Section W (T - W)TX =6.5 14.0 ft
Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.658 0.372
Discharge outside the Gutter Section W, carried in Section TX QX =0.9 7.2 cfs
Discharge within the Gutter Section W (QT - QX)QW =1.8 4.3 cfs
Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs
Maximum Flow Based On Allowable Spread QT =2.7 11.5 cfs
Flow Velocity within the Gutter Section V =4.2 5.9 fps
V*d Product: Flow Velocity times Gutter Flowline Depth V*d =1.2 2.6
Maximum Capacity for 1/2 Street based on Allowable Depth Minor Storm Major Storm
Theoretical Water Spread TTH =14.5 18.7 ft
Theoretical Spread for Discharge outside the Gutter Section W (T - W)TX TH =12.5 16.7 ft
Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.409 0.318
Theoretical Discharge outside the Gutter Section W, carried in Section TX TH QX TH =5.4 11.5 cfs
Actual Discharge outside the Gutter Section W, (limited by distance TCROWN)QX =5.4 11.5 cfs
Discharge within the Gutter Section W (Qd - QX)QW =3.7 5.4 cfs
Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs
Total Discharge for Major & Minor Storm (Pre-Safety Factor)Q =9.1 16.9 cfs
Average Flow Velocity Within the Gutter Section V =5.6 6.4 fps
V*d Product: Flow Velocity Times Gutter Flowline Depth V*d =2.3 3.2
Slope-Based Depth Safety Reduction Factor for Major & Minor (d > 6") Storm R =1.00 1.00
Max Flow Based on Allowable Depth (Safety Factor Applied)Qd =9.1 16.9 cfs
Resultant Flow Depth at Gutter Flowline (Safety Factor Applied)d =5.00 6.00 inches
Resultant Flow Depth at Street Crown (Safety Factor Applied)dCROWN =0.00 0.00 inches
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =2.7 11.5 cfs
Version 4.06 Released August 2018
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Enter Your Project Name Here
I-25 Fornatge Rd (OS1, O4)
Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
UD-Inlet_v4.06 (7).xlsm, I-25 Fornatge Rd (OS1, O4)1/19/2021, 4:30 PM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf-G =
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf-C =
MINOR MAJOR
Total Inlet Interception Capacity Q =cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =cfs
Capture Percentage = Qa/Qo =C% =%
INLET ON A CONTINUOUS GRADE
Version 4.06 Released August 2018
UD-Inlet_v4.06 (7).xlsm, I-25 Fornatge Rd (OS1, O4)1/19/2021, 4:30 PM
Project:
Inlet ID:
Gutter Geometry (Enter data in the blue cells)
Maximum Allowable Width for Spread Behind Curb TBACK =5.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.080 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.013
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =40.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.002 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =11.0 20.8 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.5 inches
Allow Flow Depth at Street Crown (leave blank for no)check = yes
Maximum Capacity for 1/2 Street based On Allowable Spread Minor Storm Major Storm
Water Depth without Gutter Depression (Eq. ST-2)y =2.64 4.99 inches
Vertical Depth between Gutter Lip and Gutter Flowline (usually 2")dC =2.0 2.0 inches
Gutter Depression (dC - (W * Sx * 12))a =1.51 1.51 inches
Water Depth at Gutter Flowline d =4.15 6.50 inches
Allowable Spread for Discharge outside the Gutter Section W (T - W)TX =9.0 18.8 ft
Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.532 0.285
Discharge outside the Gutter Section W, carried in Section TX QX =0.8 5.8 cfs
Discharge within the Gutter Section W (QT - QX)QW =0.9 2.3 cfs
Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs
Maximum Flow Based On Allowable Spread QT =1.7 8.1 cfs
Flow Velocity within the Gutter Section V =1.7 2.5 fps
V*d Product: Flow Velocity times Gutter Flowline Depth V*d =0.6 1.4
Maximum Capacity for 1/2 Street based on Allowable Depth Minor Storm Major Storm
Theoretical Water Spread TTH =18.7 20.8 ft
Theoretical Spread for Discharge outside the Gutter Section W (T - W)TX TH =16.7 18.8 ft
Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.318 0.285
Theoretical Discharge outside the Gutter Section W, carried in Section TX TH QX TH =4.2 5.8 cfs
Actual Discharge outside the Gutter Section W, (limited by distance TCROWN)QX =4.2 5.8 cfs
Discharge within the Gutter Section W (Qd - QX)QW =2.0 2.3 cfs
Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs
Total Discharge for Major & Minor Storm (Pre-Safety Factor)Q =6.2 8.0 cfs
Average Flow Velocity Within the Gutter Section V =2.3 2.5 fps
V*d Product: Flow Velocity Times Gutter Flowline Depth V*d =1.2 1.4
Slope-Based Depth Safety Reduction Factor for Major & Minor (d > 6") Storm R =1.00 1.00
Max Flow Based on Allowable Depth (Safety Factor Applied)Qd =6.2 8.1 cfs
Resultant Flow Depth at Gutter Flowline (Safety Factor Applied)d =6.00 6.50 inches
Resultant Flow Depth at Street Crown (Safety Factor Applied)dCROWN =0.00 0.00 inches
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =1.7 8.1 cfs
Version 4.06 Released August 2018
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
Enter Your Project Name Here
Redman Dr (OS2,O2,O3)
Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
UD-Inlet_v4.06 (7).xlsm, Redman Dr (OS2,O2,O3)1/19/2021, 4:30 PM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf-G =
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf-C =
MINOR MAJOR
Total Inlet Interception Capacity Q =cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =cfs
Capture Percentage = Qa/Qo =C% =%
INLET ON A CONTINUOUS GRADE
Version 4.06 Released August 2018
UD-Inlet_v4.06 (7).xlsm, Redman Dr (OS2,O2,O3)1/19/2021, 4:30 PM
21
APPENDIX E
Geotechnical Evaluation
Proposed Poudre Valley Development
Redman Drive and NW Frontage Road
Fort Collins, Colorado
Comunale Properties
1855 South Pearl Street, Suite 20 | Denver, Colorado 80210
July 2, 2019 | Project No. 501710001 DRAFT
Kelley Lange, EI
Senior Staff Engineer
Brian F. Gisi, PE
Principal Engineer
Geotechnical Evaluation
Proposed Poudre Valley Development
Redman Drive and NW Frontage Road
Fort Collins, Colorado
Mr. Josh Heiney
Comunale Properties
1855 South Pearl Street, Suite 20 | Denver, Colorado 80210
July 2, 2019 | Project No. 501710001
KL/BFG/lm
Distribution: (1) Addressee (via e-mail)
6001 South Willow Drive, Suite 195 | Greenwood Village, Colorado 80111 | p. 303.629.6000 | www.ninyoandmoore.com
07/2/2019 DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 i
CONTENTS
1 INTRODUCTION 1
2 SCOPE OF SERVICES 1
3 SITE DESCRIPTION AND BACKGROUND REVIEW 2
4 PROPOSED CONSTRUCTION 2
5 FIELD EXPLORATION AND LABORATORY TESTING 2
6 GEOLOGY AND SUBSURFACE CONDITIONS 3
6.1 Geologic Setting 3
6.2 Subsurface Conditions 3
6.2.1 Loam 3
6.2.2 Alluvium 4
6.3 Groundwater 4
7 GEOLOGIC HAZARDS 4
7.1 Faulting and Seismicity 4
7.2 Expansive Soils 6
7.3 Compressible/Collapsible Soils 7
7.4 Liquefaction Potential 7
8 CONCLUSIONS 8
9 RECOMMENDATIONS 9
9.1 Earthwork 9
9.1.1 Excavations 9
9.1.2 Site Grading 10
9.1.3 Re-Use of Site Soils 11
9.1.4 Fill Placement and Compaction 11
9.1.5 Imported Soil 12
9.1.6 Controlled Low Strength Material 12
9.1.7 Utility Installation 13
9.1.8 Temporary Cut Slopes 14
9.2 Spread Footing Foundations 14
9.3 Slab-On-Grade Floors 15
9.4 Earth Pressures and Below-Grade Walls 17DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 ii
9.5 Pavements 17
9.5.1 Pavement Design 18
9.5.2 Dolly Pads 20
9.5.3 Pavement Subgrade Preparation 20
9.5.4 Pavement Materials 21
9.5.5 Pavement Maintenance 21
9.6 Concrete Flatwork 22
9.7 Corrosion Considerations 23
9.7.1 Concrete 23
9.7.2 Buried Metal Pipes 24
9.8 Scaling 24
9.9 Frost Heave 25
9.10 Construction in Cold or Wet Weather 25
9.11 Site Drainage 26
9.12 Construction Observation and Testing 26
9.13 Plan Review 27
9.14 Pre-Construction Meeting 27
10 LIMITATIONS 27
11 REFERENCES 29
TABLES
1 – 2015 International Building Code Seismic Design Criteria 5
2 – Slab Performance Risk Categories 6
3 – Lateral Earth Pressures 17
4 – Recommended Pavement Thickness 19
FIGURES
1 – Site Location
2 – Boring Locations
APPENDICES
A – Boring Logs
B – Laboratory Testing DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 1
1 INTRODUCTION
In accordance with your authorization and our proposal dated May 29, 2019, we have
performed a geotechnical evaluation for the proposed Poudre Valley Development located on
the northwest corner of the intersection of Redman Drive and the NW Frontage Road in Fort
Collins, Colorado. The approximate location of the site is depicted on Figure 1.
The purpose of our study was to evaluate the subsurface conditions and to provide design and
construction recommendations regarding geotechnical aspects of the proposed project. This
report presents the findings of our subsurface exploration program, results of our laboratory
testing, conclusions regarding the subsurface conditions at the site, and geotechnical
recommendations for design and construction of this project.
2 SCOPE OF SERVICES
The scope of our services for the project generally included:
• Review of referenced background information, including aerial imagery, published geologic
and maps, in-house geotechnical data, and available topographical information pertaining to
the project site and vicinity.
• Performance of a geologic reconnaissance and mark-out of the boring locations at the
project site.
• Notification of Utility Notification Center of Colorado of the boring locations prior to drilling.
• Drilling, logging, and sampling of 17 small-diameter exploratory borings within the project
site to depths ranging between approximately 15.5 and 20.5 feet below ground surface
(bgs). The boring logs are presented in Appendix A. Boring locations are presented on
Figure 2.
• Performance of laboratory tests on selected samples obtained from the borings to evaluate
engineering properties including in-situ moisture content and dry density, Atterberg limits,
percent materials finer than the No. 200 sieve and gradation, consolidation/swell potential,
and soil corrosivity characteristics (including pH, resistivity, water soluble sulfates, and
chlorides). The results of the laboratory testing are presented on the boring logs and in
Appendix B.
• Compilation and analysis of the data obtained.
• Preparation of this report presenting our findings, conclusions, and geotechnical
recommendations regarding design and construction of the project. DRAFT
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3 SITE DESCRIPTION AND BACKGROUND REVIEW
The site is an approximately 20-acre parcel of land in Fort Collins, Colorado. The project site is
bounded by agricultural land followed by East Vine Drive to the north, by the NW Frontage Road
to the east, by Redman Drive to the south, and by a creek followed by agricultural land to the
west. The site is approximately 2.5 miles southeast of Lindenmeier Lake and Long Pond
Reservoir.
The project site was used as farmland at the time of our subsurface exploration. Aerial
photograph review indicates that the subject site has existed similar to its current condition since
1999 or earlier. The approximate location of the site is presented on Figure 1.
4 PROPOSED CONSTRUCTION
The development of the site includes the design and construction of two industrial buildings with
plan areas ranging from approximately 74,400 to 94,000 square feet (sf). Ancillary construction
of pavement areas surrounding the development and an approximately 40,500 sf detention
pond are also anticipated.
Based on the site conditions and the anticipated construction, cut/fill thicknesses of generally
less than 5 feet are anticipated for the development. Deeper cut/fill should be anticipated for
deeper utilities. Detailed information regarding the finished floor elevations and anticipated
loading information was not available for review at the time of this report.
5 FIELD EXPLORATION AND LABORATORY TESTING
On June 3, 2019, Ninyo & Moore conducted a subsurface exploration at the site to evaluate the
existing subsurface conditions and to collect soil samples for laboratory testing. The evaluation
consisted of the drilling, logging, and sampling of 17 small-diameter borings using a truck-
mounted drill rig equipped with 4-inch diameter solid-stem augers. The borings were drilled to
depths ranging between approximately 15.5 and 20.5 feet bgs. The approximate locations of the
borings are presented on Figure 2. Relatively undisturbed and disturbed soil samples were
collected at selected intervals. The sampling methods used during the subsurface evaluation
are presented in Appendix A.
Soil samples collected during the subsurface exploration were transported to the Ninyo & Moore
laboratory for geotechnical laboratory analyses. Selected samples were analyzed to evaluate
engineering properties including in-situ moisture content and dry density, Atterberg limits,
percent materials finer than the No. 200 sieve and gradation, swell/consolidation potential, and DRAFT
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soil corrosivity characteristics (including resistivity, pH, water soluble sulfates and chlorides).
The results of the in-situ moisture content and dry density tests are presented on the boring logs
in Appendix A. Descriptions of the laboratory test methods and the remainder of the test results
are presented in Appendix B.
6 GEOLOGY AND SUBSURFACE CONDITIONS
The geology and subsurface conditions at the site are described in the following sections.
6.1 Geologic Setting
The site is located approximately 9 miles east of the Rocky Mountain Front Range, within the
Colorado Piedmont section of the Great Plains Physiographic Province. The Laramide Orogeny
uplifted the Rocky Mountains during the late Cretaceous and early Tertiary Periods. Subsequent
erosion deposited sediments east of the Rocky Mountains, including the Pierre Shale in the
area. As a result of regional uplift approximately 5 to 10 million years ago streams, such as the
South Platte River, downcut and excavated into the Great Plains forming the Colorado Piedmont
section (Trimble, 1980).
The surficial geology of the site is mapped by Colton (1978) as Pleistocene-age Broadway
Alluvium generally consisting of sand and gravel. The Pierre Shale bedrock is mapped as
underlying the site at depth.
6.2 Subsurface Conditions
Our understanding of the subsurface conditions at the project site is based on our field
exploration, laboratory testing, review of published geologic maps, historic aerial imagery, and
our experience with the general geology of the area. The following sections provide a
generalized description of the subsurface materials encountered. More detailed descriptions are
presented on the boring logs in Appendix A.
6.2.1 Loam
Loam was encountered at the surface in each boring and extended to depths between
approximately 2 and 9 feet bgs. The loam generally consisted of various shades of brown,
white, and red, moist, firm to very stiff, fat clay with varying amounts of sand and gravel and
lean clay with varying amounts of sand and gravel. As the site is used for agricultural
purposes, a surficial plow zone with loosened soil should be anticipated. DRAFT
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Based on the results of the laboratory testing, selected samples of the loam generally
exhibited moderate to high plasticity, had in-place moisture contents ranging from
approximately 10.4 to 21.9 percent, and dry densities ranging from approximately 102.0 to
119.9 pounds per cubic foot (pcf).
6.2.2 Alluvium
Alluvium was encountered in each boring beneath the loam and extended to the borings’
termination depths of up to approximately 20.5 feet bgs. The alluvium was generally
composed of various shades of brown, red, yellow, and gray, moist to wet, very loose to
very dense, fine to coarse sand with varying amounts of clay, silt, and gravel, and firm to
stiff, sandy, silty clay and sandy lean and fat clay.
Based on the laboratory test results, the selected samples of the alluvium had in-place
moisture contents ranging from approximately 1.1 to 27.0 percent and dry densities ranging
from approximately 93.9 to 128.1 pcf.
6.3 Groundwater
Groundwater was encountered in our borings at depths ranging between approximately 8.5 and
12 feet bgs during drilling. Groundwater levels can fluctuate due to seasonal variations,
precipitation, irrigation, groundwater withdrawal or injection, and other factors. Depending on the
time of year construction occurs, groundwater, particularly perched groundwater within the
upper loam soils, could be encountered. However, based on the knowledge of the area and the
results of our subsurface exploration, groundwater is not considered to be a constraint to the
construction of this project, but may be encountered during deep utility excavation and
installation.
7 GEOLOGIC HAZARDS
The following sections describe potential geologic hazards at the site including faulting and
seismicity, expansive soils, compressible/collapsible soils, and liquefaction potential.
7.1 Faulting and Seismicity
Historically, several minor earthquakes have been recorded around the Front Range area.
Based on our field observations and our review of readily available published geological maps
and literature there are no known active faults underlying or adjacent to the subject site. The
faults closest to the project site include the Walnut Creek and Rock Creek Faults and the
Golden Fault. DRAFT
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The Rock Creek and Walnut Creek Faults lay approximately 45 miles southwest of the site
(Widmann, Kirkham, and Rogers, 1998). Both faults are mapped as 3 kilometer long reverse
faults with slip rates of less than 0.2 millimeters per year. Both Faults are located in the High
Plains region, just east of the Front Range. They are downthrown to the southeast and may
become listric at depth where it is floored within the Laramie Formation (Risk Engineering,
1994). The surface of the Quaternary-age alluvium above the bedrock does not appear to be
displaced so there is not strong evidence of Quaternary faulting.
The Golden Fault lies approximately 50 miles southwest of the site. The fault is considered to be
late Quaternary in age and has not shown displacement in Holocene time, as Pleistocene
deposits overlie the fault (approximately 75 to 125 thousand years before the present [Kirkham,
1977]). Therefore, the probability of damage at the site from seismically induced ground surface
rupture from this fault is considered to be low.
Design of any proposed improvements should be performed in accordance with the
requirements of the governing jurisdictions and applicable building codes. Table 1 presents the
preliminary seismic design parameters for the site in accordance with the 2015 International
Building Code guidelines and adjusted maximum considered earthquake spectral response
acceleration parameters evaluated using the web-based OSHPD ground motion calculator
(OSHPD, 2019).
Table 1 – 2015 International Building Code Seismic Design Criteria
Seismic Design Factors Value
Site Class D
Site Coefficient, Fa 1.6
Site Coefficient, Fv 2.4
Mapped Spectral Acceleration at 0.2-second Period, Ss 0.178 g
Mapped Spectral Acceleration at 1.0-second Period, S1 0.057 g
Spectral Acceleration at 0.2-second Period Adjusted for Site Class, SMS 0.284 g
Spectral Acceleration at 1.0-second Period Adjusted for Site Class, SM1 0.137 g
Design Spectral Response Acceleration at 0.2-second Period, SDS 0.190 g
Design Spectral Response Acceleration at 1.0-second Period, SD1 0.092 g DRAFT
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7.2 Expansive Soils
One of the more significant geologic hazards in Colorado is the presence of swelling clays in
bedrock or surficial deposits. Moisture changes to bedrock or surficial deposits containing
swelling clays can result in volumetric expansion and collapse of those units. Changes in soil
moisture content can result from rainfall, irrigation, pipeline leakage, surface drainage, perched
groundwater, drought, or other factors. Volumetric change of expansive soil may cause
excessive cracking and heaving of structures with shallow foundations, concrete slabs-on-
grade, or pavements supported on these materials. Construction on soils known to be
potentially expansive could have a significant impact to the project.
A review of a Colorado Geological Survey map delineating areas based on their relative
potential for swelling in the Front Range area by Hart (1973-1974) indicates soil and bedrock
materials in the project vicinity typically exhibit low swell potential.
Based on the results of our laboratory testing, the loam deposits exhibited swell percentages of
up to approximately 5 percent when inundated against surcharge pressures of 200 pounds per
square foot (psf). The alluvial deposits exhibited swell percentages of up to approximately 1.5
percent at surcharge pressures of 500 psf.
Based on the results of our subsurface exploration, laboratory testing, and the information
obtained from our background review, the on-site soils expected to be encountered during
project development would have a slab performance risk category of “LOW ”, based on the
criteria presented in Table 2. Recommendations intended to reduce the risk for post-
construction movement due to swelling soils are included in this report.
Table 2 – Slab Performance Risk Categories
Slab Performance Risk
Category
Representative Percent
Swell
(500 psf Surcharge)
Representative Percent
Swell
(1,000 psf Surcharge)
LOW 0 to <3 0 to <2
MODERATE 3 to <5 2 to <4
HIGH 5 to <8 4 to <6
VERY HIGH > 8 > 6
Note: Based on Colorado Association of Geotechnical Engineers, Guidelines for Slab Performance Risk Evaluation
and Residential Basement Floor System Recommendations (Denver Metropolitan Area, 1996). DRAFT
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We recommend supporting the proposed buildings on shallow foundations and slab-on-grade
floors bearing on a zone of moisture conditioned and compacted fill material (i.e., fill prism). The
recommendations provided in this report assume supporting the proposed improvements on a
fill prism is acceptable to the Owner and can be accommodated by the structural design. It
should be recognized that the proposed buildings may experience distortions of approximately
1-inch (vertical) over 50 feet (horizontal) due to the swell potential of the on-site soils that will be
used to construct the fill prism. Failure to follow the site drainage recommendations provided in
Section 9.10 may also result in additional building movement that is difficult to quantify.
7.3 Compressible/Collapsible Soils
Compressible soils are generally comprised of soils that undergo consolidation when exposed
to new loadings, such as fill or foundation loads. Soil collapse (or hydro-collapse) is a
phenomenon where soils undergo a significant decrease in volume upon an increase in
moisture content, with or without an increase in external loads. Buildings, structures, and other
improvements may be subject to excessive settlement-related distress when compressible soils
or collapsible soils are present.
Based on our subsurface evaluation, the results of our laboratory testing, and provided the
recommendations provided herein are followed, it is our opinion post-construction settlements
due to the imposed foundation loads will be within generally accepted construction practices.
7.4 Liquefaction Potential
Liquefaction is a phenomenon in which loose, saturated soils lose shear strength under short-
term (dynamic) loading conditions. Ground shaking of sufficient duration results in the loss of
grain-to-grain contact in potentially liquefiable soils due to a rapid increase in pore water
pressure, causing the soil to behave as a fluid for a short period of time.
To be potentially liquefiable, a soil is typically cohesionless with a grain-size distribution
generally consisting of sand and silt. It is generally loose to medium dense and has a relatively
high moisture content, which is typical near or below groundwater level. The potential for
liquefaction decreases with increasing clay and gravel content, but increases as the ground
acceleration and duration of shaking increase. Potentially liquefiable soils need to be subjected
to sufficient magnitude and duration of ground shaking for liquefaction to occur. Based on our
subsurface exploration, laboratory testing, and the relatively low ground motion anticipated at
the site, liquefaction is not considered a hazard at this site. DRAFT
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8 CONCLUSIONS
Based on the results of the subsurface evaluation, laboratory testing, and data analyses, it is
our opinion that the proposed project is feasible from a geotechnical standpoint, provided the
recommendations presented herein are implemented and appropriate construction practices are
followed. Geotechnical design and construction considerations for the proposed project include
the following:
• Loam was encountered at the surface in each boring and extended to depths between
approximately 2 and 9 feet bgs. The loam generally consisted of various shades of brown,
white, and red, moist, firm to very stiff, fat clay with varying amounts of sand and gravel and
lean clay with varying amounts of sand and gravel. Laboratory testing indicates the loam
deposits exhibit high swell potential.
• Alluvium was encountered in each boring beneath the loam and extended to the borings’
termination depths of up to approximately 20.5 feet bgs. The alluvium was generally
composed of various shades of brown, red, yellow, and gray, moist to wet, very loose to very
dense, fine to coarse sand with varying amounts of clay, silt, and gravel, and firm to stiff,
sandy, silty clay and sandy lean and fat clay. Laboratory testing indicates the alluvial
deposits exhibit low swell potential.
• Based on our aerial imagery review, the site has been used for agricultural purposes since
1999 or earlier. A plo w zone should be anticipated at the subgrade level. The loosened soil
within the plow zone should be removed and recompacted as engineered fill.
• As an alternative to deep foundation systems, overlot grading improvements should be
designed carefully so that the swelling soils are removed and replaced to create a zone of
low-swelling material below the proposed structures and surface improvements. Chemical
treatment of pavement subgrade could also be considered to reduce the swell potentials.
• The on-site soils should generally be excavatable with medium- to heavy-duty earthmoving
or excavating equipment in good operating condition.
• Groundwater was encountered at depths ranging between approximately 8.5 and 12 feet
bgs during drilling. Groundwater levels will fluctuate due to seasonal variations from
precipitation, irrigation, groundwater withdrawal or injection, and other factors. In general,
groundwater is not anticipated to be a constraint to the proposed construction but may be
encountered during excavation and installation of deep utilities.
• Based on our laboratory data and our experience with similar materials at adjacent sites, the
sulfate content of the tested soils presents a moderate risk of sulfate attack to concrete. We
recommend the use of Type II cement for construction of concrete structures at this site.
• Based on our laboratory data and our experience with similar materials at adjacent sites, the
subgrade soils at the site are moderately corrosive to ferrous metals. Therefore, special
consideration should be given to the use of heavy gauge, corrosion-protected, underground
steel pipe or culverts, if any are planned. As an alternative, plastic pipe or reinforced
concrete pipe could be considered. A corrosion specialist should be consulted for further
recommendations.
• No known or reported active faults are reported underlying, or adjacent to, the site. Based
on the low ground motion hazard, the likelihood or potential for liquefaction is considered to DRAFT
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be negligible and therefore not a design consideration.
9 RECOMMENDATIONS
Based on our understanding of the project, the following sections present our geotechnical
recommendations for design and construction of the proposed buildings and other site
improvements.
9.1 Earthwork
The following sections provide our earthwork recommendations for this project. We anticipate
the site grading may consist of material cuts and fills on the order of 5 feet. Deeper cuts and fills
may be needed to install buried utilities.
9.1.1 Excavations
Our evaluation of the excavation characteristics of the on-site materials is based on the
results of the subsurface exploration, our site observations, and our experience with similar
materials. The on-site surface and near surface soils (loam and alluvium) may generally be
excavated with moderate- to heavy-duty earthmoving or excavation equipment in good
operating condition.
Equipment and procedures that do not cause significant disturbance to the excavation
bottoms should be used. Excavators and backhoes with buckets having large claws to
loosen the soil should be avoided when excavating the bottom approximately 6 to 12 inches
of excavations as such equipment may disturb the excavation bases.
The site has been used as agriculture fields. It should be anticipated that loose and
disturbed soil will be encountered at the subgrade level which will need to be compacted
and moisture-conditioned prior to fill placement.
The contractor should provide safely sloped excavations or an adequately constructed and
braced shoring system, in compliance with Occupational Safety and Health Administration
(OSHA) (OSHA, 2005) guidelines, for employees working in an excavation that may expose
employees to the danger of moving ground. If material is stored or equipment is operated
near an excavation, stronger shoring should be used to resist the extra pressure due to
superimposed loads. DRAFT
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9.1.2 Site Grading
Prior to grading, the ground surface in proposed structure and improvement areas should
be cleared of any surface obstructions, debris, topsoil, organics (including vegetation), and
other deleterious material.
Materials generated from clearing operations should be removed from the project site for
disposal (e.g. at a legal landfill site). Obstructions that extend below finish grade, if present,
should be removed and resulting voids filled with compacted, engineered fill or Controlled
Low Strength Material (CLSM).
The proposed buildings may be supported on shallow foundation systems consisting of
spread-footings bearing on a relatively uniform thickness of moisture-conditioned and
compacted engineered fill extending to 12 or more inches below the bottom of the footings.
The buildings may be provided with slab-on-grade floors bearing 3 or more feet of moisture
conditioned and compacted engineered fill. The limits of this fill layer should extend 5 or
more feet out beyond the footings to reduce the swell potential within the structures, as well
as the surrounding building appurtenances, such as exterior flatwork adjacent to the
building.
There are risks associated with supporting pavements over expansive soils without soil
modification. However, the costs associated with remediating pavement subgrades for
expansive soils are generally considered cost-prohibitive. Therefore, the following
recommendation for pavement subgrade preparation is provided assuming the owner is
willing to accept some risk of poor pavement performance as a result of post-construction
vertical movements associated with the high swell potential of the overburden soils.
Asphalt and concrete pavements and flatwork may be placed on 24 or more inches of
moisture conditioned and compacted engineered fill. As an alternative, the upper 12 or
more inches of subgrade below the pavements sections could be chemically treated using
fly ash or lime to reduce plasticity, reduce swell-potential, and increase strength of the
treated subgrade soils.
The geotechnical consultant should be retained to observe the remedial excavations, and
the elevations of the excavation bottoms should be surveyed by the project civil engineer.
The exposed subgrade materials should be firm and unyielding prior to fill placement. The
extent of and depths of removal should be evaluated by our representative during the
excavation work based on observation of the soils exposed. Additional recommendations DRAFT
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specific to the site conditions encountered may be provided at the time of construction. The
project budget should include additional cost associated with the removal and replacement
of additional fill material. Subgrade materials that are disturbed during grading should be
moisture conditioned and re-compacted according to the recommendations provided in
this report.
9.1.3 Re-Use of Site Soils
The onsite soils encountered during our subsurface exploration consisted of loam and
alluvium. Laboratory testing indicates the onsite soils have high swell potential at low
confinement pressures (near surface soils) at their in-situ moisture contents. Soils
generated from on-site excavation activities in the loam and alluvium deposits that are free
of deleterious materials and organic matter, do not contain particles larger than 3 inches in
diameter, can generally be used as engineered fill as evaluated by the geotechnical
consultant provided they are compacted and moisture conditioned as recommended in this
report.
Fragments of rock, cobbles, and inert construction debris (e.g., concrete or asphalt) larger
than 3 inches in diameter may be incorporated into the project fills in non-structural areas
and below the anticipated utility installation depths. A Geotechnical Engineer should be
consulted regarding appropriate recommendations for usage of such materials on a case-
by-case basis when such materials have been observed during earthwork. Care should be
taken to avoid nesting of oversized materials during placement. Recommendations
provided in Section 203 of the current CDOT Standard Specifications for Road and Bridge
Construction should be followed during the placement of oversized material.
9.1.4 Fill Placement and Compaction
Fine-grained soils (on-site soils that classify as CL or CH) used as engineered fill should be
moisture-conditioned to moisture contents between optimum moisture content and 3
percent over optimum moisture content. Granular soils (on-site soils that classify as SC,
SW, SP-SC, or import soils) used as engineered fill should be moisture-conditioned to
moisture contents within 2 percent of optimum moisture content. Engineered fill should be
placed in uniform horizontal lifts. Engineered fill should be compacted to a relative
compaction of 95 percent, or more, as evaluated by the American Society for Testing and
Materials (ASTM) D698.
The engineered fill should be compacted by appropriate mechanical methods. Lift thickness
for fill will be dependent upon the type of compaction equipment utilized. Backfill should be DRAFT
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placed in lifts not exceeding 8 inches in loose thickness in areas compacted by other-than
hand operated machines. Backfill should be placed in lifts not exceeding 6 inches in loose
thickness in areas compacted by hand operated machines.
Fill materials should not be placed, worked, rolled while they are frozen, thawing, or during
poor/inclement weather conditions.
Compaction areas should be kept separate, and no lift should be covered by another until
relative compaction and moisture content within the recommended ranges are obtained.
Use of controlled low-strength material (CLSM) should be considered in lieu of compacted
fill for areas with low tolerances for surface settlements, for excavations that extend below
the groundwater table and in areas with difficult access for compaction equipment. CLSM
should be placed in lifts of 5 feet or less with a 24-hour or more curing period between each
lift.
9.1.5 Imported Soil
Imported soil to be used as engineered fill should be free of organic material and other
deleterious materials should consist of relatively impervious material with a very low to low
expansion potential (less than 1 percent against a surcharge pressure of 500 psf when
remolded at optimum moisture content). Imported fill should have less than 50 percent
passing the No. 200 Sieve and should have a plasticity index that is between 10 and 20.
Import soil in contact with ferrous metals should have low corrosion potential. Import
material in contact with concrete should have a soluble sulfate content less than
0.1 percent.
We further recommend that proposed import soils be evaluated by the project’s
geotechnical consultant at the borrow source for its suitability prior to importation to the
project site. Import soil should be moisture-conditioned and placed and compacted in
accordance with the recommendations set forth in Section 9.1.4.
9.1.6 Controlled Low Strength Material
Use of CLSM should be considered in lieu of compacted fill for areas with low tolerances for
surface settlements, for excavations that extend below the groundwater table and in areas
with difficult access for compaction equipment. CLSM consists of a fluid, workable mixture
of aggregate, Portland cement, and water. CLSM should be placed in lifts of 5 feet or less
with a 24-hour or more curing period between each lift. DRAFT
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The use of CLSM has several advantages:
• A narrower excavation can be used where shoring is present, thereby minimizing the
quantity of soil to be excavated and possibly reducing disturbance to the near-by traffic;
• Compaction requirements do not apply;
• There is less risk of damage to improvements, since little compaction is needed to
place CLSM;
• CLSM can be batched to flow into irregularities in excavation bottoms and walls; and
• The number of workers needed inside the trench excavation is reduced.
The CLSM mix design should be submitted for review prior to placement. The 28-day
strength of the material should be no less than 50 pounds per square inch (psi) and no
more than 150 psi. CLSM should be observed and tested by the geotechnical consultant.
9.1.7 Utility Installation
The contractor should take particular care to achieve and maintain adequate compaction of
the backfill soils around manholes, valve risers and other vertical pipeline elements where
settlements are commonly observed. Use of CLSM or a similar material should be
considered in lieu of compacted soil backfill in areas with low tolerances for surface
settlement. This would also reduce the permeability of the utility trenches.
Pipe bedding materials, placement and compaction should meet the specifications of the
pipe manufacturer and applicable municipal standards. Materials proposed for use as pipe
bedding should be tested for suitability prior to use.
Special care should be exercised to avoid damaging the pipe or other structures during the
compaction of the backfill. In addition, the underside (or haunches) of the buried pipe
should be supported on bedding material that is compacted as described above. This may
need to be performed with placement by hand or small-scale compaction equipment.
Surface drainage should be designed to divert the surface water away from utility trench
alignments. Where topography, site constraints or other factors limit or preclude adequate
surface drainage, the granular bedding materials should be surrounded by a non-woven
geotextile fabric (e.g., TenCate Mirafi® 140N or the equivalent) to reduce the migration of
fines into the bedding which can result in severe, isolated settlements.
Development of site grading plans should consider the subsurface transfer of water in utility
trenches and the pipe bedding. Sandy pipe bedding materials can function as efficient DRAFT
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conduits for re-distribution of natural and applied waters in the subsurface. Cut-off walls in
utility trenches or other water-stopping measures should be implemented to reduce the
rates and volumes of water transmitted along utility alignments and toward buildings,
pavements and other structures where excessive wetting of the underlying soils will be
damaging. Incorporation of water cut-offs and/or outlet mechanisms for saturated bedding
materials into development plans could be beneficial to the project. These measures also
will reduce the risk of loss of fine-grained backfill soils into the bedding material with
resultant surface settlement.
9.1.8 Temporary Cut Slopes
Temporary excavations will be needed for this project to construct utilities. Based on the
subsurface information obtained from our exploratory excavations and our experience with
similar projects, we anticipate that the soil conditions and stability of the excavation
sidewalls may vary with depth. Soils with higher fines content may stand vertically for a
short time (less than 12 hours) with little sloughing. However, as the soil dries after
excavation or as the excavations are exposed to rainfall, sloughing may occur. Soils with
low cohesion (e.g., predominately sandy or gravelly material), may slough or cave during
excavation, especially if wet or saturated.
The contractor should provide safely sloped excavations or an adequately constructed and
braced shoring system, in compliance with OSHA regulations as mentioned in
Section 9.1.1.
In our opinion, the site soils should generally be considered a Type C soil when applying
the OSHA regulations. For these soil conditions, OSHA recommends a temporary slope
inclination of 1.5H:1V or flatter for excavations 20 feet or less in depth. Appropriate slope
inclinations should be evaluated in the field by an OSHA-qualified “Competent Person”
based on the conditions encountered.
9.2 Spread Footing Foundations
Perimeter footings should extend to 36 inches or more below the lowest exterior finished grade
(for frost protection), and bear on 12 or more inches of moisture-conditioned and compacted
engineered fill as described in Section 9.1.2 of this report. Continuous wall footings should have
a width of 18 inches or more and column footings should have a width of 24 inches or more.
Footings should be reinforced in accordance with the recommendations of the Structural
Engineer. DRAFT
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Footings may be designed using an allowable bearing pressure of 2,500 pounds psf for static
conditions. The bearing capacity may be increased by one-third when considering loads of short
duration such as wind or seismic forces. The foundations should preferably be proportioned
such that the resultant force from design loads, including lateral loads, falls within the kern (i.e.,
middle one-third of the footing base).
Uplift resistance can be developed from the weight of the footings, the effective weight of any
overlying soil, and the weight of the supported structure itself. The effective unit weight of the
soil can be assumed to be 120 pcf. Soil uplift resistance may be calculated as the weight of the
soil prism defined by a diagonal line extending from the perimeter of the foundation to the
ground surface at an angle θ equal to 20 degrees from the vertical. Under large moment and/or
shear loading, the effective size of the uplift soil prism may be reduced. An appropriate safety
factor should be applied.
The bottom surface of foundation excavations should be compacted with hand-held dynamic
compaction equipment (i.e., jumping jack, flat-plate vibrator) prior to placement of forms and
reinforcing steel. The base of foundation excavations should be free of water and loose soil prior
to placing concrete. Concrete should be placed soon after subgrade compaction to reduce
bearing soil disturbance. Should the soils at bearing level become excessively dry, disturbed, or
saturated, the affected soil should be moisture conditioned and compacted. It is recommended
that Ninyo & Moore be retained to observe, test, and evaluate the soil foundation bearing
materials.
Based on the results of our subsurface exploration and laboratory testing, and provided our
grading recommendations provided in Section 9.1 are followed, we estimate total and
differential settlement of approximately 1-inch and 1/2-inch, respectively. Distortions of
approximately 1-inch (vertical) over 50 feet (horizontal) are possible due the swell potential of
the on-site soils.
9.3 Slab-On-Grade Floors
The buildings may be provided with slab-on-grade floors bearing 3 or more feet of moisture
conditioned and compacted engineered fill as described in Section 9.1.2 of this report.
For slab design, a design modulus of subgrade reaction (K) of 150 pounds per square inch per
inch of deflection (pci) may be used for the subgrade soils in evaluating such deflections. This
value is based on a unit square foot area and can be adjusted for large slabs. Adjusted values DRAFT
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of the modulus of subgrade reaction, Kv, can be obtained from the following equation for slabs
of various widths:
Kv = K[(B+1)/2B]2 (pci)
B in the above equation represents the width of the slab in feet between line loads/point loads.
The design of the floor slabs (including jointing and reinforcement) is the responsibility of the
Structural Engineer. Joints should be constructed at intervals designed by the Structural
Engineer to help reduce random cracking of the slab. Floor slabs should be adequately
reinforced. Recommendations based on structural considerations for slab thickness, jointing,
and steel reinforcement should be developed by the Structural Engineer in accordance with
American Concrete Institute recommendations. Proper placement of reinforcement in the slab is
vital for satisfactory performance.
The slab should be constructed so that it “floats” independent of the foundations. Floor slabs
should be separated from bearing walls and columns with expansion joints, which allow
unrestrained vertical movement. Joints should be observed periodically, particularly during the
first several years after construction. Slab movement can cause previously free-slipping joints to
bind. Measures should be taken so that slab isolation is maintained in order to reduce the
likelihood of damage to walls and other interior improvements. If post-construction vertical slab
movement of approximately 1 inch cannot be tolerated or desired, then we recommend utilizing
a structural floor system spanning over a void or a crawl space.
Interior partitions resting on floor slabs should be provided with slip joints so that if the slabs
move, the movement cannot be transmitted to the upper structure, including wallboards and
door frames. A slip joint that allows 2 or more inches of vertical movement is recommended for
placement at the bottoms of the interior partitions. If slip joints are placed at the tops of walls, in
the event that the floor slabs move, it is expected that the wall will show signs of distress,
especially where the floors meet the exterior wall. Interior plumbing lines that penetrate interior
partition walls, where the slip joints are placed at the top of the walls, should be provided with
flexible connections that can handle 2 or more inches of vertical movement.
The need for a moisture retarding and/or vapor retarding system should be considered by the
Structural Engineer or Architect, based on the moisture sensitivity of the anticipated flooring.
The placement of a vapor retarder is recommended in areas where moisture-sensitive floor
coverings are anticipated. DRAFT
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9.4 Earth Pressures and Below-Grade Walls
Earth pressures are used to compute the lateral forces acting on below-grade walls. These
pressures can be classified as at-rest, active, and passive. The direction and magnitude of the
soil/wall movement just before failure affects the resulting pressure condition. At-rest conditions
exist when there is no movement, such as for a restrained wall. Active stresses are exerted
when the wall moves out and the soil moves toward the wall away from the soil mass, thereby
mobilizing the shear strength of the soil. Passive stresses exist when the wall moves toward the
soil mass.
The recommended equivalent fluid pressures in Table 3 assume moisture-conditioned and
compacted engineered fill with an angle of internal friction (φ) of 26 degrees and a unit weight of
120 pcf. The values listed below are for static conditions.
Table 3 – Lateral Earth Pressures
Soil Condition Active Pressure
(pcf)
At-rest Pressure
(pcf)
Passive Pressure
(pcf)
Engineered Fill 47 67 307
The use of heavy compaction equipment adjacent to below-grade walls could result in lateral
earth pressures well in excess of those predicted in Table 3. We recommend that the upper 24
inches of soil that is not protected by pavement or a concrete slab, be neglected when
calculating passive resistance. This zone, where applicable, should be backfilled with cohesive
soils to minimize infiltration of surface water into the backfill. For frictional resistance to lateral
loads, we recommend that an ultimate coefficient of friction of 0.35 be used between soil and
concrete.
To limit long-term hydrostatic pressure behind the wall, we recommend measures, such as
placement of sealants, be taken such that surface water is not allowed to penetrate between the
loading dock walls and exterior slabs.
9.5 Pavements
We understand project pavements will be privately maintained. Pavement section alternatives
are included herein for the paved surfaces, which include standard duty automobile parking
areas and driveways, and heavy duty drive lanes and fire lanes.
The pavement sections recommended below were developed in general accordance with the
guidelines and procedures of the American Association of State Highway and Transportation DRAFT
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Officials (AASHTO), (AASHTO, 1993), CDOT, and Larimer County. Table 4 summarizes the
minimum pavement sections for asphaltic concrete (AC) pavements and Portland cement
concrete pavements (PCCP). Pavement sections may be modified once more detailed
information regarding traffic volumes and vehicle usage is available for review.
9.5.1 Pavement Design
Specific traffic loadings for the project were not available at the time of this report
preparation. Based on our experience with similar commercial facilities, an equivalent 18-
kip single axle load value of 36,500 was assumed for standard-duty automobile parking
areas and 365,000 was assumed for heavy-duty drive lanes and loading areas for 20-year
design lives, respectively. If design traffic loadings differ significantly from this assumed
value, we should be notified to re-evaluate the pavement recommendations below.
The current subgrade soils encountered in our borings typically consisted of lean clay to fat
clay with varying amounts of sand and gravel that classify as A-6 and A-7 soils in
accordance with the AASHTO classification system. It is anticipated that fill imported to the
site will classify as A-6 or better. We utilized a design R-Value of 5 for the pavement
subgrade soils for the project.
The design of flexible pavements was based on the following input parameters:
Initial Serviceability: 4.5
Terminal Serviceability: 2.0
Reliability 80%
Overall Standard Deviation: 0.44
Resilient Modulus (untreated): 3,025 psi (R-Value of 5)
Stage Construction: 1.0
The design of rigid pavements was based on the following input parameters:
Initial Serviceability: 4.5
Terminal Serviceability: 2.0
Reliability 80%
28-Day Mean PCC Modulus Rupture: 650 psi
28-Day Mean Modulus of Elasticity: 3.6 x 106 psi
Mean Effective k value: 100 psi/in
Overall Standard Deviation: 0.34
Load Transfer Coefficient: 4.2
Overall Drainage Coefficient: 1.0 DRAFT
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Based on the above-mentioned guidelines, procedures, and input parameters, Table 4
provides our recommended pavement section thicknesses for pavements supported on 2 or
more feet of moisture conditioned and compacted engineered fill (overexcavated and
recompacted in-situ deposits).
Table 4 – Recommended Pavement Thickness
Traffic Type Full Depth AC
(inches)
Composite AC /
ABC (inches)
PCCP
(inches)
Standard-Duty Areas 6.0 4.0 / 6.0 5.0
Heavy-Duty Areas 8.0 6.0 / 8.0 6.0
Notes: AC = Asphalt Concrete, ABC = Aggregate Base Course, PCCP = Portland Cement Concrete Pavement
We recommend PCCP be utilized in entrance and exit sections, dumpster pads, loading
areas, or other areas where extensive wheel maneuvering are expected. The dumpster pad
should be large enough to support the wheels of the truck, which will bear the load of the
dumpster.
Although the use of ABC is not integral for structural support in PCCP pavements, the
placement of 4 or more inches of ABC below PCCP pavements will develop a more stable
subgrade for concrete truck traffic associated with the pavement construction and help
reduce potential slab curl, shrinkage cracking, and subgrade “pumping” through joints.
Adequate joint spacing and reinforcement is recommended to prevent loss of load transfer
across saw-cut crack control joints. Joints should be sealed to reduce water infiltration. The
design guidelines provided in the referenced ACI 330R-01 guide should be followed for joint
spacing and reinforcing.
Where practical, we recommend “early-entry” cutting of crack-control joints in PCCP.
Cutting of PCCP in its ‘green” state typically reduces the potential for micro-cracking of the
pavements prior to the crack control joints being formed, compared to cutting the joints after
the concrete has fully set. Micro-cracking of pavements may lead to crack formation in
locations other than the sawed joints, and/or reduction of fatigue life of the pavement.
Ninyo & Moore has observed dishing in some AC parking lots. Dishing is observed in
frequently-used parking stalls (such as near the front of buildings), and occurs under the
wheel footprint in these stalls. The use of higher-grade AC, or surfacing these areas with
PCCP, could be considered. The dishing is exacerbated by factors such as irrigated islands
or planter areas, and sheet surface drainage to the front of structures. DRAFT
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If AC pavements are utilized in the trailer parking areas, dishing of the AC pavements
should be anticipated where trailer dollies are in contact with the AC surface due to the
concentrated loads which occur at the trailer dollies. As a result, we recommend a PCCP
dolly pad be constructed within the heavy-duty AC areas. The dolly pad should have a width
of 5 feet or more. Reinforcing and joint spacing should be designed by the project structural
engineer.
9.5.2 Dolly Pads
If trailer parking is desired in the heavy-duty AC areas, dishing of the AC areas should be
anticipated where trailer dollies are in contact with the AC surface due to the concentrated
loads which occur at the trailer dollies. As a result, we recommend a PCCP dolly pad be
constructed within the heavy-duty AC areas if trailing parking is desired in these areas. The
dolly pad should be constructed on both the shipping and receiving pavements and should
have a width of 5 feet or more. Reinforcing and joint spacing should be designed by the
project structural engineer.
9.5.3 Pavement Subgrade Preparation
Due to the measured swell potential of the subgrade fill materials, we recommend
pavements are placed on a zone of moisture-conditioned and compacted fill extending 24
or more inches below the bottom of the pavement section or flatwork as discussed above in
Section 9.1.2. As an alternative, the pavements can be placed on a zone of 12 or more
inches of CTS using fly ash, lime, or Portland cement to reduce plasticity, reduce swell-
potential, and increase strength of the treated subgrade soils.
The contractor should be prepared either to dry the subgrade materials or moisten them, as
needed, prior to compaction. Some site soils may pump or deflect during compaction if
moisture levels are not carefully monitored. The contractor should be prepared to process
and compact such soils to establish a stable platform for paving, including use of chemical
stabilization or geotextiles, where needed.
The prepared subgrade should be protected from the elements prior to pavement
placement. Subgrades that are exposed to the elements may need additional moisture
conditioning and compaction, prior to pavement placements.
Immediately prior to paving, the subgrade should be proofrolled with a heavily loaded,
pneumatic tired vehicle and checked for moisture. Areas that show excessive deflection
during proof rolling should be excavated and replaced and/or stabilized. Areas allowed to
pond prior to paving may need to be re-worked prior to proofrolling. DRAFT
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It should be noted that the subgrade recommendations included in this report are provided
based on the owner accepting some risk of poor pavement performance due to the on-site
swelling soils. The measures recommended above are intended to minimize this risk.
Additional recommendations could be provided to further reduce this risk.
9.5.4 Pavement Materials
The AC pavement shall consist of a bituminous plant mix composed of a mixture of high
quality aggregate and bituminous material, which meets the requirements of a job-mix
formula established by a qualified engineer. The asphalt material used should be based on
a SuperPave Gyratory Design Revolution of 75. Lower lifts should be constructed using an
asphalt mix Grading S and asphalt cement binder grade PG 58-28. The top lift should be
constructed using an asphalt mix Grading SX and asphalt cement binder grade PG 64-22.
Pavement layer thickness should be between 2 and 3 inches for the lower lifts and 2 to 2.5
inches for the top lift. The geotechnical engineer should be retained to review the proposed
pavement mix designs, grading, and lift thicknesses prior to construction.
PCCP should consist of a plant mix composed of a mixture of aggregate, Portland cement
and appropriate admixtures meeting the requirements of Larimer County. Concrete should
have a modulus of rupture of third point loading of 650 psi or more. The concrete should be
air-entrained with approximately 6 percent air and should have a cement content of six or
more sacks per cubic yard. Allowable slump should be approximately 4 inches.
Thickened edges should be used along outside edges of PCCP. The edge thickness
should be 2 inches or more than the recommended PCCP thickness and taper to the
recommended PCCP thickness 36 inches inward from the edge. Integral curbs may be
used in lieu of thickened edges.
PCCP should have longitudinal and transverse joints that meet the applicable requirements
of Larimer County.
9.5.5 Pavement Maintenance
The collection and diversion of surface drainage away from paved areas is vital to
satisfactory performance of the pavements. The subsurface and surface drainage systems
should be carefully designed to facilitate removal of the water from paved areas and
subgrade soils. Allowing surface waters to pond on pavements will cause premature
pavement deterioration. Where topography, site constraints or other factors limit or preclude
adequate surface drainage, pavements should be provided with edge drains to reduce loss DRAFT
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of subgrade support. The long-term performance of the pavement also can be improved
greatly by backfilling and compaction behind curbs, gutters, and sidewalks so that ponding
is not permitted and water infiltration is reduced.
Landscape irrigation in planters adjacent to pavements and in “island” planters within paved
areas should be carefully monitored or differential heave and/or rutting of the nearby
pavements will result. Drip irrigation systems are recommended for such planters to reduce
over-spray and water infiltration beyond the planters. We recommend edge drains where
the profile/slopes are less than 1 percent.
The standard care of practice in pavement design describes the recommended flexible
pavement section as a “20-year” design pavement; however, many pavements will not
remain in satisfactory condition without routine, preventive maintenance and rehabilitation
procedures performed during the life of the pavement. Preventive pavement treatments are
surface rehabilitation and operations applied to improve or extend the functional life of a
pavement. These treatments preserve, rather than improve, the structural capacity of the
pavement structure. In the event the existing pavement is not structurally sound, the
preventive maintenance will have no long-lasting effect. Therefore, a routine maintenance
program to seal joints and cracks, and repair distressed areas is recommended.
9.6 Concrete Flatwork
Ground-supported flatwork, such as walkways, will be subject to soil-related movements
resulting from heave/settlement, frost, etc. Thus, where these types of elements abut rigid
building foundations or isolated/suspended structures, differential movements should be
anticipated. We recommend that flexible joints be provided where such elements abut the main
structure to allow for differential movement at these locations.
We recommend that exterior concrete flatwork and the target structures be supported on
improved subgrade as described in Section 9.1.2 of this report. Positive drainage should be
established and maintained adjacent to flatwork. Water should not be allowed to pond on
flatwork.
In no case should exterior flatwork extend under any portion of the building where there is less
than 2 inches of clearance between the flatwork and any element of the building. Exterior
flatwork in contact with brick, rock facades, or any other element of the building can cause
damage to the structure if the flatwork experiences movements. DRAFT
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The ground-supported flatwork should be provided with crack-control and expansion joints in
accordance with Larimer County Specifications.
9.7 Corrosion Considerations
The corrosion potential of on-site soils to concrete and buried metal was evaluated in the
laboratory using selected samples obtained from the exploratory borings. Laboratory testing
was performed to assess the effects of sulfate on concrete and the effects of soil resistivity on
buried metal. Results of these tests are presented in Appendix B. Recommendations regarding
concrete to be utilized in construction of proposed improvements and for buried metal pipes are
provided in the following sections.
9.7.1 Concrete
The test for water-soluble sulfate content of the soils was performed using CDOT Test
Method CP-L 2104. The laboratory test results are presented in Appendix B. The
percentage of water-soluble sulfates in water measured was 0.025 percent, corresponding
to 250 parts per million, respectively. Based on Table 601-2 of the CDOT 2011 Standard
Specifications for Road and Bridge Construction, the on-site soils represent a Class 1
severity of sulfate exposure to concrete on a scale that ranges between Class 0 and Class
3. Therefore, we recommend that the concrete used for this project should have a
maximum water to cementitious material ratio of 0.45 and the cementitious materials should
meet one of the below outlined requirements.
• ASTM C 150 Type II or V; Class C fly ash shall not be substituted for cement.
• ASTM C 595 Type IP(MS) or IP(HS); Class C fly ash shall not be substituted for
cement.
• ASTM C 1157 Type MS or HS; Class C fly ash shall not be substituted for cement.
• When ASTM C 150 Type III cement is allowed, as in Class E concrete, it shall have no
more than 8 percent C3A. Class C fly ash shall not be substituted for cement.
The Structural Engineer should ultimately select the concrete design strength based on the
project specific loading conditions. However, higher strength concrete may be selected for
increased durability, resistance to slab curling and shrinkage cracking. We recommend the
use of concrete with a design 28-day compressive strength of 4,000 psi or more, for
concrete slabs at this site. Concrete exposed to the elements should be air-entrained. DRAFT
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9.7.2 Buried Metal Pipes
The corrosion potential of the on-site materials was analyzed to evaluate its potential
effects on buried metals. Corrosion potential was evaluated using the results of laboratory
testing of samples obtained during the subsurface evaluation that were considered
representative of soils at the subject site.
The results of the laboratory testing indicate the on-site materials have low resistivity and
could potentially be moderately corrosive to ferrous metals. Therefore, special
consideration should be given to the use of heavy gauge, corrosion protected, underground
steel pipe or culverts, if any are planned. As an alternative, plastic pipe or reinforced
concrete pipe could be considered. A corrosion specialist should be consulted for further
recommendations.
9.8 Scaling
Climatic conditions in the project area including relatively low humidity, large temperature
changes and repeated freeze-thaw cycles, may cause surficial scaling and spalling of exterior
concrete. Occurrence of surficial scaling and spalling can be aggravated by poor workmanship
during construction, such as “over-finishing” concrete surfaces and the use of de-icing salts on
exterior concrete flatwork, particularly during the first winter after construction. The use of de-
icing salts on nearby roadways, which can be transferred by vehicle traffic onto newly placed
concrete, can be sufficient to induce scaling.
The measures below can be beneficial for reducing the concrete scaling. However, because of
the other factors involved, including workmanship, surface damage to concrete can develop
even though the measures provided below were followed. The mix design criteria should be
coordinated with other project requirements including the criteria for soluble sulfate resistance
presented in Section 9.7.1.
• Curing concrete in accordance with applicable codes and guidelines.
• Maintaining a water/cement ratio of 0.45 by weight for exterior concrete mixes.
• Including Type F fly ash in exterior concrete mixes as 20 percent of the cementitious
material.
• Specifying a 28-day, c ompressive strength of 4,500 or more psi for exterior concrete that
may be exposed to de-icing salts.
• Avoiding the use of de-icing salts through the first winter after construction.
• If colored concrete is being proposed for use at this site, Ninyo & Moore should be consulted
for additional recommendations. DRAFT
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9.9 Frost Heave
Site soils are susceptible to frost heave if allowed to become saturated and exposed to freezing
temperatures and repeated freeze/thaw cycling. The formation of ice in the underlying soils can
result in two or more inches of heave of pavements, flatwork and other hardscaping in sustained
cold weather. A portion of this movement may be recovered when the soils thaw, but due to loss
of soil density some degree of displacement will remain. Frost heave of hardscaping could also
result in areas where the subgrade soils were placed on engineered fill.
In areas where hardscape movements are a design concern (i.e. exterior flatwork located
adjacent to the building within the doorway swing zone), replacement of the subgrade soils with
2 or more feet of clean, coarse sand or gravel, or supporting the element on foundations similar
to the building, or spanning over a void should be considered. Recommendations in this regard
can be provided upon request.
9.10 C onstruction in Cold or Wet Weather
During construction, the site should be graded such that surface water can drain readily away
from the building areas. Given the soil conditions, it is important to avoid ponding of water in or
near excavations. Water that accumulates in excavations should be promptly pumped out or
otherwise removed and these areas should be allowed to dry out before resuming construction.
Berms, ditches, and similar means should be used to decrease stormwater entering the work
area and to efficiently convey it off site.
Earthwork activities undertaken during the cold weather season may be difficult and should be
done by an experienced contractor. Fill should not be placed on top of frozen soils. The frozen
soils should be removed prior to the placement of fill or other construction material. Frozen soil
should not be used as engineered fill or backfill. The frozen soil may be reused (provided it
meets the selection criteria) once it has thawed completely. In addition, compaction of the soils
may be more difficult due to the viscosity change in water at lower temperatures.
If construction proceeds during cold weather, foundations, slabs, or other concrete elements
should not be placed on frozen subgrade soil. Frozen soil should either be removed from
beneath concrete elements, or thawed and recompacted. To limit the potential for soil freezing,
the time passing between excavation and construction should be minimized. Blankets, straw,
soil cover, or heating may be used to discourage the soil from freezing. DRAFT
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9.11 Site Drainage
Infiltration of water into subsurface soils can lead to soil movement and associated distress, and
chemically and physically related deterioration of concrete and masonry structures. To reduce
the potential for infiltration of moisture into subsurface soils at the site, we recommend the
following:
• Positive drainage should be established and maintained away from the proposed buildings.
Positive drainage may be established by providing a surface gradient for paved areas of 2 to
5 percent or more for a distance of 10 feet or more away from structures. Where concrete
flatwork is placed adjacent to structures and other considerations are required by law, such
as ADA requirements, slopes of 1 percent or more are considered acceptable. For unpaved
areas, positive drainage may be established by a slope of 5 to 10 percent for 10 feet or
more away from structures, where possible.
• Adequate surface drainage should be provided to channel surface water away from on-site
structures and off paved surfaces to a suitable outlet such as a storm drain. Adequate
surface drainage may be enhanced by utilization of graded swales, area drains, and other
drainage devices. Surface run-off should not be allowed to pond near structures.
• Building roof drains should have downspouts tightlined to an appropriate outlet, such as a
storm drain or the street, away from structures, pavements, and flatwork. If tightlining of the
downspouts is not practicable, they should discharge 5 feet or more away from structures
and onto surfaces that slope away from the structure. Downspouts should not be allowed to
discharge onto the ground surface adjacent to building foundations or on exterior walkways.
• The possibility of moisture infiltration beneath a structure, in the event of plumbing leaks,
should be considered in the design and construction of underground water and sewer
conduits. Permitting increases in moisture to the building supporting soils may result in a
decrease in bearing capacity and an increase in settlement, heave, and/or differential
movement. Incorporating a perimeter drainage system around the building foundations that
will aid in reduction of the moisture infiltration of subsurface soils may be considered. Due to
the proposed construction and anticipated utilities within the structures, not placing the
perimeter drainage would be considered a low risk to the owner.
• Irrigated landscaping, consisting of sprinklers to water plants with high demands for water,
should not be placed within 10 feet of the building(s). Drip irrigation is considered acceptable
within this zone.
• Utility trenches should be backfilled with compacted, low permeability fill (i.e. permeability of
5-10 cm/s or less) within 5 feet of the building. Planters, if any, should be maintained 10 feet
or more from the building and constructed with closed bottoms or with drainage systems to
drain excess irrigation away from the building.
9.12 Construction Observation and Testing
A qualified geotechnical consultant should perform appropriate observation and testing services
during grading and construction operations. These services should include observation of any
soft, loose, or otherwise unsuitable soils, evaluation of subgrade conditions where soil removals
are performed, evaluation of the suitability of proposed borrow materials for use as fill, DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 27
evaluation of the stability of open temporary excavations, evaluation of the results of any
subgrade stabilization or dewatering activities, and performance of observation and testing
services during placement and compaction of engineered fill and backfill soils.
The geotechnical consultant should also perform observation and testing services during
placement of concrete, mortar, grout, asphalt concrete, and steel reinforcement. If another
geotechnical consultant is selected to perform observation and testing services for the project,
we request that the selected consultant provide a letter to the owner, with a copy to Ninyo &
Moore, indicating that they fully understand our recommendations and that they are in full
agreement with the recommendations contained in this report. Qualified subcontractors utilizing
appropriate techniques and construction materials should perform construction of the proposed
improvements.
9.13 Plan Review
The recommendations presented in this report are based on preliminary design information for
the proposed project and on the findings of our geotechnical evaluation. When finished, project
plans and specifications should be reviewed by the geotechnical consultant prior to submitting
the plans and specifications for bid. Additional field exploration and laboratory testing may be
needed upon review of the project design plans.
9.14 Pre-Construction Meeting
We recommend a pre-construction meeting be held. The owner or the owner’s representative,
the architect, the contractor, and the geotechnical consultant should be in attendance to discuss
the plans and the project.
10 LIMITATIONS
The field evaluation, laboratory testing, and geotechnical analyses presented in this
geotechnical report have been conducted in general accordance with current practice and the
standard of care exercised by geotechnical consultants performing similar tasks in the project
area. No warranty, expressed or implied, is made regarding the conclusions, recommendations,
and opinions presented in this report. There is no evaluation detailed enough to reveal every
subsurface condition. Variations may exist and conditions not observed or described in this
report may be encountered during construction. Uncertainties relative to subsurface conditions
can be reduced through additional subsurface exploration. Additional subsurface evaluation will
be performed upon request. Please also note that our evaluation was limited to assessment of DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 28
the geotechnical aspects of the project, and did not include evaluation of structural issues,
environmental concerns, or the presence of hazardous materials.
This document is intended to be used only in its entirety. No portion of the document, by itself, is
designed to completely represent any aspect of the project described herein. Ninyo & Moore
should be contacted if the reader requires additional information or has questions regarding the
content, interpretations presented, or completeness of this document.
This report is intended for design purposes only. It does not provide sufficient data to prepare an
accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant
perform an independent evaluation of the subsurface conditions in the project areas. The
independent evaluations may include, but not be limited to, review of other geotechnical reports
prepared for the adjacent areas, site reconnaissance, and additional exploration and
laboratory testing.
Our conclusions, recommendations, and opinions are based on an analysis of the observed site
conditions. If geotechnical conditions different from those described in this report are
encountered, our office should be notified and additional recommendations, if warranted, will be
provided upon request. It should be understood that the conditions of a site could change with
time as a result of natural processes or the activities of man at the subject site or nearby sites.
In addition, changes to the applicable laws, regulations, codes, and standards of practice may
occur due to government action or the broadening of knowledge. The findings of this report may,
therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore
has no control.
This report is intended exclusively for use by the client. Any use or reuse of the findings,
conclusions, and/or recommendations of this report by parties other than the client is
undertaken at said parties’ sole risk.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 29
11 REFERENCES
American Association of State Highway and Transportation Officials (AASHTO), 1993, AASHTO
Guide for Design of Pavement Structures.
American Association of State Highway and Transportation Officials (AASHTO), 2011, Standard
Specifications for Transportation Materials and Methods of Sampling and Testing, 31st
Edition, and Provisional Standards.
American Concrete Institute (ACI), 2010, Guide to Design of Slabs-On-Ground (ACI 360R-10).
American Concrete Institute (ACI), 2011 , Building Code Requirements for Structural Concrete
(ACI 318-11 ) and Commentary.
American Concrete Institute (ACI), 2015, Guidelines for Concrete Floor and Slab Construction
(ACI 302.1R-15).
American Society for Testing and Materials (ASTM), 2015 Annual Book of ASTM Standards.
Colorado Association of Geotechnical Engineers (CAGE), 2007, Geotechnical Study Guidelines
for Light Commercial and Residential Buildings in Colorado, dated September.
Colorado Association of Geotechnical Engineers (CAGE), 1996, Guideline for Slab Performance
Risk Evaluation and Residential Basement Floor System Recommendations (Denver
Metropolitan Area), dated December.
Colorado Department of Transportation (CDOT), 2017, Standard Specifications for Road and
Bridge Construction.
Colton, Roger B., 1978, Geologic Map of the Boulder-Fort Collins-Greeley Area, Colorado,
United States Geological Survey.
Hart, Stephen S., 1973-1974, Potentially Swelling Soil and Rock in the Front Range Urban
Corridor, Colorado: Colorado Geological Survey, Sheet 1 of 4.
International Code Council, 2015, International Building Code.
Kirkham, R.M., and Rogers, W.P., 1981, Earthquake potential in Colorado: Colorado Geological
Survey Bulletin 43, 171 p., 3 pls.
Ninyo & Moore, In-house proprietary information.
Occupational Safety and Health Administration (OSHA), 2005, OSHA Standards for the
Construction Industry, 29 CFR Part 1926: dated June.
OSHPD, 2019, Seismic Design Maps, http://seismicmaps.org/.
Rogers, W. P. and Widmann B. L., Fault Number 2324, Golden Fault; in Quaternary Fault and
Fold Database of the United States: U.S. Geological Survey website,
http://earthquakes.usgs.gov/regional/qfaults.
Trimble, Donald E., 1980, The Geologic Story of the Great Plains, Geological Survey Bulletin
1493.
United States Geological Survey and Colorado Geological Survey (USGS & CGS), 2019,
Quaternary fault and fold database for the United States, accessed April 18, 2019, from
USGS web site: http://earthquakes.usgs.gov/regional/qfaults/.
Google Earth, October 1999, October 2017. DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
Appendix A
Photographic Documentation
FIGURES
DRAFT
FIGURE 1
bsm file no: 1710vmap0619501710001 | 6/19
REDMAN DRIVE AND NORTHWEST FRONTAGE ROAD
FORT COLLINS, COLORADO
POUDRE VALLEY DEVELOPMENT
SITE LOCATION
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
Source: US Geological Survey 7.5-minute topographic map, Fort Collins and Timnath, Colorado, 2016.
0 2000
FEET
NN
APPROXIMATE
SITE LOCATION
DRAFT
Source: NAVTEQ, 10/14/17.bsm file no: 1710blm0619FIGURE 2
501710001 | 6/19
REDMAN DRIVE AND NORTH WEST FRONTAGE ROAD
FORT COLLINS, COLORADO
POUDRE VALLEY DEVELOPMENT
BORING LOCATIONS
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
0 120
FEET
NN
Geotechnical & Environmental Sciences Consultants
B-16
B-9 B-10
B-1
B-2
B-2B-4
B-17
B-14 B-15 B-7 B-8
B-3
B-6
B-13
B-12
B-11
5
REDMAN DRIVE NORTH WEST FRONTAGE ROADU.S. INTERSTATE 25LEGEND
Boring LocationB-17
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX A
Boring Logs
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX A
BORING LOGS
Field Procedure for the Collection of Disturbed Samples
Disturbed soil samples were obtained in the field using the following methods.
Bulk Samples
Bulk samples of representative earth materials were obtained from the exploratory borings.
The samples were bagged and transported to the laboratory for testing.
Field Procedure for the Collection of Ring-lined Samples
Ring-lined soil samples were obtained in the field using the following methods.
The Modified California Split-Barrel Drive Sampler
The sampler, with an external diameter of 3.0 inches, was lined with thin brass rings with
inside diameters of approximately 2.4 inches. The sample barrel was driven into the ground
with the weight of a hammer in general accordance with ASTM D 3550. The driving weight
was permitted to fall freely. The approximate length of the fall, the weight of the hammer or
bar, and the number of blows per foot of driving are presented on the boring logs as an
index to the relative resistance of the materials sampled. The samples were removed from
the sample barrel in the brass rings, sealed, and transported to the laboratory for testing.
The California Drive Sampler
The sampler, with an external diameter of 2.4 inches, was lined with four 4-inch long, thin
brass rings with inside diameters of approximately 1.9 inches. The sample barrel was
driven into the ground with the weight of a hammer in general accordance with ASTM
D 3550. The driving weight was permitted to fall freely. The approximate length of the fall,
the weight of the hammer, and the number of blows per foot of driving are presented on the
boring logs as an index to the relative resistance of the materials sampled. The samples
were removed from the sample barrel in the brass liners, sealed, and transported to the
laboratory for testing.
DRAFT
SOIL CLASSIFICATION CHART PER ASTM D 2488
PRIMARY DIVISIONS SECONDARY DIVISIONS
GROUP SYMBOL GROUP NAME
COARSE-
GRAINED
SOILS
more than
50% retained
on No. 200
sieve
GRAVEL
more than
50% of
coarse
fraction
retained on
No. 4 sieve
CLEAN GRAVEL
less than 5% fines
GW well-graded GRAVEL
GP poorly graded GRAVEL
GRAVEL with
DUAL
CLASSIFICATIONS
5% to 12% fines
GW-GM well-graded GRAVEL with silt
GP-GM poorly graded GRAVEL with silt
GW-GC well-graded GRAVEL with clay
GP-GC poorly graded GRAVEL with clay
GRAVEL with
FINES
more than
12% fines
GM silty GRAVEL
GC clayey GRAVEL
GC-GM silty, clayey GRAVEL
SAND
50% or more
of coarse
fraction
passes
No. 4 sieve
CLEAN SAND
less than 5% fines
SW well-graded SAND
SP poorly graded SAND
SAND with
DUAL
CLASSIFICATIONS
5% to 12% fines
SW-SM well-graded SAND with silt
SP-SM poorly graded SAND with silt
SW-SC well-graded SAND with clay
SP-SC poorly graded SAND with clay
SAND with FINES
more than
12% fines
SM silty SAND
SC clayey SAND
SC-SM silty, clayey SAND
FINE-
GRAINED
SOILS
50% or
more passes
No. 200 sieve
SILT and
CLAY
liquid limit
less than 50%
INORGANIC
CL lean CLAY
ML SILT
CL-ML silty CLAY
ORGANIC
OL (PI > 4)organic CLAY
OL (PI < 4)organic SILT
SILT and
CLAY
liquid limit
50% or more
INORGANIC
CH fat CLAY
MH elastic SILT
ORGANIC
OH (plots on or
above “A”-line)organic CLAY
OH (plots below
“A”-line)organic SILT
Highly Organic Soils PT Peat
USCS METHOD OF SOIL CLASSIFICATION
Explanation of USCS Method of Soil Classification
PROJECT NO.DATE FIGURE
APPARENT DENSITY - COARSE-GRAINED SOIL
APPARENT
DENSITY
SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER
SPT (blows/foot)
MODIFIED SPLIT BARREL (blows/foot)
SPT (blows/foot)
MODIFIED SPLIT BARREL (blows/foot)
Very Loose < 4 < 8 < 3 < 5
Loose 5 - 10 9 - 21 4 - 7 6 - 14
Medium
Dense 11 - 30 22 - 63 8 - 20 15 - 42
Dense 31 - 50 64 - 105 21 - 33 43 - 70
Very Dense > 50 > 105 > 33 > 70
CONSISTENCY - FINE-GRAINED SOIL
CONSIS-TENCY
SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER
SPT (blows/foot)
MODIFIED SPLIT BARREL
(blows/foot)
SPT (blows/foot)
MODIFIED SPLIT BARREL (blows/foot)
Very Soft < 2 < 3 < 1 < 2
Soft 2 - 4 3 - 5 1 - 3 2 - 3
Firm 5 - 8 6 - 10 4 - 5 4 - 6
Stiff 9 - 15 11 - 20 6 - 10 7 - 13
Very Stiff 16 - 30 21 - 39 11 - 20 14 - 26
Hard > 30 > 39 > 20 > 26
LIQUID LIMIT (LL), %PLASTICITY INDEX (PI), %0 10
107
4
20
30
40
50
60
70
0 20 30 40 50 60 70 80 90 100
MH or OH
ML or OLCL - ML
PLASTICITY CHART
GRAIN SIZE
DESCRIPTION SIEVE
SIZE
GRAIN
SIZE
APPROXIMATE
SIZE
Boulders > 12”> 12”Larger than
basketball-sized
Cobbles 3 - 12”3 - 12”Fist-sized to
basketball-sized
Gravel
Coarse 3/4 - 3”3/4 - 3”Thumb-sized to
fist-sized
Fine #4 - 3/4”0.19 - 0.75”Pea-sized to
thumb-sized
Sand
Coarse #10 - #4 0.079 - 0.19”Rock-salt-sized to
pea-sized
Medium #40 - #10 0.017 - 0.079”Sugar-sized to
rock-salt-sized
Fine #200 - #40 0.0029 -
0.017”
Flour-sized to
sugar-sized
Fines Passing #200 < 0.0029”Flour-sized and
smaller
CH or OH
CL or OL
DRAFT
BORING LOG EXPLANATION SHEET
0
5
XX/XX
10
15
Bulk sample.
Modified split-barrel drive sampler.
2-inch inner diameter split-barrel drive sampler.
No recovery with modified split-barrel drive sampler, or 2-inch inner diameter split-barrel
drive sampler.
Sample retained by others.
Standard Penetration Test (SPT).
No recovery with a SPT.
Shelby tube sample. Distance pushed in inches/length of sample recovered in inches.
No recovery with Shelby tube sampler.
Continuous Push Sample.
Seepage.
Groundwater encountered during drilling.
Groundwater measured after drilling.
SM MAJOR MATERIAL TYPE (SOIL):
Solid line denotes unit change.
CL Dashed line denotes material change.
Attitudes: Strike/Dip
b: Bedding
c: Contact
j: Joint
f: Fracture
F: Fault
cs: Clay Seam
s: Shear
bss: Basal Slide Surface
sf: Shear Fracture
sz: Shear Zone
sbs: Shear Bedding Surface
The total depth line is a solid line that is drawn at the bottom of the boring.
20
BORING LOG
Explanation of Boring Log Symbols
PROJECT NO. DATE FIGUREDEPTH (feet)BLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)CLASSIFICATION U.S.C.S.6<0%2/%XON'ULYHQ6$03/(6DRAFT
0
10
20
30
40
17
5
43
7
34
20.9
15.0
6.7
106.6
106.2
122.2
CH
CL-ML
SW
SM
SP
LOAM:Brown, moist, very stiff, fat CLAY; trace sand and gravel.
ALLUVIUM:Red, moist, firm, sandy silty CLAY.
Red with yellow and gray, wet, dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Light brown with red, wet, loose, silty SAND; trace iron oxide staining.
Light brown with red, wet, very dense, fine to medium SAND; trace clay.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 1
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-1
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
5
15
90/10"
21.4
17.3
103.9
104.3
CH
CL
SW
LOAM:Brown with white, moist, very stiff, sandy fat CLAY with few calcium mineralizations.
ALLUVIUM:Red, moist, firm, sandy lean CLAY; trace gravel.
Light brown with red, moist, medium dense, fine to coarse SAND; trace clay.
@12': Groundwater encountered during drilling.
Wet; very dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 12 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 2
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-2
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
12
5
25
7
16.8
17.1
3.8
111.8
106.8
CH
CL
SW
LOAM:Brown, moist, sandy fat CLAY.
ALLUVIUM:Pale red to red, moist, stiff, lean CLAY with sand.
Firm.
Pale red to light brown, moist to wet, moderately dense, fine to coarse SAND with gravel;
trace clay.
@11': Groundwater encountered during drilling.
Loose with few clayey interlayers.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 3
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-3
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
10
3
36
17
14.4
16.0
6.1
113.2
109.5
123.7
CL
SC
SW
LOAM:Light brown to brown, moist, stiff, sandy lean CLAY; trace gravel.
ALLUVIUM:Reddish brown, moist, very loose, clayey SAND.
Reddish brown, moist to wet, medium dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 4
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-4
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
19
6
24
20
20.8
15.3
106.7
107.8
CH
CL
SW
LOAM:Reddish brown to brown mottled, moist, very stiff, fat CLAY; trace sand.
Red, moist, firm, sandy lean CLAY.
ALLUVIUM:Light brown to red, moist, medium dense, fine to coarse SAND; trace clay.
@11': Groundwater encountered during drilling.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 5
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-5
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
7
24
9
19.1
27.0
2.4
106.1
93.9
CH
CH
SW
LOAM:Reddish brown, moist, stiff, fat CLAY; trace sand and gravel.
ALLUVIUM:Pale red to red, moist, stiff, fat CLAY; trace sand.
Reddish brown with white and gray, moist, medium dense, fine to coarse SAND with
gravel; trace clay.
@11': Groundwater encountered during drilling.
Total Depth = 15.5 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 6
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-6
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
14
6
37
37
20
16.0
15.8
5.7
110.7
107.6
128.1
CL
CL
SW
LOAM:Red to brown, moist, very stiff, lean CLAY; trace sand.
Red to reddish brown, moist, firm, sandy lean CLAY.
ALLUVIUM:Pale red to red, moist to wet, medium dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Pale brown to yellowish brown.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 7
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-7
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
19
20
27
32
51
26.9
7.7
98.6
126.0
CL
CH
SW
LOAM:Brown to reddish brown, moist, very stiff, fat CLAY; trace sand, gravel, and few calcium
mineralizations.
ALLUVIUM:Red to reddish brown, moist, very stiff, fat CLAY; trace sand and gravel.
Red to reddish brown, moist, medium dense, fine to coarse SAND with gravel; trace clay.
@12': Groundwater encountered during drilling.
Wet; dense.
Very dense; grading to clayey sand.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 12 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 8
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-8
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
17
16
50/5"
20
21.9
1.8
102.0
123.1
CH
SW-SC
LOAM:Brown with white, moist, very stiff, sandy fat CLAY with few calcium mineralizations.
ALLUVIUM:Reddish brown to yellowish brown, moist, medium dense, fine to coarse SAND with clay
and gravel.
@9': Groundwater encountered during drilling.
Very dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 9
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-9
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
14
6
22
15
30
21.2
8.2
103.7
120.5
CH
SC-SM
SW
LOAM:Brown and reddish brown mottled, moist, very stiff, sandy fat CLAY.
ALLUVIUM:Red to reddish brown, moist, loose, silty, clayey SAND with gravel.
@9': Groundwater encountered during drilling.Light brown to reddish brown, wet, medium dense, fine to coarse SAND; trace clay.
Dense.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 10
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-10
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
6
12
50/3"
23
11.4
2.0
107.8
CL
SP
LOAM:Pale red to red, moist, firm, lean CLAY; trace sand.
ALLUVIUM:Reddish yellow to pale red, moist, loose, fine to medium SAND.
@9': Groundwater encountered during drilling.Very dense.@10': Scattered cobbles.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 11
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-11
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
15
13
8
9
1.1
CH
SW
LOAM:Brown, moist, very stiff, sandy fat CLAY with gravel.
ALLUVIUM:Red to reddish brown, moist, loose, fine to coarse SAND with gravel; trace clay.
@8.5': Groundwater encountered during drilling.
Wet; medium dense; with few clayey fine sand interlayers.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 8.5 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 12
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-12
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
4
6
50
30
15.5
4.1
106.5
106.0
CH
CL
SC
SW
LOAM:Brown, moist, sandy fat CLAY.
ALLUVIUM:Red, moist, firm, sandy lean CLAY; trace gravel.
Red with gray and brown, moist, loose, clayey SAND with gravel.
Red with gray and brown, moist, very dense, fine to coarse SAND; trace clay.
@9': Groundwater encountered during drilling.
Dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/07/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 13
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/07/2019 BORING NO.B-13
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
17
64
37
14
10.4
8.0
119.9
142.4
CH
SW-SC
LOAM:Brown to dark brown, moist, stiff, sandy fat CLAY.
ALLUVIUM:Reddish yellow to yellow, dry, medium dense, fine to coarse SAND with clay and gravel.
@9': Groundwater encountered during drilling.Wet; dense.
Medium dense.
Light brown.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 14
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-14
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
10
50
27
19
17.2
6.8
109.5
102.6
CH
SM
SP-SC
LOAM:Brown to dark brown, moist, very stiff, fat CLAY with sand; trace gravel and calcium
mineralizations.
ALLUVIUM:Pale red to reddish yellow, dry, loose, silty SAND; trace gravel.
Pale red to reddish yellow, wet, very dense, fine to medium SAND with clay and gravel.
@10': Groundwater encountered during drilling.
Dense.
Medium dense.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 15
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO.B-15
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
5
50/2"
11
14
12.4 110.9
CL
SC
LOAM:Brown with white and red, moist, stiff, sandy lean CLAY; trace gravel.
ALLUVIUM:Pale red to pale reddish brown, moist to wet, loose, clayey SAND; trace gravel and
scattered cobbles.
@8.5': Groundwater encountered during drilling.Very dense.
Medium dense; few clayey interlayers.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 8.5 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 16
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-16
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
14
29
19
16.7
5.8
8.1
109.9
124.6
132.7
CL
SC
SW
LOAM:Brown with white and red, moist, very stiff, lean CLAY with sand; trace gravel.
ALLUVIUM:Reddish brown to brown, moist, loose, clayey SAND with gravel.
@8': Groundwater encountered during drilling.
Wet; medium dense.
Reddish brown, wet, medium dense, fine to coarse SAND; trace clay and gravel.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/07/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 17
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 |7/19DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO.B-17
GROUND ELEVATION --SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer)DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT~4851.5
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX B
Laboratory Testing
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX B
LABORATORY TESTING
Classification
Soils were visually and texturally classified in accordance with the Unified Soil Classifications
System (USCS) in general accordance with ASTM D 2488. Soil classifications are indicated on
the logs of the exploratory excavations in Appendix A.
In-Place Moisture and Density Tests
The moisture content and dry density of ring-lined samples obtained from the exploratory
borings were evaluated in general accordance with ASTM D 2837. These test results are
presented on the logs of the exploratory borings in Appendix A.
Atterberg Limits
Tests were performed on selected representative fine-grained soil samples to evaluate the liquid
limit, plastic limit, and plasticity index in general accordance with ASTM D 4318. These test
results were utilized to evaluate the soil classification in accordance with the Unified Soil
Classification System. The test results and classifications are shown on Figures B-1
through B-4.
No. 200 Sieve Analysis
An evaluation of the percentage of particles finer than the No. 200 sieve in selected soil
samples was performed in general accordance with ASTM D 1140. The results of the tests are
presented on Figures B-5 through B-7.
Consolidation/Swell Tests
Consolidation/swell tests were performed on selected ring-lined soil samples in general
accordance with ASTM D 4546. The samples were inundated during testing to represent
adverse field conditions. The percent of consolidation or swell for each load cycle was recorded
as a ratio of the amount of vertical compression to the original height of the sample. The results
of the tests are summarized on Figures B-8 through B-25.
Soil Corrosivity Tests
A soil pH test was performed on a representative sample in general accordance with ASTM Test
Method D 4972. A soil minimum resistivity test was performed on a representative sample in
general accordance with AASHTO T288. The sulfate content of a selected sample was
evaluated in general accordance with CDOT Test Method CP-L 2103. The chloride content of a
selected sample was evaluated in general accordance with CDOT Test Method CP-L 2104. The
test results are presented on Figure B-26.
DRAFT
∆
X
+
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
18 35
15 36
4217
CH
CH
CH
CH
CH
CHB-5
4.0-5.0 17
CL
59
29
CL
16
7
13
16 31
CL-ML
CL
2.0-3.0
13
17
CL
2.0-3.0 4057
SC
CH
CL-ML
CH
EQUIVALENT
USCS
CL
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft)LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-1
PLASTIC
LIMIT
17
B-6 4.0-5.0
4.0-5.0
14.0-15.5
24
30
B-6
B-1
B-1
B-2
B-4
2.0-3.0
2.0-3.0
47
51
53
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
CH or OH
CL or OL
MH or OH
ML or OLCL -ML
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120PLASTICITY INDEX, PI LIQUID LIMIT, LL
FIGURE B-1
ATTERBERG LIMITS TEST RESULTS DRAFT
∆
X
+
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
B-15 4.0-5.0
2.0-3.0
4.0-5.0
51
56
B-15
B-8
B-8
B-10
B-10
2.0-3.0
2.0-3.0
22
54
NP
EQUIVALENT
USCS
CH
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft)LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-7
PLASTIC
LIMIT
17
16
SC-SM
2.0-3.0 3046
CH
CL
CH
CL
B-12
2.0-3.0 23
CL-ML
62
62
CH
45
28
39
17 5
CH
CH
4.0-5.0
17
SM
CH
CH
NP
CH
CH
NP NP
17 37
4418
CH or OH
CL or OL MH or OH
ML or OLCL -ML
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120PLASTICITY INDEX, PI LIQUID LIMIT, LL
FIGURE B-2
ATTERBERG LIMITS TEST RESULTS DRAFT
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
2.0-3.0 18
CL
31
-
CL
17
2.0-3.0 2946
SC
CL
CL
CL
EQUIVALENT
USCS
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft)LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-16
PLASTIC
LIMIT
134.0-5.0
49
-
B-17
B-17
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
CH or OH
CL or OL
MH or OH
ML or OLCL -ML
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120PLASTICITY INDEX, PI LIQUID LIMIT, LL
FIGURE B-3
ATTERBERG LIMITS TEST RESULTS DRAFT
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
7/19501710001
B-6 100Pale Red to Red Fat CLAY; Trace Sand4.0-5.0 96 CH
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
DESCRIPTION
99 88
EQUIVALENT
USCS
4.0-5.0
2.0-3.0
B-3
B-1
B-1
Red Sandy Lean CLAY; Trace Gravel
Pale Red to Red Lean CLAY with Sand
Brown Fat CLAY; Trace Sand and Gravel
Red Sandy Silty CLAY CL-ML
2.0-3.0
B-4
2.0-3.0B-5
Red Sandy Lean CLAY
Reddish Brown Fat CLAY; Trace Sand and Gravel
B-5
B-6
Light Brown to Brown Sandy Lean CLAY; Trace Gravel
Reddish Brown to Brown Mottled Fat CLAY; Trace
Sand
100 57
CH
4.0-5.0
2.0-3.0
2.0-3.0
4.0-5.0
B-2
99
92
100
100 91
62
CH
CL
88
CL69
CH
99
100
CL
CL
65
80
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-4DRAFT
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
7/19
99
100
CH
CH
90
98
Brown to Reddish Brown Fat CLAY; Trace Sand and
Gravel
Red to Reddish Brown Fat CLAY; Trace Sand and
Gravel
CH
CL
77
SC-SM25
CH
79
96
82 55
67
100 70
CL
2.0-3.0
4.0-5.0
2.0-3.0
4.0-5.0
B-8
992.0-3.0
B-10
2.0-3.0B-12 Brown Sandy Fat CLAY with Gravel
Red Sandy Lean CLAY; Trace GravelB-13
B-15
Red to Reddish Brown Silty, Clayey SAND with Gravel
Brown to Dark Brown Fat CLAY with Sand; Trace
Gravel
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
DESCRIPTION
100 93
EQUIVALENT
USCS
2.0-3.0
4.0-5.0
B-8
B-7
B-7
Red to Brown Lean CLAY; Trace Sand
Red to Reddish Brown Sandy Lean CLAY CL
501710001
B-15 964.0-5.0 23 SM
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
Pale Red to Reddish Yellow Silty SAND; Trace Gravel
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-5DRAFT
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
7/19501710001
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
DESCRIPTION
95 60
EQUIVALENT
USCS
B-16
B-17
Brown with White and Red Sandy Lean CLAY; Trace
Gravel
Brown with White and Red Lean CLAY with Sand;
Trace Gravel
Reddish Brown to Brown Clayey SAND with Gravel
95 77
CL
4.0-5.0
2.0-3.0
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
2.0-3.0
B-17 75
CL
SC18
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-6DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SW2.25 11.3 1.0 4.4
Passing
No. 200
(percent)
Cc
--0.20 0.67B-1 9.0-10.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-7DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SW-SC4.50 19.6 1.2 5.4
Passing
No. 200
(percent)
Cc
--0.23 1.10B-9 4.0-5.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-8DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
Cu
Equivalent
USCS
SP4.75 31.7 0.4 4.6
Passing
No. 200
(percent)
Cc
--0.15 0.54B-11 4.0-5.0
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-9DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SW3.90 9.8 1.0 3.2
Passing
No. 200
(percent)
Cc
--0.40 1.25B-12 4.0-5.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-10DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SC------16
Passing
No. 200
(percent)
Cc
------B-13 4.0-5.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-11DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SW-SC5.40 18.0 1.4 5.1
Passing
No. 200
(percent)
Cc
--0.30 1.50B-14 4.0-5.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-12DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SP-SC2.50 83.3 3.1 12
Passing
No. 200
(percent)
Cc
--0.03 0.48B-15 9.0-10.5
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-13DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SC------32
Passing
No. 200
(percent)
Cc
------B-16 14.0-15.5
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-14DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2"1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
----
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
7/19501710001
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)D30
Fine
Sample
Location
100
D10
16 200
D60 Cu
Equivalent
USCS
SC------13
Passing
No. 200
(percent)
Cc
------B-17 9.0-10.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-15DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-1
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
19.8%
21.8%
3.4
5700
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-16DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-1
4.0-5.0
CL-ML
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
15.8%
20.9%
-
-
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-17DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-4
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
14.7%
18.7%
3.6
3370
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-18DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-6
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
18.9%
21.5%
2.9
2600
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-19DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-6
4.0-5.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
24.2%
27.8%
0.6
680
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-20DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-7
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
15.6%
21.0%
3.3
4000
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-21DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-8
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
16.8%
22.9%
5.0
2700
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-22DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-8
4.0-5.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
22.2%
23.7%
1.5
1850
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-23DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-10
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
18.9%
22.3%
3.8
3800
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-24DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-12
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
16.9%
21.1%
1.4
2350
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-25DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-15
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
18.2%
20.7%
4.2
6400
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-26DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-16
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
12.9%
20.4%
2.4
3000
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-27DRAFT
1 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4972
2 PERFORMED IN GENERAL ACCORDANCE WITH AASHTO T288
3 PERFORMED IN GENERAL ACCORDANCE WITH CDOT TEST METHOD CP-L 2103
4 PERFORMED IN GENERAL ACCORDANCE WITH CDOT TEST METHOD CP-L 2104
7/19
pH 1SAMPLE
DEPTH (ft)
SAMPLE
LOCATION
RESISTIVITY 2
(ohm-cm)
SULFATE CONTENT 3
(ppm) (%)
8.1 401,667 250 0.025B-16 and B-17 0.0-5.0
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001
CHLORIDE
CONTENT 4
(ppm)
CORROSIVITY TEST RESULTS
FIGURE B-28DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
6001 South Willow Drive, Suite 195 | Greenwood Village, Colorado 80111 | p. 303.629.6000
ARIZONA | CALIFORNIA | COLORADO | NEVADA | TEXAS | UTAH
www.ninyoandmoore.com
DRAFT
309 South Summit View Drive, Unit 6 | Fort Collins, Colorado 805241 | p. 303.629.6000 | www.ninyoandmoore.com
October 3, 2019
Project No. 501710003
Mr. Josh Heiney
Comunale Properties
1855 South Pearl Street, Suite 20
Denver, Colorado 80210
Subject: Supplemental Geotechnical Evaluation
Percolation Testing
Mulberry Connection
Redman Drive & NW Frontage Road
Fort Collins, Colorado
Reference: Ninyo & Moore, 2019, Geotechnical Evaluation, Proposed Poudre Valley
Development, Redman Drive & NW Frontage Road, Fort Collins, Colorado, dated
July 2.
Dear Mr. Heiney:
In accordance with your authorization, we have performed a supplemental geotechnical evaluation
for the proposed Mulberry Connection industrial project located at the northwest corner of Redman
Drive and Northwest Frontage Road in Fort Collins, Colorado (Figure 1). The purpose of our
supplemental geotechnical evaluation was to assess the percolation rate within the proposed
stormwater detention ponds (Figure 2). This report presents the results of the percolation testing.
Our referenced report dated July 2, 2019 presented our methodology, findings, conclusions, and
limitations regarding the geotechnical conditions and our geotechnical recommendations for the
proposed development. Recommendations and limitations provided in the referenced report
remain valid, except where superseded herein.
PROPOSED CONSTRUCTION
As a part of the proposed development, detention basins will be constructed to the south, west,
and east of the proposed structures. We understand the basins will require excavations ranging
from less than 1 foot to up to approximately 3 feet below existing site grades.
PERCOLATION TESTING
Percolation testing was performed by hand-excavating 12, approximately 8- to 10-inch diameter,
percolation holes that ranged from approximately 30 to 37 inches below the existing site grades.
Borings performed as a part of our subsurface exploration in the vicinity of the detention basins
Ninyo & Moore | Mulberry Connection Percolation Tests, Fort Collins, Colorado | 501710003 | October 3, 2019
were utilized for determination of soil profiles in the area. Along the eastern and southeastern
portion of the site, subsurface conditions generally consisted of approximately 2 to 4 feet of clay
loam underlain by clay alluvial soils to depths of approximately 9 to 9.5 feet below ground surface
(bgs). Sandy alluvial deposits were encountered below the clay alluvial deposits. Along the western
and southwestern portion of the site, approximately 4 feet of clay loam was encountered underlain
by sandy alluvial deposits. Groundwater was observed in our borings at depths of approximately
8.5 to 12 feet bgs.
Our percolation testing procedures consisted of excavating the percolation holes with an electric
auger. Once excavated, the sides of the holes were roughening, as needed, and the percolation
holes were pre-soaked. Approximately 2 inches of sand was added to the bottom of the holes prior
to the holes being pre-soaked for approximately 24 hours. In accordance with Larimer County
Health and Environment percolation testing requirements, each percolation test was conducted
over a 4-hour period with measurements obtained at 30-minute intervals. The water level drop in
the final 30-minute interval was used to calculate the percolation rate.
The results of the percolation testing are presented in Appendix A. In order to account for the site
variability, the limited number of tests performed, and to account for siltation, a correction factor of
2 should be applied to the calculated average percolation rate per basin.
This report is intended exclusively for use by the client. Any use or reuse of the findings,
conclusions, and/or recommendations of this report by parties other than the client is undertaken at
said parties’ sole risk.
We appreciate the opportunity to be of continued service to you during this phase of the project.
Respectfully submitted,
NINYO & MOORE
Kelley Lange, EI
Senior Staff Engineer
Brian F. Gisi, PE
Principal Engineer
KL/BFG
Attachments: Figure 1 – Site Location
Figure 2 – Percolation Test Locations
Appendix A – Percolation Test Results
Distribution: (1) Addressee (via email)
(1) Mr. Dan Skeehan, PE, Kimley Horn (via email)
10/3/2019
Ninyo & Moore | Mulberry Connection Percolation Tests, Fort Collins, Colorado | 501710003 | October 3, 2019
Appendix A
Photographic Documentation
FIGURES
FIGURE 1
bsm file no: 1710vmap0619501710003 | 10/19
REDMAN DRIVE AND NORTHWEST FRONTAGE ROAD
FORT COLLINS, COLORADO
POUDRE VALLEY DEVELOPMENT
SITE LOCATION
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
Source: US Geological Survey 7.5-minute topographic map, Fort Collins and Timnath, Colorado, 2016.
0 2000
FEET
NN
APPROXIMATE
SITE LOCATION
FIGURE 2
bsm file no: 1710sp0919501710003 | 9/19
PERCOLATION TEST LOCATIONS
FORT COLLINS, COLORADO
MULBERRY CONNECTION PERCOLATION TESTING
SOURCE: KIMLEY-HORN AND ASSOCIATES, 08/14/2019.
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
0 120
FEET
NN
Geotechnical & Environmental Sciences Consultants
LEGEND
Percolation Test LocationP4-3
P1-1
P1-2
P1-3
P2-1 P2-2 P2-3 P3-1 P3-2 P3-3
P4-3
P4-2
P4-1
REDMAN DRIVE NORTHWEST FRONTAGE ROAD
Ninyo & Moore | Mulberry Connection Percolation Tests, Fort Collins, Colorado | 501710003 | October 3, 2019
APPENDIX A
Percolation Tests
Project Number:501710003 Test Date:9/13/2019
Project:Mulberry Connection Tested By:FT
Location:Fort Collins Elevation:-+/- (MSL)
Hole Number Hole Depth Time Interval Initial Water
Level Height
at Start
Final Water
Level
Height at
End
Drop in
Water Level
Average
Percolation
Rate
Time Start Time Stop
(inches)(minutes)(inches)(inches)(inches)(min/in)(hh:mm)(hh:mm)
P1-1 37 0 29.00 29.00 0.00
Height of Sand/Gravel 30 29.00 27.00 2.00 15.00
added at bottom (in):2.0 30 28.50 27.50 1.00 30.00
30 29.50 25.50 4.00 7.50
30 29.00 25.00 4.00 7.50
30 29.00 27.00 2.00 15.00
30 29.50 27.00 2.50 12.00
30 28.50 26.50 2.00 15.00
30 29.00 27.00 2.00 15.00
P1-2 31 0 23.00 23.00 0.00
Height of Sand/Gravel 30 23.00 19.00 4.00 7.50
added at bottom (in):2.0 30 23.00 21.50 1.50 20.00
30 22.50 20.00 2.50 12.00
30 23.00 21.50 1.50 20.00
30 23.00 22.00 1.00 30.00
30 23.50 21.50 2.00 15.00
30 23.00 21.50 1.50 20.00
30 23.00 21.00 2.00 15.00
P1-3 32 30 24.00 24.00 1.25
Height of Sand/Gravel 30 24.00 23.00 1.00 30.00
added at bottom (in):2.0 30 25.00 24.00 1.00 30.00
30 23.50 21.50 2.00 15.00
30 24.00 22.50 1.50 20.00
30 24.00 21.50 2.50 12.00
30 24.50 22.00 2.50 12.00
30 24.00 21.00 3.00 10.00
30 23.50 21.50 2.00 15.00
Average Percolation Rate =15.00 min/in
Corrected Percolation Rate =30.00 min/in
PERCOLATION TEST RESULTS
Project Number:501710003 Test Date:9/13/2019
Project:Mulberry Connection Tested By:FT
Location:Fort Collins Elevation:-+/- (MSL)
Hole Number Hole Depth Time Interval Initial Water
Level Height
at Start
Final Water
Level
Height at
End
Drop in
Water Level
Average
Percolation
Rate
Time Start Time Stop
(inches)(minutes)(inches)(inches)(inches)(min/in)(hh:mm)(hh:mm)
P2-1 31 0 21.5 21.50 0.00
Height of Sand/Gravel 30 22 18 4.00 7.50
added at bottom (in):2.0 30 23 19.5 3.50 8.57
30 22.5 20.5 2.00 15.00
30 23 20.5 2.50 12.00
30 23 21.5 1.50 20.00
30 23.5 21 2.50 12.00
30 23 20 3.00 10.00
30 22.5 20 2.50 12.00
P2-2 33 0 24.5 24.50 0.00
Height of Sand/Gravel 30 24.5 22.5 2.00 15.00
added at bottom (in):2.0 30 25 22.5 2.50 12.00
30 25 22 3.00 10.00
30 25 22 3.00 10.00
30 24.5 22 2.50 12.00
30 25 23 2.00 15.00
30 25 22 3.00 10.00
30 25 23 2.00 15.00
P2-3 36 0 27 27.00 0.00
Height of Sand/Gravel 30 27 24.5 2.50 12.00
added at bottom (in):2.0 30 28 25.5 2.50 12.00
30 27.5 24 3.50 8.57
30 27.5 23 4.50 6.67
30 27 24 3.00 10.00
30 28 26 2.00 15.00
30 27.5 24.5 3.00 10.00
30 28 26 2.00 15.00
Average Percolation Rate =14.00 min/in
Corrected Percolation Rate =28.00 min/in
PERCOLATION TEST RESULTS
Project Number:501710003 Test Date:9/13/2019
Project:Mulberry Connection Tested By:FT
Location:Fort Collins Elevation:-+/- (MSL)
Hole Number Hole Depth Time Interval Initial Water
Level Height
at Start
Final Water
Level
Height at
End
Drop in
Water Level
Average
Percolation
Rate
Time Start Time Stop
(inches)(minutes)(inches)(inches)(inches)(min/in)(hh:mm)(hh:mm)
P3-1 33 0 24.5 24.50 0.00
Height of Sand/Gravel 30 24.5 20 4.50 6.67
added at bottom (in):2.0 30 24 21.5 2.50 12.00
30 24.5 21 3.50 8.57
30 24.5 22 2.50 12.00
30 25 23.5 1.50 20.00
30 25 22.5 2.50 12.00
30 24.5 23 1.50 20.00
30 25 23.5 1.50 20.00
P3-2 30 0 22 22.00 0.00
Height of Sand/Gravel 30 22 18 4.00 7.50
added at bottom (in):2.0 30 21 18.5 2.50 12.00
30 21 20 1.00 30.00
30 22 20 2.00 15.00
30 21.5 19 2.50 12.00
30 22 21 1.00 30.00
30 22.5 21 1.50 20.00
30 22 21 1.00 30.00
P3-3 30 0 22 22.00 0.00
Height of Sand/Gravel 30 22 20 2.00 15.00
added at bottom (in):2.0 30 21.5 20.5 1.00 30.00
30 22 20.5 1.50 20.00
30 22 19.5 2.50 12.00
30 23 22 1.00 30.00
30 21.5 20 1.50 20.00
30 22 20 2.00 15.00
30 22 21 1.00 30.00
Average Percolation Rate =26.67 min/in
Corrected Percolation Rate =53.33 min/in
PERCOLATION TEST RESULTS
Project Number:501710003 Test Date:9/13/2019
Project:Mulberry Connection Tested By:FT
Location:Fort Collins Elevation:-+/- (MSL)
Hole Number Hole Depth Time Interval Initial Water
Level Height
at Start
Final Water
Level
Height at
End
Drop in
Water Level
Average
Percolation
Rate
Time Start Time Stop
(inches)(minutes)(inches)(inches)(inches)(min/in)(hh:mm)(hh:mm)
P4-1 30 0 22 22.00 0.00
Height of Sand/Gravel 30 22 20 2.00 15.00
added at bottom (in):2.0 30 22 18.5 3.50 8.57
30 22.5 19.5 3.00 10.00
30 21.5 18 3.50 8.57
30 22 19.5 2.50 12.00
30 22 19.5 2.50 12.00
30 21 19 2.00 15.00
30 22 19.5 2.50 12.00
P4-2 30 0 21.5 21.50 0.00
Height of Sand/Gravel 30 21.5 18.5 3.00 10.00
added at bottom (in):2.0 30 22 18.5 3.50 8.57
30 22 20 2.00 15.00
30 23 22 1.00 30.00
30 21.5 20 1.50 20.00
30 22 20.5 1.50 20.00
30 22 20 2.00 15.00
30 22 20 2.00 15.00
P4-3 31 0 22 22.00 0.00
Height of Sand/Gravel 30 23 20 3.00 10.00
added at bottom (in):2.0 30 23 21 2.00 15.00
30 22.5 19.5 3.00 10.00
30 23 21 2.00 15.00
30 23.5 23 0.50 60.00
30 23 21 2.00 15.00
30 22.5 21 1.50 20.00
30 23 21.5 1.50 20.00
Average Percolation Rate =15.67 min/in
Corrected Percolation Rate =31.33 min/in
PERCOLATION TEST RESULTS