THE NEW HEART
Uniting a Divided Campus Through innovative Green Infrastructure Design
Faculty Advisor:
Jake Powell, Assistant Professor of Landscape Architecture and Environmental
Planning
Utah State University Design Team: D32
Chris Brown, Bio-Regional Planning
Kali Clarke, Landscape Architecture
Dani Delahoz, Environmental Engineering
Avery Holyoak, Environmental Engineering
Briana Kistler, Environmental Engineering
Nicholas LeSchofs, Landscape Architecture
Josh Quigley, Landscape Architecture
Sarah Tooley, Landscape Architecture
Dallen Webster, Environmental Engineering
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Abstract
Utah State University is located in Logan, Utah. The original campus buildings surrounded the
Quad, a centralized grassy location at the heart of all university activities. Through years of
campus expansion to the north, 700 N (Aggie Boulevard) has taken the central position the
Quad once held. Aggie Boulevard bisects the campus and is the artery through which students,
faculty, and the public frequently travel. This causes congestion far beyond what the road was
designed for. This report presents a design to establish Aggie Boulevard as the new heart of
campus, as well as reduce current stormwater and transportation inefficiencies.
Currently, Aggie Boulevard produces a high stormwater runoff volume due to the large
amounts of impermeable hardscape, nearly 80% of the site area. Large storm gutters on either
side of the road channel stormwater runoff to storm drains that convey water to groundwater
via shallow drywells without treatment. Vehicles in the area idle for long periods of time,
adding to emissions in a location that is frequently out of attainment for PM2.5, a secondary
pollutant originating from car (NOx) and agriculture (NH4) emissions.
The goals of this design are to recharge groundwater with treated runoff, reduce impermeable
surfaces, retain design storms as required by local municipalities, eliminate the need for
supplemental irrigation in a climate where water is in short supply, emphasize native
landscaping, and, create a new cultural center of campus.
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Site Selection
Location Description and Aerial View
Situated on Utah State University's campus, Aggie Boulevard
(Figure 1) is 80% impermeable hardscape with scattered
planting beds and features a two-way asphalt roadway with
concrete sidewalks on either side (Figure 1). At present,
conventional gutters on either side of the roadway are used
to convey stormwater. This area experiences high volumes
of pedestrian, bicycle, and slow-moving vehicle traffic during
the school day. As the student and faculty population of
Utah State University (USU) continue to grow, the site is
expected to experience higher volumes of vehicle and foot
traffic than ever before. Current discussions among USU
facility managers to address these concerns have provided
the opportunity to present a design that instills a sense of
unity among students and faculty through green
infrastructure.
Figure 2. Aggie Boulevard in its current state
Figure 1. Aerial view of 700 N (Aggie Boulevard) site study area.
Site Analysis
Existing Site Conditions and Improvement Needs
As campus has expanded, it has lost the centralizing element that the Quad once provided.
Aggie Boulevard has become the new center for Utah State University, and because of this
transition, it experiences high volumes of pedestrian and vehicle traffic. The improvements
needed in this area are to reduce impermeable surfaces, retain and treat stormwater, reduce
traffic, and create a new aesthetically pleasing green infrastructure-based center of campus.
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Because an adjustment to the current site is considered a "new development", the area is
subject to new regulations. Logan City, local municipality, requires new developments to retain
the 90th percentile storm on site. The 90th percentile storm in this area is 0.66 inches.
Additionally, the 100-year, 24-hour storm must be retained so only 0.2 cubic feet per second is
discharged from the location. The 100-year, 24-hour storm depth in this area is 3.02 inches.
The current Curve Number is 88.2. The runoff depth calculated from the curve number was
0.09 inches for the 90th percentile storm and 1.85 inches for the 100-year, 24-hour storm (NRCS
1986). Presently, stormwater discharges into a gutter and has a potential for contamination due
to decaying organic matter and oil and grease from cars. Aggie Boulevard is flat and has a
current watershed consisting only of the road area.
The movement through Aggie Boulevard is
show in Figure 3. The green circle denotes
the old center of campus, the Quad. The
orange arrows represent the direction of
growth of campus infrastructure. The red
circles are placed on location on Aggie
Boulevard where high pedestrian and vehicle
traffic create high congestion. These circles
are located on crosswalk areas. The black
dotted arrows represent main pedestrian
pathways throughout campus.
Figure 3. Movement Description Through Site
Design Program
Objective
The objective of this project is to remove vehicle traffic from Aggie Boulevard and replace it
with natural landscape that retains the stormwater for use on site. The new landscape will
potentially include art features that are accentuated and brought to life by rainfall. A walking
path composed of permeable pavers will be available to students walking or biking to class. This
will create a more centralized atmosphere on campus while also providing filtration of
stormwater through the landscape and soils. To ensure that bus transportation is minimally
impacted by the removal of the road, two roundabouts will be placed at the ends of the
proposed campus common area. These roundabouts will also allow for vehicle access to all
existing parking lots and bus access to campus.
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Project Goals
The proposed design aims to meet certain goals and objectives outlined below:
Recharge Groundwater After Treatment - Treat groundwater before discharge by
channeling it through soil media and plants.
Reduce Impermeable Surface Area - Replace hardscape that has high runoff potential with
permeable surfaces such as permeable pavers and raingardens that allow stormwater to
infiltrate the surface.
Retain Design Storms - Retain the 90th percentile and 100-year, 24-hour storms as required
by local governments.
Reduce Need for Supplemental Irrigation Past Establishment Period - Store enough water
on site to sustain plant life through dry periods after plant establishment.
Emphasize Native, Xeric Landscaping - Reduce irrigation needs by utilizing native plant
species requiring minimal water. Native plantings will also highlight the importance of rain
in Utah's arid climate.
Improve Circulation and Accessibility - Create a more accessible thoroughfare for
pedestrians and bicyclists to reduce congestion during peak commute hours. Reduce
emissions from idling cars to help meet current campus-wide goal of producing zero net
emissions by 2050.
Create New Cultural Center of Campus - Generate open space for University events and
create areas for students to congregate and take advantage of the cultural and aesthetic
benefits of green infrastructure. Install art pieces that celebrate the wonder of precipitation
in the desert and provide instructional materials on site to educate students and the public
about green infrastructure utilized in the design.
Design Methods and Preliminary Analyses
Design Tools
The NRCS runoff curve number will be used to quantify runoff in this location. Physical
properties of soil will be used to size the green infrastructure implemented. The CNT National
Green Values Stormwater Calculator and various costs found from literature will be used
to estimate the cost of the green infrastructure.
The principles of low impact development and best management practices will be used.
Additionally, landscape architecture approaches to the project will be used to ensure that the
location will be a cultural asset and be functionally and aesthetically pleasing.
Water Retention
In order to create a self-sustaining system, the water falling on the catchment area must be
used in the pervious area. Figure 4 demonstrates the average yearly water flow within the site
area. The inflow represents precipitation the falls within the catchment area, and the outflow
represents the average evapotranspiration rate in Logan, Utah over the previous area (Moller
and Gillies 2007). To eliminate the need for supplemental irrigation in the times where
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evapotranspiration exceeds precipitation, storage of rainwater in excess of evapotranspiration
is necessary.
60000.0
5 / \
10000.0
0.0
January Fd^ruary March April May June July August September October November December
Inflow Outflow
Figure 4. Average Yearly Water Flow
Utah Water Rights laws allow for one 2,500-gallon cistern for every parcel of land. Aggie
Boulevard splits two parcels, meaning a total of 5,000 gallons can be stored in cisterns on site.
More than 5,000 gallons are needed during the June, July, and August, so water must be stored
in the soil. In order to retain the needed water in the soil which has high hydraulic conductivity
(60 inches per hour), a geosynthetic clay liner will be placed under the soil media to prevent
water from draining out of the site area.
Design Description
Design Overview
To meet the design objective and goals, the asphalt covering Aggie Boulevard will need to be
removed. To avoid negatively impacting students who use public transit and people needing to
access commuter parking lots, two roundabouts will be installed on the East and West as shown
in Figure 5 below. The roundabouts will have bus stops on the inner circle to avoid lines of
vehicles waiting to access parking lots, as well as exits leading toward parking lots.
Figure 5. Rendered Plan View of Proposed Redesign.
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The pedestrian and bike pathways, made of porous pavers arranged in circular patterns,
connect the area between the two roundabouts, as well as provide emergency vehicle access to
surrounding buildings, The pathways are angular, broken up by geometric sections of rain
gardens. Beneath the porous pavers and intermittent rain gardens lies a geosynthetic clay liner
to retain water on site to alleviate the need for supplemental irrigation past the establishment
period of the plants. The east wall of the clay liner is 7 ft tall, whereas the west wall of the clay
liner is 6 ft tall. This gentle underground slope was added to provide a drain in order to protect
water rights of downstream individuals. The western-most rain garden will be unlined to
release water that has percolated through the soil media to the groundwater. The water
channeled into the area originates from roofs of surrounding buildings as well as nearby parking
lots. The water will be channeled via underground downspouts.
Throughout the pedestrian corridor, educational signage and art work will be placed to raise
awareness for xeric landscaping, as well as other types of green infrastructure. The location will
contain areas for static enjoyment of the surroundings, as well as areas for facilitating
pedestrian and bike movement.
The cross section of the design is shown in Figure 6 below. This drawing is not to scale by width
for the purpose of highlighting the gravel river which will facilitate water flow from one side of
the area to the other. It is, however, to scale by depth. The side view of the design is shown in
Figure 7. It shows an underground cistern with a capacity of 2,500 gallons. There will be two of
these cisterns on site.
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Figure 6. Cross sections of design.
Figure 7. Side View of design.
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Retention of Design Storms
In order to retain the 90th percentile storm on the 1.93 ac site (using a 6-acre catchment area),
the depth of native soil (porosity 0.185) needed is 0.93 ft (NRCS 2018). Although retention of
the 100-year, 24-hour storm is not required by local municipalities, the depth to capture the
storm in native soils was calculated and is 4.23 ft.
Because the team would iike to have native trees in the landscape which require 5 ft of depth,
both storms will be retained in the clay liner. The depth of the soil on top of the clay liner will
be 6 ft for safety. Because the location can retain both the 90th percentile storm and the 100-
year, 24-hour storm, the runoff from this site has been reduced 100%. This means that 100% of
pollutants have been removed from surface water runoff.
Reduction in Impervious Area
The curve number for the existing site (1.93 acres) is 88,2, but the curve number for the
proposed site is estimated to be 47. This is a 47% reduction in the curve number, which
corresponds to a large reduction in impervious area.
Reduction in Irrigation Water Required
In order to avoid supplemental irrigation, enough water to sustain plants during long dry
periods needs to be retained in the pervious area. The soil has a saturated capacity (assuming
soil available for storage is 1,200ft by 70 ft by 6 ft and a porosity of 0.185) of 93,240 ft3 (NRCS
2018). Figure 8 below demonstrates the 6-acre catchment area, consisting of the redesigned
Aggie Boulevard (1.93 acre, pervious, shown in red) and surrounding rooftops and parking lots
(shown in yellow) which will have drains channeled toward the pervious area. Figure 9 shows a
water balance of the yearly precipitation over the 6-acre catchment area, evapotranspiration
over the 1.93-acre pervious area, and storage available over time in both cisterns and the
ground.
Figure 8. Stormwater Catchment Area
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Figure 9. Water Balance of Precipitation, Evapotranspiration, and Storage Available
Based on the water balance above, the months of the year in which evapotranspiration exceeds
precipitation are June, July, and August. However, the available stored water (in cisterns and
the ground) for those times of year, accounting for those water needs, never drop below
20,000 ft3 per month, meaning there is more than enough water for average plant needs in
Logan's climate. Because no supplemental irrigation will be required past the establishment
period for the plants, this design reduces the need for irrigation water by 100%.
Native Landscaping
The team plans to use water-wise, native
plants in this area. The plants selected are
plants that can survive inundation as well
as long dry periods, which a typical
precipitation pattern in Utah, The
proposed native planting blooming chart
and plant palette are shown in Figures 10
and 11, The blooming chart shows the
seasons in which the proposed native
plantings will bloom, with most blooms
happening in the spring, summer, and
fall. Some plants continue to bloom into
the winter. The aim of choosing these
plants is to create an appreciation among
the community of native plants in a place
where many in the public consider native
plants to be weeds. This site will be a
demonstration of water-wise landscaping.
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Figure 10. Proposed Blooming Chart for Native Plantings
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January Fd^ruary March April May June July August September October November December
Cumutative Precipstation-Evapotranspjratbn Storage Available
Figure 12. Groundwater Recharge Throughout the Year
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Circulation and Accessibility
Vehicle traffic was removed from Aggie Boulevard, thus relieving congestion. The roundabouts
placed on the east and west will allow campus and city buses to access the area, as well as
allow smaller passenger vehicles to access key parking lots on campus. Figure 13 depicts the
traffic flow through these roundabouts. The green arrows indicate small passenger vehicle
paths to parking lots, and the blue arrows indicate bus routes.
Decreasing congestion in this area will help meet the greater University goal of producing zero
net emissions by 2050. On average, a total of 5,800 cars drive on Aggie Boulevard per day (USU
2016). The design team assumed traffic idles for 15 minutes before the start of every 1-hour
class period from 8 a.m. to 3:30 p.m., every car has a standard 2,0 L engine, and each car burns
0.3 gallons per hour while idling (US Energy 2015). The team estimates 562,660 lbs of CO2 are
currently produced on Aggie Boulevard annually (US EIA 2017). The team calculated that
removing the road and implementing roundabouts will reduce CO2 emissions in this area by
approximately 62.5%.
Campus Cultural Center
The increased natural space and reduced hardscape will create an atmosphere which will draw
people to the area. The landscape will be designed to be a moving space, as well as a space to
gather. There will be designated areas along the varying paths for people to congregate.
Potential art installations, such as sculptures that move when water is directed onto it, would
draw interest to the area during a rainstorm. This would help facilitate a celebration of water in
a climate that receives minimal rainfall.
A preliminary economic analysis was performed to estimate the total cost of construction and
project implementation. The site survey and other aspects of preconstruction were included.
Removal cost of the current asphalt road that overlays Aggie Boulevard was estimated for a 40
Figure 13. East (left) roundabout traffic flow and West (right) roundabout traffic flow
Project Costs
Project Capital Costs
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ft by 1,200 ft road with a 1 ft thickness. The excavation necessary to install the geosynthetic
clay liner was estimated for 10,700 cubic yards of soil material at $16.50 a cubic yard (USDA
2017). The two - 2,500-gallon storage cisterns were priced at $15,000 for each installed cistern
(CostHelper 2018). The itemized costs also include the cost of two roundabouts which are to be
installed on the east and west exits of Aggie Boulevard. The estimated costs were $386,145.00
for each roundabout (FHA, 2010). Additional cost estimates are presented in Table 1.
Table 1. Itemized Cost of Proposed Project
Itemized Project Cost
Item tt
Item
Quantity
Unit
Unit Price (USD)
Total Amount
1
Mobilization
10%
$ 354,398.20
2
Traffic Control
8%
$ 283,518.56
3
Site and Construction Survey
1
LS
$ 8,900.00
$ 8,900.00
4
Excavation of Asphalt Road
48000
CF
$ 30.00
$ 1,440,000.00
5
Excavation of Soil
10667
CY
$ 16.50
$ 176,000.00
6
Construct Temporary Construction Entrance
300
CY
$ 67.00
$ 20,100.00
7
Storage Cisterns
2
EACH
$ 15,000.00
$ 30,000.00
8
Install Permeable Pavers
84000
SF
$ 12.00
$ 1,008,000.00
9
Geosynthetic Clay Liner
100510
SF
$ 0.60
$ 60,306.00
10
Roundabout
2
EACH
$386,145
$ 772,290.00
11
Downspouts
IS
LS
$ 202.00
$ 3,636.00
12
Install Trees
40
EACH
$ 275.00
$ 11,000.00
13
Install Rock and Boulders
100
CY
$ 100.00
$ 10,000.00
14
Native Plants
500
EACH
$ 7.50
$ 3,750.00
TOTAL CONSTRUCTION COST
$3,712,281.10
ADD 25% CONTINGENCY ON TOTAL $4,640351.38
Operation and Maintenance Costs
Operation and Maintenance costs (O&M) associated with the current site include snow removal
(November to March), road repair, and upkeep of grass park strips along Aggie Boulevard. The
proposed site design will reduce the area of road that is subject to repair by USU facilities while
also lessening the amount of area that needs to be plowed during the winter months. If the
design is implemented, the site's new maintenance costs will primarily stem from landscaping
along the pedestrian corridor, upkeeping the porous pavement, and maintaining the water
retention system.
In accordance with the wishes of USU Facilities, our team incorporated native plants that would
require minimal maintenance because of their slower growth. The primary maintenance of
these landscaped areas would be completed in the spring and fall. Incorporating perennial
plants would reduce the cost of installing annual bedding plants every spring, which the
University currently does. Removing grass park strips along the pedestrian walkways also
eliminates the need for periodic mowing and supplemental irrigation. The O&M cost of
upkeeping these native planting areas is estimated to be $1,900 per year.
The porous pavement along the pedestrian corridor will need to be power washed seasonally to
alleviate sediment that builds up inside the pores of the pavement. Snow removal on the
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porous pavement will be done with a rubber tipped plow to increase the longevity of the
surface. Estimated annual O&M costs for the porous pavement are $3,000.
The water retention system (including storage cisterns and infiltration areas) was designed to
require minimal maintenance. Leaves and other debris will need to be occasionally cleaned
from infiltration areas to improve water flow into the porous ground. The storage cisterns will
also need to be inspected annually for wear. The estimated annual O&M costs associated with
the water retention system are $600.
Valuation of Secondary Benefits
Implementing Green Infrastructure design alternatives in the proposed project provides runoff
reduction, but also provides ancillary benefits such as avoided water treatment costs, energy
savings, and air quality benefits. Primary and ancillary benefits are quantified in Table 2.
Table 2. Quantified Primary and Ancillary Benefits in the Proposed Site Design
Quantified Valuation of LID Design
EXPECTED OUTCOME
AMOUNT
Total Runoff Reduction
3,194,605
gallons/year
Avoided StormwaterTreatment Costs 1
4,280
$/year
Energy Savings from Avoided Treatment2
4,373
kWh/year
Avoided Cost of Conventional Infrastructure3
2,320,396
$
Quantified Valuation of Air Quality Benefits4
1,260
$/year
Reduced N02 Emissions5
8
lbs/year
Reduced SQ2 Emissions5
23
lbs/year
Source: 1. UDWR, 2010 2. EPRI, 2002 3. Green Values, 2018 4. McPherson, 2006 & Wangand Santii 1995
5. USEPA, 2005
Project Funding
Discussions with USU Facilities have made it clear that the University Planning Office is actively
working to redesign this section of campus, specifically Aggie Boulevard. Because there is a high
potential for a renovation, it was assumed that the majority of the funding for this project
would be acquired from USU's existing infrastructure budget.
Additional funding could be acquired through Student Sustainability Grants provided by USU's
Blue Goes Green initiative, which provides funding for campus sustainability projects. The Utah
Department of Environmental Quality also provides funding for innovative, water quality
improvement projects through the Utah Clean Water State Revolving Fund (CWSRF). Capital
funding could also be acquired through an EPA Source Reduction Assistance Grant.
Summary & Conclusion
The recommended design celebrates and utilizes stormwater in a climate which does not
receive much annual rainfall. It creates a new cultural center of campus, which incorporates
movement as well as stationary activities. There will be educational signage placed in strategic
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locations to highlight the benefits of the green infrastructure implemented. The road is
removed and replaced with a pervious pedestrian pathway. Vehicle traffic is directed through
roundabouts to help traffic flow and reach essential parking lots, which is estimated to reduce
carbon emissions from idling by 62.5%. Additionally, the proposed native plant palette will
sequester an estimated 16,800 lbs CO2 every year. This will help the university meet its goal of
zero net emissions by 2050.
Rainfall is collected from the surrounded 6 acres and is channeled into a 1.93-acre pervious
area, under which two 2,500-gallon cisterns are placed on site to retain water. For additional
water storage, a geosynthetic clay liner was placed under the soil to retain additional water
without violating water rights. The 1 ft drop in height from East to West of the geosynthetic clay
liner is estimated to release an estimated 55,050 ft3 of treated water for groundwater recharge.
The stored water will be used during long dry periods in the summer months and will eliminate
the need for supplemental irrigation after plants are established. In addition to removing the
need for supplemental irrigation and recharging groundwater, this design also retains 100% of
design storms, resulting in a 100% reduction in pollutants discharged to surface water.
This design demonstrates the possibilities of sustainability in a location where drought is
common. This design recharges treated groundwater, reduces impermeable surfaces, retains
design storms, eliminates need for supplemental irrigation, emphasizes native landscaping, and
creates a new cultural center of campus.
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