SPECIFIERUPDATE

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Contents CASE STUDIES

2 Amazon.com4 Rossland

6 Ekka Plaza8 105th Street Edmonton

10 Lansdowne Park14 Marrickville

Electronic commerce and cloud computing company,

Amazon.com, has leveraged Citygreen’s cutting-edge

StrataCell system in its new multi-million office head-

quarters in South Lake Union, Seattle. Purpose-built to accommo-

date 20,000 employees, the new headquarters consists of multiple

buildings surrounded by mingling areas and plazas.

One plaza, located between two buildings on 6th Avenue, has

been constructed above a parking structure, and is home to sever-

al feature trees (Cercidiphyllum japonicum and Magnolia laevifolia)

requiring large planting areas.

Engineering plans allowed enough soil volume beneath the plaza to

house the trees, but a significant challenge emerged – how to pro-

vide sufficient structural support to cope with the weight of heavy

vehicles such as a boom lift, to be used for maintenance. Soil cells

were identified as an ideal solution, however many products were

rejected because they lacked the structural strength required.

Citygreen’s 60-series StrataCell system fulfilled the strength re-

quirements, and Citygreen worked directly with the consulting

landscape architect – Site Workshop of Seattle – to design the

structural elements of the plaza. This consists of 500 StrataCells,

supported by a concrete slab, a drain-mat, and another slab

above. Citygreen provided plan views of the installation to calcu-

late the quantity of cells required, and to show how the slab would

be supported. Construction was completed by Pacific Earthworks.

Site Workshop, along with the project architect, are very happy

with the solution, making particular note of how quickly the cells

went together and how easy it was to thread the drip irrigation

through the structure. Time will tell how the rigidity of the plaza

structure performs, but all signs point towards to successful out-

come, with beautiful trees for Amazon employees to enjoy.

Project supplied by Citygreen West.

E: matthew.biggs@citygreen.com • Ph: 780.462.5064

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Citygreen® SPECIFIER UPDATE 3

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Many Canadians would know and love the town of

Rossland, BC. Nestled in the wooded mountains

of the West Kootenay region, Rossland has been

a charming ski resort and quiet mountain getaway for many

generations of Canadian families.

With a population of less than 3500 that fluctuates significantly

according to the season, Rossland depends on tourist traffic to

maintain its reputation as a mecca for enthusiasts of the outdoors.

In 2011, the town engaged ISL Engineering to come up with a

revised main street design, looking for a smart, well-planned

central thoroughfare that would look beautiful for decades to come.

ISL’s design was installed during summer 2012, and employed

Citygreen Stratacells beneath the sidewalks and under some of the

angle parking areas. Stratacells were selected for their unrivalled

compressive and lateral strength; other soil cells having been ruled

out due to structural concerns.

Allen Tower, Vice President of Sierra Landscaping, Ltd. and

Director of the Rossland project, said, “The StrataCell was

incorporated beneath the hardscaping for the length of the

project, installed 1000 mm deep, 1500 mm wide, and included

StrataCell, geo textile, subgrade base gravels, and topsoil. Water

harvesting for irrigation and electrical was also included within

the StrataCell matrix.”

The installation of the StrataCell took about five weeks, which

included subgrade, base installation, topsoil delivery and

placement, and geogrid installation. Jeff Schurek, CSLA,

Landscape Manager / Senior Landscape Architect of ISL

Engineering and Land Services Ltd said, “CityGreen was

there throughout the various stages of the process in terms

of technical review. They were out onsite solving real issues

to work with the contractor to come up with better solutions

in the best way possible.”

The design for this project also required a drip-line irrigation

system that was installed throughout the many linked tree pit

systems. But due to the tree pits being enclosed, the ArborVent

system was installed, which helps to provide oxygen as a permanent

Establishing Green Canopy in Rossland BC

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irrigation/aeration solution and to prevent soil stagnation. The tree

root systems, being set in the StrataCells, allow for the tree roots to

grow in the adequate and sufficient root volume which is necessary

for healthy growth. This project also used the StrataCell system to

provide for a storm water tree trench down the length of the street

which bridged areas where there were existing utility lines.

Schurek said, “Within 1.5 weeks, the StrataCell systems were

installed on one side of the street (approximately four blocks). That

was extremely fast. The contractor was so pleased at the rate. He

had worked without this product in the past, but the process took

much longer. Another selling point of using the StrataCell system is

that the price is reasonable. We were sold on using this product on

the basis that it provides trees the room to grow. This is the most

important thing for developing a healthy streetscape – healthy trees

for the future.”

Now, 3 years post-installation, the streetscape has been

transformed and is truly beautiful. Jim Markin, the Arborist on site

reports that, “Tree uptake has been 100% successful, the trees

maturing quickly and establishing well.” Allen Tower says he has

been, “Impressed with the results, especially compared to

a nearby installation where structural soils were employed,

with very poor uptake and significant early failure rate in the

young trees.”

Rossland considers the cost of this streetscape a worthy

investment, and now it’s easy to see why. Downtown Rossland will

have a manageable and sustainable urban forest forming a living

heart through its downtown core for generations to come.

Project supplied by Citygreen West.

E: matthew.biggs@citygreen.com • Ph: 780.462.5064

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Citygreen® SPECIFIER UPDATE 5

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The visually-striking ‘Ekka’ Plaza was the first key public

space to be delivered as part the Brisbane Showground’s

rejuvenation. The new plaza delivers a much-needed

and contemporary open space for the local community, and acts

as the front door to the new Royal International Convention Centre

(RICC). Officially opened during the 2013 Ekka (Royal Queensland)

Show, The Plaza’s flexible design supports a variety of exhibitions

and events.

Matthew Nolan, Associate Director at Lat27, worked closely on the

conception and design of The Plaza. He says, “The redevelopment

of the Brisbane Showgrounds was a key urban renewal opportunity

for Brisbane, creating a new mixed use urban centre just north-east

of the CBD. Lat27 was commissioned to prepare the landscape

master plan for the public realm, supporting a submission to the

Urban Land Development Authority (ULDA). The project presented

the opportunity to reveal the historic narrative of a site traditionally

only accessible during show times and to integrate it into its

surrounding context.

“This new space was created through the removal of several

small buildings, revealing the heritage RICC façade and providing

a robust new open public plaza supporting the existing heritage

spaces of Gregory’s Rest and Stockman’s Rest. The hierarchy of

the new space references the historic structure and functionality of

the Showgrounds; with large flexible spaces for events and smaller

densely shaded spaces for respite within a highly connected

network.

“The inclusion of significant trees was critical to the success of the

new plaza for shade and balancing the scale of the space. However,

the project brief to provide multi-purpose, high-loading hardstand

for event modes, circulation routes, and changing levels across the

site meant we were unable to have broad expanses of open deep

planting. High rock shelves and multiple service infrastructures

added further restrictions on below surface designs.

“During the design phase, development assessments between

traditional structural soil trenches and tree pits with Stratacell were

carried out in regards to achieving the required soil volumes versus

the costs of excavating the surrounding rock, providing the 40t

pavement capacities, and construction programing. At this point,

we consulted Citygreen to review options for soil pits and tree

grate integration. Stratacell was the clear choice for its horticultural

benefits and economic efficiencies.

“The final design consisted of Stratacell Series 30 cells in 3x3m

(wide) x 2m (deep) tree pits excavated into varying densities of

rock. Into the tree pits, we planted nine advanced (6 – 8 metre)

StrataCell brings Lat27’s striking landscape design to life at Ekka Plaza

6 ISSUE 16

Elaeocarpus Grandis, which make a striking visual statement.

Irrigation was imperative to the trees’ success, so the bases of the

tree pits were interconnected with subsurface drainage lines back

to the stormwater system.

“Two years down the track, the use of the Stratacells has achieved

notable good health and vigour for the trees, while surrounding

pavements have remained completely stable through multiple

events including two Ekka Shows.

“Citygreen were fantastic to work with, and continually

provided horticultural and engineering advice throughout

the design development process, which was much

appreciated. During construction, Citygreen provided on-

site supervision for installation and structural certification

on completion. The support provided by Citygreen

throughout the whole project greatly assisted us to achieve

the overall goal of significant trees within the physical and

functional constraints of the project. The end result speaks

for itself.”

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In September 2016, the second largest city in Alberta, Canada will celebrate the completion of a progressive stormwater management project in its city of Edmonton. Prior to its completion, a project update offers some compelling and exciting information on the project’s progress.

Taking place just northwest of the downtown core on

105th Street, Canada’s “festival city” has partnered

with ISL Engineering, Carmack’s, a large civil contrac-

tor, and Citygreen West, an international leader in sustainable land-

scape systems. The project’s stakeholders focus on the revitaliza-

tion of existing streets, sidewalks, and curbs that are, “well past

their lifetime,” reported Matthew Biggs of Citygreen West.

Edmonton’s city limits holds seven sectors, with the mature down-

town sector at its core. Surrounding it are six suburban neighbor-

hoods. The majority of the buildings and infrastructure built prior

to the 1970’s, and the new generation is taking steps to revitalize

their city infrastructure and take an active role in the management

of stormwater.

“Primary goals of the city are to remodel the streetscape as part of

a plan to upgrade the area...The present street is an aging ware-

City of Edmonton Strengthens Its Core

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house and industrial zone, which is being upgraded to a modern,

sustainable multi-family dwellings,” said Biggs.

Upgrades are meant to allow for a flourishing urban forest, in con-

junction with a responsibly planned stormwater management sys-

tem that proves successful, “by directing street stormwater into

large soil filled tree pits and draining it through collection pipes at

the base of the tree growing areas,” said Biggs. The ultimate so-

lution for Edmonton’s design challenges is Citygreen’s innovative

Stratavault soil cell system.

The open matrix design boasts unique advantages that presented

solutions to challenges and considerations like project cost, trans-

port, installation, as well as the need for green infrastructure and

stormwater quality objectives. The cell’s components are able to

nest inside one another and are constructed of lightweight poly-

mers, allowing for significantly lower costs in freight. Once the

product is at the installation site, their simple construction doesn’t

require unique tools or specialized labor, thus also allowing for a

smaller task force.

The Stratavault’s open design allows for the unhindered installation

of all necessary subterranean construction, such as water pipes.

Even so, with its “quick and simple to assemble” matrix design, the

cell system continues to provide the surrounding sidewalks, “with

sufficient structural integrity to withstand traffic loads,” Biggs noted.

The open voids allow for tree roots to establish and grow as natu-

rally as possible in the oxygen-rich soil, a thing of the future com-

pared to conventional single slab planters. These conventional

builds have soil that is too compacted for natural root growth,

or for rainfall to be properly absorbed and redirected, resulting

in unhealthy or dying trees, eroding landscaping, and ultimately,

unnecessary expense in the city’s green infrastructure plans and

initiatives.

With 105th Street’s central location inside the city, the active efforts

to reduce the damaging effects of unmanaged stormwater levels

require large pipe sweeps to be safely integrated into the Strat-

avault installations. In short, Citygreen’s cell systems are offering

the city of Edmonton solutions to all the project’s concerns and

goals with a single product.

An innovative process “approved by the Stratavault manufacturer”

was proposed featuring 200mm, eight-inch water pipes, which

were able to be safely integrated and routed through the cells, “with

minimal interruption to the structure.” Because the Stratavaults are

interlocking, void of bolts or other connectors, individual single leg

sections of the matrix system can be removed for the pipe sweeps,

leaving the top layer in place. The sidewalk structure is then rein-

forced with a bridging section layered on top of these particular

areas. This engineering modification would not have been as likely

with another form of green technology.

Since the project’s onset in May 2015, the first tree pits have been

installed, and were backfilled with soil quickly and efficiently by

Carmack’s subcontractor, 7M Landscaping.

In a final statement on the partnership with Edmonton’s city staff,

Biggs reported that the installations are already showing positive re-

sults. “This retains the key feature of the Stratavault cell structure –

it’s strength as a connected matrix….” just like the interconnecting

streets and communities within the city of Edmonton itself.

Project supplied by Citygreen West.

E: matthew.biggs@citygreen.com • Ph: 780.462.5064

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Ottawa’s Lansdowne Park has gone through

extensive redevelopment with three major

components that makes the venue a significant

national and international attraction.

The revitalisation was planned early 2009 as part of a series

of initiatives approved by the Ottawa Council. In June 2010,

the council voted to continue the Lansdowne Partnership

Plan (LPP), “an innovative and dynamic solution to redevelop

Lansdowne Park” through a partnership of the city with the

Ottawa Sports and Entertainment Group (OSEG).

Lansdowne Park is a world-class attraction that “blends

modern amenities, courtyards, heritage buildings and green

space”. The urban public destination, well situated in the

heart of Ottawa, features events and activities for all ages

and all seasons.

The new Lansdowne revitalisation is a “model of modern-

day innovation in an urban form where people can go to

walk, cycle, shop, enjoy a good meal, be entertained, work,

like and play” in an environment respectful of the city’s

architectural heritage.

The plan included the renovation of the TD Place stadium,

mixed-use area with shops, residences and offices, and the

18-acre urban park.

The main aim of the refurbished stadium is to “seamlessly

integrate the facility into the new urban setting by using varied

and natural features”. The TD Place Stadium features 24,000

seats and newly refurbished 10,000 seat indoor arena. It will

host sports events, concerts and performances by headline

acts. The first major park event in the renovated stadium was

held in July this year.

The urban park redevelopment enabled Lansdowne Park to

be “re-integrated with the Rideau Canal Corridor as the site

once was connected historically”. The majority of the asphalt

was removed and replaced with a “front lawn”, stretching

Binding the old with the new in Lansdowne Park

By Kristyn M. Levis

10 ISSUE 16

across the eastern portion of the overall site along the

Queen Elizabeth Driveway and the Rideau Canal. The urban

park feature also incorporated the two heritage structures

– the Horticulture Building and the Aberdeen Pavilion, as

centrepieces for the park.

The proposed mixed-use area aims to create a “unique urban

village that includes a mix of commercial and residential

buildings, open spaces and corridors, which will serve a

variety of purposes”.

“This component of the redevelopment plan provides a unique

pedestrian environment focused on a retailing area that will

complement and support activities at Lansdowne and be

integrated with existing commercial uses along Bank Street,”

the website said.

The mixed-use area also includes residential uses that

integrate with the surrounding community and provide an 18-

hour cycle of activity for the overall site.

Continued on next page

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Jeffrey Staates, partner at PFS Studio and project landscape

architect for Lansdowne Park, has been involved with the

project since 2010 and led the team for the international design

competition. They were awarded the project in June 2010 and

design started in July 2010.

Staates said they were tasked with the redevelopment of the

urban park. They refurbished the heritage building Horticulture

Pavilion next to Aberdeen Square where the Citygreen®

modular Stratacell® system was installed.

The system was included in the recommendation to pursue the

largest soil volume possible from the standpoint of longevity.

The major installation of soil cells was in the centre of Aberdeen

Square, named after the heritage structure in the site.

“It was a proposed alternate during the tender process.

A good deal of the public realm is over slab. We do have

some hesitation using the Citygreen product because of its

configuration,” Staates said.

“There were concerns about the longevity of trees particularly

rooting. It’s a new product so we don’t have 30 years of field

trials. But we felt in this case we only have about 30 years

before we see all this stuff replaced anyway that we decided

that wasn’t a concern. Given the soil volumes we wanted

to achieve and the time frame, it seemed like a reasonable

product to accept as an alternative,” Staates said.

The Aberdeen Pavilion is a city landmark with a capacity for

2,800 visitors. The Aberdeen Square north of the pavilion is

home to Ottawa’s Farmer’s Market. The park features more

than 800 trees, including an orchard of heirloom apple trees.

The Horticulture building has also been revitalised for special

events and community use.

Lansdowne Park Continued

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Staates said he isn’t aware of any issues with the product

during installation and after the project was finished. The

only complications with the project were more in terms of

jurisdiction. The team was obliged to consult with several

organisations with lengthy approvals of plans and a number of

jurisdictional reviews that had to be satisfied. But in the end, all

bodies approved the use of the Stratacell system.

As for the integration of water harvesting, the design allowed for

the collection of water from the roof of the horticulture building

and recycling water from the water play area in the urban park

and using that for irrigation at night.

The city’s Parks, Recreation and Cultural Services (PRCS)

department is already scheduling a program of activities and

events to suit the unique spaces in the Aberdeen Pavilion and

the Horticulture Building.

Project supplied by GreenBlue Urban. www.greenblue.com. Ph: 1.866.282.2743

Citygreen® SPECIFIER UPDATE 13Citygreen® SPECIFIER UPDATE 13

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The City of Marrickville has taken a bold step forward in ensuring the har-monious union of urban infrastructure and urban trees in an initiative called Connecting Marrickville. Citygreen played an important role in making sure the project is delivered. This is a great example of what can be achieved in urban development with the right thinking.

Trees usually come second to footpaths, roads, kerbs

and gutters – but Marrickville Council is determined to

turn this thinking around.

So when a footpath was being upgraded in Cavendish Street Stan-

more, Council’s ‘whole of street’ approach presented an oppor-

tunity to remove and replace three very large Ficus hillii with an

in-road tree planting of three super-advanced Waterhousea flori-

bunda (Weeping Lilly Pilly).

This new approach by Council means that damage from tree roots

to nearby properties and structures will be prevented. It’s all part of

a new initiative called Connecting Marrickville.

Connecting Marrickville puts people and the places they live in at the

centre of all infrastructure planning. It aims to make streetscapes

better now and into the future. How? By integrating all elements

that make up a liveable sustainable community.

Gwilym Griffiths, Council’s Coordinator Tree Management, was

part of the multi-disciplinary team who worked on the design,

construction and communication. He said the objectives were to

demonstrate a new way of managing the conflicts between trees

and infrastructure; plan for large trees in tight urban spaces so that

there is significantly less need for pruning and patching of dam-

aged infrastructure, and to integrate tree works and footpath re-

placements in one project.

The project site construction started early May 2014 and finished

in June 2014.

“There is more and more pressure on street trees,” he said.

“In many towns and cities, development means that people and

trees are brought into increasingly closer contact. Space for large

trees to establish to full maturity is limited. It’s all exacerbated by

poor or disturbed soil conditions in built up areas, and conflicts

with underground and aboveground services,” Griffiths said.

“And there’s this idea that large trees cause damage or can be

dangerous. They might drop branches, or block sunlight, or dam-

age infrastructure,” he added.

Connecting Marrickville will manage these issues by planning for

the needs of the trees (providing them with the soil and space for

long term growth) instead of just planting trees in the spaces ‘left

over’ after development.

In a council video about the project, residents commented on the

bumpy footpaths, saying while they wanted more greenery, they

didn’t want tree roots ripping up the path.

Bold Green Vision inMarrickville, Sydney

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The three large trees roots were also growing into people houses,

with one even growing into someone’s bath.

Council removed those trees, fixed the footpath, and planted the

new trees in-road using the Citygreen® Stratacell system®.

“We chose this system because it provided the best soil

volume per dollar when compared with other structural

soil systems such as aggregate soil and pier and beam

vaulted systems,” Griffiths said.

“Adequate soil volumes are crucial for sustainable tree growth. Pro-

viding soil volumes upfront for trees provide better trees and less

impact on infrastructure,” he said.

The system, Griffiths said, is very easy to install and doesn’t require

specialist skills. They had very minor difficulties fitting cells around

numerous services, and during the initial design phase, in getting

the specification correct.

For example, in one of the pits, Griffiths said a sewer pipe required

relocation before the project could continue.

“We also received a lot of rain during construction, which required

pumping out and modification of the gutter to reduce the amount

of water flowing into the pits,” he said.

Ryan Hawken, Council’s urban water engineer, said although the

upfront cost was higher than previous projects, there are long term

benefits such as much less damage to footpaths and houses.

Council will monitor costs over time in order to continuously im-

prove performance and management of streets and trees. Since

the project was completed, Griffiths said the biggest issue has

been to maintain adequate water to the trees.

“Initial water budget estimates were quite low and since comple-

tion have been increased to accommodate actual site require-

ments,” he said.

The project included planting of biodiverse species of grass and

ground cover and stormwater management by adding permeable

paving over the tree pit to capture surface water. “And the Strata-

cell fits well with this,” Griffiths said.

“Today, the trees look good and are stable. We would definitely use

a similar system again,” he said.

The project is being used as a case study for Council’s Connect-

ing Marrickville initiative. This project delivers on a range of Council

strategies and provides Council with a great example of what can

be achieved with the right thinking.

Citygreen® SPECIFIER UPDATE 15

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