The Anchor: Residential development in North Vancouver is home to healthy trees
The Anchor is a 7 storey mixed-use development located in North Vancouver. Completed in early 2017, it is comprised of 56 luxury units above commercial shops at street level. The Anchor epitomises high-end living, with premium finishes, lush landscaping and a sustainable green roof.
The project’s landscape and stormwater management design was a collaborative effort of the City of North Vancouver, Citiwest Consulting, Senga Landscape Architecture, and Kamcon Construction who managed both the building and development of the project. Citygreen was engaged to help enhance The Anchor’s streetscape with healthy trees that would add visual impact and deliver water harvesting benefits.
Project goals
As well as adding to the luxury aesthetic of this world-class development, the project stakeholders wanted a solution that would ensure long-term growth of the trees. The City of North Vancouver specified that soil cells were to be included as a standard detail of the project, even before a provider was chosen.
As Kamran Tafreshi from Kamco Construction explained, “The City of North Vancouver, along with other municipalities in North America are moving to higher standards with regards to street trees. For this project, they wanted trees to be planted in cells with up to 10 cubic meters of soil available for the root systems, compared with the 1 cubic metre that is commonly used.”
The project also had clear goals relating to water harvesting and stormwater control. It was important to implement systems which would allow water to be collected and distributed as sustainably as possible around infrastructure.
Project challenges and solutions
The builder, landscapers and civil contractors were presented with several challenges during this project. One was to find a soil cell solution that would provide the required soil volume, while being easy to install around a compact space with utility installation constraints.
Citygreen’s Stratavault system was recommended by Kamcon Construction. The City of North Vancouver were impressed by Stratavault’s ability to deliver over 94% of total soil volume for healthy tree root growth. The fact that Stratavault comes with much greater structural integrity than other systems, and is made from 100% recycled materials, also made it a great fit for this project.
Stratavault was installed across two trenches, each measuring 18.85 x 2.1m x 800mm deep (2 cells depth), providing 30 m3 total soil volume per trench. The excavation dimensions were designed to accommodate the Stratavault cells, with the advantage being that the excavation did not have to be as deep, due to better load distribution and support.
To complement the Stratavault system, a 600mm root barrier was placed around the exterior of the cell structure, together with geo-grid (non-woven biaxial grid) landscape fabric over the top. In terms of the trees chosen, Columnar European Hornbeam (Carpinus Betulus Fastigiata) were selected to avoid canopies spreading too wide and overpowering the streetscape.
The civil consultant, Citiwest Consulting Ltd., described how Citygreen’s systems work in conjunction with existing infrastructure and contribute to sustainability goals: “Rainwater runoff from the streets and boulevard area is collected in street catch basins. The rainwater is then distributed to the soil via a perforated drain system. Flows which exceed the capacity of the system are directed back to the city’s storm sewers via overflow pipes in the street catch basins.”
“The sustainability benefits include supplemental stormwater management, infiltration, and water quality facilities for a portion of the previously unaddressed municipal roadway. The system also reduces the cost of irrigation for the street trees.”
Despite the complexities of the site, the installation went smoothly, with the building crew praising the Citygreen team for their support.
“Our Citygreen rep, Matthew, was very helpful throughout the process. He came out to Vancouver to join us during the installation of the soil cells, providing invaluable support”, said Kamran Tafreshi from Kamco Construction.
Project outcomes
Two years since the installation, Kamran confirms that the trees are growing well. He reports they appear “very healthy”, which he attributes to the greater volume of soil available via the Stratavault cells.
From a commercial perspective, The Anchor has been a resounding success, with all homes selling out quickly. The green streetscape has surely contributed to the appeal and success of the project.