A Case Study Highlighting 10 Years of Success for Silva Cells and the Salford Quays

An oasis of nine trees thrives below a bustling roundabout in Salford, U.K. Part of the Gateway Quays project, the Himalayan Birch (Betula Utilis Jacquemontii) trees are supported by 184 Silva Cells, providing over 47m3 of shared rooting volume.

The Regent Road Roundabout and Gateway Triangle were reconstructed 10 years ago to the day. The gateway is a triangle that turns into a tunnel underneath the roundabout and sits just beside and below a portion of where Regent Road becomes the M602.

This location is a key gateway to Central Salford and the Regional Centre and has been a major pedestrian and cycle route link to Salford Quays.

The Project: A Gateway Between the Quays and the Community
A central design theme of the project was to enhance what already existed: transit routes, paths to the quays from central Salford and nearby Manchester’s surrounding communities. The 1landscape architect, Urban Vision Partnership (which has since been amalgamated with Salford City Council), envisioned walkable and bike-friendly paths along an aesthetically pleasing route. The project team was able to construct a new underground passageway for pedestrians that met these criteria. The flourishing birch trees continue to add to the attractiveness and functionality of the restoration space. Since September 2010, there has been more positive change to the area.

The town of Salford is just west of Manchester, bordered by the River Irwell. The Salford Quays have shaped the character of the city for the most recent centuries. Throughout the 19th and 20th centuries, the dockyards and the river served as a major transport hub for people and goods in and out of Manchester to Liverpool and beyond.

In 2007, plans to renovate the historic peninsula of the Quays, which would become the mixed-use development and home of the BBC known as MediaCityUK, were on the horizon. Today, in 2020, the expansion continues. Salford City Council notes, “The city has a bold new vision to deliver 40,000 new homes and 40,000 new jobs by 2040.” This will certainly impact the foot and pedal traffic throughout the town. The council showed great foresight in encouraging and initiating the renovation of the triangle walkway bordering the roundabout.

Before Silva Cells …
The location of the project was unique in that it bordered a tunnel and led to the River Irwell and Salford Quays. The project team constructed a new underground passageway for pedestrians. Photos before construction show that the project area was a field of grass, in a bowl shape, conducive to stormwater flooding. Trees and Silva Cells together act as a sponge, supportive infrastructure, and flood mitigator. The design incorporated Silva Cells and gabion baskets to create more void for stormwater.

Project site before construction in 2008. Photo courtesy of Google Street View

A Seamless Transition to Green Infrastructure

One big benefit of using Silva Cells is that soil can be mechanically loaded into the cells, saving a huge amount of time and labor. Project Manager for GPL Civils Chris Wright noted, “Installing the Silva Cell is very simple and straightforward, there really is nothing to it. The supply and on-site installation support we were given was invaluable, we would happily install the Silva Cells in future projects.”

When I asked project manager of DeepRoot Urban Solutions, Steve Chatwin-Grindey, about whether the project’s goals have been achieved, he said, “Absolutely and then some. The trees are performing extremely well, no settlement, and the onsite stormwater is controlled.”

Silva Cell installation, September 27, 2010

Below is a series of photos taken over the past decade that highlights the success of the project site.

ONE YEAR AFTER INSTALLATION

Quays Gateway one year after installation. Photo is south facing toward the tunnel connecting to the quays.

FOUR YEARS AFTER INSTALLATION

Quays Gateway four years after project completion. Photo taken May 2014. Photo is facing west. See the Stowell Memorial Spiral Church in the background, the tunnel is just to the right of the photo.

NINE YEARS AFTER INSTALLATION

DeepRoot is thrilled to see such positive results from the Quays Gateway project. We look forward to what the next 10 years will bring as the urban development trend continues in and around Salford.

 

Installation Summary:
Number of Silva Cell: 184
Amount of Soil volume per tree: 5.3m3
Number of trees and type: 9, Betula Utilis Jacquemontii
Type of Project: Stormwater, Pedestrian and Cycling path
Application Type: Government
Project Designer: Urban Vision Partnership
Project Contractor: GPL Civil Engineering
Installation Date of Silva Cells: September 27, 2010
Project timeline: 2010-2011