Small’s Creek ravine consultations - top questions get answers
Metrolinx is providing Danforth-Woodbine residents with more information on a GO Expansion project.
Dec 24, 2020
Transit advances always bring questions, and the need for detailed answers for communities and those impacted.
In order to bring faster more frequent GO Train service to communities along the Lakeshore East and Stouffville lines, Metrolinx is expanding the rail corridor within certain neighbourhoods in eastern Toronto.
Each neighbourhood is unique. There are so many factors that go into transit projects, depending on the proximity to the tracks and what work needs to be done.
Metrolinx community relations staff have been consulting with residents in the Danforth-Woodbine area about what GO Expansion work will mean for their nearby ravine.
Recently, Metrolinx staff walked through the Small’s Creek ravine with community members to hear their feedback in advance of construction that will see the railway embankment widened to support a future four-track, electrified Lakeshore East line.
Whether it’s in-person, over the phone, or digitally, the transit agency’s community relations team have been talking with many engaged citizens in the last few weeks.
Here are some of the top questions that have come up in these discussions and answers from Metrolinx experts.
#1 – What rationale does Metrolinx have that the proposed retaining wall in Small’s Creek Ravine is the best technical, social and environmental solution? What alternatives were considered and why were they rejected?
Metrolinx is working closely with the City of Toronto and the Toronto and Region Conservation Authority (TRCA) to find a solution that is least disruptive to the natural environment. The retaining wall option has been reviewed by TRCA staff, including a geotechnical engineer and is the least intrusive option.
Let’s explore that a little bit.
First, in order to add more frequent, electrified service, this segment of railway corridor needs to expand from three to four tracks, and specialized electrification infrastructure, like the portal structures that hold up the overhead catenary system (OCS), will be installed alongside them.
Although in this particular area, all this new infrastructure will fit within the Metrolinx property line, the flat portion on the top of the current embankment is not wide enough before the grounds slopes away. To address this, the corridor needs to be widened to the north side, and grading work is required. This was identified and assessed in the project’s Environmental Assessment (EA).
One option would have been to just build out the slope further, to support the future fourth track. Because there is a limit on how steep a slope can be while stably supporting the weight of passing trains, this would have resulted in a regraded slope extending deep into the valley, across the Metrolinx property line into City-owned lands. Such an approach would result in more of the creek being buried and would require significantly more tree removals.
Instead, a retaining wall was selected as the least intrusive option. It limits most of the work to Metrolinx property instead of the City’s ravine lands. The retaining wall will be fully within Metrolinx property.
The trees on the slope above the wall still need to be removed and cannot be replaced, as they would be in too close proximity to the future electrification infrastructure.
The retaining wall is made of pre-cast concrete T-Sections, which are backfilled. A chain link fence will then be located at the top of the wall for safety and security.
The retaining wall will be three metres at its highest point, and as low as 1.5 metres as the grading requires. The retaining wall will not be to the height of the rail corridor, but rather will support a new slope leading up to the track level.
A different type of wall, called a secant pile wall, was also considered. However, it was found far more disruptive as the process includes the use of an augur, concrete trucks and other heavy equipment.
The retaining wall design meets the safety and regulatory requirements set out by Transport Canada and the American Railway Engineering and Maintenance-of-Way Association (AREMA). It is designed to support the weight of any passenger and freight trains that will travel the corridor.
Metrolinx looks forward to meeting with the community in the New Year to work through this design in more detail and answer questions.
Further detailed information will be made available at this meeting and will be posted online.
#2 – Will Metrolinx provide a detailed plan and schedule acceptable to the City for the rehabilitation and replanting of the ravine when construction is complete?
Tree removals are carefully studied and considered by a qualified arborist and reviewed by the Toronto and Region Conservation Authority (TRCA) and the City of Toronto’s Urban Forestry department. The tree removal plan includes dead and hazardous trees, and only native species will be planted further aiding in the restoration of the area back local wildlife.
The restoration plan has been developed by a landscape architect and reviewed by TRCA which provides post-construction planting of native species, and stabilization of the disturbed area. The TRCA has provided phase 1 approval of this plan.
Metrolinx will meet with the community in the New Year to walk through the specific details included in this restoration plan, but in the meantime here are some of the highlights:
- A total of 268 trees (210 within Metrolinx property and 58 outside of Metrolinx property) will be removed from the TRCA regulated boundaries, and an additional 188 trees will be preserved and protected during the work. Once the work is finished, 260 trees and 932 shrubs will be planted in the area to support re-naturalization.
- Trees cannot be replanted on the slope above the retaining wall because they would be too close to the future electrification infrastructure, however Metrolinx will provide voluntary compensation for these trees to the TRCA to support re-naturalization initiatives.
In other words, while there will be full restoration around the retaining wall itself, there will also be an opportunity for the community to work with the TRCA and Metrolinx on additional environmental initiatives as part of this compensation plan.
The restoration plan also includes a two-year warranty, during which time the contractor will maintain the area and replace any trees or plants as needed. Trees or plants replaced at the end of the two-year warranty period, will be guaranteed for a further 12 months.
#3 – Will Metrolinx provide a construction schedule that provides a reasonable balance of construction personnel safety and commuter convenience on the one hand and minimizes the need for night work on the other?
Once the successful contractor is on board, likely in January 2021, they will develop a detailed schedule, including work hours. Metrolinx’s initial forecasts suggest the work in Small’s Creek will potentially last approximately eight-to-ten months total, but the project team will update the community once something more definitive is available from our successful contractor.
Metrolinx will work with the City of Toronto and the community to step through this project schedule early in the New Year so that the exact type of work and impacts are well understood, and that construction disruptions or mitigations can be provided where possible.
The preference of Metrolinx and its contracting partners is to complete work during regular daylight hours. As our neighbours clearly understand, however, it’s a busy railway corridor. The nature of some construction activities means they can only be safely or efficiently completed when train traffic is reduced or stopped altogether, which can mean work on evenings, weekends and overnight.
Metrolinx will work with the contractor to limit the amount of overnight work where possible, while still maintaining Lakeshore East rail safety and scheduling requirements.
Overnight work will only occur when it is unsafe to proceed with work that conflicts with the operation of the trains on the tracks.
Metrolinx will establish a Construction Liaison Committee where information from Metrolinx and its contractor will be shared on a regular basis.
This information will also be shared online, through the project newsletter and notices to those who are directly impacted by the work. Metrolinx will also be working with community leaders to also ensure this information is shared in any community communication channels that have already been established.
Metrolinx encourages all community members to sign up for the newsletter so they can stay up to date on all information shared.
#4 – Will Metrolinx provide a detailed plan for noise mitigation both during and after construction?
In order to control the noise and vibration impacts of these individual projects on neighbours, Metrolinx has devised a rules-based approach to construction noise and vibration management, which includes comprehensive requirements to effectively manage construction impacts, including:
- Strict noise and vibration exposure limits and monitoring requirements
- Strict adherence to industry best practices
- Requirement for comprehensive pre-project noise and vibration management plans
- Requirement to deploy equipment that meets noise and vibration emission standards
- Requirement to notify affected public, in advance, of potentially impactful construction activities.
After early works construction, Metrolinx has proposed additional noise walls under the GO Expansion scope of work along the Lakeshore East corridor as a mitigation measure that goes above and beyond the Ontario Provincial protocol to ensure noise walls are recommended in communities that are already experiencing high background noise.
Construction of the noise walls planned under the GO Expansion program will take place once a proponent for the GO Expansion project is selected and could start as early as 2023.
5. Can Metrolinx delay the start of construction until the above issues have been resolved? We understand that this work is an ‘early works’ project and delaying the construction start will have no impact on the larger GO Expansion project schedule.
This project is critical to the overall GO Expansion project schedule. Delaying the widening of the railway corridor in the Small’s Creek area would have significant cascading impacts on other projects, most critically the follow-up project to install tracks and electrification. This would mean thousands of people would be waiting longer to access more frequent transit options.
However, Metrolinx will continue to work through the questions and concerns raised in the above questions in the coming weeks.
Metrolinx won’t know the start of construction date on the works in the Small’s Creek area until the successful contractor is on board, likely early in 2021. Once the contractor is on board a detailed schedule, including a start date for work in the Small’s Creek area, the approximate span of time in which impacts will be felt, and work hours will be identified. Metrolinx will engage with the City of Toronto and the community on this project schedule early in the New Year so that the exact type of work and impacts are well understood, and that construction disruptions or mitigations can be provided where possible.Click here to see the detailed restoration plansDOWNLOAD
Keep informed by signing up to get the latest construction notices and updates. Metrolinx Community Relations will continue to share information and will also be setting up a construction liaison committee meeting to help answer questions and concerns from the community during the project.
Sign up for updates on Toronto Lakeshore East Rail Corridor early works project here and follow us on social media at @Metrolinx and @GOExpansion.