proposed don valley layover – what will the layover facility ......the don river valley, which is...

GO Expansion - New Track & Facilities Project

Proposed Don Valley Layover – What will the Layover Facility be used for?

Storage

• Off-peak storage of 3 GO trains in a linear configuration.

Maintenance

• The following types of maintenance activities will be carried out at the Don Valley Layover: o Daily Inspections - general visual inspections to identify any obvious defect or

damage to equipment prior to trainsets entering revenue service. These types of inspections usually take less than an hour to complete per trainset.

o Cleaning, servicing and temperature control of rolling stock. o Sanitary flushing and replenishment of washroom supplies. This includes emptying

sanitary tanks from rolling stock into temporary storage facilities. Temporary storage facilities will be pumped out at regular intervals.

Don Branch looking south from Bloor Viaduct (DVP is to the left)

Don Branch looking north from Bloor Viaduct (DVP is to the right)


• In order to achieve the targeted GO Expansion service levels, layovers are required across the network for train storage and maintenance.

• A layover at this location would reduce congestion at Union Station which is a bottle-neck in the GO network.

• A layover at this location would reduce frequency and length of non-revenue train movements and provide storage and light maintenance for 3 trains during off-peak periods.

• Some GO Expansion upgrade works and other infrastructure construction through the Lower Don portion of the City will reduce storage capacity in the Don/Wilson yard further necessitating the need for train storage in this area.

• Sites to the south of the Union Station corridor have been considered, but to cross the entire corridor with these 3 terminating trains is beyond the capability of the infrastructure creating congestion on the approach to Union Station.

• A layover at this location would make use of the existing track on the Metrolinx-owned Don Branch.

Proposed Don Valley Layover - Why is a Layover Needed at this Location?

The Don Valley Layover Facility design has been updated since Round 2 of public consultation to reflect stakeholder feedback. Changes have been made to relocate buildings to a higher elevation to further floodproof the facility and shift building facilities away from the Lower Don Trail.

Proposed Don Valley Layover Facility - City of Toronto

Proposed Site Plan


Proposed Don Valley Layover Facility - City of Toronto Revised Design Elements:

• Crew services and buildings have been moved to a higher elevation, adjacent to the storage track, within Metrolinx’s right-of-way.

• The storage track remains within Metrolinx’s right-of-way.

Design Elements:

• Storage and light maintenance of 3 GO Trains in a linear configuration.

• Trains will be serviced by wayside power. This is a non-electrified layover facility.

• The facility includes crew services building, sanitary storage and staff parking.

• Retaining walls will be required to limit fill.

• Similar to previous design iterations, the layover will utilize the inactive Metrolinx-owned Don Branch for track storage and access to the mainline track leading to Union Station to the south.

• Vehicle access will be provided from the Don Valley Parkway/Bayview Avenue ramp using an existing park access road.

• Construction fencing/gates will provide a separation between Lower Don Parklands users and construction activities.

• Permanent fencing will delineate the facility from the Lower Don Trail.

• The facility will be secured through an access gate and security fencing.



Proposed Site: Aerial View Note: conceptual design subject to further study

Proposed Site: View from Don Valley Parkway looking North Note: conceptual design subject to further study



Proposed Site: View from the Lower Don Trail Note: conceptual design subject to further study


Natural Heritage Update • The revised design has shifted buildings and other layover

facilities outside of Environmentally Significant Areas (ESAs), as designated by the City of Toronto. The ESA boundaries are represented by the orange area in the map on the left.

• The overall footprint of the layover facility has been significantly reduced to limit vegetation removals and make use of previously disturbed area to the greatest extent possible.

• The site will utilize existing tracks (Don Branch) which are currently not in use, therefore, no additional tracks will be required.

• Access to the site during construction, operation and maintenance will be via an existing park access road that is currently utilized by Hydro One and the City of Toronto to access a hydro substation and the Prince Edward Viaduct, respectively. Metrolinx will improve and extend the existing park access road in consultation with the City of Toronto.

• The layover has been designed to minimize intrusion into Helliwell's Hill wetland by utilizing an existing park access road for the Prince Edward Viaduct. The wetland area is shown in green in the map on the left.

• Utilizing the existing park access road also reduces the amount of fill that is required within the regulatory floodplain (shown in yellow in the map on the left)

Natural Heritage Features Map



Floodplain Update Proposed Don Valley Layover Facility - City of Toronto

• The map shown to the left represents the flood risk within the Don River Valley, which is regulated by Toronto and Region Conservation Authority (TRCA).

• Changes have been made to the Don Valley Layover to relocate the buildings to a higher elevation and further floodproof the facility, as well as, to provide a separation from the Lower Don Trail.

• Buildings are now located outside of the 100-year floodplain and at higher elevation to accommodate TRCA's regulatory storm level. The revised location means that buildings and other facilities are less likely to be impacted in the event of a major storm.

• The facility will be designed to ensure hydraulic conveyance is conserved to minimize on-site or off-site impacts.

• Additional studies to reduce future flooding risks will be undertaken during detailed design.

• Metrolinx is committed to continued consultation with the City of Toronto and TRCA as it relates to the Don Valley Layover design. TRCA Floodplain Map


Effects and Proposed Mitigation Measures Proposed Don Valley Layover Facility - City of Toronto Type of Effect Description of Potential Effects Proposed Mitigation Measure

Stormwater Management

• The proposed access road is located in close proximity to the Don River, which may result in potential challenges with erosion and sediment control.

• The proposed layover requires approximately 370 metres of retaining wall, which will result in disruption to existing drainage patterns and additional challenges with temporary drainage management during construction.

• A Drainage and Stormwater Report, an Erosion and Sediment Control Plan and detailed drainage design will be prepared to further inform stormwater management and identify erosion and sediment controls that will be implemented during construction.

• Requirements for stormwater quantity and quality controls will be carefully reviewed and implemented as required.

• A hydraulic assessment will be completed for the Don River prior to construction to determine potential flooding effects and identify further mitigation measures, if required.

• Further mitigation measures for flooding will be determined in consultation with the TRCA.

Visual

• The need for retaining walls to limit fill will result in increased visual disturbance.

• Impacts on the composition and character of current views along the Lower Don Trail and surrounding park space.

• As part of detailed design, efforts will be made to minimize visual impacts as much as possible.

• A Design Excellence process will be followed to integrate the new infrastructure into the existing environment to reduce the extent of visual impacts. This will include landscaping and screened enclosures, with particular attention given to waste disposal and material storage areas.

• Light sources will be used that minimize layover visibility to Lower Don Parklands users and environmentally sensitive areas.

• Anti-graffiti coating will be applied on public-facing retaining walls.



Natural Environment

• Greater vegetation removals are required for the revised layover configuration since facilities have been shifted away from the already-disturbed areas beneath the Prince Edward Viaduct.

• Siting of the layover buildings has the potential to increase flooding potential downstream.

• Proposed infrastructure is now closer to wetland areas, increasing the potential for impacts during construction.

• Tree/Vegetation removal or injury, compensation and permitting/approvals (as required) will be undertaken in accordance with Metrolinx’s Vegetation Management Guidelines and Tree Removal Strategy.

• Performing vegetation removal outside the typical breeding period for birds, which is between March and September. This will consider potential occupation of treed roosts (individual trees) by bats and Milkweed by Monarch caterpillars.

• An Integrated Vegetation Management Plan will be developed and implemented in accordance with Metrolinx’s Vegetation Management Guidelines and Tree Removal Strategy.

• The revised design has shifted buildings and other layover facilities outside of Environmentally Significant Areas (ESAs), as designated by the City of Toronto.

• The layover has been designed to minimize intrusion into Helliwell's Hill wetland by utilizing an existing park access road for the Prince Edward Viaduct.

• Utilizing the existing park access also reduces the amount of fill that is required within the regulatory floodplain.

• Facility has been redesigned to ensure buildings can be floodproofed to the TRCA regulatory design storm. The revised location means that buildings and other facilities are less likely to be impacted in the event of a major storm.

• Additional studies to reduce future flooding risks will be undertaken during detailed design.

• Metrolinx is committed to continued consultation with the City of Toronto and TRCA.


Effects and Proposed Mitigation Measures Proposed Don Valley Layover Facility - City of Toronto

Type of Effect Description of Potential Effects Proposed Mitigation Measure

Land Use

• Construction of the layover has the potential to impact Lower Don Trail.

• Layover construction has the potential to affect the City of Toronto’s Master Plan for the Lower Don Trail, as well as recreational activities and public art installations.

• Construction and operation of the layover will require an agreement between Metrolinx and the City of Toronto for the access road.

• Nuisance effects may be experienced by the public during construction, which are short-term construction effects that are difficult to prevent (noise, dust, etc.).

• Construction fencing/gates will provide separation between Lower Don Parklands users and construction activities.

• Permanent fencing will delineate the facility from the Lower Don Trail. Where the proposed access road is close to the Lower Don Trail, Metrolinx is proposing removable bollards in the permanent condition for separation between Lower Don Parkland users and service vehicles.

• Metrolinx will engage with the City of Toronto to incorporate municipal requirements as a best practice, where practical, and may obtain associated permits and approvals.

• Metrolinx will obtain a permanent easement from the City of Toronto for the use of the park access road connecting the layover facility with the entrance from the Don Valley Parkway/Bayview Avenue interchange.

• A Communication and Complaints Protocol will be developed prior to and implemented during construction.

• A Construction Monitoring Plan will be developed that identifies site-specific mitigation measures to be enacted before work begins. Mitigation measures contained within the plan will be regularly monitored during construction.



Cultural Heritage

• Construction of the proposed layover, including its various components (buildings, layover yard tracks, parking area, fencing, etc.) has the potential to result in indirect negative effects to the Prince Edward Viaduct, which is a known cultural heritage resource. These indirect disturbances may result from soil disturbance, potential vibration effects, and construction of ancillary buildings to the north of the bridge.

• Baseline vibration monitoring will be completed to ensure the • Prince Edward Viaduct is not affected by construction. • Staging areas will be selected so that they are non-invasive and avoid heritage

attributes. • A Heritage Impact Assessment will be completed to qualify and mitigate the indirect

heritage impacts that are expected for the Prince Edward Viaduct.

Utilities

• Proposed facilities are in proximity to utilities (oil pipelines, gas main, hydro lines and telecommunication cables, amongst others).

• Potential utility impacts have been classified into three different categories: minor, medium or major. Conflicts will be resolved with affected utility companies and relocations will occur, where appropriate.

• All utility assets within the Metrolinx layover site will need to be removed and relocated and/or locally lowered with a casing pipe across all tracks.

• Where new utility crossings are proposed, application for a new utility crossing agreement will be required. Where modifications to an existing utility crossing takes place, updates to an existing utility crossing will be needed.



Earth Management

• Excavation and backfill may be required to accommodate building footprints.

• An Erosion and Sediment Control Plan will be prepared to identify erosion and sediment controls that will be implemented during construction to minimize the risk of sedimentation.

• A Spill Prevention and Response Plan will be developed prior to and implemented during construction to ensure procedures and policies are in place to minimize effects to wetlands and watercourses.

Archaeological

• All projects begin with a comprehensive Stage 1 Archaeological Assessment of affected lands to determine and evaluate areas of archaeological potential.

• Based on results of the Stage 1 assessment, further Stage 2 Archaeological Assessment was completed that cleared the site of future archaeological potential.

• In the event that previously unknown archaeological materials or human remains are encountered during construction, all work will cease. The location will be protected by employing a buffer and further Archaeological Assessment will occur. The local police/coroner as well as the Bereavement Authority of Ontario will be contacted, as appropriate.

• If final limits of the Project footprint are altered and fall outside of the assessed study area, additional Archaeological Assessments will be conducted.

• All Archaeological Assessment findings will be shared with Indigenous communities.



Traffic

• Temporary short-term road closures may be required during construction.

• The proposed layover is not expected to result in significant effects to the surrounding transportation system because the number of expected daily trips to/from the facility is very low.

• A Construction Management Plan and Traffic Management Plan will be developed prior to construction to further identify impacts and associated mitigation. These plans will be circulated to local municipalities/road authorities for review and discussion before being implemented during construction.

Contamination

• A Phase I Environmental Site Assessment (ESA) was completed for the proposed Don Valley Layover Site. Based on information gathered to-date and observations made, the Phase I ESA indicates the likelihood of encountering contamination is low.

• Geotechnically unsuitable soils will likely be removed during construction in order to achieve a proper substrate. Similarly, backfill materials will likely need to be imported to form the foundation.

• A Soil and Excavated Materials Management Plan will be developed prior to construction for the handling, management and disposal of all excavated material.

• Baseline condition sampling will be completed for soil and groundwater (a pre-construction assessment). By completing these studies, baseline conditions can be compared to the post-construction soil and groundwater conditions to determine if additional mitigation or remediation is required.


The following key commitments will be adhered to as Metrolinx continues to advance the design of the Don Valley Layover following the TPAP:

• To support safety and wayfinding, signage and fencing shall be provided for Lower Don Parklands users during construction of the facility.

• The Lower Don Trail will remain open and accessible to the public during construction, and reconstructed (if required) to pre-construction conditions.

• The layover facility shall be designed to be floodproofed to the Regulatory Storm event.

• Maintenance activities, such as snow clearing, will not impact the Lower Don Trail.

• Erosion and sediment control measures will be implemented and maintained during construction to avoid impacts to the Lower Don Trail and Don River.

Particular attention will be given to the architecture and landscape design of the facility in order to reduce visual impacts where feasible. The facility will include:

• Landscaped and planted areas that are environmentally sustainable and will be selected with consideration of the surrounding area and the City of Toronto's Green Standards.

• Screened enclosures to minimize visual impacts (particular attention will focused on the waste disposal and material storage areas).

• Light sources that minimize impacts on Lower Don Parklands users and environmentally sensitive areas.

• Anti-graffiti coating on public-facing retaining walls.

Metrolinx shall continue to communicate and engage with stakeholders during detailed design and construction planning to address municipal concerns.

Future Design Commitments Proposed Don Valley Layover Facility

Retaining wall with planting to provide visual screening – Years 1-5

Retaining wall with planting to provide visual screening – Years 5-10 The benefits of landscape screening will accrue over time

Lighting will be shielded to minimize visibility from adjacent sensitive areas


proposed don valley layover – what will the layover facility ......the don river valley, which is...

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