GO Rail Network Electrification Project Final Environmental Project Report Addendum

APPENDIX C5: Heritage Impact Assessment: Cherry Street USRC Bridge

Final Heritage Impact Assessment Cherry Street USRC Bridge, Toronto

For

[INSERT DISCIPLINE] BASELINE CONDITIONS REPORT

Prepared by:

AS I

Reviewed by:

Gannett Fleming Project No. 060277 Metrolinx Electrification Project

Contract No. QBS-2014-IEP-002

Prepared By: Morrison HershfieldSubmittal Date:2/9/21 February 2021 i | P a g e

GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

METROLINX GO RAIL NETWORK ELECTRIFICATION

Quality Assurance

Document Release Form

Name of Firm: Archaeological Services Inc. (ASI)

Document Name: Final Heritage Impact Assessment: Cherry Street USRC Bridge, Toronto

Submittal Date: February 5, 2021

Discipline: Cultural Heritage

Prepared By: Lindsay Graves Date: February 1, 2021

Reviewed By: Amber Saltarelli Date: February 2, 2021

Approved By: Andrew Gillespie Date: February 4, 2021 Project Manager

The above electronic signatures indicate that the named document is controlled by ASI, and has been:

1. Prepared by qualified staff in accordance with generally accepted professional practice. 2. Checked for completeness and accuracy by the appointed discipline reviewers and that the discipline reviewers did not perform the original work. 3. Reviewed and resolved compatibility interfaces and potential conflicts among the involved disciplines. 4. Updated to address previously agreed-to reviewer comments, including any remaining comments from previous internal or external reviews. 5. Reviewed for conformance to scope and other statutory and regulatory requirements. 6. Determined suitable for submittal by the Project Manager.

GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

REVISION HISTORY

Revision Date Comments

00 August 18, 2020 Final Submission to Metrolinx.

01 February 5, 2021 Revised Final Submission to Metrolinx

GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Executive Summary ASI was contracted by Gannett Fleming on behalf of Metrolinx to conduct a Heritage Impact Assessment (HIA) for the Cherry Street USRC Bridge (Structure 508) along the Union Station Rail Corridor (USRC) at Mile 1.25 in the City of Toronto. The subject bridge carries the USRC over Cherry Street and is being assessed as a requirement of the Metrolinx Electrification Project. As part of the Metrolinx Electrification Program, Metrolinx is working with Hydro One (HONI) to define the areas in the vicinity of Metrolinx rail corridors where proposed electrification infrastructure will conflict with existing Hydro One Infrastructure (i.e., HONI transmission lines) and to establish Environmental Assessment (EA) requirements that may need to be fulfilled in relation to the identified conflict areas. With respect to the Metrolinx USRC, there is existing HONI infrastructure in conflict with the proposed electrification infrastructure between approximately USRC Mile 0.72E to 1.72E (City of Toronto) and will therefore need to be relocated in order to mitigate the conflict. The proposed solution to mitigating the conflict is as follows: • Relocating Hydro One transmission infrastructure using utility bridges adjacent to the Lower Sherbourne Street USRC Bridge (Subway)1, Parliament Street USRC Bridge (Subway) and Cherry Street USRC Bridge (Subway)2; • Relocating two (2) overhead circuits and one (1) underground circuit to a new underground transmission corridor from the Esplanade Transmission Station (TS) to the Don Fleet Junction (JCT). o The proposed underground transmission corridor is to accommodate a spare circuit, therefore, the relocated corridor will be designed to contain up to four (4) transmission cables utilizing a combination of surface troughs, cable banks and utility bridges; • Replacement of three (3) existing potheads, and replacement/extension of the existing chain link fence with durisol wall to capture existing Hydro One Tower #9 at the existing Don Fleet JCT (located on the east side of the Lower Don Trail); and • Removal of existing Hydro One Tower #10A, installation of two (2) new BPEX structures3, overhead connection of two (2) circuits from BPEX structures to the existing Hydro One Tower #9, and installation of durisol wall at the new Don Fleet JCT (located on the west side of the Lower Don Trail). Additionally, Metrolinx and Hydro One have identified the need to locate an additional Hydro One transmission structure (i.e., steel monopole) between the Lower Don Valley River and Corktown Commons to accommodate clearance requirements for the USRC Overhead Catenary System (OCS). A future addendum is to be completed to address environmental assessment requirements; at which time the extent and significance of potential impacts will be determined.

1 Utility bridge at Lower Sherbourne Street will be attached to the future expanded bridge, as approved in 2018 under the USRC East Enhancements Environmental Project Report. 2 Proposed utility bridges are anticipated to be a truss structure clad in either horizontal or vertical fins, regardless of which treatment options are applied. 3 Each BPEX structure will contain three (3) new potheads. Prepared By: ASI 2/9/21 iv | Page Rev. 01 GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

As a result, Metrolinx will assess the potential impacts of these proposed works and will document the changes within the 2021 GO Rail Network Electrification Significant EPR Addendum Report. This HIA determined that the proposed solution will result in direct impacts to the subject bridge, including construction of a utility bridge carrying electrical transmission lines and featuring a louvred covering, which has the potential to have negative direct impacts on the Cherry Street USRC Bridge with alterations to the concrete wingwalls, potential vibration impacts, visual impacts, soil disturbance, and the introduction of infrastructure not compatible with the bridge. The Cultural Heritage Report: Existing Conditions and Preliminary Impact Assessment (CHR) (ASI In Progress) recommended that should it not be feasible to alter the preferred solution, an HIA is required to determine appropriate site-specific mitigation measures. This HIA satisfies this recommendation. The Cherry Street USRC Bridge was evaluated and recommended to be a provincial heritage property (PHP) in the Cultural Heritage Evaluation Report (CHER) (Taylor Hazell Architects Ltd. 2016). Metrolinx Heritage Committee (MHC) determined that the bridge was a Metrolinx PHP. The present HIA follows the Ontario Heritage Bridge Guidelines for Provincially Owned Bridges (Ministry of Transportation 2008), the Standards and Guidelines for Conservation of Provincial Heritage Properties (MHSTCI 2010), and Information Bulletin 3: Heritage Impact Assessment for Provincial Heritage Properties (MHSTCI 2017). The concrete wingwalls, identified heritage attributes of the Cherry Street USRC Bridge, are anticipated to be impacted through the addition of a HONI utility bridge on the south side of the rail corridor. The proposed intervention is anticipated to have both direct and indirect impacts on the subject bridge with alterations to the concrete wingwalls, potential vibration impacts, visual impacts, and the introduction of new infrastructure on the bridge. As such, the following mitigation measures should be undertaken and implemented: 1. The preferred alternative has been chosen to allow for the introduction of the HONI utility bridge in a manner that will result in minor permanent, direct impacts to the decorative cast-in-place concrete wingwalls on the south elevation of the subject bridge. Mitigation measures outlined in this report have been prepared to decrease the severity of these impacts, and should be implemented as appropriate to the extent practicable. 2. Concrete removals on the east wingwall to the south of the rail track should be designed to retain the existing ‘1928’ date stamp on the south portion of the east abutment. Construction and staging should be planned to allow for the proposed modifications of the east wingwall in a manner that retains this date stamp in situ. According to preliminary design drawings which depict the proposed concrete removals as minor in scale relative to the overall size of the wingwalls and the overall bridge, the date stamp will not be impacted in the proposed concrete removals or additions. 3. The intervention should be planned to limit the visual impacts of the modifications, where feasible based on technical constraints and road clearance requirements. In order to reduce the visual impacts of the utility bridge, the scale and massing of the structure should be limited, where feasible. Similarly, consideration should be given to using materials, colours, and finishes that will make the utility bridge physically and visually compatible with, subordinate to, and distinguishable from the surrounding landscape and the subject bridge. A qualified person(s) with individual expertise, recent experience, and knowledge relevant to the conservation of road and/or rail bridges should be consulted in this regard.

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4. All interventions should be designed to be reversible. In this respect, the removals and additions to the wingwalls on the south elevation should be limited and designed in a manner that is reversible should the HONI utility bridge be removed in the future. According to available documentation, the removal of the original 1928 concrete on the wingwalls in the preferred solution is considered to be irreversible. However, should operational priorities change, the utility bridge could be removed, the new concrete utility bridge abutments could be removed, and the original cast-in-place concrete wingwalls could be repaired to match the original 1928 construction. While irreversible and permanent, careful and sympathetic rehabilitation could functionally and visually return the subject bridge to its original 1928 state should the HONI utility bridge be removed in the future. 5. Additional indirect temporary negative impacts are anticipated as a result of soil disturbance adjacent to the wingwalls to facilitate concrete removals and to construct the new utility bridge abutments. Where feasible, soil disturbance should be limited to the areas required for removals and abutment construction, and post-construction grading should be employed to return the slope adjacent to the wingwalls to its pre-construction conditions. 6. The proposed intervention should be carried forward with an emphasis on decreasing the physical and visual impacts of the intervention where practical. The detailed design and implementation of interventions at the Cherry Street USRC Bridge should be guided by a qualified person(s) with individual expertise, recent experience, and knowledge relevant to the type of cultural heritage resources being considered and the nature of the activity being proposed, such as a heritage engineer, architect, or conservator with recent and relevant experience in the conservation of cultural heritage resources. Qualified persons should have specialized knowledge and expertise with experience with the conservation of road and/or rail bridges. Membership in good standing with the Canadian Association of Heritage Professionals (or comparable accredited organization) in a relevant area of practice is considered to be an asset. 7. Construction and staging should be suitably planned and executed to ensure that there are no unintended impacts to the subject bridge. The contractor responsible for construction should be informed of the cultural heritage value of the structure and no-go zones with fencing or other barriers should be installed adjacent to the work zone prior to construction, if feasible to obstruct pedestrian and vehicular traffic, to ensure there are no additional impacts. 8. To ensure the subject bridge is not adversely impacted during construction, a qualified engineer should undertake a condition assessment of the structures within the vibration zone of influence. Further, Metrolinx must make a commitment to repair any damages caused by vibrations. According to Metrolinx communication (16 July 2020), no negative vibration impacts are anticipated for the adjacent provincially-significant Cherry Street Interlocking Tower as a result of the proposed undertaking. 9. As the subject bridge is anticipated to be directly impacted with the addition of the proposed Hydro One utility bridge, a Strategic Conservation Plan (SCP) should be completed for this structure to guide impacts and mitigation measures. 10. This HIA should be submitted in draft form for review and comment to the City of Toronto Heritage Preservation Services, the Ministry of Heritage, Sport, Tourism and Culture Industries, Waterfront Toronto, and any other relevant heritage stakeholder with an

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interest in this project. Upon completion, the final HIA should be submitted to the City of Toronto and other applicable stakeholders for archival purposes.

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Project Personnel

Senior Project Manager: Lindsay Graves, MA, CAHP Senior Cultural Heritage Specialist | Senior Project Manager Cultural Heritage Division

Project Coordinator: Katrina Thach, BA (Hon) Archaeologist | Project Coordinator, Environmental Assessment Division

Report Preparation: John Sleath, MA Cultural Heritage Specialist | Project Manager Cultural Heritage Division

Graphics Preparation: Andrew Clish, BES Senior Archaeologist | Geomatics Specialist Operations Division

Report Reviewers: Lindsay Graves

Rebecca Sciarra, MA, CAHP Partner | Director, Cultural Heritage Division

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Summary of Qualified Persons Involved Senior Project Management, report review, and quality control for this Heritage Impact Assessment is provided by Lindsay Graves (MA, Heritage Conservation), Senior Cultural Heritage Specialist and the Environmental Assessment Coordinator for the Cultural Heritage Division at ASI. Ms. Graves is academically trained in the fields of heritage conservation, cultural anthropology, archaeology, and collections management and has over 15 years of experience in the field of cultural heritage resource management. This work has focused on the assessment, evaluation, and protection of above ground cultural heritage resources. Ms. Graves has extensive experience undertaking archival research, heritage survey work, heritage evaluation and heritage impact assessment. She has also contributed to cultural heritage landscape studies and heritage conservation plans, led heritage commemoration and interpretive programs, and worked collaboratively with multidisciplinary teams to sensitively plan interventions at historic sites/places. In addition, she is a leader in the completion of heritage studies required to fulfil Class EA processes and has served as Project Manager for over 100 heritage assessments during her time at ASI. Ms. Graves is a member in good standing with the Canadian Association of Heritage Professionals. Corporate responsibility and senior quality control for this HIA is provided by Rebecca A. Sciarra (MA, Canadian Studies), Partner and Director of the Cultural Heritage Division of ASI. She has managed and conducted numerous built heritage and cultural landscape assessments, heritage bridge evaluations, impact assessment reports and heritage evaluations as required for various environmental assessment and planning studies in the Province of Ontario. She also has extensive experience conducting literature reviews of heritage conservation policy and practice and developing Official Plan policies. Ms. Sciarra has a specific interest in methods for identifying, analyzing, and evaluating cultural heritage landscapes and has conducted cultural heritage landscape assessments in a wide variety of settings, including analysis of a site’s significant views. Ms. Sciarra is a member in good standing of the Canadian Association of Heritage Professionals (Environmental Assessment and Planning Areas of Practice). Report preparation and field review was conducted by John Sleath (MA, Anthropology) who is a Cultural Heritage Specialist and Project Manager within the Cultural Heritage Division with ASI. John has worked in a variety of contexts within the field of cultural heritage resource management for the past 13 years, as an archaeologist and as a cultural heritage professional. In 2015 John began working in the Cultural Heritage Division researching and preparing a multitude of cultural heritage assessment reports and for which he was responsible a variety of tasks including: completing archival research, investigating built heritage and cultural heritage landscapes, report preparation, historical map regression, and municipal consultation. Since 2018 John has been a project manager responsible for a variety of tasks required for successful project completion. This work has allowed John to engage with stakeholders from the public and private sector, as well as representatives from local municipal planning departments and museums. John has conducted heritage assessments across Ontario, with a focus on transit and rail corridor infrastructure including bridges and culverts.

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Table of Contents EXECUTIVE SUMMARY IV PROJECT PERSONNEL VIII SUMMARY OF QUALIFIED PERSONS INVOLVED IX TABLE OF CONTENTS X 1 INTRODUCTION 1 1.1 DESCRIPTION OF PROPERTY 1 2 STATEMENT OF CULTURAL HERITAGE VALUE 3 2.1 DESCRIPTION OF PROPERTY 3

2.2 CULTURAL HERITAGE VALUE 3

2.3 HERITAGE ATTRIBUTES 4 3 ASSESSMENT OF EXISTING CONDITION 13 4 DESCRIPTION AND PURPOSE OF PROPOSED ACTIVITY 14 5 IMPACT ASSESSMENT 23 6 CONSIDERED ALTERNATIVES AND MITIGATION MEASURES 28 7 SUMMARY OF COMMUNITY ENGAGEMENT 31 8 RECOMMENDATIONS 33 9 REFERENCES 36

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List of Tables

Table 1 Impact Assessment...... 24

Table 2 Results of Agency Data Collection ...... 31

List of Figures

Figure 1 Location of the subject bridge in the City of Toronto ...... 2

Figure 2 Location of the subject bridge in the City of Toronto. Note the Cherry Street Interlocking Tower to the northeast of the bridge...... 5

Figure 3: USRC East Corridor HONI Conflict Study Area with Proposed Underground Hydro Corridors.... 16

Figure 4: Cherry Street Utility Bridge, General Arrangement ...... 17

Figure 5: Cherry Street Utility Bridge, Structural Steel Plans ...... 18

Figure 6: Cherry Street Utility Bridge, Concrete Wingwall Modifications ...... 19

Figure 7: Preliminary Design Rendering, 3D Model base (DTAH n.d.) ...... 20

Figure 8: Preliminary Design Rendering of Horizontal Louvre Cladding on HONI Utility Bridge on Lower Sherbourne USRC Bridge (DTAH n.d.) ...... 21

Figure 9: Preliminary Design Rendering of Vertical Louvre Cladding on HONI Utility Bridge on Lower Sherbourne USRC Bridge (DTAH n.d.) ...... 22

List of Plates

Plate 1 North elevation of the subject bridge, looking south. Note the Cherry Street Interlocking Tower at left...... 6

Plate 2 Cherry Street Interlocking Tower adjacent to northeast wingwall, looking southeast...... 6

Plate 3 Sidewalk on west side of Cherry Street, looking south under the subject bridge...... 7

Plate 4 Centre steel girder bent, looking southeast from the northwest abutment...... 7

Plate 5 Representative cross-braces in bent panel...... 8

Plate 6 Representative riveted and bolted steel gusset on girder bent...... 8

Plate 7 South elevation of the subject bridge, looking northeast from Lake Shore Boulevard East. Note the curved wingwalls ...... 9

Plate 8 West portion of south elevation and southbound Cherry Street vehicular lanes, looking north. ... 9

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Plate 9 East and central portion of the south elevation, looking north...... 10

Plate 10 West wingwall on the south elevation, looking northwest. Note the decorated cast-in-place concrete...... 10

Plate 11 East wingwall on the south elevation, looking northeast...... 11

Plate 12 East wingwall on the south elevation, with date stamp on abutment face under the deck soffit outlined in red (emphasis added by ASI)...... 11

Plate 13 Bridge soffit and west wingwall on the south elevation, looking west...... 12

Plate 14 Intersection of Cherry Street and Lake Shore Boulevard East, with the Gardiner Expressway elevated above grade, looking south from the subject bridge...... 12

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1 Introduction ASI was contracted by Gannett Fleming on behalf of Metrolinx to conduct a Heritage Impact Assessment (HIA) for the Cherry Street USRC Bridge (Structure 508) along the Union Station Rail Corridor (USRC) at Mile 1.25 in the City of Toronto. The subject bridge carries the USRC over Cherry Street and is being assessed as a requirement of the Metrolinx Electrification Project. Metrolinx and Hydro One, as EA co-proponents, completed a TPAP in 2017 in accordance with Ontario Regulation 231/08 – Transit Project and Metrolinx Undertakings for electrification of six GO-owned rail corridors from diesel to electric propulsion, including the USRC. As part of the Metrolinx Electrification Program, Metrolinx is working with Hydro One (HONI) to define the areas in the vicinity of Metrolinx rail corridors where proposed electrification infrastructure will conflict with existing Hydro One Infrastructure (i.e., HONI transmission lines) and to establish Environmental Assessment (EA) requirements that may need to be fulfilled in relation to the identified conflict areas. The Cultural Heritage Report: Existing Conditions and Preliminary Impact Assessment (CHR) (ASI In Progress) recommended that should it not be feasible to alter the preferred solution to avoid all impacts, an HIA is required to determine appropriate site-specific mitigation measures. This HIA satisfies this recommendation. The identified heritage attributes of the Cherry Street USRC Bridge are anticipated to be directly impacted through the addition of a HONI utility bridge on the south elevation. The preferred alternative is anticipated to have direct impacts on the subject bridge with select concrete removals and the addition of new concrete, visual impacts due to the introduction of new infrastructure, soil disturbance, and potential vibration impacts during construction. Mitigation measures outlined in this report have been prepared to minimize these impacts, and should be implemented as appropriate to the extent practicable. Implementation of the proposed intervention should be planned to decrease the physical and visual impacts of the intervention where practicable. The present HIA follows the Ontario Heritage Bridge Guidelines for Provincially Owned Bridges (Ministry of Transportation 2008), the Standards and Guidelines for Conservation of Provincial Heritage Properties (MHSTCI 2010), and Information Bulletin 3: Heritage Impact Assessments for Provincial Heritage Properties (MHSTCI 2017). As both Metrolinx and Hydro One are public bodies prescribed under Ontario Regulation 157/10, this assessment must comply with the Standards and Guidelines for Conservation of Provincial Heritage Properties (MHSTCI 2010). 1.1 Description of Property The Cherry Street USRC Bridge (Structure 508) is located within the USRC at Mile 1.25 in the City of Toronto. The subject bridge carries the USRC over Cherry Street in an east-west orientation approximately two km east of Union Station. The Cherry Street USRC Bridge is a four-span steel plate girder structure with three riveted steel girder bents and cast-in-place concrete abutments. The cast-in-place concrete abutments, wingwalls, and deck fascia feature decorative panel moulding. The structure spans the 66’-5” (20.3 m) road allowance with a sidewalk on either side and in approximately 170’ (51.8 m) in overall width (Taylor Hazell Architects Ltd. 2016). The subject bridge was constructed in 1928 as part of the Waterfront Viaduct grade separation project east of Union Station and is owned by Metrolinx (Figure 1). The Cherry Street Interlocking Tower is located adjacent to the northeast quadrant of the subject bridge, adjacent to the USRC. The Cherry Street Interlocking Tower was constructed in

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1930-31 to control train movements in the USRC, and is classified as a Provincial Heritage Property of Provincial Significance (PHPPS) (Taylor Hazell Architects Ltd. 2018). The Cherry Street Interlocking Tower is anticipated to be relocated approximately 240 m east of its current location4. The Cherry Street USRC Bridge has been classified as a PHP for its significant historical, design, and contextual values (Taylor Hazell Architects Ltd. 2016). There is no SCP in place for this PHP as of January 2021.

Figure 1: Location of the subject bridge in the City of Toronto

(Source: (c) Open Street Map contributors, Creative Commons n.d.)

4 Ministerial Consent to relocate this PHPPS was received by Metrolinx on 7 September 2018 (Minister of Tourism, Culture and Sport 2018).

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2 Statement of Cultural Heritage Value The Cherry Street USRC Bridge (Subway), Toronto, was classified by Metrolinx on June 8, 2016 as a PHP. The property has been included on the list of provincial heritage properties maintained by the MHSTCI. The classification was based on the Cultural Heritage Evaluation Report dated August 2016 prepared by Taylor Hazell Architects Inc (Taylor Hazell Architects Ltd. 2016). At this time, there are no other heritage recognitions by other jurisdictions. 2.1 Description of Property The Cherry Street USRC Subway passes under the eastern portion of the USRC in downtown Toronto. The Subway is a riveted steel plate girder bridge, providing a 66’-5” road allowance under the elevated rail corridor. Two concrete abutments and three frame lines support the steel deck beams above. Each frame is roughly 170’ in length, composed of four three-panel sections separated by expansion joints. In each section the middle panel has cross bracing. The Subways provide two sidewalks on the east and west sides, with two lanes of traffic between them. The Subway was built between 1928 and 1929 as part of the Waterfront Viaduct grade separation project, a joint undertaking of the City of Toronto, CNR and CPR. The Cherry Street USRC Subway is a Provincial Heritage Property. 2.2 Cultural Heritage Value The Cherry Street USRC Subway is of cultural heritage value or interest for its historical, design and contextual values. Historical Values The Cherry Street USRC Subway is associated with historical themes at the local level. The Subway is associated with the City of Toronto`s efforts, spearheaded by the Public Works Department and the Toronto Harbour Commission, to improve rail and water transportation along the reclaimed shoreline. The Cherry Street USRC Subway is part of a set of four almost identical underpasses along the eastern portion of the USRC. The others, at Lower Jarvis, Lower Sherbourne and Parliament Streets have nearly identical designs, structural systems and aesthetics. The major difference is their respective widths, which vary depending on the number of tracks that pass atop. The aesthetic and functional relationships of the Subways connect them with a single infrastructural undertaking, the construction of the Waterfront Viaduct between 1925 and 1930. The viaduct is a raised rail embankment used to carry train traffic east of Union Station. The raised tracks allowed road traffic to pass under the rail corridor through the use of Subways. This eastern portion of the future USRC had been planned since 1909, but the public-private nature of the agreement, World War I, and the subsequent bankruptcy of the GTR delayed the project into the 1920s. By the time the project was completed, the USRC was a continuous, grade separated east-west rail corridor serving Union Station. Design Values The Cherry Street USRC Subway demonstrates design values at the local level. The Subway demonstrates a high standard of accuracy in its construction. The steel frame joinery remains tightly aligned, and is generally in excellent condition. The concrete abutments and deck fascia utilize elegant falsework, and also retain a very high level of structural integrity. The concrete-encased steel plate girder design is representative of Subway structures built as part of the USRC Grade Separation Project.

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Contextual Values The Cherry Street USRC Subway has contextual values at the local level. The Cherry Street USRC Subway is strongly associated with transportation infrastructure, specifically with the Waterfront Viaduct. The Subway`s industrial materials and location within the massive embankment help to define the area as a railway corridor. The proximity to, and visual connections with the former Gooderham and Worts distillery, and the abandoned Victory Soya Mills Silos support the industrial character that once defined the entire area. Through the rail lines it carries, the Subway is physically connected to the broader railway corridor, and Union Station. Its close relationship with the Cherry Street Interlocking Tower emphasizes its functional and historical connections to the railway corridor. 2.3 Heritage Attributes The heritage attributes essential to the cultural heritage value of the Subway are: • Attributes related to its historical associations at a local level including: o Its construction between 1928 and 1929 as one of four similar Subways in the Waterfront Viaduct, a major part of the City of Toronto’s initiative to establish a continuous, grade-separated rail line across the southern part of the city. • Attributes related to its design associations at a local level including: o The concrete-encased steel plate girder design and structural configuration; o The precise construction, and excellent overall condition of the built up steel frame sections; and o The concrete abutments and deck fascia: board-formed with elegant falsework panelling and curved returns to the south, all in excellent overall condition. • Attributes related to its contextual associations at a local level including: o Its location within the elevated USRC corridor; o The view of the Subway and adjacent Cherry Street Interlocking Tower, looking south on Cherry Street from Mill Street; o Its historic and functional connections with the Cherry Street Interlocking Tower; o Its visual connection with the former Gooderham & Worts distillery site to the north; and o Its visual connection with the Victory Soya Mills Silos to the south.

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Cherry Street Interlocking Tower

Figure 2: Location of the subject bridge in the City of Toronto. Note the Cherry Street Interlocking Tower to the northeast of the bridge.

(Source: Taylor Hazell Architects Ltd. 2016, label added by ASI)

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Plate 1 North elevation of the subject bridge, looking south. Note the Cherry Street Interlocking Tower at left.

Plate 2 Cherry Street Interlocking Tower adjacent to northeast wingwall, looking southeast.

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Plate 3 Sidewalk on west side of Cherry Street, looking south under the subject bridge.

Plate 4 Centre steel girder bent, looking southeast from the northwest abutment.

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Plate 5 Representative cross-braces in bent panel.

Plate 6 Representative riveted and bolted steel gusset on girder bent.

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Plate 7 South elevation of the subject bridge, looking northeast from Lake Shore Boulevard East. Note the curved wingwalls

Plate 8 West portion of south elevation and southbound Cherry Street vehicular lanes, looking north.

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Plate 9 East and central portion of the south elevation, looking north.

Plate 10 West wingwall on the south elevation, looking northwest. Note the decorated cast-in-place concrete.

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Plate 11 East wingwall on the south elevation, looking northeast.

Plate 12 East wingwall on the south elevation, with date stamp on abutment face under the deck soffit outlined in red (emphasis added by ASI).

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Plate 13 Bridge soffit and west wingwall on the south elevation, looking west.

Plate 14 Intersection of Cherry Street and Lake Shore Boulevard East, with the Gardiner Expressway elevated above grade, looking south from the subject bridge.

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3 Assessment of Existing Condition A site visit to the subject bridge was conducted on 10 June 2020 by John Sleath, Cultural Heritage Specialist, ASI. The site visit included photographic documentation of the subject resource and adjacent lands. The assessment was conducted from publicly-accessible roadways under and adjacent to the bridge (Plate 1 to Plate 14). The site visit confirmed that the subject bridge and vicinity were in a similar physical and material condition to the description in the Statement of Cultural Heritage Value (SCHV) in Section 2.0. The Cherry Street USRC Bridge at Mile 1.25 of the USRC carries the USRC over Cherry Street in an east-west orientation approximately two km east of Union Station in the City of Toronto. The Cherry Street USRC Bridge is a four-span steel plate girder structure with three riveted steel girder bents and cast-in-place concrete abutments. The cast-in-place concrete abutments, wingwalls, and deck fascia feature decorative panel moulding. The structure spans the 66’-5” (20.3 m) road allowance with a sidewalk on either side and in approximately 170’ (51.8 m) in overall width (Taylor Hazell Architects Ltd. 2016). The superstructure of the four span structure is constructed of steel I-beam girders with a closed, cast-in-place concrete deck. The deck fascia is cast-in-place concrete with panelled decorations and features vertical railing at deck level. The superstructure rests on cast-in-place concrete abutments with wingwalls, both of which feature a similar decorated panel design as the deck fascia. Three riveted steel plate girder bents measuring 51.8 m in length support the deck, each bent featuring four three-panel sections with the middle panel in each featuring cross-braces. The subject bridge carries eight tracks of the USRC in an east-west orientation over two lanes of Cherry Street vehicular traffic, two cycling lanes, and two pedestrian sidewalks. Northbound vehicular traffic is carried under the second span from east, southbound traffic is carried under the third span from east, and pedestrian sidewalks are under the first and fourth spans. An overhead signal gantry is located immediately west of the subject bridge at deck level. The Cherry Street USRC Bridge is located in a mixed residential and commercial to the north of the railway with the Gardiner Expressway and Lake Shore Boulevard East immediately south. The residential structures include high-rise condominiums and associated Distillery Lane to the northwest. The Distillery District (A proposed Heritage Conservation District designated under part V of the Ontario Heritage Act) is located further to the northwest and is not directly adjacent to the bridge. The Cherry Street Interlocking Tower, a PHPPS (Taylor Hazell Architects Ltd. 2016) is to the immediate northeast of the bridge, with the TTC streetcar Distillery Loop further to the northeast. Roadways south of the subject bridge include Lake Shore Boulevard East (at-grade) and the Gardiner Expressway (elevated about Lake Shore Boulevard East and above-grade in this area). South of the subject bridge Cherry Street merges with Lake Shore Boulevard East for approximately 150 m before separating and leading to the industrial Portlands area (Figure 2). Rehabilitations including sandblasting and repainting the entre bridge were conducted in 2014 according to the 2019 inspection report (Veresk Inc. 2019). This inspection report also notes that “new fascias on both sides recently installed”, however this was cited from an earlier inspection report and no additional information or justification for this is included (Veresk Inc. 2019:18). The subject bridge is also assumed to have undergone undocumented routine maintenance and cleaning in its nearly 100 year history.

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4 Description and Purpose of Proposed Activity As part of the Electrification Program, Metrolinx is working with Hydro One (as Co-Proponents) to define the areas in the vicinity of Metrolinx rail corridors where proposed electrification infrastructure will conflict with existing Hydro One transmission lines and to establish environmental assessment requirements that need to be fulfilled for the identified conflict areas, that were not previously assessed as part of the 2017 GO Rail Network Electrification EPR. Specifically, Hydro One Conflict Areas have been identified within the USRC. Further details regarding the identified conflicts, proposed solutions, and cultural heritage studies undertaken as part of the Significant Addendum can be read here. With respect to the Metrolinx USRC, there is existing HONI infrastructure in conflict with the proposed electrification infrastructure between approximately USRC Mile 0.72E to 1.72E and it will therefore need to be relocated in order to mitigate the conflict. In the case of the Cherry Street USRC Bridge, the proposed solution would mitigate this conflict by relocating existing HONI transmission infrastructure on a utility bridge affixed to the subject bridge. The proposed solution would result in direct impacts to the subject bridge, including construction of a utility bridge carrying electrical transmission lines and featuring a louvred covering, which has the potential to have negative direct impacts on the Cherry Street USRC Bridge with alterations to the concrete wingwalls, potential vibration impacts, soil disturbance, and the introduction of new infrastructure to the bridge. The proposed undertaking consists of the construction of a utility bridge on the south side of the provincial heritage property and would include: • Modifications to the south portion of the east and west wingwalls of the bridge by removing the top section of the existing sloped concrete wingwall approximately 3250mm wide and a minimum of 600mm deep; • Extending a portion of the concrete abutment for the HONI utility bridge in the area of concrete removal to ensure appropriate bridge clearance over the roadway; • Installation of a steel through truss utility bridge approximately 2500mm in width and 2100mm in height to carry HONI transmission infrastructure (including wires, conduit, and maintenance walkways) to the south portion of the east and west wingwalls on top of the new concrete abutments; and • Cladding the HONI utility bridge in metal louvres/fins (aluminum construction in either a vertical or horizontal orientation) to protect the infrastructure from the elements (to be completed at a later date if commissioned by a third-party). The HONI utility bridges would carry HONI electrification infrastructure above-grade at the subject bridge, and then will be buried below-grade within the rail corridor south of the rail tracks to the east and west of the subject bridge. A site plan illustrating the extent of the proposed installation/relocation of HONI infrastructure within the USRC (Figure 3), the 60% design drawings for the subject bridge provided by 4Transit (22 May 2020) (Figure 4 to Figure 6), preliminary 3D modeling of the proposed design (Figure 7), and preliminary conceptual renderings (Figure 8 to Figure 9) (DTAH Architecture, Landscape Architecture, and Urban Design n.d.) were reviewed and are included below. The preliminary concept renderings that outline the potential visual impacts of the proposed HONI utility bridges include examples of both vertical and horizontal fin cladding on the nearby Lower Sherbourne Street USRC Bridge, however they were judged to be comparable and similar enough to facilitate an analysis of the Cherry Street USRC Bridge for the purposes of this

Prepared By: ASI 2/9/21 Rev. 01 14 | P a g e GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto assessment. According to consultation with the PDT, the basic version of the utility bridge will be constructed with allowances for the installation of protective cladding at a later date (NOTE- these preliminary renderings are for conceptual illustrative purposes only and subject to change during detailed design).

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Cherry Street USRC Bridge

Figure 3: USRC HONI Conflicts Study Area

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Figure 4: Cherry Street Utility Bridge, General Arrangement

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Figure 5: Cherry Street Utility Bridge, Structural Steel Plans

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Figure 6: Cherry Street Utility Bridge, Concrete Wingwall Modifications

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Figure 7: Preliminary Design Rendering, 3D Model base (DTAH n.d.)

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Figure 8: Preliminary Design Rendering of Horizontal Louvre Cladding on HONI Utility Bridge on Lower Sherbourne USRC Bridge (DTAH n.d.)

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Figure 9: Preliminary Design Rendering of Vertical Louvre Cladding on HONI Utility Bridge on Lower Sherbourne USRC Bridge (DTAH n.d.)

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

5 Impact Assessment To assess the potential impacts of the proposed works required as part of the HONI USRC Conflicts to the cultural heritage value of the Cherry Street USRC Bridge, the identified heritage attributes outlined in Section 2.0 were considered against a range of possible impacts. These impacts are outlined in Information Bulletin 3: Heritage Impact Assessments for Provincial Heritage Properties (MHSTCI 2017), and the City of Toronto’s Terms of Reference for Heritage Impact Assessments (City of Toronto 2019) 5. As part of the analysis of impacts, factors such as scale or severity of impacts, whether they are to be temporary or permanent, reversible, or irreversible, are also considered. In addition, the Information Bulletin 3: Heritage Impact Assessments for Provincial Heritage Properties, created by the MHSTCI (MHSTCI 2017) was consulted to ensure this assessment was compliant with MHSTCI standards guiding Heritage Impact Assessments for Provincial Heritage Properties. In accordance with this document, direct adverse impacts are identified where the following resulting conditions are anticipated: • a permanent and irreversible negative affect on the cultural heritage value or interest of a property; and • loss of a heritage attribute on all or part of the provincial heritage property. Indirect adverse impacts are identified where activities on or near the property may adversely affect its cultural heritage value or interest and/or heritage attributes. Positive impacts may also result where a property’s cultural heritage value or interest and/or heritage attributes is conserved or enhanced. The following table (Table 1) presents the results of impact assessment based on the 60% design drawings of the preferred solution (22 May 2020) (Figure 4 to Figure 6) and preliminary conceptual renderings (Figure 7 to Figure 9) (NOTE- these preliminary renderings are for conceptual illustrative purposes only and subject to change during detailed design. If significant changes occur during detailed design this HIA should be updated accordingly). It considers possible direct adverse impacts, indirect adverse impacts, and positive impacts. See Section 2.0 for a description of the cultural heritage attributes identified for the subject bridge. The top portion of the east and west decorative cast-in-place concrete wingwalls south of the rail corridor are anticipated to be directly impacted through concrete removal and the construction of new concrete utility bridge abutments. The removal of the existing concrete and addition of new concrete is considered to be a permanent impact to the subject bridge, however the scale of these concrete removals is considered minor in relation to the overall size of the wingwalls and the overall structure. Based on a review of design drawings (Figure 6), only a small section approximately 600mm deep and 3250mm long is anticipated to be removed, which is minor in scale in terms of the overall depth and less than one half of the total length of the wingwall. The subject bridge is also anticipated to be indirectly impacted due to potential vibration impacts, soil disturbance, and the introduction of new infrastructure on the bridge.

5 While not directly applicable to this undertaking, the City of Toronto’s Terms of Reference for Heritage Impact Assessments was reviewed and considered to ensure compliance should the City of Toronto become a partner on the project as part of construction activities or should any future heritage permits be pursued with the City of Toronto.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Table 1: Impact Assessment

Severity Heritage Attribute Nature of Impact Direct or Indirect (permanent/temporary, reversible/irreversible) Potential impacts to attributes related to its historical associations at a local level. Its construction between The preferred alternative None N/A 1928 and 1929 as one of will not impact the four similar Subways in historical associations of the Waterfront Viaduct, a the subject bridge as a major part of the City of component of the 1928- Toronto’s initiative to 1929 grade-separation establish a continuous, project in the City of grade-separated rail line Toronto. All four across the southern part structures will be retained of the City. and the Waterfront Viaduct, as a whole, will be retained as a continuous, grade- separated rail line. Potential impacts to attributes related to its design associations at a local level. The concrete-encased The preferred alternative None N/A steel plate girder design will not impact the and structural concrete-encased steel configuration. girders or their configuration in the structure. These elements will not be removed or altered. The precise construction, The preferred alternative None N/A- and excellent overall will not impact the precise condition of the built up construction or overall steel frame sections. excellent condition of the steel frame sections. These elements will not be removed or altered. The concrete abutments The preferred alternative Direct- The preferred Permanent- The preferred and deck fascia: board- will result in select alternative will result in alternative will permanently formed with elegant removal of the top portion direct impacts to the alter the original 1928-1929 falsework panelling and of the board-formed board-formed concrete cast-in-place concrete curved returns to the concrete wingwalls on the abutments with falsework abutments through the south, all in excellent south elevation of the panelling. removal of a section of the overall condition. bridge. A small section of Direct- The top portion of south wingwalls. the southern concrete the bridge fascia on the Irreversible- The preferred wingwalls (approximately south elevation will be alternative will result in the 600mm deep and partially obstructed by the select removal of a portion 3250mm long) will be proposed basic Hydro of the original concrete removed and replaced One utility bridge wingwalls, which is with new concrete and structure. Based on a irreversible. integrated with a new review of design concrete abutment for the Reversible- Visual impacts drawings, these visual to the top portion of the HONI utility bridge. obstructions are Overall, this change is not south fascia are considered anticipated to be minor, reversible if the proposed considered significantly and the vast majority of adverse given the limited basic Hydro One utility the decorative fascia will bridge were removed. scale of the intervention remain visible. Overall, in proportion to the overall

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Severity Heritage Attribute Nature of Impact Direct or Indirect (permanent/temporary, reversible/irreversible) size of the wingwall and the structure will continue Overall, the scale and of the overall structure. to express its cultural magnitude of these Indirect impacts to views heritage value. interventions is anticipated of the decorated cast-in- to be minor, as the place concrete deck structure, although altered fascia are anticipated for and directly impacted, will pedestrians and motorists continue to be able to on Parliament Street, express its cultural heritage Lake Shore Boulevard value. East, and the Gardiner Expressway. Impacts to attributes related to its contextual associations at a local level. Its location within the The preferred alternative None N/A elevated USRC. will not impact the location of the subject bridge or its relationship to the elevated USRC corridor. The location of the subject bridge on the elevated USRC corridor, will be retained and it will continue to function as a continuous, grade- separate rail line. The view of the Subway The preferred alternative None N/A and adjacent Cherry will not impact views Street Interlocking Tower, south from Mill Street to looking south on Cherry the bridge or the Cherry Street from Mill Street. Street Interlocking Tower. These views will not be altered. Its historic and functional The preferred alternative None N/A connections with the will not impact the historic Cherry Street Interlocking and functional Tower. connections with the Cherry Street Interlocking Tower. Its visual connection with The preferred alternative None N/A the former Gooderham & will not impact the visual Worts distillery site to the connection with the north. former Gooderham & Worts distillery site to the north. These views will not be altered. Its visual connection with The preferred alternative Indirect- The top portion Permanent- The the Victory Soya Mills will result in limited of the bridge fascia on the introduction of the Hydro Silos to the south. impacts to the visual south elevation will be One utility bridge is connection to the Victory partially obstructed by the considered to be a minor Soya Mills Silos to the proposed basic Hydro and permanent alteration to south. One utility bridge this heritage attribute. structure, which will result Reversible- The minor in minor alterations to the impacts to the visual visual connection with the connections to the Victory

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Severity Heritage Attribute Nature of Impact Direct or Indirect (permanent/temporary, reversible/irreversible) Victory Soya Mills. Based Soya Mills to the south of on a review of design the subject bridge are drawings, these visual considered to be reversible obstructions are if the Hydro One utility anticipated to be minor, bridge is removed in the and the vast majority of future. the decorative fascia will remain visible. Overall, the structure will retain its visual connection to the Victory Soya Mills to the south.

Alterations to the top portions of the east and west decorative cast-in-place concrete wingwalls south of the rail corridor are anticipated to include the addition of new cast-in-place concrete abutments in the areas of select concrete removals. The addition of concrete abutments for the Hydro One utility bridge is required to provide a flat bearing plate to support the proposed works. Alterations are anticipated to be confined to the east and west wingwalls south of the rail corridor, while the wingwalls to the north of the rail corridor, the riveted steel plate girder piers, and the bridge superstructure are not anticipated to be directly impacted as a result of project works. Select concrete removals on the east wingwall to the south of the rail track are not anticipated to remove or directly impact the ‘1928’ date stamp on the south portion of the east abutment. Additional alterations are anticipated with the construction of the Hydro One utility bridge and include: the introduction of new infrastructure; minor changes to the existing shadows on the south elevation of the bridge as a result of the new infrastructure; minor obstruction of views towards the decorated cast-in-place concrete deck fascia on the south elevation of the bridge; minor alterations to the visual connection with the Victory Soya Mills Silos to the south; soil disturbance, and potential vibration impacts as a result of construction-related activities. Visual obstructions to the south decorated cast-in-place concrete fascia are anticipated to be minor, as the bottom of the proposed Hydro One utility bridge is anticipated to obstruct only the very top portion of the fascia, as depicted in Figure 4. Based on a review of all available drawings and renderings (Figure 4 to Figure 9) this visual obstruction is considered to be minor and will only impact views to the south fascia, as experienced by motorists and pedestrians on Cherry Street and Lake Shore Boulevard East. Overall, the bridge’s original materials will continue to be visible and as pedestrians and motorists approach the bridge, views that provide visual experiences of the original 1928 structure will be maintained. The addition of the proposed Hydro One utility bridge will result in minor indirect impacts to the visual connection between the subject bridge and the Victory Soya Mills to the south through the introduction of a new element on the south elevation of the bridge. Based on a review of design drawings (Figure 4 to Figure 9), these visual changes are anticipated to be minor, and the vast majority of the decorative fascia will remain visible. Overall, the structure will retain its visual connection to the Victory Soya Mills to the south. The preferred alternative also has the potential to result in minor indirect impacts due to soil removal adjacent to the south wingwalls to facilitate the required select concrete removals, and

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto potential vibration impacts as a result of select concrete removal. These potential impacts are anticipated to be minor in severity, temporary in duration, and limited in scale to only the top portion of the south wingwalls. The proposed addition on the Hydro One utility bridge is not anticipated to result in any impacts the historical or functional connections with the Cherry Street Interlocking Tower to the northeast. No impacts to significant views to the Gooderham and Worts Distillery or the Cherry Street Interlocking Tower to the north are anticipated. The subject bridge is not anticipated to be impacted by the USRC East Enhancements project, however, it may be impacted by the proposed construction of the Ontario Line Subway. Potential impacts as a result of this project will be confirmed as design advances and will be assessed in a separate report for the Ontario Line Subway Project. The addition of OCS infrastructure to the USRC as part of the GO Electrification project was assessed in 2017 as part of the GO Rail Electrification EPR. Based on the current RCD, impacts due to OCS attachments on the Cherry Street Bridge are not anticipated. Potential OCS impacts should be confirmed during detailed design. As the subject bridge is anticipated to be directly impacted with the addition of the proposed Hydro One utility bridge, a SCP should be completed for this structure to guide short and long- term conservation of the structure.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

6 Considered Alternatives and Mitigation Measures As part of the Metrolinx Electrification Program, Metrolinx is working with HONI to define the areas in the vicinity of Metrolinx rail corridors where proposed electrification infrastructure will conflict with existing Hydro One Infrastructure (i.e., HONI transmission lines) and to establish EA requirements that may need to be fulfilled in relation to the identified conflict areas. With respect to the Metrolinx USRC, there is existing HONI infrastructure in conflict with the proposed electrification infrastructure between approximately USRC Mile 0.72E to 1.72E and will therefore need to be relocated in order to mitigate the conflict. The proposed solution to mitigating the conflict is as follows: • Relocate Hydro One transmission infrastructure using utility bridges adjacent to the Lower Sherbourne Street USRC Bridge (Subway), Parliament Street USRC Bridge (Subway) and Cherry Street USRC Bridge (Subway). As part of the Metrolinx Electrification Project, alternative designs were considered in regards to the relocation of HONI infrastructure within the project area. One alternative that was evaluated but eliminated from consideration prior to the 60% detailed design phase was to relocate the HONI transmission infrastructure within the USRC ROW entirely underground. This alternative would involve tunnelling beneath the footings of the subject bridge and Cherry Street in order to avoid all direct visual impacts to the subject bridge. This option was eliminated from consideration due to the potential impacts to a large number of existing utilities beneath the bridge and because of increased difficulty with repairing, maintaining, and inspecting the transmission infrastructure. Due to these concerns, the tunnelling option was eliminated from consideration in favour of the preferred solution of carrying the transmission infrastructure on a separate utility bridge (Communication with Metrolinx and Gannett Fleming design team 16 April 2020). The use of a separate utility bridge is also considered to be compatible with the other approved and proposed projects within the vicinity of the subject bridge, including the GO Electrification and the Ontario Line Subway, as discussed briefly in Section 5.0. The preferred design for the proposed HONI utility bridge was not selected at the time of report submission, however the proposed bridge is anticipated to be a truss structure clad in either horizontal louvres or fins or vertical fins as described in Section 4.0. At the time of report preparation, the orientation of the protective aluminum fin cladding on the HONI utility bridge was not decided. According to preliminary design renderings, the fins will either be oriented vertically or horizontally, are anticipated to be aluminum, and will be painted to ensure an aesthetic that reflects Metrolinx design guidelines while being complementary to the specific context and colours of the bridge area (DTAH Architecture, Landscape Architecture, and Urban Design n.d.). The preferred solution is anticipated to result in direct impacts to the subject bridge, including the select removal of the top portions of the east and west decorative cast-in-place concrete wingwalls, alterations to the bridge with the addition of new cast-in-place concrete abutments in the areas of concrete removals to support the utility bridge, and the construction of a utility bridge carrying electrical transmission lines and featuring a louvred covering. The Hydro One utility bridge will result in direct impacts to the Cherry Street Bridge. Mitigation measures outlined in this report have been prepared to minimize these impacts and should be implemented as appropriate to the extent practicable. With suitable mitigation, the preferred solution will allow for the construction of the utility bridge in a manner that will result in limited permanent, direct impacts to the cultural heritage attributes identified in Section 2.0. Select concrete removals on the east wingwall to the south of the rail track should be designed to

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto retain the existing ‘1928’ date stamp on the south portion of the east abutment. Construction and staging should be planned to allow for the proposed modifications of the east wingwall in a manner that retains this date stamp in situ. According to preliminary design drawings (Figure 4 to Figure 6), the date stamp will not be impacted in the proposed select concrete removals or additions. This avoidance strategy should continue to be prioritized. The intervention should be planned to limit the visual impacts of the modifications. In order to reduce the visual impacts of the utility bridge, planning should ensure that the intervention is sympathetic and compatible with the PHP. Similarly, consideration should be given to using materials, colours, and finishes that will make the utility bridge physically and visually compatible with, subordinate to, and distinguishable from the surrounding landscape and the subject bridge. In this respect, preliminary design with aluminum louvres painted to be complementary with the setting is considered to be a suitable means of reducing visual impacts of the overall structure. As part of the final detailed design, the orientation of the louvred fin cladding on the subject bridge should be selected to be consistent with the other two USRC bridges that are included in this project. A qualified person(s) with individual expertise and recent experience and knowledge relevant to the conservation of road and/or rail bridges should be consulted in this regard. In this respect, a design should be selected that is appropriate for use in the Cherry Street USRC Bridge, the Lower Sherbourne Street USRC Bridge, and the Parliament Street USRC Bridge to the west to maintain a compatible and cohesive aesthetic for the entire HONI Conflict Study Area. Further, the new concrete utility bridge abutments on the existing wingwalls should be constructed to be complimentary to the 1928 decorative cast-in-place concrete wingwalls. In this respect, consideration should be given to implementing a decorative panel design on the face of the new abutment faces and to using colours and finishes similar to the existing wingwalls to ensure visual compatibility with the subject bridge. By implementing suitable decorative finishes and colours on the new utility bridge abutments, the visual impacts of the concrete additions would be decreased. According to consultation with the PDT, the extensions to the abutments are anticipated to match the existing concrete wingwalls. All interventions should be designed to be reversible. In this respect, the removals and additions to the wingwalls on the south elevation should be limited and designed in a manner that is reversible should the HONI utility bridge be removed in the future. According to available documentation, the removal of the original 1928 concrete on the wingwalls in the preferred solution is considered to be irreversible. However, should operational priorities change, the utility bridge could be removed, the new concrete utility bridge abutments could be removed, and the original cast-in-place concrete wingwalls could be repaired to match the original 1928 construction. While irreversible and permanent, careful and sympathetic restoration could functionally and visually return the subject bridge to its original 1928 state should the HONI utility bridge be removed in the future. Additional modifications to the subject bridge that may be required to address technical or safety considerations should be designed to be sympathetic and compatible with the subject bridge and with the other USRC Bridges that are included in this project. According to consultation with the PDT, the guardrails and fencing on the bridge and wingwalls will have a contemporary design and be compatible with the other USRC bridges at the request of the Waterfront Toronto Design Review Panel. As the guardrails and fencing on the bridge are not identified as heritage attributes in Section 2.0, their modification is not considered to be a significant impact to the cultural heritage value of the subject bridge. Additional indirect temporary negative impacts are anticipated as a result of soil disturbance. The proposed modifications to the subject bridge are anticipated to result in limited soil disturbance to the south of the subject bridge adjacent to the

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto wingwalls to facilitate concrete removals required to construct the new utility bridge abutments. This soil disturbance is anticipated to result in temporary negative impacts to the subject bridge in general, and the concrete wingwalls in particular, however no permanent negative impacts are anticipated. Where feasible, soil disturbance should be limited to the areas required for removals and construction and post-construction grading should be employed to return the slope adjacent to the wingwalls to its pre-construction conditions. The proposed intervention should be carried forward with an emphasis on decreasing the physical and visual impacts of the intervention where practicable. The detailed design and implementation of interventions at the Cherry Street USRC Bridge should be guided by a qualified person(s), with individual expertise and recent experience and knowledge relevant to the type of cultural heritage resources being considered and the nature of the activity being proposed, such as an engineer, architect, or conservation practitioner with recent and relevant experience in the conservation of built heritage resources and cultural heritage landscapes. Qualified persons should have specialized knowledge and expertise with recent experience with the conservation of road and/or rail bridges. Membership in good standing with the Canadian Association of Heritage Professionals (or comparable accredited organization) in a relevant area of practice is considered to be an asset. Construction and staging should be suitably planned and executed to ensure that there are no unintended impacts to the subject bridge. The contractor responsible for construction should be informed of the cultural heritage value of the structure and no-go zones with fencing or other barriers should be installed adjacent to the work zone prior to construction, if feasible to obstruct pedestrian and vehicular traffic, to ensure there are no additional impacts. To ensure the subject bridge is not adversely impacted during construction, a qualified engineer should undertake a condition assessment of the structures within the vibration zone of influence. Prior to construction, if it is found that there is potential for adverse impacts to the provincially- significant Cherry Street Interlocking Tower as a result of the vibration zone of influence, the qualified engineer should include the Tower property in the condition assessment of structures within the vibration zone of influence. Further, Metrolinx must make a commitment to repair any damages caused by vibrations. According to Metrolinx communication (16 July 2020), no negative vibration impacts are anticipated for the Cherry Street Interlocking Tower as a result of the proposed undertaking.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

7 Summary of Community Engagement Agency data collection was conducted by Gannett Fleming on behalf of ASI as part of this HIA in an effort to obtain more information on the identified cultural heritage attributes of the subject bridge. Results are included in Table 2. Additional consultation with Waterfront Toronto and the City of Toronto was conducted by the Project Team regarding the proposed intervention (consultation record on file with the Project Team and provided to ASI in May 2020). Additional consultation was also conducted during the USRC TPAP and HIA (Metrolinx communication 6 July 2020). This report should be submitted to planning staff at the City of Toronto in draft form for review and upon completion for archival purposes, as dictated by best practices. Following review, City staff should determine if they are aware of additional information that should be taken into account in the assessment of impacts, identification of mitigation measures, or implementation. Round Three of public consultation was held online via Metrolinx’s engagement and public consultation website at https://www.metrolinxengage.com/en/engagement-initiatives/go- expansion-program-pic3. The Metrolinx Engage platform is the hub for interested stakeholders and members of the public to learn more about Metrolinx’s projects and programs, including the GO Expansion Program. Participants were also able to visit the website to find out how they can participate in consultation, provide feedback, and submit questions publicly. Information regarding the proposed utility bridge was available on the website over a two-week period (November 27, 2020 to December 11, 2020), and the active commenting period was open to the public during this time. Following December 11, 2020, the active comment period ended; however, the public was still able and encouraged to ask questions through the online question and answer section, as information remains available online throughout the Addendum. Refer to 5.3.3 of the GO Rail Electrification EPR Addendum 2021 for additional detail regarding the stakeholder and public feedback received as part of the third round of public consultation. Table 2: Results of Agency Data Collection

Contact Date(s) of Description of Information Contact Organization Information Communications Received Julia Murnaghan, Transit julia.murnaghan@to May 2020 In May 2020, Gannett Senior Project Expansion ronto.ca Fleming and Metroland sent a Manager, Office letter to Julia Murnaghan at City of Toronto the City of Toronto to inquire about the heritage status of this bridge. A response received confirmed that there were no additional known cultural heritage resources within the study area and outlined the requirements for this HIA. Karla Barboza Heritage, Karla.barboza@ont May and June Confirmed that the subject

(A) Team Lead Ministry of ario.ca 2020 bridge is a PHP. Tourism, Culture and Sport

Kevin De Mille Ontario Kevin.demille@herit May 2020 The Ontario Heritage Trust

Heritage Trust agetrust.on.ca responded and confirmed that

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

Contact Date(s) of Description of Information Contact Organization Information Communications Received Heritage Planner the OHT does not have any conservation easements or Trust-owned properties within the study area. S. Vangelli Waterfront svangjeli@waterfro May and June No response received at the Toronto ntoronto.ca 2020 time of report submission.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

8 Recommendations The identified heritage attributes of the Cherry Street USRC Bridge are anticipated to be impacted through the addition of a HONI utility bridge on the east and west wingwalls on the south side of the rail corridor. The proposed intervention is anticipated to have both direct and indirect impacts on the subject bridge with alterations to the concrete wingwalls, potential vibration impacts, soil disturbance, and the introduction of new infrastructure that will result in minor visual obstructions and minor impacts to visual connections to the Victory Soya Mills to the south. As such, the following mitigation measures should be undertaken and implemented: 1. The preferred alternative has been chosen to allow for the introduction of the HONI utility bridge in a manner that will result in minor permanent, direct impacts to the decorative cast-in-place concrete wingwalls on the south elevation of the subject bridge. Mitigation measures outlined in this report have been prepared to decrease the severity of these impacts, and should be implemented as appropriate to the extent practicable. 2. Concrete removals on the east wingwall to the south of the rail track should be designed to retain the existing ‘1928’ date stamp on the south portion of the east abutment. Construction and staging should be planned to allow for the proposed modifications of the east wingwall in a manner that retains this date stamp in situ. According to preliminary design drawings which depict the proposed concrete removals as minor in scale relative to the overall size of the wingwalls and the overall bridge, the date stamp will not be impacted in the proposed concrete removals or additions. 3. The intervention should be planned to limit the visual impacts of the modifications, where feasible based on technical constraints and road clearance requirements. In order to reduce the visual impacts of the utility bridge, the scale and massing of the structure should be limited, where feasible. Similarly, consideration should be given to using materials, colours, and finishes that will make the utility bridge physically and visually compatible with, subordinate to, and distinguishable from the surrounding landscape and the subject bridge. A qualified person(s) with individual expertise, recent experience, and knowledge relevant to the conservation of road and/or rail bridges should be consulted in this regard. a) The preliminary designs with aluminum louvres painted to be complementary with the setting is considered to be a suitable means of reducing visual impacts of the basic version of the structure and should be implemented in the final design, where feasible. To ensure that the deck fascia on the south elevation is not isolated or visually obstructed from the public, the protective cladding, if required, should be minimized and designed with a limited scale, where feasible. Protective cladding should be installed in a manner that does not physically impact the deck fascia. As part of the final detailed design, the orientation of the louvred fin cladding on the USRC bridges should be selected to be consistent among all three (3) structures. In this respect, a design should be selected that is appropriate for use in the Lower Sherbourne Street USRC Bridge, Parliament Street USRC Bridge, and the Cherry Street USRC Bridge, to maintain a compatible and cohesive aesthetic for the entire Hydro One Conflicts study area. b) New concrete utility bridge abutments extending from the existing wingwalls should be constructed to be complimentary to the 1928 decorative cast-in-

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

place concrete wingwalls. In this respect, consideration should be given to implementing a decorative panel design on the face of the new abutment faces and to use colours and finishes similar to the existing wingwalls to ensure visual compatibility with the subject bridge. By implementing suitable decorative finishes and colours on the new utility bridge abutments, the visual impacts of the concrete additions would be decreased. c) The preliminary designs should be reviewed prior to finalization (at the 90% completion milestone, for example) by a qualified person with recent, relevant heritage experience to confirm that visual impacts have been suitably minimized and that the materials, colours, and finishes are compatible with the PHPs. A qualified person will be required to review detailed design drawings of the utility bridge, including cladding options to determined compliance with the recommendations of this Report. 4. All interventions should be designed to be reversible. In this respect, the removals and additions to the wingwalls on the south elevation should be limited and designed in a manner that is reversible should the HONI utility bridge be removed in the future. According to available documentation, the removal of the original 1928 concrete on the wingwalls in the preferred solution is considered to be irreversible. However, should operational priorities change, the utility bridge could be removed, the new concrete utility bridge abutments could be removed, and the original cast-in-place concrete wingwalls could be repaired to match the original 1928 construction. While irreversible and permanent, careful and sympathetic rehabilitation could functionally and visually return the subject bridge to its original 1928 state should the HONI utility bridge be removed in the future. 5. Additional indirect temporary negative impacts are anticipated as a result of soil disturbance adjacent to the wingwalls to facilitate concrete removals and to construct the new utility bridge abutments. Where feasible, soil disturbance should be limited to the areas required for removals and abutment construction, and post-construction grading should be employed to return the slope adjacent to the wingwalls to its pre-construction conditions. 6. The proposed intervention should be carried forward with an emphasis on decreasing the physical and visual impacts of the intervention where practicable. The detailed design and implementation of interventions at the Cherry Street USRC Bridge should be guided by a qualified person(s) with individual expertise, recent experience, and knowledge relevant to the type of cultural heritage resources being considered and the nature of the activity being proposed, such as a heritage engineer, architect, or conservator with recent and relevant experience in the conservation of cultural heritage resources. Qualified persons should have specialized knowledge and expertise with experience with the conservation of road and/or rail bridges. Membership in good standing with the Canadian Association of Heritage Professionals (or comparable accredited organization) in a relevant area of practice is considered to be an asset. 7. Construction and staging should be suitably planned and executed to ensure that there are no unintended impacts to the subject bridge. The contractor responsible for construction should be informed of the cultural heritage value of the structure and no-go zones with fencing or other barriers should be installed adjacent to the work zone prior to construction, if feasible to obstruct pedestrian and vehicular traffic, to ensure there are no additional impacts.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

8. To ensure the subject bridge is not adversely impacted during construction, a qualified engineer should undertake a condition assessment of the structures within the vibration zone of influence. Further, Metrolinx must make a commitment to repair any damages caused by vibrations. According to Metrolinx communication (16 July 2020), no negative vibration impacts are anticipated for the adjacent provincially-significant Cherry Street Interlocking Tower as a result of the proposed undertaking. 9. As the subject bridge is anticipated to be directly impacted with the addition of the proposed Hydro One utility bridge, a SCP should be completed for this structure to guide impacts and mitigation measures. 10. This HIA should be submitted in draft form for review and comment to the City of Toronto Heritage Preservation Services, the Ministry of Heritage, Sport, Tourism and Culture Industries, Waterfront Toronto, and any other relevant heritage stakeholder with an interest in this project. Upon completion, the final HIA should be submitted to the City of Toronto and other applicable stakeholders for archival purposes.

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GO Rail Network Electrification Final Heritage Impact Assessment - Cherry Street USRC Bridge, Toronto

9 References

ASI, (Archaeological Services Inc.) In Progress Union Station Rail Corridor Hydro One Conflict Areas Cultural Heritage Report – Existing Conditions and Preliminary Impact Assessment City of Toronto, Ontario. CHR. Report on File at ASI, Toronto, ON.

City of Toronto 2019 Terms of Reference for Heritage Impact Assessments. City of Toronto. https://www.toronto.ca/city-government/planning-development/application-forms-fees/building- toronto-together-a-development-guide/application-support-material-terms-of-reference/.

2020 Bridge Inspection Form: Prince Edward Viaduct (Structure 077), Toronto. OSIM. Report on file at ASI.

DTAH Architecture, Landscape Architecture, and Urban Design n.d. Metrolinx Downtown Utility Bridges, Architectural Cladding Concept. On file with Metrolinx.

Gannett Fleming AECOM Joint Venture 2019 Kitchener Corridor Expansion Program: Draft Infrastructure Report. Report on file at ASI.

MHSTCI, (Ministry of Heritage, Sport, Tourism and Culture Industries) 2010 Standards and Guidelines for Conservation of Provincial Heritage Properties. http://www.mtc.gov.on.ca/en/publications/Standards_Conservation.pdf.

2017 Information Bulletin No. 3: Heritage Impact Assessments for Provincial Heritage Properties.

Minister of Tourism, Culture and Sport 2018 Re: Consent to Remove the Cherry Street Interlocking Tower Including Its Equipment, and Relocate It Approximately 240 Metes East along the UnionStation Rail Corridor, and Demolish the Tower’s Concrete Foundation, Pursunt to Section F.5 of the Standards and Guidelines for Conservation of Provincial Heritage Properties. Ministry of Tourism, Culture and Sport, September 7. Memorandum on file at ASI.

Ministry of Transportation 2008 Ontario Heritage Bridge Guidelines for Provincially Owned Bridges. http://env- web2.uwaterloo.ca/hrcresearch/attachments/5101eba41b59b2.23220210.pdf.

Taylor Hazell Architects Ltd. 2016 Four USRC Subways (Bridges) Cultural Heritage Evaluation Report. CHER. On file with ASI.

2018 Cherry Street Interlocking Tower Heritage Impact Assessment. HIA. Report on File at ASI, Toronto, ON.

Veresk Inc. 2019 Bridge Visual Inspection Report, USRC Bridges. OSIM. Report on File at ASI, Toronto, ON.

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