The City of Toronto will be carrying out waterproofing and structure rehabilitation work on the Rosehill Reservoir at David Balfour Park. These necessary upgrades will help to ensure the structural integrity of the reservoir, extend its service life and bring the infrastructure to a state of good repair.

Parks staff will be reaching out to families who have memorial trees and benches in and around David A. Balfour Park. Some records contain family contact information that is out of date, such as phone numbers no longer in service. Please contact if you have questions about the plans for the memorial plaques after the construction work is completed and to make sure your family’s tree or bench is included.

Update #21, July 9, 2019.

Phase 2B will begin August 6, to start work on the East Cell Basin. This will result in a full park closure and will also restrict access from the park into the ravine. The ravine trail will still be open with access from Avoca Avenue, north of the work site.

Work on Saturdays will also continue to Spring, 2021.

Noise complaints, such as work starting prior to the City’s Noise By-law, please contact 311, as there are other construction activities in the neighbourhood. In your call or email to 311, please include as many details as possible, such as:

  • Date
  • Time of Day
  • Vehicle license plate number
  • Company name on vehicle
  • Exact location or address

More information in Construction Update #6.

Update #20, May 16, 2019.

We have recently received a few inquiries from residents located in the high-rise towers overlooking the park about some of the water proofing system protection boards lifting in the windy weather. See the photo below (Permission of Ian Darragh). We would like to provide some background and information about the reservoir’s exterior work including the waterproofing membrane and protection boards that we see today. This is a long update.

Photo: the yellow circle shows the protection boards lifted by the wind. The red shows protection boards affixed to the membrane. The orange dash shows exposed membrane without protection boards.

How the Membrane is Installed

After removing the existing waterproofing membrane and rehabilitating the concrete roof deck, there are a number of layers that will be installed on the exterior of the reservoir roof to protect the structure and the water supply within. This process follows industry standard practices and is in compliance with the waterproofing manufacturer’s installation protocol and warranties.

See the graphic below:

  1. Reservoir concrete exterior/roof deck
  2. Primer is applied on the concrete exterior of the reservoir. This helps to affix the membrane to the reservoir’s concrete roof deck.
  3. Waterproofing membrane – is a hot-applied rubberized asphalt membrane and consists of the following:
    • Black – A base layer of Hot Rubber-ized Asphalt – (HRA)
    • Grey – Polyester Fabric (Remay) is a non-woven fabric and used as reinforcement between two layers of waterproofing membranes. It provides additional structure to the HRA.
    • Black – A top layer of Hot Rubber-zed Asphalt (HRA)
  4. Protection Boards – more details below.
  5. Styrofoam – to provide further protection to the waterproofing membrane and manage the effects of cold weather (freeze-thaw action) against the concrete roof deck of the reservoir
  6. Drainage Boards – to assist with drainage off the reservoir.
  7. This layer would consists of granular backfill, topsoil and grass for the field areas and granular and road pavement for the walkways.

All of these layers would have about a 0.6 metre depth from the finished grade to the top of the reservoir’s concrete deck.

After crews apply the primer (B), three layers (C) of the membrane are applied. Similar to other construction practices, such as steel rebar in concrete columns to build high-rise towers, the layer of Remay enhances/reinforces the structural integrity and durability of the HRA.

Additional Details on the Protection Boards

Crews have progressed and have applied the membrane in many sections of the reservoir in Phase 1. This has been followed by crews laying down (D) protection boards on top of the membrane. The protection boards serve three (3) purposes.

  1. They protect the membrane from light construction activities
  2. They comply with the manufacturer’s requirements to install various other layers as shown in the graphic above which include (E) styrofoam layer (F) drainage board layer and (G) layers of granular, soil and grass.
  3. They separate the waterproofing layer from the Styrofoam insulation

Update on the Membrane Installation

Many residents who have a view of the park and construction work have seen protection boards lift or in some cases completely remove.

Each protection board is typically glued to the waterproofing membrane with additional asphalt applied in multiple spots. The board itself and the bonding force (adhesion) between the board and waterproofing membrane was not manufactured or designed to resist severe winds, which we have recently experienced.

Strong winds from all directions lift these protection boards and with frequent bending in the boards, some have completely detached from the membrane. To advance the work schedule as much as possible and make up for poor weather days that affected exterior rehabilitation activities, the contractor elected to lay down protection boards, even if some may bend or detach. For those protection boards that detached from the membrane, there is no additional cost to the City’s project budget to attach new protection boards. Both the project’s consultant with agreement from the City’s project manager, support this work by the contractor to advance the schedule as much as possible.

Monitoring and Inspection

The methods to install the membrane and protection boards follow industry standards and the material manufacturer’s requirements. The membrane is inspected daily by the City’s inspector and weekly by the material manufacturer to comply with the manufacturer’s warranty. No issues or concerns regarding the waterproofing membrane have been identified in reports by the City’s inspector or the manufacturer to date. Any missing protection boards will be replaced at the contractor’s expense prior to proceeding with the rest of the waterproofing system and subsequent soils/sod overburden.

Another round of inspections will take place before the layers (E) to (G) are installed.

Please contact me with any questions that were not included here.

Update #19, April 12, 2019.

The contractor will be resuming construction work on the reservoir on Saturdays, starting tomorrow April 13, weather dependent.

We apologize for the late notification. Please refer to Construction Notice #5 on January 17, 2019.

Update #18, March 27, 2019.

  • Presentation from March 26 public meeting
  • Phase 2A begins today
  • Four tree removals this week

Public Meeting Presentation Materials

Around 100 residents attended last night’s meeting. If you weren’t able to join us, please see the presentation with annotations to learn more about the park design. Please send us your feedback by April 5, 2019.

  • What do you like about the park design for David A Balfour Park?
  • What are your concerns or questions about the park design?
  • Do you have any additional comments?

Phase 2A begins today

Today is the start date for Phase 2A construction. Hoarding will go up in the eastern and south section below the Garden. See the map for Phase 2A.

Aerial map of Rosehill Reservoir and David A Balfour Park showing the areas closed for Phase 1 and 2A, as well as a portion near the playground for a temporary three week closure. Access to the Garden via Summerhill Avenue will be open in Phase 2A until late July. Phase 2B starts in August to December, 2019 and results in a full park closure.
Rosehill Reservoir Phase 2A map

Four tree removals this week

In Update #16 (January 17, 2019) and Construction Notice #5, staff identified a temporary closure in the south east corner of the park to carry out tree protection and removals. Based on the detailed review of tree roots, certified arborists and City Urban Forestry staff have identified that four (4) trees will be impacted by the contractor’s activities and are located directly in line with the rehabilitation work. The following trees will be removed:

  • One (1) memorial tree located in Phase 1 hoarding will be removed. Parks staff are in contact with the family to determine where a new tree will be located.
  • Three (3) trees are located at the south-east corner of the park on top of the reservoir. These three (3) trees must be removed to carry out structural rehabilitation to the reservoir.

These four (4) trees removals will take place today, Wednesday March 27 to Friday March 29 to ensure they are removed before the Bird Migratory Protection Act.

Access to Rosehill Garden will remain open and a southern portion may be temporarily closed to ensure a safe work zone around these trees. The playground may be closed for safety purposes. Trees will be replanted in a variety of locations around Rosehill Reservoir to coincide with the upgrades to David A Balfour Park.

Project Updates

If you would like to receive email updates about this project, please contact Kate Kusiak at

View Prevous Updates

Arial view of Rosehill Reservoir bordered by Rosehill Avenue
Map of Rosehill Reservoir

Construction Update #5 January 17, 2019.

A Construction Notice was provided to update the community that Phase 2 schedule was advancing in two parts, Part 2A from Feburary to July, 2019 and Phase 2B which keeps with the original schedule starting in August to December, 2019.

Construction Update #4 November 28, 2018.

A Construction Notice was provided to update the community that the public washroom will be demolished.

Construction Update #3 October 26, 2018.

A Construction Notice was provided to update the community that work will be starting on Saturdays.

Construction Update #2 October 17, 2018.

A Construction Notice was provided to update the community on the tree root exploration activities along the eastern perimeter path.

Construction Update #1 August 10, 2018.

A Construction Notice was provided to update the community on the temporary pathways and washroom access.

Public Drop-in Event

March 19, 2018

Members of the public were invited to drop in to learn about the rehabilitation of the reservoir, the details of the construction process, and efforts to mitigate impacts on the community. City of Toronto staff were present to answer any questions and receive feedback from the public.

Public Drop-in Event Notification Flyer

Public Drop-in Event Display Boards

Any questions, comments or feedback about the project can be directed to Kate Kusiak

Previous Consultation

Starting in 2015, the project team met with local stakeholders, permit holders, schools, and other groups that use the green roof of the reservoir regularly. Notices were distributed to area residents and signs have been posted on site.

September 2017 Public Meeting

September 13, 2017

Thank you to all who attended the Rosehill Reservoir Rehabilitation Public Meeting on September 13, 2017 at Yorkminster Park Baptist Church.

If you were unable to attend the meeting, you can view the presentation slides.

Summerhill Residents Association Meeting

October 13, 2016

On October 13, 2016 the project team was invited to give a presentation to the Summerhill Residents Association on the preliminary state of the project. You can view the presentation slides below. Please note that the timelines in this presentation are outdated. The most updated timelines are included in the May 31, 2017 Rosehill Vision Committee Meeting Presentation.

Rosehill Vision Committee Meeting

May 31, 2017

On May 31, 2017 the Rosehill Vision Committee (comprised of neighbourhood residents) held a community meeting to discuss their proposed plans for the green roof of the reservoir and Little Park. The Committee kindly invited City staff to attend the meeting and give a brief presentation that outlines the revised project schedule. View the presentation slides.


On October 26, 2015 the City distributed a notice to properties adjacent to David A Balfour Park regarding a tree inventory to be completed in the first few weeks of November. View the October 26 Notice of Site Work.

On November 10, 2015 the City distributed a notice to properties adjacent to David A Balfour Park regarding survey work to be completed from mid-November to mid-December. View the November 10 Notice of Site Work.

Rosehill Pumping Station

The Rosehill Pumping Station located at 240 Mount Pleasant Road in Toronto, south of St. Clair Avenue, is one of the eighteen pumping stations operated by Toronto Water. In 2008, the City of Toronto conducted a study to evaluate system sustainability during a City wide area power failure. One of the recommendations from this study was the installation of standby power at Rosehill Pumping Station, which include building extension to house 2 generators and a fuel storage tank. In 2013, the City of Toronto also conducted a system-wide review of its drinking water infrastructure and determined through this process that the Rosehill Pumping Station requires rehabilitation to bring to a state of good repair. It is the City’s intent is to realize efficiencies by combining the rehabilitation work and the standby power installation into one project, the Rosehill Pumping Station Rehabilitation and Standby Power Installation. This project is expected to be completed by the Spring of 2020.

Rehabilitate an Aging Reservoir

The Rosehill Reservoir stores and provides drinking water for approximately 675,000 residents located in downtown Toronto. It is vital in managing water distribution in the City as well as ensuring a constant supply of water is available during emergencies such as fires, water main breaks and power outages.

The reservoir was originally built in 1873, making it the oldest and largest of the ten ground level reservoirs located in the City. The last rehabilitation took place in 1966 and the current rehabilitation activities are expected to last for another 50 years. This work will extend the reservoir’s service life, bring it into a state of good repair and meet improved provincial guidelines for safe drinking water.

Work to rehabilitate the reservoir includes:

  • Replacing the waterproofing membrane on top of and one metre down the side walls of the reservoir. This require the removal of park features, trees and soil from the top of the reservoir and partly down its slopes.
  • Reinforcing, patching the reservoir’s interior structures, such as its walls, columns and joints.
  • Replacing and upgrading the mechanical and electrical systems that operate the reservoir within the water supply and distribution network.
  • Cleaning, upgrading, replacing related infrastructure around the reservoir, such as the watermains, storm sewer system, footing drain systems, as well as the Access and Valve House located on the south side of the park.

Improvements to David A Balfour Park

In addition to the rehabilitation activities, the City’s contractor will also be installing new park features as part of a park enhancement plan. The project team has been working with the Rosehill Vision Committee to develop a landscape enhancement plan. Some highlights of new park features include:

  • A new public washroom
  • Re-design of park entrance on Rosehill Avenue
  • Widening stairs at Jackes Avenue entrance and near the Valve House
  • A new water feature at the relocated historical Molecule
  • Additional benches and picnic tables
  • Improved lighting
  • Pavers and pathway materials

The Rosehill Garden will be reinstated in its original location on top of the reservoir.

The landscape plan will be developed and shared with the community once the design concept has been finalized. The contractor will install the park elements once the rehabilitation work is complete.

Improvements to the playground is not part of the rehabilitation contract or park enhancement plan.

The Construction Schedule

The rehabilitation work began in April 2018 and is expected to be completed by Spring 2021. The reservoir has two cells/basins and the construction schedule carries out work on one cell/basin while the other cell/basin continues to operate. The construction schedule is separated into three phases:

  1. Phase 1 is from April 2018 to January 2019
  2. Phase 2A is from February 2019 to July 31, 2019 and Phase 2B is from August 2019 to December 31, 2019
  3. Phase 3 is from January 2020 to Spring 2021

Summary of Construction Phases

During Phase 1, structural rehabilitation and waterproofing work over the West Cell/Basin will be completed. This work will require the closure of the west side of the park, and will continue until the park features in the enhancement plan are installed.

Phase 2A will advance the work along the lower perimeter pathway south of the washroom around the playground towards Little Park/Summerhill Entrance. Within Phase 2A, a three-week temporary closure starting late February, around the playground and outer perimeter path is required to remove and install tree protection zones. If this three-week closure will affect access to the Garden, a Construction Notice will be issued in advance.

Phase 2B includes a full park closure as per the original March 2018 Construction Notice. At this time, rehabilitation and waterproofing work over the East Cell/Basin will begin. Phase 3 will complete the rehabilitation work and park features installation prior to the end of the project in Spring 2021. Construction updates will be provided prior to these milestones.

Construction Work Hours

Work will take place Monday to Fridays starting at 7 a.m. to 7 p.m. and on Saturdays starting at 9 a.m. to 5 p.m. Soil removal, removing existing waterproofing membrane and the process to install a new membrane (and replacing soil) is weather dependent and unfortunately the rain and wet weather has impacted the schedule in Phase 1. Work on Saturdays is required to recoup this time and meet the completion date. See the City’s Noise By-Law for more information and previous Construction Notice for Phase 1 Saturday Work.

Park Access during Construction

The City previously committed to providing access through the park and around construction. However, due to concerns raised regarding the safety of the temporary pathways, access from Rosehill/Avoca avenues was closed off. Please read this construction notice for more information.

During Phase 2A, access to the remaining open park spaces at the Garden and around the playground will be provided via Little Park/Summerhill Entrance. If the three-week closure affects access to the Garden, a Construction Notice will be issued in advance

During Phases 2B and 3, the park will be fully closed and no access around the construction will be provided.

Access from the trails in the ravine will continue to be open during Phase 2A, however, the trails are steep, rough terrain and not maintained by the City. Signs will be posted in the ravine to prevent access to the park during Phase 2B and 3, as well as during the temporary three-week closure near the playground in late February. The alternate route around construction are the local roads via Yonge Street. Please make a request with 311 regarding Parks Maintenance by calling 311 within City of Toronto or email

Impacts to Park Trees

The City is making every effort to minimize the number of trees that will be removed or impacted. The project team is working closely with arborists, landscape architects, City of Toronto Forestry staff and the Rosehill Vision Committee’s dedicated arborist to determine tree protection zones (TPZ), impacts, transplants and removals. The City has directed the contractor to carry out a Tree Root Exploration process to expose the tree roots (which does not damage the trees) for arborists to determine its conditions in review of the rehabilitation activities and park design. Trees located on top of the reservoir and partially down the slope will be removed and not replanted.

A replanting plan is being developed as part of the park enhancement design. This plan will address trees that were removed during construction. Memorial trees will also be included in this plan. The City Forestry staff have reached out to family members of dedicated trees and benches to work together and determine where those impacted trees can be replaced. Some records have family contact information that is out of date, such as phone numbers no longer in service. Please contact to ensure your family’s memorial tree or bench is included in the replanting plan.

In addition the park trees, the Rosehill Garden Volunteers have worked closely with the project team to transplant a number of plants from the original garden to the expanded Avoca Beds prior to Phase 2 work. These plants will be reinstated back to their location in the Garden near the south-east corner of the park after rehabilitation work is complete.

Traffic Impacts

Extensive trucking logistics are required as part of the rehabilitation activities due to:

  • Constrained opportunities on-site
  • Large volume of soil to remove (and replace)
  • Load bearing capacity of the reservoir structure
  • Large and heavy equipment and mechanical elements to replace and install

Trucking at Main Access Point

The main access point or hub of rehabilitation and truck activities is located at the north-east corner of the park at Rosehill Avenue and Avoca Avenue, as it is off of the reservoir structure, and has sufficient space to transfer removed soil into trucks and make deliveries for the north-end of the reservoir. All exterior and interior work activities, such as soil removal and delivering equipment and supplies, will use this access point, with the exception of work at the Valve House and Summerhill Entrance/Little Park.

Trucking at Summerhill Avenue

Trucks will also be required to access the Valve and Access House located at the south end of the park via Summerhill Avenue, as these are the entry ways to much of the reservoir’s mechanical and electrical systems. Jackes Avenue will be a third access point to allow watermain connection activities to be carried out.

The City has worked with the contractor to minimize the number of trucks at Jackes and Summerhill Avenue by redirecting trucks that would remove soil at the south end of the park, to the Main Access Point at the north end of the park.

Idling Trucks

The City’s Idling Policy restricts idling to 1 (one) minute within a 1 (one) hour period. If you see idling on local streets beyond this restriction, please send an email to,,, and include the following information:

  • License plate number
  • Location where the infraction is taking place
  • Approximately how long the vehicle was idling
  • Time of day – to establish a pattern (i.e., every Tuesday at 10:30 a.m. etc.)

On-Street Parking Impacts on Summerhill Avenue

Trucks required to make deliveries at the Valve House located near Little Park/Summerhill Entrance require a large turning radius. Staff have worked with residents and the City’s Permit Parking staff to use about four car spaces on the south curb at the foot of Little Park for these deliveries. The benefit of this arrangement meant that park plantings and features in Little Park were not impacted or removed. Please see the Phase 1 Notice for more details. Another notice will be issued to continue this arrangement in Phase 2A.

Dogs Off-Leash

Dogs are required to be on-leash (Toronto Municipal Code Chapter 608- section 34) as there is no dog off-leash area (DOLA) in this park. Signs have been posted on construction hoarding asking dog owners to keep their dogs on-leash. Please email or phone 311 to request by-law enforcement for dogs off leash.