An Environmental Assessment (EA) Study was completed on the Algonquin Island Bridge in 2014, which recommended replacing the existing bridge. However, in 2016 a detailed condition assessment was conducted and identified an opportunity to rehabilitate the bridge instead of building a new structure. A revised design is being prepared that will address the unique challenges of replacing the underwater substructure of the bridge.
The City is currently working with local utilities to relocate utility infrastructure near the bridge to allow for the upcoming rehabilitation work.
Rehabilitation of the Algonquin Island Bridge is anticipated to begin October 2020 and be completed in April 2021. Construction on and around the bridge is limited to the period of September to April due to government restrictions in place to protect fisheries and wildlife habitat.
This rehabilitation work will cost $4.35 million. The bridge will remain open to pedestrians and traffic during rehabilitation work.
During the EA process, area residents identified a number of key concerns with the bridge, including: lack of traction on the bridge surface; a handrail which is not easily accessible; and the grade of the bridge. Aside from the grade of the bridge, which is limited by the profile of adjacent roadways and property impacts, the key issues raised during the EA process can be addressed through rehabilitation.
Rehabilitation will consist of the following key elements:
The Algonquin Island Bridge is the primary and only fixed access for pedestrians, bicycles and service vehicles between Algonquin Island and Ward’s Island on the Toronto Islands. Originally constructed in 1938, the structure was rehabilitated in 1998 with ongoing maintenance.
The bridge supports a watermain along the west side and a gas pipeline underwater below the bridge deck. Currently there is a load restriction of 12 tonnes due to the aging structure and it does not meet City’s full service vehicle requirements. The bridge structure is in need of major repairs or possible replacement.
This study has identified and evaluated options for rehabilitation or replacement which accommodate all users, both over and under the bridge, essential vehicles and the heritage value of the existing bridge structure.
An Environmental Assessment Study was completed on the Algonquin Island Bridge in 2014, which recommended replacing the existing bridge. However, in 2016 a detailed condition assessment was conducted and identified an opportunity to rehabilitate the bridge instead of building a new structure.
In response to new information that has recently become available, the City is changing its approach to addressing the deteriorating condition of the Algonquin Island Bridge.
The 2014 Algonquin Island Bridge Municipal Class Environmental Assessment (EA) recommended replacing the existing bridge. However, a detailed condition assessment was conducted in June 2016 which identified an opportunity to rehabilitate the existing bridge instead of building a new bridge. The condition assessment identified that the life of the bridge can be extended by 30 years at a fraction of the estimated $6.0 million cost to replace the bridge.
After review and evaluation of this opportunity, City staff have determined that the reduced scope and cost warrant proceeding with rehabilitation instead of replacement.
Due to the flooding on the Toronto Islands and utility relocations the project was delayed over the years.
Built in 1938, the Algonquin Island Bridge is currently the sole link between Algonquin Island and Ward’s Island. The bridge is primarily used by pedestrians, cyclists and City of Toronto and other service vehicles. The bridge currently has a posted advisory load restriction of 12 tonnes.
In 1992, the City of Toronto commissioned a limited bridge condition survey to determine the condition of the existing bridge structure. Based on the findings of this survey, the bridge was rehabilitated in 1998 and received a new deck. Recent bridge inspections have identified some decay in the timber piles and a need for additional repairs or possible replacement.
Due to the age and historical significance of this structure, an Environmental Assessment was required to determine how best to address the condition and rehabilitation needs of this structure. The Algonquin Island Bridge Environmental Assessment Study has been completed in accordance with the requirements under the Municipal Class Environmental Assessment (the Class EA). While the latest timber pile inspection has determined that some components would need to be replaced within the next year, this repair would address only the specific piles identified in the inspection as having experienced significant decay, and would not be nearly at the scale or cost of any of the rehabilitation options considered to date. The inspection report also recommends at minimum reassessing the condition of the remainder of the piles and caps within three years. This timing coincides roughly with the intended construction period for bridge replacement.
The EA Study was carried out with the assistance of technical consultants and supported by a Technical Advisory Committee (TAC) with staff from Transportation Services; City Planning; Parks, Forestry & Recreation; and Engineering & Construction Services.
Part of the Environmental Assessment consisted of a Cultural Heritage Resource Assessment. The study concluded that the location of the existing bridge holds historical significance and that a number of design elements should be preserved or recognized. Much of the original material, however, has been replaced over the years through regular maintenance and rehabilitation.
The EA investigated a number of alternative solutions, including:
Based on a number of evaluation criteria including Heritage and Design, Accessibility, Lifecycle Needs, and Cost, the following alternative solutions were investigated in further detail:
Rehabilitate the Existing Bridge: This option considered the replacing approximately up to 80 percent of the timber components of the bridge, would cost up to approximately $4.3 million, and would require significant continuing maintenance.
Build a New Trestle Bridge: This option considered the replacement of the bridge with a new structure of similar design, but built with modern materials including concrete. This option is also expected to cost approximately $4.3 million, and would last approximately 75 years, requiring limited regular maintenance.
The short-listed alternative solutions were further developed into five alternative designs:
These alternative designs have been compared based on total lifecycle costs, potential to address immediate community concerns with the existing design, and public feedback received. It should be noted that the existing load restriction would remain under the Minor Rehabilitation design, although a non-slip coating would be applied to the existing timber deck surface and drainage would be improved under this option. The Major Rehabilitation would reduce the grade of the approach span, and would accommodate heavy vehicles (as would the Moderate Rehabilitation).
To view complete report, list of figures, tables and appendices contact Steven.Ziegler@toronto.ca.
Ontario’s Environmental Assessment (EA) program promotes good environmental planning by determining and managing the potential effects of a project prior to implementation.
The EA program ensures that public concerns are heard. EA balances economic, social, cultural and natural environmental needs so that projects benefit Ontario.
This study is being carried out according to the Municipal Class Environmental Assessment process. This is an approved approach to satisfying requirements of the Environmental Assessment Act specifically tailored to municipal infrastructure. The process includes identifying the problem or opportunity to be addressed, developing and evaluating a range of alternative solutions, providing opportunities for public input and identifying a preferred solution.