Gibraltar Point Erosion Control Project

PROJECT STATUS

Spring 2023

The sand dune construction phase of the Gibraltar Point Erosion Control Project is now complete!

The completion of the sand dune complements the nearshore reef and protective groyne that Toronto and Region Conservation Authority (TRCA) constructed in 2022 to further mitigate erosion risks.

More than 50,000 tonnes of sand were imported to recreate the natural shoreline, helping prevent future flooding further inland as the new shoreline will provide a buffer during high water events.

The restored sand dune will provide habitat for many wildlife species, including shorebirds, small mammals, and insects.

TRCA will continue to adaptively manage and monitor the beach for erosion, adding sand periodically depending on how much is lost from the area.

Building and Planting the Restored Sand Dune

After the in-water nearshore reef construction was complete, TRCA embarked on the sand dune restoration phase of the project in late 2021 through early 2022. This involved barging in more than 50,000 tonnes of sand and using heavy equipment to place and shape the sand into a dune feature.

Once the sand was placed, TRCA strategically placed logs and other woody debris to provide habitat features within the new dune. These features trap wind-blown sand and seeds, helping to spur vegetation growth in the dune and provide wildlife habitat.

Fencing was installed around the new dune system to protect it from people – dunes are fragile systems designed to be resilient in the face of waves and wind, but are vulnerable to people trampling them.

In fall 2022, TRCA and the City of Toronto turned their focus to planting the new sand dune with native sand-loving plants.

The back area of the dune was planted with over 3,000 native trees and shrubs, while the mid-dune and foredune areas were planted with over 5,000 beach marram grass and other native herbaceous species.

Dune restoration will continue in 2023, with more plantings planned, which will finally accomplish the vision of a restored sand dune system, improved aquatic habitat, and natural resilience to future erosion.

TRCA wishes to thank the generous funders of this project, including the City of Toronto, Environment and Climate Change Canada, and Ministry of Environment, Conservation and Parks.

Previous Updates

June 2021

Both the nearshore reef and the groyne structure are complete!

We are now beginning to implement the final phase of this project: the Sand Dune. This phase will complement the nearshore reef and protective groyne and further mitigate erosion, restoring the shoreline and dune habitat.

This project will include the creation of marram grass beach-dune habitat, wetland features and native tree and shrub plantings.

Select image below to view a full-sized version of the concept design.

The objective is to provide long-term protection of critical infrastructure and function of the Toronto Islands.

TRCA staff will begin constructing the natural dune habitat in June 2021, lasting until late Fall 2021. In Spring 2022 the project site will be planted and continue to be adaptively managed.

Lakeshore Avenue will remain open for the duration of the project but an increase in traffic is expected.

While the Gibraltar Point project site will be closed to the public, Gibraltar Point Beach and Hanlan’s Point Beach will remain open.

October 2020

The nearshore reef has been constructed and the groyne structure is close to completion!

Construction of the Gibraltar Point Erosion Control project is separated into three phases of work. This phased approach is being carried out by marine based equipment used to place 85,000 metric tonnes of various types of aggregate along the eroded shoreline.

Even though weather is a constant challenge for marine based construction, the creation of the nearshore reef (successfully completed in July 2020) is functioning as designed: shoreline erosion has halted, and aquatic life has already been observed living within the nearshore reef structure.

Construction of Phase 2, the groyne structure, placed 6,000 metric tonnes of aggregate material. The groyne structure commenced in August 2020 and was completed in December 2020.

Summer 2020: marine based equipment placed 85,000 metric tonnes of various types of aggregate along the eroded shoreline.

November 2018

Construction of the nearshore reef is underway!

August 2016

In 2016, partial funding was secured from the City of Toronto to implement the Gibraltar Point Erosion Control Project.

As erosion control measures were not implemented within five years of the 2008 approval of the Conservation Ontario Class Environmental Assessment for Remedial Flood and Erosion Control Projects (Class EA), an addendum under Section 6.0 of the process is required.

The objective of this addendum is to reconfirm our understanding of the existing conditions of the shoreline and to ensure that the underlying conditions and results of the Class EA remain valid. The amendment will be completed prior to the start of construction.

• Notice of Intent – August 18, 2016

For more information, please contact Clifton Coppolino, Restoration & Resource Management, at clifton.coppolino@trca.ca or (416) 661-6600 ext. 5772.

PROJECT BACKGROUND

Gibraltar Point is located at the southwesterly tip of the Toronto Islands, on Lake Ontario.

Erosion has been documented at Gibraltar Point since 1879. In 1972, significant storm damage prompted the first of several studies recommending various long-term remedial solutions.

Despite these recommendations, no major remedial actions were financially supported. Attempts were made to protect the Gibraltar Point shoreline with gabion baskets and rubble. These attempts had only short-term success, as they failed to address the large-scale coastal processes affecting the site.

A severe storm event in February 2004 caused significant damage to an existing washroom building and associated infrastructure, prompting the City of Toronto to request the assistance of Toronto and Region Conservation Authority (TRCA).

TRCA responded by immediately securing the shoreline adjacent to the washroom with emergency shoreline protection.

With support from the City of Toronto, TRCA completed an Environmental Study Report (ESR), in accordance with Conservation Ontario’s Class EA process, to develop a long‐term solution to address the shoreline erosion around Gibraltar Point (TRCA, 2008).

As part of the Class EA process, TRCA retained Shoreplan Engineering to complete a coastal analysis to determine the regional processes around Gibraltar Point and assist with the development of alternative long-term solutions to the shoreline erosion.

The results of Shoreplan’s investigations determined that although erosion and deposition are occurring at various locations between the Western Gap and Gibraltar Point, there is an overall net loss of sand resulting in ongoing shoreline erosion.

A comparison of hydrographic survey data shows a lowering of the lakebed in the nearshore area around Gibraltar Point, which is consistent with the undermining and eventual failure of previous local shoreline protection works.

Furthermore, Shoreplan’s findings indicated that, over the next 100 years, a substantial loss of highly valuable recreational and ecological land is projected, ultimately resulting in the breaching of the Islands from Lake Ontario to the Inner Lagoons within the next 20-25 years.

The preferred alternative identified through the Class EA process was a sand management approach, which recognized that some form of offshore structure would likely be required to reduce the volume and frequency of sand required to be placed at Gibraltar Point. The preferred offshore concept developed through the Class EA process was a breakwater.

On March 17, 2008 the findings of the Gibraltar Point Erosion Control Project were approved under the Class EA process.

In 2009, TRCA and the City of Toronto retained W. F. Baird and Associates (Baird) to undertake a Phase II Coastal Engineering Study (Phase II Study), which included coastal engineering analysis and final design for the Class EA outcomes.

As part of their Phase II Study, Baird was directed to complete two supporting assessments:

1. Evaluate potential offshore sand sources for an active sand management approach at Gibraltar Point.
2. Assess the project’s potential impacts on the formation of transitional hind dune system present at Hanlan’s Beach.

Baird concluded that if an entirely non-structural approach for erosion control was selected, approximately 30,000 to 60,000 cubic metres of sand (or 3,000 to 6,000 truckloads) would be required every year in the area of Gibraltar Point, to avoid continued erosion through the existing coastal processes.

Given the uniqueness of the sand dune processes along Hanlan’s Beach, the sand selected would also need to meet very specific conditions to allow those dune processes to continue.

The report evaluated a variety of local nearshore sand sources along Lake Ontario. It concluded that all of the sources were either inappropriate for use at Gibraltar Point due to physical limitations (e.g., grain size, sand quality, volume) and/or incompatibilities with other shoreline management strategies.

It is also fundamentally impractical to deliver the required volumes of sand on an annual basis, without significant costs and significant disruption to beach users.

In 2010, in order to address comments raised on the projects potential impact to the formation of the transitional hind dune system present at Hanlan’s, Baird and TRCA met with two independent volunteer experts on the project Community Liaison Committee.

The two experts agreed with Baird’s analysis that:

• The observed westward advance of Hanlan’s Beach and the formation of transitional hind dunes was due to human expansion of the Toronto Island Airport.
• Hanlan’s Beach has likely reached capacity, and hence the beach front will no longer migrate westward as a result of ongoing erosion at Gibraltar Point. Therefore, the observed transitional hind dunes will shortly, or have already begun to stabilize to upland forested habitat, even without any intervention (i.e. no focused sand management or off-shore structure).

As a result of the supporting studies, Baird’s Phase II Study will complete a detailed assessment of offshore structures that could be combined with a sand management approach, involving the placement of locally acquired sand onto the shoreline in the area of Gibraltar Point, over a period basis, to restore land lost to erosion.

Possible offshore structures for a preferred alternative identified in the 2008 Class EA include:

• Submerged sills
• Low-crested structures
• Emergent breakwaters
• Groynes

Two additional alternatives will be assessed including a stand-alone sand management approach and an offshore breakwater, groyne, with focused sand management.

Subject to the findings of the addendum process and prior to construction, Baird will finalize their Phase II Study.

Since 2008, the unprotected land around Gibraltar Point continues to be subject to significant erosion, putting places of culture, natural ecosystems (such as an Environmentally Significant Area, an Area of Natural and Scientific Interest, and Provincially Significant Wetlands) and built infrastructure in jeopardy of complete loss.

This project seeks not only to protect the loss of the island, and risks to infrastructure, but also to ensure that sand transport remains in place to maintain existing beaches and sand dunes.

In 2016, partial funding was secured from the City of Toronto to implement the Gibraltar Point Erosion Control Project.

In accordance with the Class EA five-year review process the 2008 EA requires an amendment. The objective of this amendment is to reconfirm our understanding of the existing conditions of the shoreline and to ensure that the underlying conditions and results of the Ministry of the Environment and Climate Change approved Class EA remain valid.

The amendment will be completed prior to the start of construction.

2018 Addendum

• Gibraltar Point ESR Addendum 2018

Appendices

1. Gibraltar Point 2008 Environmental Study Report
2. Record of Public Engagement Addendum Report
3. Record of Indigenous Engagement
4. Marine Archeology
5. Terrestrial Archeology
6. Baird Nearshore Reef Technical Design Report
7. Pre-Addendum Detailed Design CLC Materials
8. Gibraltar Point Erosion Control Final Design Report Draft 2015 08 21

PROJECT OBJECTIVE

The objective of the Gibraltar Point Erosion Control project is to provide long-term protection and viability of the functions and uses of the Toronto Islands, such as: recreation; critical infrastructure (parks, water, roads); and aquatic as well as terrestrial habitats.

PLANNING MECHANISMS UNDERTAKEN

TRCA must conduct remedial flood and erosion control projects in accordance with the Environmental Assessment Act (EAA).

Recognizing that common elements exist in addressing flood and erosion problems, a coordinated approach to environmental assessment was developed by Conservation Ontario for all conservation authorities known as the Class Environmental Assessment for Remedial Flood and Erosion Control Projects (Class EA).

In 2004, TRCA initiated the Gibraltar Point Erosion Control Project under the Class EA process (2002). The project was granted approval on March 17, 2008.

VIEW THE ENVIRONMENTAL STUDY REPORT

As erosion control measures were not implemented within five years of the approval, an addendum under Section 6.0 of the process is required.

The objective of this addendum is to reconfirm our understanding of the existing conditions of the shoreline and to ensure that the underlying conditions and results of the 2008 Class EA remain valid. The amendment will be completed prior to the start of construction.

PUBLIC AND AGENCY CONSULTATION

The Class EA addendum process provides an opportunity for all views respecting a proposed remedial flood or erosion control project be taken into consideration.

As in 2008, there will be a Community Liaison Committee (CLC) that will allow citizens, local interest groups, and non-governmental organizations to voice their opinions and assist in the planning and design process of the project.

In addition to the CLC, those wishing to participate in the addendum process are invited to attend a public meeting (date to be determined) and/or contact the project team directly.

PROJECT CONTACT

For more information on this project, please contact:
Clifton Coppolino, Restoration & Resource Management
clifton.coppolino@trca.ca
(365) 566-2359