Fish habitat compensation structure in the Îles-de-la-Paix National Wildlife Area

Montreal's Champlain Bridge was replaced by the Samuel-de Champlain Bridge through a public-private partnership between Infrastructure Canada (INFC) and the Signature sur le Saint-Laurent group (SSLC). As part of this work, SSLC was required to develop a project to compensate for the loss of fish habitat and uses associated with the presence of piers in the Île des Soeurs channel, the Grand bassin de La Prairie and the Petit bassin de La Prairie.


The suggested fish habitat compensation project consists of constructing a dyke in the Île-de-la-Paix National Wildlife Area. This dike will protect a coastal marsh (1.5 ha), create a calm water habitat (0.6 ha) suitable for spawning, nursery and feeding of several fish species. The proposed project will also protect the west shore of Thomas Island and Napoleon Island, both located in the Îles-de-la-Paix National Wildlife Area, from erosion.


The outer (seaward) slope of the dike will be 600-1000 mm rockfill, while the shoreward slope and the core of the dike will be 100-300 mm rockfill. The outer face is characterized by a 4:1 slope while the inner face will have a 2:1 slope. The structure of the dike rests on a bed of clean stones. In the center of the dike, organic soil will be contained in a geotextile, which will allow a vegetation regrowth. The surface area of the dike will be approximately 4227m². The total volume of rockfill will be approximately 6089m³, of which 1330 m³ will be net stone for the filter layer. The volume of organic soil will be approximately 325 m³. The design of the dike includes several openings to facilitate fish access and circulation. The work will be carried out mainly from barges using hydraulic excavators.


Latest update

February 01, 2024 - The assessment decision statement has been issued to the proponent.


Key documents

Key documents
Document Number Document Title File Date
1 Notice of Determination - Environment and Climate Change Canada / Transport Canada - November 17, 2022


Canadian Wildlife Service - Environment and Climate Change Canada
Charles Desrosiers, Protected area specialist
Québec, Quebec G1J 5E9
Telephone: 418-648-5095

  • Location

    • Île-de-la-Paix National Wildlife Area (Quebec)
  • Nature of Activity

    • Remediation and conservation
  • Assessment Status

  • Start Date

  • Proponent

    Signature sur le Saint-Laurent
  • Authorities

    • Environment and Climate Change Canada
    • Transport Canada
  • Assessment Type

    Project on federal lands
  • Reference Number


This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.


Nearby assessments

...within 200 kilometres
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