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Landscape Architects: Vlan Paysages
Lead Designers: Micheline Clouard and Micheline Clouard
Contractor: Construction PCL Inc. / ED
Client: Public Services and Procurement Canada (PSPC) and Architecture and Engineering Services (AES)
Photographers: Vlan and Ottawa Vintage Photography

A national treasure and tourist destination, the Parliamentary Precinct, attracting more than 1.5 million visitors each year, must continue to be a safe, welcoming, and meaningful place for Canadians and visitors. The escarpment, running along the Ottawa River, is one the most visible and important heritage assets in Canada.

This multidisciplinary project was developed and led by landscape architects, in collaboration with a multidisciplinary team. The global vision was defined through the comprehension and conservation of the picturesque landscape's heritage value - designed by Calvert Vaux at the end of the 1870s - and the ecological value of the terrestrial community, representative of the river corridor's vegetation. The intervention on the abrupt incline situated behind Parliament Hill, formerly composed of a healthy mixed forest, is based on a three-pronged approach seeking to maintain and optimize existing conditions, improve them, and create wildlife habitats. The objective was therefore reforestation, including vegetation control through selective pruning, the elimination of invasive strains, and the planting of native species.

In 2015, a pilot project targeting a part of the eastern slope demonstrated the success of such a proposal in restoring a diverse plant community. To follow through on this achievement, and confirmed by monitoring over a two-year period, a concerted effort on the remaining parts of the slope was completed in 2022 by the PWGSC, with upkeep assured by NCC. The escarpment project is the result of the orchestration of a multidisciplinary team, assembling expertise in landscape architecture, heritage conservation, biology, ecology, forestry, civil and geotechnical engineering, archeology, health, and safety. Led by landscape architects, the team worked together to design vegetation and compensation strategies within a context of high heritage value. These innovative scenarios permitted to resolution of numerous issues, assuring health and safety, as well as the continuity of the escarpment's scenic landscape. The natural heritage conservation approach, based on best practices, attained the safekeeping of listed views, the stewardship of protected species, and the restoration of forest cover. The reforestation program contributed to the stabilization of slopes with depleted soil - causing falling rocks - through the implementation of a root system built from trees, shrubs, and herbaceous strata. The salvage of snags has reinforced the sustained care of the existing moss strata while protecting wildlife habitats. Based on a sequence of multiple inventories, the management of undesirable vegetation has been transformed into an evolving plan of eradication. Simultaneously, portions of the Lovers' Walk, one of the protected archeological remains, have been secured.

The reforestation strategy and its application divide the escarpment into seven sections and target 12 specific situations on its hill. The sections define changes within the forest cover, whereas the situations present particular characteristics of flora, fauna, topography, the presence of archeological remains, heritage, and landscape values. Situations at the top, middle, or bottom of the slope are distinguished by the proposed planted compositions, to ensure continuous coverage specific to the surrounding environment. Planting formulas for each situation are conditioned by a synthesis of studies and existing references and draw upon several flora and fauna inventories. The maintenance guide, elaborated for a time span of ten years, is a key piece to the success of the mandate, which aims to leave space for the regeneration of the ecosystem while favoring control of erosion and unwanted plants. This guide brings the role of the landscape architect into perspective, within the continuance and sustainability of landscaping through time, beyond the completed intervention.