Marine Infrastructure at Puvirnituq
October 1, 2006
By Canadian Consulting Engineer
Despite the fundamental importance of water access for the Inuit community of Puvirnituq in Nunavik, its maritime infrastructure used to be practically non-existent. The remote village is located on the 60th parallel on the Hudson Bay coast, one of 14 Inuit villages dispersed over the vast Nunavik territory of 500,000 square kilometres.
Because of the extreme climate and rudimentary facilities, access to the water constituted a real danger for the small boat users in this village of around 1,300 people. Commercial shipping to the village also faced perilous conditions. The absence of appropriate docking facilities therefore not only curtailed the residents’ traditional hunting and fishing activities, but also prevented the socio-economic development that is vital for the future of the community.
In order to improve this situation, in 2002, Makivik Corporation asked consulting engineers CIMA+ of Rivire-du-Loup, Quebec to provide engineering services for the construction of safe marine infrastructure. The marine facilities have to accommodate the barges of Groupe Desgagnes and Nunavut Eastern Arctic Shipping. The infrastructure is also to serve commercial fishing vessels and 150 canoes.
The work included the construction of an access ramp for commercial barges, two service areas totalling 4,500 sq.m, two access roads and a 6,375 sq.m harbour.
The harbour is now protected by two breakwaters and includes a reinforced concrete wharf as well as floating docks with anchoring systems for the fishing crafts. The project also provided the harbour with navigation aids, electrical power and lighting.
Built to last 50 years
The design team faced a number of logistic and technical challenges mainly associated with Puvirnituq’s geographical location. The list of challenges due to the arctic climate and remoteness included difficult material procurement, a lack of specialized local labour, and a scarcity of studies and data on the region. There were budget and schedule constraints, and several stakeholders to co-coordinate. There is a unique and fragile ecosystem, and poor geotechnical conditions (soft clay underwater and pergelisol). The idea of a “harbour” was also unique in this region, which meant having to communicate new concepts to the community.
The greatest challenge for CIMA+ was to develop solutions adapted to the Canadian North that could readily be implemented by Inuit workers using northern means and methods. They also had to design infrastructure that would require little maintenance and would last 50 years — a crucial element given the arctic region’s harsh climate.
Numerous studies and surveys revealed complex phenomena that the engineers had to contend with — including significant water level variations. The main hurdle was associated with the Puvirnituq River estuary’s geotechnical conditions that precluded using traditional breakwater construction methods, i.e. the placement of breakwater materials in a single phase on the river bottom.
The design team assessed solutions such as a rubble-mound breakwater, a concrete-caisson breakwater on piles, and floating breakwaters in order to build a protection that would suit Puvirnituq’s river soil conditions. None of these could be used due to complex factors associated with the arctic conditions.
Excavating and building on-shore
Under these circumstances, the design team decided to excavate the rocky outcrop to create a basin for the marine infrastructure. The solution is original in that it is contrary to marine construction methods generally used in the south. In traditional methods, marine structures are built in the submerged part of the shore, while Puvirnituq structures are built directly on the shore by blasting through the outcrop. This approach created the space required for the harbour basin and wharf. It also solved the problems of the inadequate capacity of the local submerged soils.
Building the wharf on dry land achieved significant savings over the initial budget. First, the outcrop was blasted and excavated to make room for the harbour’s basin and wharf, but part of the outcrop was preserved to keep the basin dry during construction. Once construction of the wharf and basin excavation were completed, the remaining outcrop was blasted to create a marine access to the harbour.
The design resolved the problem of congestion and minimized the risk of accidents due to local and commercial users sharing the same areas.
To design the structures to be sustainable for a 50-year life cycle, environmentally friendly materials that are suited to arctic conditions were used. The floating docks structure, for instance, is made of aluminum. It will not corrode, whereas treated wood products would contaminate the harbour.
Marine engineering went on through the whole project, bringing insights into the difficulties of building in an arctic environment and finding new, more cost-effective solutions.
The marine structures help to bring socio-economic benefits to the Puvirnituq people. They help to improve the mobility of people and goods, and lower transportation costs. They also help to maintain traditional fishing and make commercial fishing easier. They could contribute to the development of ecotourism and by reinforcing partnerships between north and south, they can help to boost the regional economy.
The project’s success prompted Makivik Corporation to make it a benchmark model for other Inuit villages in Nunavik. CIMA+ was awarded contracts for several other marine infrastructure projects in the region.
Name of project: Infrastructures Maritimes de Puvirnituq
Award-winning firm: CIMA+ – prime consultant (Rejan Mass, P.Eng., Francis Lavoie, Francis Bellavance, tech.)
Owner: Makivik Corporation
Subconsultants: Techmat (geotechnical investigations); Consultants Ropars (design and marine engineering); Interives (oceanographic survey)