Lachine Rapids

From Wikipedia, the free encyclopedia

The Lachine Rapids are a series of rapids on the Saint Lawrence River, between the Island of Montreal and the south shore. They are located near the former city of Lachine.

The Lachine Rapids contain the largest standing (permanent) waves in the world, because the water volume and current do not change with respect to the permanent features in the riverbed, namely its shelf-like drops. Seasonal variation in the water flow does not change the situation of the waves.

In the past these represented a considerable barrier to maritime traffic. Until the construction of the Lachine Canal through Montreal, the rapids had to be portaged. Even with the canal, the difficulty was such that it was usually more convenient to ship goods by rail to Montreal, where they could be loaded at the city's port. Montreal was long a major rail hub and Canada's largest port for that reason.

The Lachine Rapids are now passed by the South Shore Canal (Saint-Lambert and Côte Sainte-Catherine locks) of the Saint Lawrence Seaway.

The rapids contain a number of islands used by migratory birds. Heron island is a wildlife refuge. Whitewater rafting and jet boat expeditions to the rapids are available in Montreal.