Do you have a question about rivers?
If so, go ahead and ask! We will do our very best to answer it. These questions can be on any topic related to the quantity and the quality of water in rivers. We especially welcome questions you may have about Quebec rivers. The questions you ask may be on the mind of others as well, so with your permission we may publish your questions and our answer to them on this website.
What can be done to make our rivers healthier?
Florence Dancose
FAQ
What's the difference between a river, a creek and a lake?
Creeks, rivers, and lakes are all aquatic systems. Lakes are bodies of standing water, surrounded by land on all sides, while creeks and rivers are channels through which water flows. Rivers are large, flowing bodies of water that ultimately feed water into another river, a sea, or an ocean, while creeks are smaller and shallower channels with flowing water.
How many creeks and rivers are there in Québec?
A lot! The exact number depends on a variety of factors, including the quality of the aerial photos or satellite images used to map creeks versus rivers, and whether those creeks and rivers are named or not. A document submitted by Hydro-Québec to the Bureau d’audiences publiques en environnement in 2008 listed 513 rivers and creeks in Québec. According to Wikipedia and the Commission de toponymie du Québec, there are approximately 12,000 named creeks and 3,000 named rivers in Québec. According to the HydroSHEDS database, all rivers and creeks in Québec, named and unnamed, flowing intermittently or all year long, cover a cumulative length of over 105,000 km in the province.
Sources: Hydro-Québec, BAPE, Wikipedia, HydroSHEDS
What is the longest river in Québec?
The St-Lawrence River stretches over 1,197 km. That said, the river takes its source outside of Québec, at the outlet of Lake Ontario, so its entire length is not in Québec.
Another very long river is the Rivière des Outaouais, or Ottawa River, that flows in Ontario and Québec over a distance of 1,271 km and forms part of the border between the two provinces from Lake Timiskaming to Carillon. Other long rivers include the La Grande (893 km, in Northern Québec), Churchill (856 km, shared with Labrador), Nottaway (776 km, contributing to James Bay), Eastmain (756 km, also contributing to James Bay), and Manicouagan (560 km, flowing from the crater-shaped Manicouagan Reservoir) rivers.
Sources: Commission de toponymie du Québec, Répertoire du patrimoine culturel du Québec, The Canadian Encyclopedia.
Does the island of Montreal have rivers?
The Island of Montreal is surrounded by major rivers, notably the St. Lawrence River to the south, the des Prairies River in the north, and the Rivière des Outaouais to the west. However, no large rivers originate on the island itself, and only small creeks remain. Most creeks and rivers that used to exist on the island of Montreal—such the Petite rivière Saint-Pierre or the rivière Saint-Martin—have disappeared with urban expansion, with some buried under roads. The only remaining river on the island of Montreal is the Rivière à l’Orme: it is only 8 km long and flows from Pierrefonds to Beaconsfield before joining the Lac des Deux Montagnes.
Sources: La Presse – Protéger la dernière rivière de l’île de Montréal
What makes part of the Saguenay River a fjord?
The Saguenay Fjord National Park is a well-known tourist attraction in Québec. It stretches 105 km from St-Fulgence to Tadoussac and was carved by continental glaciers during their retreat at the end of the last Ice Age, about 10,000 years ago. This glacial activity created deep U-shaped valleys with steep hills on each side and a riverbed averaging 210 m in depth. Unlike rivers, the fjord becomes shallower and narrower near its mouth, as the thinning glacial ice sheets deposited the rock and sediment they had been carrying.
Sources: The Canadian Encyclopedia, Société des établissements de plein air du Québec (SEPAQ)
What is the most polluted river in Québec?
It is difficult to find a consensus on what the most polluted river in Québec is, because it depends on which individual or combination of pollutants we rely on. However, a few rivers have been identified in the past as particularly problematic. These rivers tend to be located in regions with intense agricultural or industrial activities, where river water has high concentrations of pesticides, fecal matter and nutrients originating from fertilizers or wastewater. The government of Québec computes an aggregated water quality indicator which can be used to compare rivers (and lakes) across the province, as recently outlined by the Journal de Montreal in June 2024. Among others, the Chibouet, Hurons, Yamaska and Yamachiche rivers have been recently highlighted by various media sources as among the most polluted in the province.
Sources:
Journal de Montréal – Quelle est la qualité de l’eau près de chez vous
TVA Nouvelles – Soupe de pesticides et coliformes fécaux
La Presse – Pesticides : la rivière aux horreurs
ICI Radio-Canada – Trois cours d’eau de la Mauricie parmi les plus pollués du Québec
La Presse – Un filtre prometteur pour agir à la source
How does climate change the quantity and quality of water in rivers?
Hydrological change resulting from climate change will be different depending on the geographic location considered. In general, drier and warmer summers will decrease river water levels, due to lower runoff amounts and higher evapotranspiration. Warmer winter will create thinner snowpacks, earlier snowmelt periods, or an increase frequency of winter melt events and rain-on-snow events, potentially causing winter and spring flooding. Extreme rainfall events will also lead to more floods, especially flash floods. River water quality may decline due to higher temperatures, causing higher pollutant concentrations (same amounts of pollutants in less water) and exacerbating negative ecological reactions such as harmful algal blooms.