The Hudson Bay area covers the part of the west coast of Northern Quebec extending from Point Louis-XIV in the south to Point Bonissant in the north. The main Aboriginal villages in the area are located on the coast: Whapmagoostui, Kuuijjuarapik, Umiujaq and Inukjak. The extremely well developed drainage network consists of a large number of lakes and rivers, the two largest being the Grande rivière de la Baleine (Great Whale River) and the Nastapoca River.

The Lower Estuary area extends from Tadoussac to Pointe des Monts on the north shore of the St. Lawrence, and from Trois-Pistoles to Les Méchins on the south shore. This section of the river comprises 210 km of shoreline running southwest/northeast. It borders on the regional county municipalities (RCMs) of Les Basques, Rimouski–Neigette, La Mitis and Matane on the south shore and the RCMs of La-Haute-Côte-Nord and Manicouagan on the north shore. There are 41 municipalities located along the shores of the river: 24 on the south shore and 17 on the north shore.

The Moyenne-Côte-Nord area stretches more than 500 km from Pointe-des-Monts in the east to the Natashquan River in the west. Anticosti Island is also included in this area.

Administratively, the Moyenne-Côte-Nord takes in three RCMs (Manicouagan, Sept-Rivières and Minganie), 13 shoreline municipalities and four Indian reserves in addition to Anticosti Island. The main urban centres are Port-Cartier, Havre-Saint-Pierre and Sept-Îles.

The area’s main tributaries are the Romaine (296 m3/s), Natashquan (350 m3/s) and Moisie (395 m3/s) rivers. Most of the rivers on Anticosti Island are small, the largest being the Jupiter, with an average annual flow of 15 m3/s.

The Ungava Bay area covers all of the water between Baffin Island and Northern Quebec, including Hudson Strait. It extends from Cape Chideley in the east, where the Inuit village of Killiniq marks the border with Newfoundland, to Point Bonissant in the west, where the Inuit village of Inukjuak is located at the north end of Hudson Bay. Many other Aboriginal villages are also located in the area, including Kangiqsualujjuaq, Kuujjuaq, Tasiujuaq, Aupaluk, Kangiqsuk, Quaqtaq, Kangiqsujuaq, Salluit, Ivujivik, Akulivik and Povungnituk. The region’s main tributaries are the George, Caniapiscau, Koksoak, Arnaud and Puvurnituk rivers, the Rivière à la Baleine [Whale River] and the Rivière aux Feuilles.

The James Bay area is bounded by latitudes 50°59'45" and 54°40'30" North and by longitudes 75°30' and 81°53'45" West. It encompasses a territory stretching from the Ontario border in the south to Point Louis-XIV in the north. The main Aboriginal villages in the region are located on the coast: Waskaganish, Eastmain, Wemindji Mailasikkut and Chisasibi. A number of rivers empty into James Bay, the main ones being the Harricana, Nottaway, Broadback, Rupert and Opinaca rivers and the La Grande Rivière.

The Chaleur Bay area encompasses the coastal zone south of the Gaspé Peninsula. It extends from Grande-Rivière in the east to the mouth of the Restigouche River in the west. The region’s main tributaries are the Bonaventure, Cascapedia and Nouvelle rivers.

The Basse-Côte-Nord area stretches more than 500 km, from the Natashquan River in the west to the Labrador border in the east. It takes in the municipalities of the north shore of the Gulf of St. Lawrence, Gros-Mécatina, Saint-Augustin, Bonne-Espérance and Blanc-Sablon and the Indian reserve at La Romaine.

There are several major tributaries on the Lower North Shore of the St. Lawrence, including six having average annual flows of over 50 m3/s. The Petit-Mécatina River is the largest in the region, with an average annual flow of 495 m3/s, followed by the Saint-Augustin (180 m3/s) and the Saint-Paul (140 m3/s).

The Upper Estuary area goes from L’Ange Gardien to Baie-Sainte-Catherine on the north shore of the St. Lawrence, and from Saint-Michel to Trois-Pistoles on the south shore. This territory encompasses the downriver part of the fluvial estuary, characterized by tidal fresh water, and the whole of the upper estuary where fresh water mixes with salt water.

The Gaspe Peninsula area embraces all of the north shore of the Gaspé Peninsula, including saltwater intrusions extending up to 5 km inland. It stretches approximately 430 km from Sainte-Félicité in the east to Grande-Rivière in the west. In addition to these two localities, it also takes in the coastal towns of Capucins, Sainte-Anne-des-Monts, Mont-Louis, Rivière-de-la-Madeleine, Cloridorme, Gaspé and Percé.

The Îles-de-la-Madeleine area takes in all the islands of the archipelago, all the seabed where the water is less than 35 m deep and a part of the seabed 35 to 55 m deep surrounding the archipelago.

This area is located at the centre of a large coastal platform less than 100 m in depth (the Magdalen Shallows) that covers the whole southern part of the Gulf of St. Lawrence. The Magdalen Islands archipelago is composed of isolated rocky outcroppings overlain with sand and gravel that are connected together by sand spits of varying width. These sand spits support dunes which are anchored to some extent by vegetation and feature lagoons and saltwater ponds.

The Saguenay Fjord area extends 120 km, from Tadoussac at the river’s mouth to the Shipsaw Dam upriver. Virtually the entire area lies within the borders of the Fjord-du-Saguenay RCM, except for a section of the northeast shore that falls within the limits of the La-Haute-Côte-Nord RCM. There are 13 municipalities located along the two shores of the fjord, 7 on the south side — Petit-Saguenay, L’Anse-Saint-Jean, Rivière-Éternité, Saint-Félix-d’Otis, La Baie, Chicoutimi and Jonquière — and 6 on the north side: Tadoussac, Sacré-Coeur, Mont-Valin, Sainte-Rose-du-Nord, Saint-Fulgence and Tremblay.

Geographically, the Saguenay Fjord extends from Saint-Fulgence to Tadoussac. Depths can reach over 200 m below mean sea level (270 m near Cape Éternité). The main tributaries of this part of the Saguenay are located on the south shore: Petit-Saguenay, Saint-Jean, Éternité, Mars and Des Ha! Ha!. Only the largest one, the Sainte-Marguerite, is located on the north shore.