The main watersheds near Lake Simoncouche are: • north side:
Kenogami Lake,
Chicoutimi River,
rivière-aux-Sables,
Saguenay River; • east side: Lac William brook, Henriette brook, Chiens brook,
Bras Henriette,
Bras de Jacob Ouest,
rivière du Moulin; • south side: lac des Îlets,
Cyriac River, Valiquette lake, Cyriac lake,
Bras Sec. • west side:
Cyriac River,
Normand River, Hector brook,
Chicoutimi River. The Lake Simoncouche has a length of , a width of and an altitude of . This lake is made in length by a widening of the
Simoncouche River which crosses it towards the north; this lake has three parts formed by two narrowing. This lake is located in the
Laurentides Wildlife Reserve in the massif of
Laurentian Mountains. This lake is mainly fed by the
Simoncouche River (coming from the south) and by the outlet (coming from the east) from Lac du Dépôt and Lac Hautbois. The mouth of this lake is located at: • east of
route 175; • south-east of Barrière-de-Laterrière; • north-east of a curve in the course of the
Cyriac River; • south of the confluence of the
Simoncouche River and
Kenogami Lake; • west of the course of
Bras de Jacob Ouest; • south-west of the course of the
rivière du Moulin. From the mouth of Lake Simoncouche, the current follows the course of the
Simoncouche River consecutively over north to the confluence with
Kenogami Lake; it crosses this lake for north-east to
Portage-des-Roches dam; it follows the course of the
Chicoutimi River on to the east, then the northeast and the course of the
Saguenay River on east to
Tadoussac where it merges with the
Saint Lawrence estuary. == Toponymy ==