The arm of the Ouelle River has its source at Lake Therrien (lengthː 1.6 kilometres (0.99 mi); altitudeː 381 metres (1,250 ft)), in the canton of Fournier, in the western part of the municipality of Tourville (47°01′58″N 70°06′33″W / 47.032695°N 70.109253°W / 47.032695; -70.109253), in the Notre Dame Mountains.

This confluence is located 3.1 kilometres (1.9 mi) northeast of the center of the village of Tourville.

This designation of origin evokes Louis Houël, Sieur du Petit-Pré, controller of the salt works of Brouage, member of the Compagnie des Cent-Associés and secretary to the king.

[2] The map drawn up by Jean Deshayes of 1695 bears the modern spelling of the Ouelle river.

[3] The toponym "arm of the Ouelle River" was formalized on December 5, 1968, by the Commission de toponymie du Québec.