Because of its altitude, the surface of the upper part of the Rouge East River is generally frozen from the end of November to the beginning of April; however, safe circulation on the ice is generally done from mid-December to the end of March.

The water level of the river varies with the seasons and the precipitation; the spring flood occurs in March or April.

The Rouge East River takes its source from Lac Grand (length: 3.0 kilometres (1.9 mi); altitude: 565 metres (1,854 ft)) landlocked between the mountains.

The mouth of this lake is located in the municipality of Château-Richer, at: From the mouth of this head lake, the Rouge East River descends on 3.7 kilometres (2.3 mi), with a drop of 193 metres (633 ft) according to the following segments: The Rouge River East flows on the East bank of the Rouge river.

The toponym "Rivière Rouge Est" was officialized on December 13, 1996 at the Commission de toponymie du Québec.