Río Colegual is a medium-sized stream located west of Puerto Varas in the Los Lagos Region of Chile, sitting at an elevation of approximately 200 meters (around 158 meters at the well-known Puente Colegual bridge crossing). The river flows through mostly flat terrain bordered by cleared agricultural fields, giving it an open, pastoral character. The water runs cool and clear with a distinctive brown stain — a natural tannin coloration common to streams draining through organic-rich soils in this part of Chilean Patagonia. The current ranges from moderate to slow, and the streambed is composed of cobble and gravel coated with brown algae, providing excellent habitat for aquatic invertebrates. Riparian vegetation, including willows, streamside grasses, and forbs, overhangs portions of the banks, offering shade and terrestrial insect input to the water.