Depth of the Madeira River

The Madeira River, a major Amazon tributary in Bolivia and Brazil, is relatively shallow for its volume. Typical depths in the main channel range from 17 to 18 meters (56–59 feet) in most sections. Depths vary seasonally: during the wet season (Dec–May), floodplain inundation increases cross-sectional area but main-channel depth may not increase proportionally. In the dry season, depths can drop below 10 m in some reaches. The river carries enormous sediment loads (Andean origin), forming shifting sandbars and braided channels that complicate navigation. Large vessels (barges to 2,000 tons) operate with careful piloting; depth surveys are frequent.