River Channel Characteristics

The meandering Rio Grande River
The meandering Rio Grande River in Big Bend National Park

NPS/Ann Wildermuth


The Rio Grande River, or Rio Bravo del Norte in Mexico, is the centerpiece of an international area of conservation interest and represents one of the most ecologically significant areas in North America. It is the largest river system in the Chihuahuan Desert and has sustained people and wildlife for millennia.

The river has undergone substantial changes in the past century due to construction of dams, increased water use along the river, and long periods of drought. River flow has decreased significantly and there are fewer large flood events, causing the river channel to narrow and sediment to build up over time. Water quality has also become a problem. At least seven species of fish have now disappeared from the Big Bend section of the Rio Grande River, at least five native mussels may be gone, and the Big Bend slider (a species of turtle) may soon disappear.

In response to these concerns, the Chihuahuan Desert Network is implementing a river channel characteristics monitoring program for the Rio Grande River. Knowing how the river is changing over time can help park managers prioritize exotic species control activities, implement habitat restoration and species reintroduction projects, and improve river water quality. This knowledge will also help partners on both sides of the international border work together to preserve and maintain this unique river system.

Scientists in a canoe on the Rio Grande River in Boquillas Canyon at Big Bend National Park
The Rio Grande River in Boquillas Canyon at Big Bend National Park

NPS/Tim Pine

What We Monitor

River channel width, depth, and cross section area: measured across three study reaches

Water level (stage) and flow (discharge): water level is measured with a pressure transducer and stage-discharge relationships and models are used to understand water flow

Where We Monitor

  • Big Bend National Park
  • Rio Grande Wild and Scenic River

Last updated: November 1, 2018