Existing and natural flows of the Rio Grande Río Bravo
Channel: Conservation and Adaptation Resources Toolbox
Date: 06/02/2018

Presenters: John Schmidt and Todd Blythe (Utah State University)
Sam Sandoval Solis and J. Pablo Ortiz Partida (University of California, Davis)

Because diversions of stream flow in the Rio Grande watershed predate stream gaging, there are no historical data that describe the natural flow regime of the river. We present the results of our work to define the natural flow regime of the northern branch of the river upstream from Presido/Ojinaga and of the Río Conchos. We demonstrate that more than 90% of the natural flow is not used for upstream agriculture and municipal uses or is lost due to reservoir evaporation and riparian zine evapotranspiration. Although it is impossible to restore the natural flow regime, our estimates of this regime provide essential information about the environmental cues and disturbances that provided habitat to the native fauna and flora. Understanding the natural flow regime also helps set in context present management activities in the watershed. The magnitude of change to the natural flow regime is so large that watershed stakeholders are forced to consider what kind of future river is desirable. Additionally, we discuss the geomorphic and management implications of these flow regime changes.