Characterizing the response of the coastal Rio Grande to upstream damming

Author(s): Timothy A. Goudge, Tian Y. Dong, David Mohrig

This paper describes an evaluation of the Rio Grande's coastal response to the dam constructed along its waters in the 1950s. The paper concludes that the full ~450 km reach of the Rio Grande, from Falcon Dam to the coast, became net degradational following dam closure, and that the presence of such a long degrading reach is caused by the exposure of bedrock in the Rio Grande channel for nearly 100 km downstream of the dam, which, combined with the lack of tributaries, limits downstream sediment supply to the river. The results provide new insights into the response to damming for rivers with no tributary sediment input and thin alluvial cover, and more broadly to the kinematic and channel geometry responses to a major drop in water discharge and sediment supply for coastal meandering rivers. Paper here.