Review of Regressive Channel Erosion and Grade Control Options on the Rio Coca, Ecuador

The US Army Corps of Engineers (USACE) is assisting the Ecuadorian state-run Corporacion Electrica del Ecuador (CELEC) in addressing a water resource issue involving regressive channel erosion on the Rio Coca. Reconnaissance of the site was completed the week of 21 February 2022; parts of the river system were viewed to determine if improvements could be made to the current grade control structure (GCS) mitigation plan for reducing channel erosion and stabilizing the river system downstream of the Coca Coda Sinclair (CCS) Dam. The Rio Coca is a tributary to the Amazon River system in South America. It originates on the east side of the Andes Mountains and generally flows from southwest to northeast through the project area and then turns and flows east into the Amazon basin (Figure 1).* The Rio Coca valley is a current example of how damaging regressive erosion can be to a fluvial system (Figure 2).