Sedimentation Study of Urrá Reservoir, Colombia

Client: EMEC, SAS

Contract Period: 2014 (Project Duration: 4 months)

Urrá Reservoir is located in the Sinú River in Colombia. The project consisted in the development of sediment management strategies at the 1,822 Mm3 Urrá hydropower reservoir (largest in Colombia), with 340 MW installed capacity. The reservoir is experiencing accelerated sedimentation, which also presents navigational problems in the delta region affecting protected indigenous communities.

The firm performed a preliminary bathymetric study along the reservoir to document the advancement of the delta sediments. Also reviewed bathymetric work performed by others, detecting problems with the results, and prepared recommendations for areas to be repeated and procedures to be used in the future to improve the quality of bathymetric data.

Sediment transport modeling was undertaken to better understand the rate and pattern of sediment deposition along the reach of the Sinú river over the next 100 years using the Bureau of Reclamation sediment transport model SRH-1D. The analysis document several deficiencies in the previous sedimentation analysis in relation with the sedimentation rate estimated by previous bathymetric works. In addition, the model was used to analyze several operational scenarios to maximize the useful life of the reservoir.

A hydrologic operational model was constructed to analyze the long-term energy production of the system, in relation to storage loss due to sedimentation. The analysis recommended a minimal storage that should be maintained to ensure that energy production along the year is not reduced as compared to current generation.

The study recommended and concluded that it will be possible to sustain the operation of Urrá reservoir indefinitely, relying on a combination of sediment management techniques and adjustment to operational schemes.