Canal del Dique is a 118 km waterway built in the 16th century in Colombia. The canal connects the sediment-rich Rio Magdalena with the Bay of Cartagena. It was built for navigation between Colombia’s two main colonial ports (Cartagena and Santa Marta) and the Magdalena river. Maintenance negligence, sedimentation, flood events and ecological deterioration of the many lakes along the canal demand for major improvements of the canal system. Royal HaskoningDHV was contracted to design an improved Canal del Dique system, including river diversions, and control of water and sediment discharge.
Any robust design requires a thorough understanding of the current water system, and its hydrology, hydraulic, and sediment dynamics. Based on existing information, water system analysis, identification of bottlenecks, an initial conceptual description of the flood, navigation, and environmental challenges was built.
Additional field measurements, combined with numerical hydrodynamic and sediment transport modelling, enabled us to fill data gaps, to define the magnitude of natural processes, to better understand the dynamics in the Canal del Dique – Rio Magdalena system, and to assess the impact of potential solutions. Water quality issues in the nearshore area were assessed using 3D modelling.
The proposed solution exists in a set of measures. Upstream, a weir/sluice at the entrance of the canal is needed to control the water discharge and sediment load in the canal. Multiple open connections between the lakes and the canal stimulate refreshing of water in the lakes and improve the ecological value of the lakes. In the downstream delta, closure of the northern canal branch will redirect water discharge through the southern delta and limits sedimentation in the canal.
The combination of data analysis, detailed Delft3D modelling of the bifurcation, hydraulic Sobek modelling of the canal and lake system, and detailed 3D water quality modelling of the nearshore area appeared indispensable for understanding the current water system and exploring and designing potential solutions.