Project Cartagena: "A flood free city"

Cartagena is a city located at the Caribbean coast of Colombia, founded in 1533 by the Spanish. Its population consists over one million inhabitants, making it the fifth largest city in Colombia. Due to its strategic location, the port of Cartagena has grown into the largest port of the Caribbean coast, making it very important for the Colombian economy. The city is famous for its colonial centre ’Centro Historico’, that is a UNESCO world heritage site since 1984. Together with Centro, the peninsula of Bocagrande, Castillogrande and El Laguito, attract a lot of tourists thanks to its wide stretching beaches. The areas are however prone to flooding. The focus of this project is to provide a well-structured analysis of the flood problems in the neighbourhoods Centro, Bocagrande, Castillogrande and El Laguito, because of their major importance to the touristic, economic and cultural values of Cartagena. From this analysis an integrated conceptual solution is performed to improve the drainage and coastal protection system to ensure the future development of the city in a political and social desirable way. In the current situation the studied areas suffer from frequent flooding. The coastal protection and drainage system are insufficient. The surface level gradient is too small and the outlet drains are constructed as holes through the coastal protection, allowing the seawater to intrude during high water levels at sea. Flooding already occurs at mild conditions, such as spring tide or a single heavy rainfall event. These floods cause a lot of damage to properties and the infrastructure. The salt water intrusion causes damage to cars and buildings. Also hinder to all kind of commercial activities due to significant congestion, or even inaccessibility, results in a huge loss of revenue. Prognosis is that the frequency and intensity of these problems will increase in the future, due to the expected sea level rise and land subsidence. In recent years, various studies have already been performed on these problems, but the municipality has never given priority to implement these proposals. The decision makers do not see the urgency of the problem. Since most political functions have a maximum term of four years, this hampers decision making with a long-term vision. Also there is only a very small budget available for disaster prevention, leading to a limited investment budget. Another issue is the large amount of public and private organizations that operate without good collaboration, causing a haziness of their responsibilities. A program of requirements was established after analysing the problem, to which the design levels were equipped. For feasibility of the design, it is necessary to obtain additional investors next to the municipality. Therefore an extensive stakeholder analysis was performed to indicate all potential public and private interested parties. The studied areas were divided in smaller areas and global solutions were developed on element level, where the coastal protection and drainage were distinguished. A multi criteria analysis (MCA) was performed on these global solutions to indicate the best elements for the final solution. In order to let the solution succeed, the stakeholders that have authority to start a project should sense the urgency of the problem. These stakeholders are the mayor of Cartagena, the Bolivar department and the Ministry of ADS. Since the water levels at sea are expected to increase considerably in the upcoming years, the future development of Cartagena is at stake. In order to let all parties collaborate to implement a solution, the final design is constructable within four years and will be performed in phases, where the most flood prone areas have gotten the highest priority. From the MCA, the best elements were combined to create a final solution. The final solution includes elements that bring additional value to the peninsula by constructing a marina and a promenade to attract private investors. The safety is guaranteed by upgrading the current coastal protection system and will be implemented by a strongly revised drainage system. The surface gradient will be increased by heightening two roads, the outlet drains will be equipped with check valves and a comprehensive pumping system will be installed.