Sri Lanka: reducing Colombo’s flood risk while creating a more livable city

World Bank, the

Flooding in Colombo has been occurring with worrying frequency. It destroys livelihoods and infrastructure, essentially bringing the city to a stand-still whilst wiping out years of progress and development. As the city expands in size, population, and aspirations, it must address its susceptibility to flooding in order to realize a high quality of life for its residents. The Metro Colombo Urban Development Project is helping reduce the risk and impacts of flooding while making the city more livable and competitive through making sound investments in public spaces, wetlands, and infrastructure. Once completed, 232,000 residents will have greater direct protection from flooding and the entire city will benefit from the project’s quality of life investments.


While urbanization has brought a high level of growth and development to Sri Lanka’s cities, almost 50% of the poorest 40% of the country’s population live within 30kms of urban areas. As a result, Colombo, the largest city, is also home to the greatest number of poor and vulnerable people. Though Sri Lanka is taking important steps to implement its urban vision, significant challenges to urban development are emerging. These include inadequate infrastructure and services; significant vulnerability to flooding, the impacts of which are being exacerbated by climate change; and outdated and poorly maintained drainage systems. 


Since 2013, the Metro Colombo Project has been supporting the government in reducing flooding in the catchment of the Colombo Water Basin and strengthening the capacity of local authorities to rehabilitate, improve and maintain infrastructure and services through large-scale demonstration investments. The project includes a component on flood and drainage management which involves complex, integrated works such as tunnels and pumping stations. This is complemented with the rehabilitation and management of street and drainage infrastructure including canals and flood gates. Local public facilities and other urban services have also been improved. A concerted effort has been made to coordinate the infrastructure improvements with improved access and livability interventions, providing a higher quality of life through increased public space for the residents, such as protecting wetlands coupled with providing access and education, creating bicycle paths, and rehabilitating parks and the town square. In addition, urban authorities are building up their experience and financial resources in delivering integrated large scale city-wide infrastructure projects. 


Since its approval in 2013, the project has:

  • Increased the drainage capacity of the gravity system by 100 cubic meters (end target is 185 cubic meters);
  • Implemented two micro-drainage projects reducing the risk of flooding in localized areas (10 year return period)
  • 75% of users have indicated that they satisfied with the Beira Lake Development (end target is 80% of users including Beddagana and Kotte Ramparts Parks);
  • Built and rehabilitated 39km of roads and drainage that have achieved project standards (end target is 45km);
  • Improved 2.9km of primary canals to reduce flooding (end target is 9.2km);
  • Helped coordinate metropolitan level agencies through the Project Management Unit, as well as with specialized bodies such as the Wetland Management Unit. 
  • Strengthened on-the-job capacities of local authorities, particularly in the areas of procurement, contract management and quality and safety standards of municipal roads.
  • Prepared large and complex flood-reduction works (both from an engineering and safeguard points of view).

By the project’s completion, the following results are anticipated: (i) reduction in the area under risk of flooding in the project area; and (ii) a 20 percent increase in the total urban roads maintained by the project local authorities.

Bank Group Contribution

The Government of Sri Lanka has launched an ambitious program of economic and physical regeneration for Metropolitan Colombo to transform it into a modern, world-class capital. To reflect this post-conflict development strategy and the priorities of the government, the World Bask has focused on urban engagement. The project is the first World Bank-supported urban development in Colombo with $213 million in support and the government contributing $100 million. The Bank has also mobilized a grant with the Global Facility for Disaster Reduction and Recovery (GFDRR) to conduct further studies on flood mitigation and Colombo’s urban wetlands. Technical financing has informed robust decision making such as in providing the rationale to conserve the city’s wetlands. 


The project is being implemented by the Project Management Unit within the recently created Ministry of Megapolis and Western Development. It reports to a steering committee composed of partners across a number of key agencies: the Sri Lanka Land Reclamation and Development Corporation[KD1] , the Urban Development Authority, the Ministry of Local Government and Provincial Councils, the National Water Supply and Drainage Board, the Ministry of Irrigation, Colombo Municipal Council, and other Local Authorities. MCUDP is being implemented in close consultation and collaboration with a number of other projects that have been initiated through various government agencies and the Colombo Municipal Council as part of the government’s urban development activities. 

Moving Forward

Four years into implementation, the project has already delivered considerable results. It has supported an analysis of the economic value of wetlands and increased awareness of the importance of wetlands conservation – with complete wetland loss, the Colombo Metropolitan Region would lose 1% of its GDP on average every year due to flood damage. A 1 in 100 year flood would raise water levels 1.8 meters above current levels.  The project has trained the SLLRDC on research and analysis, which has greatly improved their capacity.  In addition, the project supports an asset maintenance strategy, to help the local authorities better maintain and operate infrastructure supported by the project.  Through the implementation of the drainage components and major flood reduction infrastructure, the staff of the participating agencies will develop skills and capacities to complement the Colombo Metropolitan Region’s development requirements and ensure a sustained commitment into the future. 

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