2014年-世界发展银行全球_Restoring_the_Coastal_Environment_in_Cartagena_Colombia_20页_3mb

Summary of Restoring the Coastal Environment in Cartagena, Colombia

Core Content

This document provides an overview of the efforts made by Cartagena, Colombia, to restore its coastal environment through improved wastewater management. It highlights the city's transformation from an environmental crisis in the mid-1990s to a model of sustainable urban development, emphasizing the role of the World Bank, the Colombian Ministry of Environment, and the local water utility, ACUACAR.

Main Issues and Challenges

• Population Growth and Urbanization: Cartagena has experienced rapid population growth, doubling its population over the last two decades, which has put significant pressure on its coastal environment.
• Water Pollution: Inadequate wastewater management led to severe pollution of the coastal waters, including the Bay, the Lagoon (Cienaga de la Virgen), and the beaches, threatening public health and the tourism industry.
• Institutional Weakness: The previous water utility was inefficient, leading to poor service delivery and financial instability.
• Controversy and Opposition: The proposed submarine outfall system faced opposition from local communities and stakeholders due to concerns over environmental and social impacts.
• Infrastructure Needs: The city required significant investment to upgrade its wastewater infrastructure, estimated at over $150 million.

Key Initiatives and Solutions

Institutional Reform

• In 1994, the Colombian government passed the Public Services Law, promoting private participation in public water utilities.
• In 1995, the Cartagena District Council and the City Mayor established ACUACAR, a "mixed-capital" company, with a private Spanish company, AGBAR, owning 46% of the shares.
• The District retained 50% of the shares, and the remaining 4% was held by private shareholders.

Phased Infrastructure Development

• Improving Water Supply Service: ACUACAR focused on rehabilitating and upgrading the water supply system from 1995 to 2000, increasing treated water supply, stabilizing water pressure, and improving operational efficiency.
• Improving Drainage in High-Value Economic Areas: With support from the Inter-American Development Bank, ACUACAR improved the drainage system in key tourism and commercial areas, particularly in Bocagrande, and eliminated sewage discharges.
• Improving Water Circulation in the Cienaga de la Virgen: The La Bocana Project was implemented to restore tidal circulation and improve water quality in the lagoon, which had been severely impacted by blocked natural outlets.
• Wastewater Treatment System: A comprehensive wastewater treatment system was developed, including a central pump station, a new treatment plant, and a submarine outfall to discharge treated wastewater into the Caribbean Sea.

Environmental Institutions

• The Cartagena Convention, signed in 1983, provided a legal framework for regional environmental protection and cooperation.
• The Global Partnership for the Oceans (GPO) supported the project with technical and financial expertise.
• The Cartagena Regional Environmental Authority (CARDIQUE) played a key role in setting environmental standards and issuing licenses.

Key Achievements of ACUACAR

• Water Supply Coverage: Increased from 73% in 1995 to 99.9% in 2013.
• Water Supply Customers: Grew from 92,572 in 1995 to 233,412 in 2013.
• Length of Water Network: Expanded from 700 km in 1995 to 1,480 km in 2013.
• Continuity of Water Service: Improved from 14 hours in 1995 to 24 hours in 2013.
• Unaccounted for Water: Reduced from 45% in 1995 to 33% in 2013.
• Sewerage Coverage: Increased from 61% in 1995 to 90.3% in 2013.
• Sewerage Customers: Grew from 77,553 in 1995 to 211,022 in 2013.
• Length of Sewage Network: Expanded from 500 km in 1995 to 1,062 km in 2013.
• Wastewater Treated: Increased from 0% in 1995 to over 90% in 2013.
• Revenues (COP-Million): Increased from 25,592 in 1995 to 165,889 in 2013.

Environmental Improvements

• Pollution-Free Beaches: Cartagena's beaches are now largely free of sewage contamination, ending the "red-flag" days of beach closures.
• Improved Water Quality in Cartagena Bay: Pollution levels have significantly decreased, particularly in the "Inner Bay."
• Restoration of the Cienaga de la Virgen: Water quality parameters such as coliforms, dissolved oxygen, biochemical oxygen demand, and suspended solids are now within regulatory standards.

Future Challenges

• Contaminated Stormwater Run-off: Still a challenge in the Bay.
• Industrial Pollution: Remains an issue in the region.
• Pollution from the Canal del Dique: Untreated effluent from small municipalities continues to affect water quality.

Key Lessons

• Institutional Reform: The introduction of a mixed-capital model improved service delivery and financial sustainability.
• Phased Development: A long-term, incremental approach was necessary to address complex environmental and infrastructural issues.
• Stakeholder Engagement: Addressing community concerns and involving various stakeholders was crucial for the success of the project.
• Technical and Financial Support: Collaboration with international organizations and technical experts was vital for the implementation and approval of the wastewater treatment system.
• Environmental Compliance: The project demonstrated the importance of adhering to environmental regulations and standards.

Conclusion

Cartagena's efforts to restore its coastal environment through improved wastewater management have served as a model for other developing coastal cities. The city's transformation highlights the importance of institutional reform, stakeholder engagement, and long-term planning in achieving sustainable urban development and environmental protection.