Protecting Urban Water Sources through Forest Restoration
Summary
São Paulo's "Operação Defesa das Águas" initiative restores urban forests around key water reservoirs to improve water security, reduce pollution, and combat urban flooding.
São Paulo, a city of over 22 million people, faced a historic water crisis during the 2014-2015 drought, with reservoirs falling to just 5% of capacity. Urban sprawl and deforestation in critical watersheds, particularly around the Cantareira System (the city’s primary water source), compounded the crisis. These degraded forests were no longer able to filter water effectively or prevent soil erosion, leading to increased sedimentation in reservoirs. This drove up water treatment costs and reduced the reservoirs’ storage capacity during dry periods.
Intervention
To address these challenges, São Paulo implemented the "Operação Defesa das Águas" (Operation Water Defense) initiative, focusing on restoring and protecting forests in priority watershed areas. The project aims to improve water security by leveraging the natural infrastructure benefits of forests, such as sediment control, water filtration, and flow regulation.
The initiative prioritizes reforesting degraded land in critical watersheds using native species, which stabilize soil, reduce erosion, and enhance aquifer recharge. Strategic geospatial analysis identified priority areas where restoration would yield the greatest impact, such as the Cantareira watershed. The initiative complements these efforts with erosion control measures and enforcement of land-use regulations.
São Paulo’s water utility, Sabesp (water and waste management company owned by the state of São Paulo), partnered with local farmers, NGOs, and government agencies to integrate reforestation into watershed management. The program includes training for rural stakeholders to ensure long-term stewardship of restored areas. Public awareness campaigns highlighted the connection between forest health and water security, fostering broad support for the initiative.
The program utilizes funding from Brazil’s water usage fee system, fines from land-use violations, and private sector contributions. Sabesp has already invested in planting over 1,000 hectares of forest, with future plans to expand through partnerships and additional investments. Partners such as The Nature Conservancy and the Latin America Water Funds Partnership support the program through technical assistance and funding.
Challenges
The success of "Operação Defesa das Águas" relies on fostering strong partnerships with rural landowners, requiring ongoing negotiation and tailored incentives to ensure their continued participation in restoration efforts. Expanding the initiative to all priority areas presents a financial challenge, necessitating sustained funding and support from public-private partnerships. Additionally, effective monitoring and enforcement are essential to maintain compliance with land-use regulations and prevent illegal deforestation, which poses a significant threat to the long-term success of the program.
Outcomes
Since its inception, "Operação Defesa das Águas" has restored over 1,500 hectares of forest around São Paulo’s key watersheds and aims to expand to 4,000 hectares in priority areas. This restoration is expected to cut sedimentation by 36%, saving SABESP $106 million in treatment and dredging costs over 30 years. Reservoir turbidity levels are projected to drop by nearly 50%, while improved soil retention boosts dry-season water flows by up to 50%. The reforested areas also sequester carbon and support biodiversity, contributing to São Paulo’s climate and conservation goals.
References
Protecting Urban Water Sources through Forest Restoration
Summary
São Paulo's "Operação Defesa das Águas" initiative restores urban forests around key water reservoirs to improve water security, reduce pollution, and combat urban flooding.
São Paulo, a city of over 22 million people, faced a historic water crisis during the 2014-2015 drought, with reservoirs falling to just 5% of capacity. Urban sprawl and deforestation in critical watersheds, particularly around the Cantareira System (the city’s primary water source), compounded the crisis. These degraded forests were no longer able to filter water effectively or prevent soil erosion, leading to increased sedimentation in reservoirs. This drove up water treatment costs and reduced the reservoirs’ storage capacity during dry periods.
Issue
Intervention
To address these challenges, São Paulo implemented the "Operação Defesa das Águas" (Operation Water Defense) initiative, focusing on restoring and protecting forests in priority watershed areas. The project aims to improve water security by leveraging the natural infrastructure benefits of forests, such as sediment control, water filtration, and flow regulation.
The initiative prioritizes reforesting degraded land in critical watersheds using native species, which stabilize soil, reduce erosion, and enhance aquifer recharge. Strategic geospatial analysis identified priority areas where restoration would yield the greatest impact, such as the Cantareira watershed. The initiative complements these efforts with erosion control measures and enforcement of land-use regulations.
São Paulo’s water utility, Sabesp (water and waste management company owned by the state of São Paulo), partnered with local farmers, NGOs, and government agencies to integrate reforestation into watershed management. The program includes training for rural stakeholders to ensure long-term stewardship of restored areas. Public awareness campaigns highlighted the connection between forest health and water security, fostering broad support for the initiative.
The program utilizes funding from Brazil’s water usage fee system, fines from land-use violations, and private sector contributions. Sabesp has already invested in planting over 1,000 hectares of forest, with future plans to expand through partnerships and additional investments. Partners such as The Nature Conservancy and the Latin America Water Funds Partnership support the program through technical assistance and funding.
Challenges
The success of "Operação Defesa das Águas" relies on fostering strong partnerships with rural landowners, requiring ongoing negotiation and tailored incentives to ensure their continued participation in restoration efforts. Expanding the initiative to all priority areas presents a financial challenge, necessitating sustained funding and support from public-private partnerships. Additionally, effective monitoring and enforcement are essential to maintain compliance with land-use regulations and prevent illegal deforestation, which poses a significant threat to the long-term success of the program.
Outcomes
Since its inception, "Operação Defesa das Águas" has restored over 1,500 hectares of forest around São Paulo’s key watersheds and aims to expand to 4,000 hectares in priority areas. This restoration is expected to cut sedimentation by 36%, saving SABESP $106 million in treatment and dredging costs over 30 years. Reservoir turbidity levels are projected to drop by nearly 50%, while improved soil retention boosts dry-season water flows by up to 50%. The reforested areas also sequester carbon and support biodiversity, contributing to São Paulo’s climate and conservation goals.
Issues |
|---|
Climate Change and Water |
Water Overuse and Degradation |
Solutions |
|---|
Alternative Water Sources & Resource Diversification |
Integrated Water Resources Management (IWRM) |
References
Companhia de Saneamento Básico do Estado de São Paulo (Sabesp). (n.d.). Estratégias resilientes. Retrieved from https://www.sabesp.com.br/site/uploads/file/asabesp_doctos/livro_estrategias_resilientes.pdf
The Nature Conservancy Brasil. (n.d.). Água. Retrieved from https://www.tnc.org.br/o-que-fazemos/nossas-iniciativas/agua/
P4G. (n.d.). The Latin American Water Funds Partnership. Retrieved from https://p4gpartnerships.org/pioneering-green-partnerships/all-p4g-partnerships/latin-american-water-funds-partnership
Water Action Hub. (n.d.). The Latin American Water Funds Partnership. Retrieved from https://wateractionhub.org/organizations/1081/d/the-latin-american-water-funds-partnership
Prefeitura de São Paulo. (n.d.). O que é a Operação Defesa das Águas. Retrieved from https://capital.sp.gov.br/web/seguranca_urbana/w/defesa_das_aguas/a_operacao/1859Prefeitura de São Paulo