Overview In 2019, Indonesia announced its plan to develop Nusantara as its new capital city, to ease pressures on Jakarta and promote balanced national growth. Envisioned as a smart, sustainable forest city, Nusantara aims to reach full maturity by 2045. A key challenge in realizing this vision is water security, as the region relies primarily on surface water sources vulnerable to seasonal fluctuations and pollution, particularly from nearby agricultural and palm oil activities. The Asian Development Bank (ADB) has provided technical assistance support to the Nusantara Capital Authority (NCA) since 2022. NCA is a newly established government entity which is responsible for planning, constructing, and managing Nusantara. Through the Sustainable Infrastructure Assistance Program Phase 2 (SIAP2), funded by the Government of Australia, ADB is collaborating with NCA and the Ministry of Public Works (MPW) to strengthen institutional capacity in sustainable and water-sensitive city planning. This initiative builds upon earlier assistance supported by the Government of the Netherlands through the ADB-administered Water Resilience Trust Fund. A water-sensitive participatory approach, anchored in capacity building, emerged as an effective solution to ensure resilience, environmental stewardship, and local ownership in Nusantara’s long-term growth. Challenge Water availability and quality are critical concerns for Nusantara. Dependence on the Sepaku River exposes the city to drought and pollution risks, threatening both environmental integrity and long-term water security. Seasonal variability and contamination from agricultural runoff and palm oil plantations exacerbate these challenges. At the institutional level, NCA’s limited technical capacity compounds the problem. Established in 2022, NCA is still building systems and expertise to plan and manage complex urban infrastructure. During Nusantara’s initial development phase (2020–2024), NCA relied heavily on the Ministry of Public Works (formerly the Ministry of Public Works and Housing) for infrastructure development and on the Ministry of Environment (formerly the Ministry of Environment and Forestry) for reforestation and environmental management. Fiscal constraints, including government-wide budget efficiency measures, have further limited resources. As NCA transitions toward full responsibility for city management post-2025, sustained capacity building and knowledge transfer will be essential. Context A water-sensitive approach integrates water management into all aspects of urban design. It prioritizes efficient use, reuse, and protection of water resources while enhancing city livability and resilience. Examples include: Reusing wastewater for irrigation to reduce potable water demand. Implementing green infrastructure such as rain gardens, wetlands, and bioswales to filter and store stormwater naturally. Using permeable pavements to reduce runoff and enhance groundwater recharge. Integrating waterways into community spaces to foster environmental stewardship. For Nusantara, this approach aligns with its vision as a “smart, sustainable forest city” by embedding nature-based solutions into its urban systems. However, effective implementation depends not only on infrastructure but also on institutional capability and local ownership. Solution To strengthen institutional capacity, ADB and SIAP2 launched a training program on Water Sensitive Cities (WSC) for 31 officials from NCA and MPW. Conducted between March and October 2025, the program emphasized: Practical, context-based learning tailored to Nusantara’s needs. Hands-on case studies and co-created solutions drawn from local examples. Cross-agency collaboration to break down institutional silos. This participatory, bottom-up approach empowered officials to adapt global frameworks to local realities, fostering ownership and collaboration rather than dependency on external experts. It also created a cohort of “WSC champions” within NCA and MPW who continue to advocate for sustainable water management. The emergence of these champions was an unintended but positive outcome that highlights the program’s success in cultivating long-term institutional change. Outcomes Improved capacity: Pre- and post-training assessments showed significant gains in participants’ understanding of integrated water management and WSC applications. Enhanced collaboration: Joint project planning between NCA and MPW reduced institutional silos and improved inter-agency coordination. Pilot planning: Four potential pilot locations have been identified for implementing WSC principles in Nusantara. Institutionalization: NCA is considering establishing an internal "WSC task force" to sustain momentum and scale up best practices. Beyond these measurable outcomes, the training laid the groundwork for long-term institutional transformation, embedding water sensitivity into Nusantara’s development framework and supporting the broader goal of a resilient and sustainable capital city. Lessons Participatory design drives ownership. Allowing participants to co-create and bring real cases made the training relevant and practical. Cross-agency collaboration strengthens systems. Joint sessions fostered interdepartmental coordination and knowledge sharing. Development solutions champions sustain change. Investing in individuals as change agents ensures continuity beyond project timelines. Implementation funding gaps limit progress. Limited downstream funding at program closure prevented immediate pilot testing. A small implementation fund would enhance learning uptake and demonstrate real-world application. Resources Nusantara Capital Authority. 2023. Nusantara Net Zero Strategy. Jakarta. Republic of Indonesia. 2023. Law No. 21 Year 2023 on Nusantara. Jakarta. Singapore’s National Water Agency. 2024. Active, Beautiful, and Clean Water Design Guidelines. Singapore: Public Utility Board. Ask the Experts Alexandra Conroy Senior Urban Development Specialist, Water and Urban Development Sector Office, Sectors Group, Asian Development Bank Alex has over a decade of experience in the water sector, including managing treatment plants in Singapore, supporting WASH NGOs in Africa, and engaging in research work in Europe and Australia. She joined ADB in 2015 and has since contributed to the design and implementation of water and urban development projects across the Pacific Islands, South Asia, and Southeast Asia. She currently supports ADB’s operations in Indonesia. Follow Alexandra Conroy on Kin Wai Chan Senior Infrastructure Specialist, Southeast Asia Department, Asian Development Bank Kin has more than 19 years of professional experience supporting both the public and private sectors in developing and implementing infrastructure projects across various countries. He currently manages the $30 million Sustainable Infrastructure Assistance Program 2, which provides technical assistance to the Government of Indonesia to strengthen the investment climate, improve government policies, and enhance institutional capacity. He also co-leads ADB’s approach to supporting the Government of Indonesia’s objective of increasing private sector participation in infrastructure development. Follow Kin Wai Chan on Yulia Urban Development Specialist (Consultant), Southeast Asia Department, Asian Development Bank, Asian Development Bank Yulia is an urban planner with over 11 years of experience spanning government, development finance institutions (DFIs), consulting, and NGOs. She specializes in urban policy, sustainable infrastructure, climate resilience, municipal finance, and spatial planning. Yulia has advised on strategic urban initiatives and successfully delivered impactful projects, including climate financing for Jakarta’s renewable energy transition and the development of Nusantara. Follow Yulia on Asian Development Bank (ADB) The Asian Development Bank is a leading multilateral development bank supporting sustainable, inclusive, and resilient growth across Asia and the Pacific. Working with its members and partners to solve complex challenges together, ADB harnesses innovative financial tools and strategic partnerships to transform lives, build quality infrastructure, and safeguard our planet. Founded in 1966, ADB is owned by 69 members—49 from the region. Follow Asian Development Bank (ADB) on Leave your question or comment in the section below: View the discussion thread.