The Indonesian government is planning a new capital city in East-Kalimantan, Borneo, called Nusantara. The total appointed area for Nusantara is 56.000ha, including areas for urban development, nature reserves, industrial, and agricultural areas . The city should support two million residents in 2045. The area is in a severely degraded state caused by large scale deforestation, oil palm and eucalypt plantations, coal mining and uncontrolled urbanization. The remnants of the original ecosystems, including dipterocarp lowland forest and mangroves, are small in size and largely fragmented. Soils are impoverished, polluted, compacted and eroded. Water runs off quickly over the exposed lands, causing flooding, erosion and water shortages. The Indonesian government aims to build a ‘green, sustainable forest-city’, and to take the development of the area as an opportunity to restore ecosystems on site. In the current plans, this aim seems to be consolidated through appointing large nature reserves for restauration and a large urban area separately. The aim of this thesis is to integrate urbanisation with the restoration of the natural systems through design. Two challenges are addressed: the existing problems in the landscape, and the design of a context - sensitive future city. Many aspects of these two challenges are bound by water as an essential substance (H20) and as a force shaping physical landscapes, culture and power relations. Beyond being the connecting factor, water can be a formative power for design, creating long-term sustainability through integrating natural system dynamics. The main concepts to create an integrated approach with water as a formative power for design are derived from Landscape Based Urbanism and Design With Nature. The thesis reconsiders the large-scale planning of Nusantara with a vision and elaborates this vision through designs on the smaller scale that result in socially and ecologically valuable spaces.