With the second longest coastline in the world (after Canada), Indonesia has a big challenge in managing its coastal zone. Ecologically, Indonesia's coastal zone is rich with fascinating biodiversity; socioeconomically, it has played a long-time role as a sustainable source for food, as well as various development programs in Indonesia, such as interisland connectivity, shipping, fisheries, and logistics industries. The integrated coastal zone management (ICZM) concept is considered to be appropriate approach to deal with multi-stakeholders and multi-decision makers complexity in the coastal zone. In this paper, a decision support system (DSS) is developed based on ICZM by integrating numerical modelling and multi-parallel computing. This application system can be used as an interactive tool for managing the coastal area in Indonesia from various point of view, among other policymakers, industries, and coastal planners. The impacts after implementation of a scenario can be seen directly in the system to represent both the benefits and shortcomings. A test case is carried out in the Northern Jakarta coastal area. The system merits are highlighted in delivering direct effects after artificial islands instalment in the domain. DSS-ICZM development is intended to help policymakers in Indonesia improve the quality of their decisions and improve transparency for broad stakeholders.