This investigation scrutinized the integration of geospatial intelligence in decisionmaking related to Subak management in Tabanan Regency, Bali. Focused on ascertaining comprehensive Subak data, evaluating local government readiness for Spatial Data Infrastructure (SDI) implementation, and constructing a web GIS-based Subak information system, this study was underpinned by a three-pronged methodological approach. Primary data was collected via interviewing Tabanan's Office of Agriculture personnel, supplemented by an in-depth secondary data analysis. Additionally, a web GIS, using QGIS and JavaScript, was developed. Findings revealed a significant deficit in the Office's preparedness for SDI implementation in Subak management due to the unavailability of critical SDI components. Consequently, a web GIS was constructed to facilitate Subak data dissemination. Usability testing suggested this system was 'easy' to use for 42.5% of respondents, while 52.5% found it 'very easy'. This research underscores the importance of Subak data provision and its potential role in decision-making processes for Subak preservation. The study was delimited to the evaluation of SDI in Tabanan Regency, and the development of a web-based GIS was executed using the waterfall method.