Water governance in the Tocantins-Araguaia Hydrographic Region: Assessing viability using a participatory systemic approach

Changing weather patterns, including prolonged periods of drought and rising water demand are putting increasing pressure on water management and underlying governance systems. Our study implemented a novel methodological framework to jointly assess the physical dimension of water use and the regulatory capacity of water governance in the Lake of Palmas River Basin by combining the Water Flow Diagram (WFD) and the Viable System Model (VSM). The WFDs were built to visualise seasonal water balances and flows and highlight water consumption by different sectors. Data were obtained from reports, utility managers and the Soil and Water Assessment Tool Plus (SWAT+) hydrological model. The VSM, grounded in organisational cybernetics, provided a structural and functional framework for diagnosing governance gaps across diverse organisational levels and sectors. Data for the VSM were collected through document review, interviews with representatives from government agencies involved in water management, water users from different sectors, water resource specialist and civil society organizations. Findings from the WFD and preliminary results from VSM were reviewed during a participatory co-creation workshop involving stakeholders from the same sectors. The combined application of both tools revealed the suitability of the methodology to foster the dialogue around different conflicts of interest on water use and potential mitigation measures. The process highlighted a significant gap between regulated water allocation and actual abstraction, identified critical structural deficits in local management capacity and inter-institutional coordination, and uncovered weak feedback and monitoring mechanisms across governance levels. The study demonstrated that VSM and WFD are structurally complementary: the WFD visualizes the physical environment of the system, while the VSM maps its regulatory architecture, enabling their joint use for an integrative diagnostic process and redesign. For practitioners, the combined methodology offers a replicable, participatory approach for identifying governance failures in complex hydric systems.