The 2030 Agenda offers a list of global environmental, social, and economic objectives to attain sustainable development. However, achieving the Sustainable Development Goals (SDGs) is challenging given the complex interactions between different SDGs and their spillover effects. System dynamics models have the capacity to integrate multisectoral dynamics of SDG interactions. We developed a system dynamics model-the Local Environmental and Socio-Economic Model (LESEM)-to analyse and quantify context-based SDG interactions at the local scale using a participatory model co-design process with local stakeholders. The LESEM was developed for a case study in the Goulburn-Murray Irrigation District in northern Victoria, Australia. We present an illustrative application of the model that quantifies SDG interactions across four high-priority SDGs, namely clean water and sanitation (SDG 6), agricultural activities (SDG 2), economic growth (SDG 8), and life on land (SDG 15). Our results suggest that agricultural land area may shrink by 62,522 ha due to the decline in water resource availability (SDG 6) under a business-as-usual (BAU) scenario from 2022 to 2050. However, the results also highlight that agri-food production (SDG 2) is likely to increase due to intensification to meet future agri-food demand, and higher values of farm output may improve local prosperity. The projections also suggest that environmental pressures may increase due to increasing agricultural intensification and reduced water availability. The LESEM facilitates integrated and strategic decision-making and helps local policymakers identify and quantify potential trade-offs and synergies that benefit multiple SDGs, which eventually leads local communities toward sustainability.