<p>This study investigates the carbon cycle implications of the Murat River Watershed Rehabilitation Project (MRWRP), implemented between 2013 and 2023 across 36 microcatchments in the provinces of Bingöl, Muş, and Elazığ in eastern Turkey. Using the Ex-Ante Carbon-balance Tool (Ex-ACT), the research quantifies the carbon sequestration and emission impacts of various land management interventions, including afforestation, pasture rehabilitation, soil conservation, irrigation modernization, and the installation of energy-efficient technologies. Watershed management models, in this context referring to strategic planning frameworks rather than computational simulations, are integrated approaches aimed at promoting the sustainable utilization of natural resources, protecting water and soil resources, and enhancing ecosystem services. These models establish planning structures that incorporate components such as water management, land use, biodiversity preservation, and carbon sequestration. Techniques such as forest regeneration, erosion control, sustainable agriculture, and water management are implemented through spatial prioritization of degraded areas, participatory planning, and nature-based investments. Among these, forest regeneration and erosion control are prioritized due to their strong potential to enhance both above- and below-ground carbon storage. Unlike previous Ex-ACT applications that often rely on hypothetical or scenario-based assessments, this study uniquely integrates satellite-derived land use data with real project implementation records, enabling a regionally grounded and policy-relevant evaluation. The results show that while infrastructure investments such as concrete structures increase emissions, ecological restoration activities particularly forest and pasture rehabilitation significantly enhance carbon sequestration. This research contributes to the expanding literature on nature-based solutions by demonstrating the application of Ex-ACT in heterogeneous, data-limited regions and provides a replicable model for integrating carbon accounting into watershed-scale restoration planning. Implemented planning models are expected to yield measurable environmental benefits such as increased carbon sequestration, improved water retention, reduced erosion, and enhanced biodiversity. Socially, the project supports rural income diversification, food and water security, and adaptive capacity in vulnerable regions. By aligning ecological restoration with livelihood enhancement, these approaches strengthen the resilience and sustainability of both natural systems and local communities.</p>