This chapter investigates the estimation of ecological baseflow in small- and medium-sized rivers of the northern Qinling Mountains. Due to increasing anthropogenic pressures and climatic variability, many rivers in the area experience seasonal drying and declining runoff, threatening their ecological integrity. To address this, two primary methods were employed: the hydraulic method, particularly the wetted perimeter method, and the hydrological method using the Tennant approach. The hydraulic analysis involved field surveys at representative river cross-sections to establish wetted perimeter–discharge relationships through power or logarithmic function fitting, identifying ecological baseflow via slope-equals-one and curvature criteria. The hydrological method estimated seasonal baseflow thresholds based on historical runoff data and regional characteristics. The chapter documents the spatial variation of ecological baseflow across river sections and analyzes discrepancies between estimated baseflows and measured discharges. It further explores the ecological status of rivers in Baoji, Xi’an, and Weinan, identifying key drivers of flow interruption, such as uneven precipitation, hydrogeological conditions, and water use patterns. Finally, it proposes targeted strategies for safeguarding ecological baseflow, including monitoring enhancements, adaptive flow management, and policy implementation.