Kinematic conditions at the water table are commonly used in analytical models to interpret aquifer pumping test data. However, the existing kinematic conditions often lead to an underestimation of specific yield during the drainage process due to the assumption of instantaneous gravity drainage, which does not align with estimates from soil column experiments. This study derives a new water table condition on the basis of a full unsaturated-saturated flow model. This new condition not only integrates the hydraulic properties of the unsaturated zone that explicitly provides a comprehensive insight into the physical implications, but intriguingly retains mathematical tractability. This new condition is applied to a groundwater flow model for a pumping problem, and the drawdown solution is derived via integral transformations. The proposed solution is unitized to analyze the field data from a series of pumping test. The results demonstrate that the proposed model provides a better fit to measured data, particularly in scenarios where an unsaturated flow exerts a significant effect. Overall, the newly derived water table condition can be a handy tool to characterize the aquifer properties in an unconfined aquifer.