<p>Reducing the consumption of natural water resources is a critical aspect of the sustainable development of coal resources. In western China, Neogene red clay plays a vital role as a confining layer for mine safety and natural water resource protection. However, the uneven distribution of red clay results in many mines being situated in transition zones between areas of normal red clay deposition and those lacking it. This study focused on red clay in transition zones, examining differences in properties between normal deposition areas and transition zones, as well as the effect of coal mining on the water retention potential of red clay. The results indicated that the water retention potential of red clay is not linearly related to the thickness of the deposit; specifically, as the thickness decreased, the water retention of red clay in these transition zones declined sharply. Laboratory experiments were conducted to simulate factors influencing mining activities, including structural disturbance due to stress changes and an increased hydraulic gradient within the red clay layer. These experiments revealed that permeability increased by 1 and 2 orders of magnitude, respectively, under these two conditions. An evaluation system for water retention potential was established, incorporating geophysical parameters, regional characteristics, and mining effects. Using the analytical hierarchy process and a geographic information system, the water retention performance of red clay areas was objectively determined and mapped. This study determined a critical thickness of 10&#xa0;m for water retention and quantified the variations in water retention potential within this critical thickness. These findings have been applied in engineering practices in the Yushen mining area and other regions with widespread red clay distribution.</p>