The leading cause of limited water supplies is reduced precipitation.
Explanation:
The quantity of rainfall that a region or a biome receives is known as precipitation. It is the main water available source for public use for water sources such as lakes, streams, wetlands, groundwater. The rainfall relies on the region's growing vegetation. The plants and trees carry water through transpiration process, which amounted to the water cycle.
Vegetation scarcity may affect the regular water cycle and may reduce rainfall frequency and level. The lack of adequate precipitation would restrict the amount of water in water bodies, thereby restricting the supply of water for use.