Why does availability of water vary from time to time and place to place?

Water availability varies from time to time and place to place due to factors such as rainfall patterns, climate variability, seasonality, and human factors like water management and infrastructure development. The geographical location of an area, its topography, and proximity to water sources also play a significant role in determining water availability. Additionally, droughts, floods, and changing weather patterns can impact the quantity and quality of available water.