What is the best description of subsidence?

The best description of subsidence is the withdrawal of groundwater to the point that the earth's surface sinks. Subsidence occurs when the ground compresses as water is extracted from underground aquifers, leading to a decrease in the volume of interstitial space within soil and rock layers. This phenomenon can result in significant land-level changes and can cause structural damage to buildings, roadways, and other infrastructure above. It emphasizes the impact of groundwater extraction on the physical landscape.

Other descriptions, such as proving a sufficient water supply for 100 years, treating effluent for recycling, and using groundwater faster than it can be replenished, refer to broader water management practices and concepts. These options address aspects of water sustainability and resource management rather than pinpointing the specific phenomenon of subsidence, which is directly related to the physical consequence of groundwater depletion.