What is a key condition that must be satisfied for the water supply in a building?

A key condition for the water supply in a building is the fast removal of waste with a minimum probability of leakage. This is crucial because an effective water supply system is not just about delivering clean water; it also involves the efficient removal of wastewater. If wastewater cannot be disposed of quickly and safely, it can lead to a variety of health hazards, structural issues, and damage to the environment. Furthermore, managing the risk of leakage ensures that the system maintains its integrity and efficiency, preventing water loss and potential complications such as mold growth or damage from leaks that might occur. Ensuring that the system can rapidly transport waste helps maintain sanitary conditions and prevents backflow, thereby protecting the health of the building's occupants.

The other options, while important in their contexts, do not encompass the holistic requirements for a building’s water supply as thoroughly as the need for efficient waste removal and leak prevention does. Continuous flow may be necessary, but without proper waste management, the system's efficacy is compromised. Similarly, while reducing evaporative loss and managing pressure in supply lines can contribute to the overall performance of a water system, they do not directly address the critical aspect of waste removal and leakage prevention.