What is a drainage system designed to remove?

A drainage system is fundamentally designed to remove wastewater and sewage from residential buildings. This includes water that originates from various fixtures such as sinks, toilets, and showers. Proper drainage is essential for maintaining sanitation, preventing water backups, and ensuring that waste is transported efficiently to treatment facilities or municipal systems.

The effectiveness of a drainage system is critical in preventing health hazards associated with stagnant water and contaminated waste. It is engineered to manage the flow of wastewater to minimize odors and other related issues and to comply with health and safety regulations.

While the other choices mention important water management aspects, they pertain to specific scenarios or types of drainage systems. For instance, removing rainwater from roofs is a function of a roof drain or gutter system; groundwater removal is typically managed by sump pumps or drainage tiles, and excess stormwater management is addressed through stormwater management systems. Each of these plays a role in broader water management practices but does not define the primary function of a drainage system in a residential context.