Water is a natural resource that is important for economic activities and human health. Alternative concepts for water supply in fast-growing megacities include constructing local "waterhouses" that can supply drinking water and water for domestic use in a sustainable way by treating and reusing water to meet quality standards. Current issues with water supply systems include poor condition of pipes and sanitation systems as well as illegal tapping of water resources, worsening the distribution of water. "Waterhouses" have been proposed as a way to better satisfy water supply needs.