Book excerpt: Stepped channel design has been in use for more than 3,500 years. Recent advances in technology have triggered a regained interest in stepped design, although much expertise has been lost in the last 80 years. The steps significantly increase the rate of energy dissipation taking place along the chute and reduce the size of the required downstream energy dissipation basin. Stepped cascades are also used in water treatment plants to enhance the air-water transfer of atmospheric gases (e.g. oxygen, nitrogen) and of volatile organic components (VOC). Results from more than forty-five laboratory studies and four prototype investigations were re-analysed and compared. The book provides a new understanding of stepped channel hydraulics, and is aimed both at researchers and professionals.