River engineering is the process of planned human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the
water resources, to protect against flooding, or to make passage along or across rivers easier. From
Roman times, rivers have been used as a source of
hydropower. From the late 20th century, river
engineering has had
environmental concerns broader than immediate human benefit and some river engineering projects have been concerned exclusively with the restoration or protection of natural characteristics and
habitats.