Technical Abstract: Over the past 65 years, scientists at the USDA-ARS Hydraulic Engineering Research Unit (HERU) in Stillwater, Oklahoma, have made great strides in the design and technological development of hydraulic structures and vegetated channels. From its inception, the laboratory has gained notoriety for its accomplishments in vegetated channel design and development of design criteria for many hydraulic structures including trash racks, low-drop grade-control structures, and riprap design for rock chutes and stilling basins. Thousands of these structures and over a half-million miles of grassed waterways based on design criteria developed by the research scientists at HERU have shaped the landscape of the world into what it is today. In addition, research at the laboratory has provided field engineers with new techniques in measuring flow, soil erodibility, and controlling sediment release. Today, scientists at the laboratory remain dedicated in their study of hydraulic structures, channels, issues associated with the rehabilitation of aging watershed flood-control and multi-purpose reservoirs, and sediment control structures. The purpose of the research has been, and still is, to assist engineers in the design of safe, efficient, and economical hydraulic structures and channels.