Drainage drop structure in Tijuana, Baja California, Mexico.

Construction across the stream at Arroyo Aguaje de la Tuna, Tijuana, Baja California, Mexico

Experimental plots to measure sediment production near Evora, Portugal.

Service spillway at Oroville Dam, northern California.

Closep of service spillway at Oroville Dam, northern California.

Closep of emergency overflow spillway at Oroville Dam, northern California.

Cresta Dam in the North Fork Feather River, northern California.

Main spillway at Tucurui reservoir, Para, Brazil.