The Long Beach Unit with 3 billion bbls of oil originally in place, is a part of the giant Wilmington Oil Field, the 4th largest field in the United States. In 1989, ARCO approached the City of Long Beach and State of California with a proposal to provide technology and capital needed to redevelop the field. The optimized waterflood program (OWP) agreement took effect on January 1, 1992 and today the LBU is producing more than 25% above the oil rate predicted from the base case decline. In addition, substantial reductions in both drilling and operating costs have been achieved. This paper discusses all aspects of the OWP agreement, including negotiations, technical studies, implementation, management philosophy and critical keys to success.