The San Diego County Water Authority is planning to co-sponsor a nationwide contest to advance leak- and corrosion-detection technologies for large-diameter pipelines. The competition runs through May 8 and includes a $75,000 prize provided by the U.S. Bureau of Reclamation. The Water Authority is helping to design the competition and providing judges to identify new approaches to detecting problems with pipelines. Corrosion and leaks result in billions of gallons of wasted water annually, the authority said.