A major research program is underway in Florida to develop a durability specification and rating system for concrete mixtures and structures. As part of the program, field and laboratory water-permeability tests have been developed and are being used with the AASHTO T277 rapid chloride permeability test to predict concrete durability. Presented are the scope and accomplishments to date, including descriptions and applications of the laboratory and field permeability tests, and the development of a permeability classification system on the basis of water permeability results. The durability specification and rating system should result in significant long-term improvement of concrete structures in aggressive environments. Other benefits include effective concrete quality control, efficient use of bridge maintenance funds, and substantial reduction in the cost of bridge rehabilitation.