Rock ramp fishways are a proven solution for restoring fish passage at low-head barriers. Building on established rock ramp design principles, the development of modular precast rock ramp fishways have evolved as a practical extension of traditional rock ramps that can improve constructability, consistency and long-term asset performance while maintaining the hydraulic and ecological characteristics that support fish passage. This presentation explores the evolution of the precast rock ramp fishways in NSW over the past two decades from concept through to implementation, demonstrating how successive application has refined engineering design, hydraulic performance, module geometry, manufacturing and construction methodologies. Drawing on monitoring data, the presentation focuses on the continual learning process that has shaped the development of an increasingly practical, repeatable and adaptable fishway system. Consideration of future opportunities and constraints of modular precast rock ramp fishways will also be discussed.