The objective of the first part of this study was to validate leak detection feasibility by acoustic correlation for large diameter pipe, using a compatible PC. It meant developing and verifying a specific data acquisition line: hydrophone and amplifier. The second step included the construction of a prototype incorporating automation in detection and alarm transmission. The initial success confirms that permanent acoustic monitoring is a new technology offered to network managers and can be used to replace or back-up other systems. All decisions require a preliminary study of the characteristics of the site to be protected: existing or prospective pipe, type of pip, operating conditions, pressure, and the possible risk from which protection is sought (pipe burst, infiltrations, flooding likely to cause serious damage, etc).