Transient Pressure Monitoring Results—Nacimiento Water Project

Abstract

The Nacimiento Water Project in San Luis Obispo County, California, was completed in late 2010, and is now capable of delivering 15,750 acre-feet of raw water annually from Lake Nacimiento through 45 miles of pipeline to its service area. The Project includes three pumping stations, three storage tanks, 45 miles of pipeline ranging from 36- to 12- inches in diameter, and a Supervisory Control and Data Acquisition (SCADA) system. The hydraulic aspects of the system dictated careful attention to hydraulic design, with due consideration of normal and transient pressures. The construction contract was modified to add a very intensive hydraulic transient monitoring system. This transient monitoring program was installed during construction, and includes nine TP-1 transient pressure monitoring systems installed at locations most prone to severe hydraulic transients. These systems provide detailed information regarding transient pressures and are integrated into the SCADA system to provide real-time alerts if threshold pressures are exceeded. This paper describes the Nacimiento Water Project, the hydraulic design considerations, the network of transient monitoring systems that is installed, construction considerations, lessons learned, and the results of transient pressure monitoring collected during initial startup and testing. Results will include analysis of actual pipe rupture data that occurred during construction, and validation of hydraulic models.