Transients are one of the most common, yet least understood, challenges encountered in water distribution systems. Changes in the operation of valves, pumps, or other infrastructure may cause a pressure wave that contributes to pipe breaks, pump or valve failures, or other problems.
Hydraulic modeling revealed that new water facilities could create a risk of transients for three existing pipelines that cross Nob Hill in San Diego.
We provided geotechnical engineering and designed a new tunnel, pipelines, and an access road traversing steep terrain. Installing a replacement pipeline was challenging, since excavation of the volcanic rock required controlled detonation without disturbing nearby homes.
Our contribution allowed the construction of a hard-rock tunnel 800 feet (244 meters) long and 12 feet (3.7 meters) in diameter, and the installation of a welded-steel tunnel containing three water pipelines, without disturbing nearby residents or the nearby Miramar Dam.