South of Highland Avenue Sewer Relief Trunk

City of Morgan Hill, Santa Clara County, California

To accommodate the City of Morgan Hill’s planned growth, a new sewer relief trunk is being constructed as a series of projects over several years. The first portion of the new relief sewer was completed by the City in spring 2016.

Since May 2016, HydroScience has been providing planning and design services for the remaining segment which is to be designed and constructed in two phases. This final segment includes construction of a 30-inch diameter relief sewer trunk that extends nearly seven miles. Although a majority of the sewer trunk construction within roadways will be installed using traditional open-cut methods, micro-tunneling and horizontal directional drilling methods will be used to cross under the Union Pacific Railroad train tracks, Highway 101, other Caltrans right-of-ways, and a concrete flood control channel.

Based on HydroScience’s recent experiences on various pipeline projects, we have been proactively working with the City, Santa Clara County, neighboring cities, other utility owners, and Caltrans to address the project stakeholders’ encroachment permit and design requirements. A comprehensive pre-design effort will also help expedite the anticipated design and construction schedules so that the first phase of the project, encompassing 3.4 miles, can be designed by March 2017 and constructed by March 2019.