Jenny Creek Sewer Project,
City of Redding, CA
The City of Redding Jenny Creek Sewer pipeline was constructed over 50 years ago. It runs through the Jenny Creek canyon, serving the homes on the surrounding hills as well as conveying significant flows from up-gradient neighborhoods. Jenny Creek is a tributary to the Sacramento River, with the confluence occurring several hundred yards upstream of the intake for one of the City of Redding’s large drinking water treatment facilities, so any sewer spills into Jenny Creek cause significant concerns regarding contamination. Significant future growth is planned in the service area that feeds the Jenny Creek Sewer.
The Jenny Creek Sewer pipeline is an above-grade sewer, originally constructed from asbestos-wrapped steel pipe spanning between concrete supports, many of which were installed in the middle of the creek channel. Over the last several years, increasing maintenance requirements in the Jenny Creek Sewer, culminating in a sewer spill into Jenny Creek, led the City of Redding to decide to replace the 2500-ft of above-grade 12-inch sewer pipe with a new, larger (16-inch) sewer which would provide a longer service life as well as accommodate future growth. There were significant project challenges which included environmental constraints, constructability issues, site access issues, the need to keep the existing sewer in service during construction, and the desire to reduce the impact that the location of the sewer has on the creek channel.
The Water Works Engineers/Kimley-Horn Associates team worked to design a pipeline replacement alignment that could be installed with the existing sewer and laterals all in-service. The elevation of most of the alignment was modified so that the new sewer line ran above all of the old piping. During construction, Water Works Engineers construction management staff worked with the construction contractor to minimize creek impacts and even provide some level of invasive species removal and creek restoration with native species. The completed pipeline was out of the active creek channel, constructed of long-lasting materials and state-of-the art coating and lining systems, and reduced the City’s risk exposure due to sewer spills in this area significantly.
Jenny Creek Sewer - Original Installation
Jenny Creek Sewer - Realignment after Pipeline Replacement