Perris Valley Pipeline Interstate 215 Crossing

The Perris Valley Pipeline Interstate 215 Crossing project connects two portions of the existing 6.5-mile, 96-inch diameter pipeline, improving water delivery to Riverside County communities served by the Metropolitan Water District of Southern California. Northwest Pipe Company played a key role in this project, supplying the 120-inch trenchless steel casing pipe and the 96-inch steel carrier pipe used to complete the nearly 3,000-foot crossing beneath the busy I-215 freeway.

The northern and southern portions of the Perris Valley Pipeline were completed in 2010, but the I-215 crossing was delayed due to challenging geological conditions and high groundwater levels. Utilizing a revised project design to accommodate these challenges, the trenchless crossing was executed using a microtunneling technique, with installation performed from 30-foot-deep shafts in three drives. The final drive also passed beneath an active railway, adding another layer of complexity to the project.

The steel casing pipe, manufactured by Northwest Pipe Company at its St. Louis, MO, facility, features our patented Permalok® T-5 joints. These precision-machined, press-fit connections align seamlessly, install quickly, and eliminate the need for time-consuming field-applied butt welds. Representatives from Northwest Pipe Company’s Trenchless team provided on-site support during the final 600-foot drive, where crews from JW Fowler efficiently completed the last two Permalok joint connections in under 20 minutes each.

With the Permalok casing in place, the project advanced to its next phase: installingthe steel carrier pipe. Manufactured at Northwest Pipe Company’s Adelanto, CA, facility, the majority of the 96-inch spiralweld steel water transmission pipe features cement mortar lining with a bare exterior. The pipe connects using bell and spigot lap-welded joints designed per AWWA C200 and M11 standards. Our team also custom-fabricated the 96-inch cement mortar lined and coated fittings used in the shafts to tie the three microtunneled drives together.

The crossing’s location, adjacent to the March Field Air Museum on the east side of the freeway, required meticulous coordination among the museum, local leaders, and the Metropolitan Water District. Despite these challenges, the project was completed on time and with minimal surface disruptions.

Completion of this final section of the Perris Valley Pipeline ensures enhanced water delivery for residents and businesses throughout Riverside County. Northwest Pipe Company provided seamless support to key stakeholders, including JW Fowler, Parsons, and MWD, along with the high-quality engineered pipe solutions critical to the project’s success. The innovative weld-free Permalok® technology accelerated the casing pipe installation process and reduced construction challenges, while the engineered steel carrier pipe and custom fittings ensure durable and reliable water transmission to meet the region’s needs well into the future.