Permitting A Forcemain Replacement Through Wetlands

Check out the informative presentation from North American Society for Trenchless Technology's No-Dig Conference.



The City of Solana Beach successfully navigated a series of complex permits to replace a 40-year-old asbestos cement forcemain running through the environmentally-sensitive San Elijo Lagoon and nearby wetlands.

By selecting a horizontal directional drilling (HDD) design with a direct alignment to the San Elijo Joint Powers Authority (SEJPA) Water Recycling Facility, the city was able to secure permits in a timely fashion. Additionally, significant impacts to the public were avoided along alternative alignments at Highway 101 and Manchester Avenue through Cardiff-by-the-Sea.

“The HDD method helped achieve project approval,” said Steve Deering, Dudek’s principal engineer. “With this trenchless technique, we avoided sensitive species such as the California gnatcatcher and least terns, while also steering clear of heavily trafficked areas.”

HDD is being used to install a new corrosion-free high density polyethylene (HDPE) forcemain along a 3,000-foot section of the 5,000-foot alignment. The project also included 1,000 feet of structural rehabilitation and 1,000 feet of open trench replacement.

To move this major undertaking to the construction phase, a myriad of permits and resource agency coordination was required at the local, state and federal levels. Additionally property permissions, easement appraisals, and easement acquisitions were facilitated with five land owners:

“Unlike traditional open-trench pipeline techniques, the city only needed to acquire a sub-surface easement for this trenchless construction,” said Deering. “This saved thousands of dollars and avoided potential lengthy delays that typically arise with surface easements such as property owner disputes and eminent domain activities.”

Additionally, the City of Solana Beach coordinated during the permitting and planning process with the City of Encinitas and the U.S. Army Corps of Engineers to avoid potential impacts due to future dredging and rehabilitation of the San Elijo Lagoon, still in discussions at a conceptual level.

The city’s early and inclusive outreach to non-governmental organizations (NGOs) with an interest in the lagoon proved to be invaluable in obtaining support for moving the project forward and avoiding delays in obtaining project approvals.

“By thoroughly evaluating the project’s big picture early in the design phase, the City of Solana Beach saved millions of dollars,” explained Deering. “Thanks to trenchless technology, wetlands don’t need to be replaced or enhanced, streets don’t need to be repaved, and residents don’t need to cope with noisy machines or rerouted commutes from road closures.”