I-405 Sepulveda Pass Widening

By many metrics the most trafficked freeway in the entire world, there is no more central an artery for any area than the 405 for Southern California. Which is why any attempt to repair or upgrade the 405 is a highly visible and scrutinized project. So, the 2011 Sepulveda Pass Widening was major news in California, referred to as Carmageddon.

Chambers Group not only delivered environmental compliance monitoring for multiple construction crews on day and night shifts for this design-build contract, we also developed a contractor education brochure to sensitize construction workers to project environmental issues. Staff conducted a formal jurisdictional delineation of the site in support of Clean Water Act (CWA) Sections 401, 402, and 404; and Division 2, Chapter 6, Sections 1600-1602 of the California Department of Fish and Wildlife (CDFW) Code for U.S. Army Corps of Engineers (USACE) and Regional Water Quality Control Board (RWQCB) permits. Chambers Group conducted biological species including sensitive plants, vegetation communities, native trees, nesting birds, bats (day/night), and sensitive species constraints mapping. Right-of-way for this project is on both sides of the freeway along the 10-mile segment. Chambers Group conducted a native tree survey and mapped native trees that may be impacted during construction (trees will be replaced at a ratio of 5:1.) In addition, Chambers Group: surveyed potential areas for nesting birds and bats, rating potential areas for the upcoming spring; helped maintain the construction schedule by recommending performing a constraints analysis to provide data on areas with moderate to high potential for nesting birds and/or bats; installed exclusionary devices to prevent nesting during the nesting season; scheduled the vegetation removal in these areas and designated areas for geotechnical boring outside the nesting season to prevent future potential delays in the schedule. This was a robust scope as intended, but it wasn’t until nearly two years into the project that the Chambers Group role expanded in the most dramatic of fashions.

In 2011, CDFW ordered an immediate stop work on this project. This meant that the enormous efforts of so many different agencies and companies would meet a likely stall of several months, resulting in millions of dollars lost in stagnancy not to mention any potential implications for the project itself.

In just four working days, Chambers Group coordinated agencies to develop a workaround. Responding with multiple senior most staff working literally around the clock, and developed a Habitat Mitigation/ Monitoring Plan (HMMP.) In response, CDFW released the stop work order and allowed project-wide work to continue under the conditions outlined in the HMMP. All told, in a stretch of less than one working week, the massive Sepulveda Overpass Widening project went from regular operations to full stoppage to full resume. The work that Chambers Group delivered saved the client several months of delayed construction and millions of dollars.

While Chambers Group knows that no project ever plans to incur a stoppage, one of the pledges we are most proud to be able to make to our clients is to keep your project moving forward. Under the most time impacted and pressurized of circumstances, Chambers Group has been able to keep the project moving forward.