Alameda Creek Alliance


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Protecting Niles Canyon

Stopping Caltrans’ damaging and unnecessary project to widen Highway 84 through Niles Canyon and promoting road safety measures that do not damage the creek

As of February 2021, Caltrans is moving forward with three scaled-back highway safety improvement projects in Niles Canyon:

1) Alameda Creek Bridge Replacement Project
The project will replace and upgrade the Alameda Creek Bridge, realigning the eastern and western approaches to the bridge. It will require cut and fill, installation of large retaining walls, and cutting of several hundred trees. Environmental review for the project was completed in 2017 and the ACA challenged the approval. Under a 2019 settlement agreement, Caltrans will increase mitigations for the project impacts, including additional replanting of sycamore trees and removal of invasive trees and plants. Construction will be from 2021-2023.

2) Niles Canyon Medium-Term Safety Improvements Project
The project will reconfigure a tight curve in the middle of the canyon, add two traffic signals on Highway 84 in Sunol, widen the shoulders of some straightaways near Sunol, and install rock drapery systems. This project will also require tree cutting. Environmental review for the project was completed in 2018 and the ACA challenged the approval. Under a 2020 settlement agreement, Caltrans will also increase mitigations for this project. Construction will be from 2021-2022. Caltrans will also replace a culvert in lower Stonybrook Creek with a free-span bridge to improve migratory fish passage.

3) Arroyo de la Laguna Bridge Improvement
Environmental review for this bridge upgrade is expected in 2021. it will widen the bridge on Highway 84, near the town of Sunol, by three feet. Widening will be done to the extent feasible without adding any additional substructures.

Background: The California Department of Transportation began a damaging and unnecessary campaign to widen Highway 84 through the entire reach of Niles Canyon along Alameda Creek, supposedly for road safety. This controversial project would have actually made the canyon more dangerous for drivers and cyclists, wasted $76 million in public funds, degraded important trout habitat in Alameda Creek and jeopardized restoration efforts, and blighted a designated scenic highway and ruined the natural beauty of Niles Canyon.

Caltrans initially proposed three phases of a road widening project for much of Niles Canyon Road between Fremont and Interstate 680, with 12-foot lanes, 2-foot median and 8-foot shoulders throughout the canyon. This would require cutting 600 trees along Alameda Creek and filling the creek and floodplain with four miles of cement retaining walls and rip-rap to accommodate wide roadway shoulders. It would damage habitat for steelhead trout, Alameda whipsnakes and red-legged frogs and remove rare sycamore forest.

Caltrans did not focus on localized problem areas or evaluate simple solutions within the existing roadway such as signal lights, radar speed signs, median barriers or additional rumble strips. Caltrans internally “approved” phase one of the project in 2006 without alerting the public that it had been finalized. Caltrans filed a “Negative Declaration,” claiming no significant environmental impacts, rather than the required Environmental Impact Report for a project with significant impacts. Caltrans cut nearly 150 trees in the canyon in spring of 2011, over the protests of local residents.

The Alameda Creek Alliance filed suit challenging the inadequate environmental review, winning a court order halting construction and a settlement agreement from Caltrans in 2011 requiring them to abandon the first phase of the project. An Alameda Superior Court judge excoriated the agency’s clandestine project approval and obstruction of the public process. In January 2012 Caltrans agreed to restart the environmental review and public comment process for phases one and two of the project. After a July 2012 Federal Highway Administration Road Safety Assessment rejected Caltrans’ proposed highway widening approach, Caltrans promised a “clean slate” and pledged to consider all FHA recommendations before meeting with stakeholders and the public to develop new revised projects and a new environmental review process.

Caltrans subsequently proposed four smaller highway safety projects within Niles Canyon.