The Alameda Creek Alliance has secured a settlement agreement with Caltrans regarding mitigation planting of native sycamore trees along Alameda Creek, as part of the agency’s Alameda Creek Bridge Replacement Project in Niles Canyon, east of Fremont. Under an agreement signed by an Alameda County Superior Court judge last week, Caltrans will replant sycamore trees that are cut during the bridge project at a 4:1 replacement ratio, and will also remove invasive trees and plants within and around the project area in Niles Canyon.
“We’re satisfied that the replacement and upgrading of the Alameda Creek Bridge will now proceed without undue impacts to riparian trees along Alameda Creek,” said Jeff Miller, director of the Alameda Creek Alliance. “We focused on replacing rare sycamore trees along Alameda Creek, since they provide food, shade, streambank stability and important habitat for trout and other wildlife. We’re hopeful we can find similar mitigation solutions and design changes to reduce the environmental impacts for Caltrans’ upcoming larger road project in Niles Canyon.”
The project will replace the 90-year old Alameda Creek Bridge and add modern safety railings and road shoulders for bicyclist and motorist safety. Caltrans has added measures to the project to benefit migratory fish: removing an abandoned concrete weir from Alameda Creek and building the replacement bridge with fewer cement bridge piers in the creek channel. The bridge replacement project is on schedule to start construction in winter of 2019 and be completed by 2022.
The project will remove or impact up to 52 sycamore trees. Caltrans will replant 208 sycamore trees, primarily within Caltrans right-of-way in the lower half of Niles Canyon. Where feasible, Caltrans will plant additional sycamores at other planting locations within the Niles Canyon corridor, or in the Sunol Valley. If Caltrans is unable to plant all 208 sycamores, it will fund a Sycamore Tree Mitigation Bank Fund for other agencies to plant the remaining trees in the Sunol Valley and other stream reaches in the Alameda Creek watershed.
Caltrans will remove up to 84 invasive trees, and control invasive shrubs and weeds such as giant reed, pampas grass, French broom, and periwinkle.
In November 2017 the Alameda Creek Alliance filed a lawsuit challenging the approval and environmental review for the Alameda Creek Bridge Replacement Project, since Caltrans had improperly deferred identifying what mitigation would be provided. The Alameda Creek Alliance was particularly concerned about impacts to mature sycamore trees along Alameda Creek in the riparian zone, which provide important wildlife habitat through shading of Alameda Creek, stabilization of stream banks, and nesting cavities for birds.