Petaluma bridge project comes with environmental conditions

Construction on the Highway 101 bridge over the Petaluma River is moving along on schedule thanks in part to a mild winter that allowed a lot of the work to get done, according to Caltrans.

But the project hasn't been without roadblocks.

A year ago, work was almost shut down after a group of bird advocates sued over the project's impacts on a colony of cliff swallows. The migratory birds return from South America each spring to build conical mud nests under the Petaluma River Bridge and Highway 116 overpass.

Nets that the contractor installed to keep the swallows away ended up entangling and killing dozens of the federally protected birds.

A federal judge in July ruled against the environmentalists' request to halt the construction in order to study the cliff swallow impacts. Caltrans and the environmental coalition reached an out-of-court settlement in January.

As part of the settlement, the agency agreed to remove the nets and install hard plastic sheeting on parts of the bridges during construction to keep the birds away. Workers are scraping away nest starts. Caltrans has hired environmental consultants to monitor the construction project.

The agency is also required to meet with the conservation organizations four times per year to review measures to protect the birds — safeguards that environmentalists say are working.

"The birds seem to be not focusing their attention in areas where Caltrans installed the hard surface exclusionary material," said Veronica Bowers, director of the Sebastopol-based Native Songbird Care and Conservation, and one of the plaintiffs in the lawsuit. "Obviously, it is significantly safer for the birds."

Caltrans spokesman Allyn Amsk said the agency is spending upwards of $4 million to protect migratory birds during the duration of the project.

Other measures Caltrans is implementing to address the project's environmental impact include purchasing wetlands for salamander and frog habitat, planting trees and restoring Tolay Creek, Amsk said.