Environmentalists have reached a settlement with Caltrans in their lawsuit over the killing of cliff swallows during construction at the Petaluma River bridge last year.

Contractor C.C. Myers installed nets under the bridge to keep the migratory birds away from the construction zone during the highway widening project. Conservationists say the nets entangled and killed dozens of birds. Last September, the U.S. Fish and Wildlife Service fined C.C. Myers $3,525 for violating the Migratory Bird Treaty Act, which prohibits killing cliff swallows.

Environmentalists sued Caltrans and the Federal Highway Administration over the bird deaths. They dropped their suit against Caltrans Thursday after the agency agreed to implement measures to protect the birds including:

  • Removing all existing exclusionary netting from the bridges
  • Wherever feasible, using hard surface exclusionary materials (such as plywood or plexiglass) to prevent cliff swallows from nesting on areas of the bridges under construction. Where hard surface exclusionary materials cannot be effectively applied — including on rounded surfaces such as columns — using flexible materials such as vinyl
  • Only using netting as an exclusionary material as a last resort, after consideration of other methods proposed by the conservation groups and their swallow expert
  • Removing nest starts from construction areas before swallows have completed nests, with a biological monitor ensuring that there are no birds or eggs in nests that are removed
  • Demolishing existing bridges outside of the swallow nesting season

Caltrans will pay environmental groups $4,000 to educate the public on cliff swallow protection. In total, Caltrans says it will spend $4 million to protect migratory birds throughout the duration of the construction project.

Caltrans released the following statement on the settlement late Thursday:

“Caltrans is pleased to have reached a settlement in the case related to the cliff swallows at the Petaluma and Lakeville Bridges on Highway 101, which will result in the dismissal of the pending case against Caltrans.  The measures that will be implemented at the two bridges this season are expected to be effective and protect wildlife, while permitting construction to continue.  As it did last year, Caltrans will have biological monitoring of the birds and nesting at these bridges through the 2014 nesting season.  It will also be meeting with interest groups throughout the season to provide information about the exclusionary measures being used.  Caltrans looks forward to advancing the construction at these bridges in Petaluma which when completed will improve traffic congestion in that area and on Highway 101 through the Marin and Sonoma corridor.”