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Last Updated: Wednesday, January 17, 2018 1:29 PM

Biological Resources Issues

Caltrans complies with federal and State laws and regulations and acts as a good steward of natural lands under our control.

Caltrans must comply with federal and State environmental laws and regulations in all phases of project planning, development, permitting, construction, and maintenance.

Caltrans identifies existing sensitive biological resources and evaluates potential biological effects during project development. Through early coordination with regulatory agencies, Caltrans identifies opportunities to avoid or minimize effects where practicable, and opportunities for mitigation of unavoidable adverse impacts to natural resources.

When impact avoidance is not possible, Caltrans minimizes impacts on-site. When mitigation is necessary, on-site or off-site compensation may be required. Off-site mitigation may include land acquisition and habitat improvement. The following are considered:

  • Use conservation easements before considering a right of way purchase,
  • Avoid purchasing or improving habitat on small isolated sites; if possible, and achieve compensation in advance of project impacts; and
  • Develop or participate in mitigation banks when appropriate opportunities exist; and

Caltrans works closely with resource agencies and FHWA in both the development and implementation of mitigation necessary to satisfy State and Federal laws, ensuring that required mitigation is a reasonable expenditure of highway funds.


Final FHWA - California Division - Clean Water Act Annual Wetlands Impact and Mitigation Report Submittal for the federal fiscal year ending September 30 - This submittal provides information documenting achievement of FHWA's "No-Net-Loss" policy and 1.5+:1 minimum replacement objective. It provides an estimate of impacts and mitigation of wetlands subject to jurisdiction under Section 404 of the Clean Water Act as measured at the time of issuance of the Corps Permit.

FHWA - California Division - Endangered Species Act Annual Impact and Mitigation Report for the federal fiscal year ending September 30 - This report provides an estimate of impacts, compensation and the costs of implementing compensation for federally listed species and/or critical habitat as estimated at the time of issuance of the biological opinion, not-likely to adversely effect concurrence or no-effect findings.

Caltrans monitors and maintains mitigation sites.

San Diego wetland. Photo by H. Holman, Caltrans
San Diego Wetland - Photo by H. Holman (Caltrans)

Fisheries - Bioacoustics New Item

The California Department of Transportation (Caltrans) in coordination with the Federal Highways Administration (FHWA) and the departments of transportation in Oregon and Washington, established a Fisheries Hydroacoustic Working Group (FHWG) in order to improve and coordinate information on fishery impacts due to underwater sound pressure caused by in-water pile driving. In addition to the above transportation agencies, the FHWG is composed of representatives from NOAA Fisheries (Southwest), NOAA Fisheries (Northwest), U.S. Fish and Wildlife Service, California Department of Fish and Game, and the U.S. Army Corps of Engineers. The FHWG is supported by a panel of hydroacoustic and fisheries experts who have been recommended by the FHWG members. A Steering Committee oversees the FHWG and is composed of managers with decision-making authority from each of the members' organizations.

The goal of the Working Group is to reach agreement on:

1) The nature and extent of knowledge about the current scientific basis for underwater noise effects on fish;
2) Interim guidelines for project assessment, mitigation, and monitoring for effects of pile-driving noise on fish species, and;
3) Future scientific research needed to satisfactorily resolve uncertainties regarding hydroacoustic impacts on fish species.

For additional information on bioacoustics related to fish which includes the final report, "The Effects of Sound on Fish." by Dr. Mardi C. Hastings and Dr. Arthur N. Popper visit our Fisheries - Bioacoustics web page.

Who to Contact

If you have questions about biological issues related to state transportation projects, please contact your local district environmental branch. Or you can contact , Chief, Office of Biological Studies of the Division of Environmental Analysis in Sacramento at 916-653-6976.