Protecting the Environment

The Santa Ana River and its shoreline are home to numerous threatened or endangered species, including the Santa Ana sucker, the least Bell's vireo, the southwestern willow flycatcher, and the California gnatcatcher. To protect these birds and fish, safeguard their habitat and diminish any impacts, Orange County Flood Control District and its project partners, the Orange County Sanitation District and the Santa Ana Watershed Project Authority, have developed a comprehensive monitoring and protection plan.

Qualified biologists, who will monitor the construction sites throughout the Santa Ana River Interceptor Relocation Project, are the cornerstone of the plan. Their focus is to identify the presence or absence of any threatened or endangered species within the construction area, determine whether additional protection measures should be implemented, and confirm project compliance with permit requirements.

The following are just some of the efforts planned during the SARI Relocation Project to protect sensitive habit and threatened or endangered species:

Protecting Riparian Habitat

Wherever possible, riparian habitat will be left untouched during the course of construction. If, however, it becomes necessary to remove riparian habitat, the activity will take place outside of the breeding season, August 16 through February 28. This will minimize impacts to least Bell's vireo and other migratory birds, including disturbances which would cause them to abandon active nests containing eggs and/or young.

If vegetation removal needs to occur during the breeding season, a qualified biologist will survey the vegetation for nesting birds of all species to determine if any active nests are present. Surveys will be conducted once a week for eight consecutive weeks, at the appropriate times of day during the breeding season, and surveys will end no more than three days prior to clearing.

Survey documentation and our findings will be submitted to the U.S. Fish and Wildlife Service and the California Department of Fish and Wildlife for review and concurrence prior to conducting project activities.

Noise Measurements & Control During Vireo/Gnatcatcher Breeding Season

Weekly surveys for the least Bell's vireo and the California gnatcatcher will be conducted by a qualified biologist in areas along the Santa Ana River where the birds are most likely to breed from February 15 to September 1, or until all juveniles have fledged, within 500 feet of an active construction area. The purpose of the surveys will be to identify the limits of occupied habitat and breeding status of the birds.

Surveys will also be conducted for the California gnatcatcher prior to vegetation removal, in habitat where they are most likely to nest within 500 feet of an active construction area. If gnatcatchers are identified within this survey area, the information will be provided to the U.S. Fish and Wildlife Service. If active nest sites are within or immediately adjacent to the work area, additional coordination and/or consultation may be required to avoid an unauthorized take.


To the greatest extent possible, all reasonable efforts will be made to avoid removing or damaging mature trees. However, if mature trees within Green River Golf Course, Featherly Regional Park, and other public areas are removed or damaged as a result of construction, the trees will be replaced.

Trees within Featherly Park that cannot be avoided will be replanted in a new location at a 3:1 ratio (3 new trees for every 1 tree removed). Affected non-native trees will be replaced with native species at the same ratio. All trees replaced will be monitored for one-year and replaced as necessary.

During Construction

Open-trench construction methods will only occur during daylight hours to minimize disturbances to wildlife species that move primarily at night. In particular and whenever possible, above-ground operations near the Coal Canyon underpass, which is an important wildlife corridor, will not begin until 7 a.m. and will be completed before dusk each day. The only exception will be for an activity that must continue non-stop until it is completed for physical or engineering reasons, such as the micro-tunneling process.

For more information about the project's effort to mitigate impacts during construction, please refer to the SARI SEIS/EIR or the HMMP.

Environmental Coordination

SARI Relocation Project partners are coordinating with the following resource and governmental agencies:

  • U.S. Fish and Wildlife Agency
  • U.S. Army Corps of Engineers
  • California Department of Fish and Wildfife
  • State Historic Preservation Officer
  • Environmental Protection Agency
  • Regional Water Quality Control Broad
  • California State Parks
  • South Coast Air Quality Management District
  • National Resource Conservation Service
  • Cal/OSHA Mining and Tunneling
  • City of Yorba Linda
  • City of Anaheim
  • Yorba Linda Water District
Santa Ana Canyon Habitat