Environmental Addendum/Reevaluation/Revalidation

Environmental Addendum/Reevaluation/Revalidation

Environmental Addendum/Reevaluation/Revalidation for minor change in design/scope of work (final design of temporary river diversion to be implemented during construction) and environmental reevaluation limited to the topic of biological resources.Temporary diversion of flow of the San Gabriel River is required to construct the improvements associated with the proposed undertaking. Since the last environmental evaluation, it has been determined that the duration of construction is estimated at 1 year, and that work will be restricted to the dry season, with construction planned from April 15 to October 15. To assure that the proposed undertaking does not reduce the current channel design conveyance capacity or introduce potentially unstable flow conditions during construction, maintenance of 33% of channel design flow [19,800 cubic feet per second (CFS)] will be required from April-May and for the period of September-October. For the summer period (June-August), maintenance of 5% channel design flow (3,000 cfs) is required during temporary river diversion.

Long Beach, Los Alamitos, Seal Beach

Los Angeles, Orange

Citywide, Countywide, Nationwide, Southern California, Statewide, Unincorporated

California Air Resources Board (ARB), California Coastal Commission (CCC), California Department of Conservation (DOC), California Department of Fish and Wildlife, Marin Region 7 (CDFW), California Department of Fish and Wildlife, South Coast Region 5 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of State Parks, Division of Boating and Waterways, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 7 (DOT), California Department of Transportation, Division of Aeronautics (DOT), California Department of Transportation, Division of Transportation Planning (DOT), California Department of Water Resources (DWR), California Energy Commission, California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, Los Angeles Region 4 (RWQCB), California State Lands Commission (SLC), Office of Historic Preservation, San Gabriel and Lower Los Angeles Rivers and Mountains Conservancy (RMC), State Water Resources Control Board, Division of Water Quality

Transportation:Highway/Freeway (Maintenance, Bridge Scour Mitigation)

Use Permit

Biological Resources, Cultural Resources, Geology/Soils, Hazards & Hazardous Materials, Hydrology/Water Quality, Noise, Recreation, Utilities/Service Systems, Vegetation, Wetland/Riparian