Highway 84 Niles Canyon Widening

Wetland and Riparian Habitat Assessment for a Road Widening in Alameda County.


  • Determine the extent of wetlands and riparian habitat within the proposed work area


Project Description

The Highway 84 Road Widening Project was initiated in order to allow safer driving conditions along a 4-mile section in Niles Canyon, east of Fremont in Alameda County.  The highway in this area is a narrow two-lane road where numerous accidents had occurred over a number of years, and Caltrans determined that this section of Highway 84 could be widened within the existing right-of-way to improve driving conditions and safety for motorists.

Highway 84 at Niles Canyon

Highway 84 at Niles Canyon

WRA worked with CH2MHill to identify sensitive aquatic habitat within the proposed project area.  WRA’s wetland biologists examined the proposed road widening area for the presence of wetlands and riparian habitat potentially subject to jurisdiction by the U.S. Army Corps of Engineers, the Regional Water Quality Control Board, or the California Department of Fish and Game (CDFG).  The results of this work were used to assess potential project impacts to sensitive habitats and to determine the feasibility of modifying the project to avoid impacts.  This work also helped to inform the need to for regulatory permit applications necessary for the road widening project.


  • Wetland Delineation Report
  • Assessment of CDFG Section 1602 Riparian Areas

Tags: , , , , ,