The Big Canyon Watershed in the City of Newport Beach consists of approximately 1,062 acres that drain to the Upper Newport Bay Ecological Reserve. Big Canyon Creek, which drains the watershed, is one of the few perennial streams that discharges to Upper Newport Bay. In 2007, Big Canyon Creek was identified as having elevated levels of selenium and, according to the Santa Ana Regional Water Quality Control Board, it was anticipated that the creek would be included in a revised Total Maximum Daily Load (TMDL) for selenium before the end of 2014.
During wet weather, transportation-related pollutants enter Big Canyon Creek from thoroughfares such as Jamboree Road. These pollutants impair water quality in the creek and contribute to other regulatory issues, such as TMDLs for metals, toxins, nutrients and indicator bacteria. In addition, wet weather flows from Jamboree Road discharge through a storm drain outfall to a scour pond in the creek's riparian corridor, creating mosquito vector habitat. Thus, Big Canyon Creek presents a number of environmental problems for the city.
In 2013, Burns & McDonnell started working with Newport Beach city staff to address this multifaceted problem. The solution was a constructed wetland that would treat both dry and wet weather flows in Big Canyon Creek and eliminate vector habitat associated with storm drainage.
After several field assessments the Burns & McDonnell team developed the concept design for the Big Canyon Treatment Wetland (BCTW). When completed, the project will enhance restoration efforts that are planned for the lower Big Canyon Watershed, which include trails and public access to the restored area that will also provide public access and recreation in the area. Education materials developed for the restoration may also include the water quality enhancements achieved by the BCTW. In this way the BCTW will be a continuation of the recreational and educational opportunities provided by the lower Big Canyon restoration.
The objective of the Big Canyon Treatment Wetland and Restoration project is to reduce stormwater runoff, restore degraded habitat and improve water quality in Big Canyon Creek through a natural, integrated design.
- $2.3 million project funded by a grant-from the OCTA
- Designed to treat dry weather and wet weather flows in Big Canyon Creek to remove transportation-related pollutants and selenium
- Restores 3 acres of degraded habitat to natural conditions
- Natural system fully integrated with large-scale restoration of Big Canyon
Treatment Wetland Design
- Multiple treatment stages for efficient pollutant removal
- Unique upflow design for selenium removal
- Treats both dry and wet weather flows
- Viewing platform and informational signage
- Nature trail
- Restored habitat