Santa Ana-Delhi Channel improvements on the horizon; public invited to open house
On a bright, warm morning Tuesday, runners, bikers and joggers made their way down a low, curving path that led them to the Upper Newport Bay Nature Preserve. Visitors followed the path across the Bayview Trail Bridge, from which ducks could be observed paddling and fish leaping in the water below.
This is the site of the Santa Ana-Delhi Channel Improvement Project, and Orange County Public Works hopes both area residents and visitors to the preserve can weigh in on the upcoming infrastructure work.
The channel was built in 1965. Roughly 11 miles long, it extends from Upper Newport Bay to Warner Avenue. Much of the work has been completed upstream, according to county officials. Project manager Melissa Pasa said plans for the project area — from the intersection of Mesa Drive and Irvine Avenue to the Bayview Trail Bridge — have been around for some time.
The environmental impact report was completed in the 1990s, but studies and stakeholder agreements delayed the project’s official start date until next year, though officials will hold an open house for the public on Monday at the Muth Interpretive Center from 5 to 7 p.m. to answer questions and gather input.
Pasa said stakeholders include the California Coastal Commission, regional water control boards, the California Department of Fish and Wildlife, the U.S. Army Corps of Engineers, OC Parks and OC Public Works.
“We really needed to do our studies and analysis upfront to be able to get to where we are today,” Pasa said. “And we’re ready to go out to the community and hear their concerns and what they’d like to see as part of the project, make sure that they’re part of our mailing and distribution lists so they can be informed of the project throughout the entire process.”
The channel improvement project aims to provide flood control protection that meets current design standards, decrease the local scour along the channel and at the outlet to Upper Newport Bay to reduce the sediment transported to it, and provide habitat restoration in the associated channel system. Improvements will also be made to recreational trails in the area.
“Essentially, what we’ll be doing here is we’ll be widening the channel about double its existing width, and we’ll be replacing the Bayview Trail Bridge, which has experienced a lot of erosion,” Pasa said. “It was actually rehabilitated in 2017 just to stabilize the foundations in preparation for this capital improvement project.”
Pasa said the Santa Ana-Delhi channel is trapezoidal because of the amount of erosion it’s experienced over the years. Most of the walls lining the channels were nearly vertical on Tuesday, which she said impacts Newport Bay as the transported sediment affects water quality. Adding habitat would slow water as it travels through the channel, she said.
The total cost of the project is expected to be around $31.2 million, with construction expected to begin in fall 2024.
“We need to reduce erosion along this entire channel system to ensure that we can move the storm water safely from upstream to the bay. This bridge is also heavily used by pedestrian cyclists, so we want to make sure that the trails can stay open,” Pasa said. “If there’s too much erosion here, that bridge will have to close and would have to have emergency repairs.
“This project is getting ahead of that, and so was the rehabilitation we did in 2017. We’re doing this capital project now to address the erosion so that it’s planned, and that we can keep the trails open as much as possible ... this segment’s the last piece of the puzzle. What [this project’s] doing is upgrading our flood control channel to current design standards and providing 100-year storm protections.”
Pasa noted the team is also acknowledging the adaptive nature of the improvements with relationship to climate change and sea level rise.
The hope, she said, is to bring the contractor on board during the final design phase so it can provide its methodology before OC Public Works goes back out to the community to answer questions of what they can expect during construction work.
Monday’s public open house will also feature experts, volunteers who see and work with the preserve and some of the engineers involved in the project.
The Muth Interpretative Center is located at 2301 University Drive, Newport Beach.
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