Proposed bridge replacement benefits fish, water and people

Sandra Jacobson, George Sutherland and Bob Blankenship

Special to the Village News

The Sandia Creek Drive bridge that crosses the Santa Margarita River two miles north of Fallbrook is proposed for replacement in the next two years. This bridge is an old concrete box culvert structure that floods after big storms, blocking access for residents and trail users.

The unusual part of this story is that funding for design for a new bridge started with the fact that it's a fish passage barrier for endangered Southern California steelhead. Steelhead are a specialized form of rainbow trout that migrate between freshwater and the ocean.

Trout Unlimited in partnership with California Trout have teamed with hydraulic engineering firm River Focus and structural/civil engineering firm KPFF to generate a design that meets county standards and local approval.

Three alternatives for bridge configurations near the existing structure were developed last year. During this time, the project team reached out to landowner Fallbrook Public Utility District and Fallbrook Trails Council for their input to best fit the bridge design into public needs and the existing trail system.

The project team gave presentations at the Fallbrook Community Planning Group meeting and Fallbrook Community Forum to hear people's concerns and answer questions on design and implementation. The key message for many people that know and love the Fallbrook Trail System as a local jewel is that this bridge project won't result in restrictions to parking access or trail usage.

The design phase is funded by California Department of Fish and Wildlife and State Coastal Conservancy, and is a great example of how to integrate endangered species management into community infrastructure projects that benefit fish, water and people.

The new bridge is proposed to be built close to the existing structure and will straighten out the curve near the trailhead parking lot, making it safer for trail users and motorists. Construction funding will be raised independently through grant funding, and the current Sandia Creek Drive bridge will likely remain open until after construction to minimize traffic impact.

Although this project was originally funded to remediate the fish passage barrier; the project is multi-benefit for the Fallbrook community to improve trail user experience through better safety controls for pedestrians, bikers, equestrian and cars; improve reliable and safe access for residents during high flows that flood the bridge; promote traffic calming in a congested area; and increase quality of riparian and river habitat for multiple species.

Steelhead have historically used this river as a migratory corridor to upstream spawning and rearing habitat; and their presence in the river during seasonal high flows would be a significant step forward in recovering this species, while not diminishing recreational opportunities.

The bigger picture for steelhead is that they will have access to more than 10 miles of upstream spawning and rearing habitat that will help bring back this species from the brink of extinction. Efforts are underway to improve steelhead habitat upstream through non-native species removal in the Santa Margarita Ecological Reserve.

This project also leverages efforts on Camp Pendleton to enhance fish passage on the river through a groundwater recharge structure at Lake O'Neill. Once the Camp Pendleton and Sandia Creek Drive fish passage projects are completed, steelhead will have unimpeded passage to high quality habitat.

Together, these Santa Margarita River projects benefit fish, water and people while improving water supply reliability, reducing local dependence on imported water and efficiently meeting the long-term needs of wildlife and surrounding communities.

For more on local steelhead recovery see the recent U.S. Fish and Wildlife Service story entitled Bringing Back Steelhead to Southern California at: https://fws.maps.arcgis.com/apps/Cascade/index.html?appid=71c33534f27249c5b3fe314f2f7df564