New bridge restores spawning access for steelhead

New bridge restores spawning access for steelhead 1
A new bridge at the NRS’s Hastings Natural History Reservation allows steelhead to pass freely underneath while keeping pedestrians and vehicles safely above the water. Reserve director Jen Hunter spearheaded the $1.05 million project. Image: Jen Hunter

By Kathleen Wong, UC Natural Reserve System

Migrating to the NRS’s Hastings Natural History Reservation to spawn has long been an exercise in futility for some of the Central Coast’s most threatened fish. After swimming inland for more than 30 miles, steelhead aiming for the reserve’s largest stream, Finch Creek, encountered a nearly impassable barrier: a concrete vehicle ford. The structure’s faulty design, combined with streambed erosion, made it impossible for adult trout to continue further upstream for much of the year.

After more than a half century thwarting trout, the ford was replaced this autumn in by a pre-cast concrete bridge. The $1.05 million project not only provides unhindered passage for fish, but improves safety for pedestrians and vehicles.

“By replacing that crossing with this bridge, we are ensuring that that migrating steelhead can reach four miles of upstream spawning habitat. If all the fish that make it up this far can reach their spawning grounds, the reserve can provide a toehold for the recovery of that population,” says Jen Hunter. The director of Hastings, Hunter worked for nearly five years to make the new bridge a reality.

New bridge restores spawning access for steelhead
When not flooded, the old concrete ford over Finch Creek was impassable to migrating steelhead. The culverts were too high above water level for fish to reach, and too narrow for mature fish to swim through. Image: Jen Hunter

Watershed-wide improvements

The replacement of the Finch Creek ford is the latest of several major gains for Carmel Valley steelhead. By far the most significant was the 2015 removal of San Clemente Dam. Its demolition has restored the natural flow of water and sediment down the river, and provided fish with unhindered access to a great deal more spawning territory.

“There aren’t that many rivers in California where the watershed is saveable. Along so many of the rivers, the development is right up next to the bank; there’s no room to left the river do what it wants to do. That’s why the Coastal Conservancy has been focused on the Carmel River for many years. There’s still room to restore some of the natural dynamics of the river. And there’s local interest and support for that work that you don’t see in a lot of other areas,” Gandesbery says.

Too narrow, too low, and too dangerous

The old ford was likely built in the 1960s to connect what is now the reserve director’s residence to the area’s main artery, East Carmel Valley Road. The crossing consisted of a concrete slab enabling a single car to drive down into the streambed and back up its far bank. Four culverts pierced the base of the structure to permit water to flow underneath. All were 8-10” in diameter, too narrow for full-grown steelhead to wriggle through.

The ford became increasingly problematic in the decades after its construction. In the years after the University acquired it in 1988, various floods and reinforcements to the structure cut a deep pool on its downstream face. This left the mouths of the culverts up to six feet above the level of the stream in drought years.

Human volunteers have taken to moving marooned fish past the barrier. The area has remained popular with migrating trout; 15 percent of all the steelhead rescued in 2019 by the Carmel River Steelhead Association came from Finch Creek.

New bridge restores spawning access for steelhead
The project to replace the old ford with a new bridge involved three months of noise and mess for the reserve director and her family, who live just 75 feet from the creek crossing.

“A lot of the Carmel River tributaries aren’t so good for spawning anymore; many go dry from pumping since so many vineyards went up. But Finch is really good. It continues to have these isolated pockets of cold water in normal water years,” says Tom Gandesbery, a former project manager for the Coastal Conservancy.

The only times when trout could pass under their own power were during high flows along Finch Creek overtopped the ford. That left the roadway awash in water. “It didn’t take much for leaves and sticks to block up those culverts on the upstream side. We would just leave them blocked, because then the fish could actually get over.” Hunter says.

Those torrential conditions, however, were also hazardous for humans. Because the ford lacked rails, pedestrians and cars crossing while the ford was flooded risked being swept downstream.

New bridge restores spawning access for steelhead
Contruction for the new bridge turned a once-bucolic section of Finch Creek into a noisy construction site for three months. Image: Luciane Coletti

Funding for fish passage

At Finch Creek, the fortunes of the stranded steelhead began to change when Hunter was named reserve director in 2018. “When I got here and moved into the house, I thought immediately, oh, that’s a problem,” Hunter says.

This was a problem Hunter knew how to solve. Her previous employer was the San Mateo County Resource Conservation District, a type of agency that works with landowners to obtain state funding for habitat restoration projects like the removal of barriers facing spawning fish.

Amazingly, a dedicated source of funding already existed to bankroll the Finch Creek ford project. In 1992, local water company California American Water Co. agreed to pay a $11.2 million settlement for illegally over-pumping water from the river. That money, parceled out by the California Coastal Conservancy, is earmarked to aid steelhead and other aquatic species in the Carmel River watershed harmed by the pumping.

“Fish passage projects throughout the watershed are a high priority. People know how to deal with them. They’re just a construction engineering problem,” Gandesbery says.

A 2014 assessment by the Monterey Peninsula Water Management District identified the Finch Creek ford as the sixth-worst barrier to spawning fish in the Carmel River watershed. This made the structure a shoo-in for both the mitigation funding and other restoration funds.

Hunter and Gandesbery worked closely to secure $850,000 from the Conservancy to construct the reserve ford. The Monterey County Water Management District provided $100,000 to fund the design of the new bridge, while UC Berkeley contributed an additional $100,000 in construction funding and in-kind support.

New bridge restores spawning access for steelhead
Reserve director Jen Hunter overlooks the setup required to reroute Finch Creek during construction. The netting prevented fish from passing, while the pipe drained creek water around the work area. Image: Kathleen Wong

Belching tractors and high-flying cranes

After five years of applying for grants and pandemic delays, demolition of the Finch Creek ford commenced in mid-August 2023. Construction crews transformed the bucolic reach of stream less than 75 feet from Hunter’s front door into an industrial building site.

The noise and chaos at the site went on for three months, from 6:45 am to as late as 5 pm. Diesel-belching backhoes dodged spreading live oak branches to maneuver into the streambed. Clanking steel buckets dumped truck-sized dirt piles where riparian vegetation once sprouted. The creaky “waka-waka” of acorn woodpeckers and buzz of insects gave way to the thunder of caterpillar treads and shattering concrete. And what was once a burbling section of stream became a muddy hole deep enough to swallow an earth mover, its water pumped out and rerouted past the work site in snaking, block-long hoses.

Before work crews arrived every morning, Hunter had to sample the stream around the site to ensure construction wasn’t muddying the waters. She also performed biomonitoring for the project, seeking out and relocating any snakes, salamanders, or other organisms disturbed by the earth moving.

New bridge restores spawning access for steelhead
A crane with a 100-foot boom was required to lift the four sections of bridge deck up and over the treetops so they could be placed on the bridge footings. Image: Jen Hunter

It’s a bird… it’s a plane… it’s a bridge deck?

The most spectacular portion of the project, Hunter says, was the installation of the new bridge deck. A crane parked next to the streambed and extended its 100-foot boom out to the road, where the four deck pieces awaited. One by one, the crane operator lifted each 22,000-pound section up and over the intervening mature oaks, where workers settled them into place.

The crane operator’s skill impressed Hunter immensely. “The only thing that they knocked off the trees was a sycamore branch that was about 12 inches long, with four leaves,” she says.

Elevated above the stream, the 35-foot-long bridge allows water and fish to pass beneath unobstructed. The contractors also constructed concrete approaches to the structure on either side.

As a final touch, crews deepened the stream channel. Their efforts created a placid pool in front of the bridge for trout to rest. Boulders placed at the channel’s edge help stabilize the banks.

New bridge restores spawning access for steelhead
Despite the impassable ford, Finch Creek has been popular among steelhead for spawning. With the new bridge, fish such as this lunker, spotted swimming over the submerged ford in 2019, will be able to travel upstream unassisted to reproduce. Image: Jen Hunter

A watery welcome mat

Hunter couldn’t be more pleased by the final product. “There’s so much more capacity for the stream at this point than there was before. And I think we’ll have less erosion and runoff because of the way that the stream channel has been engineered,” she says.

Vegetation has already begun growing back at the site, sped along by the mugwort, wild rose, willow, and snowberry Hunter has replanted in areas flattened by heavy machinery.

This year’s cohort of spawning steelhead already have been spotted in the main stem of the Carmel River. The travelers are expected to reach reserve boundaries in about two weeks. With Finch Creek now clear and open, Hunter can’t wait to receive them.

3 responses to “New bridge restores spawning access for steelhead”

  1. Susan Hunter Avatar
    Susan Hunter

    Jennifer, what an amazing article about one of your many accomplishments since your arrival at Hastings. Congratulations! We couldn’t be prouder. Love, love, love!
    Mom and Dad

  2. Martha Gill Avatar
    Martha Gill

    Wow what a project you’ve accomplished. Congratulations. Having driven over the old bridge which was scary, it’s great to see a safer better bridge. Steelhead must be thrilled, Auntie M

  3. Teresa B. Salvato Avatar
    Teresa B. Salvato

    Best news I’ve heard in a long time! Congratulations on completing this magnificent project and sticking with it despite the setbacks and delays. Please keep up the great work and know that it is appreciated.

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