Cyclists along the San Lorenzo riverwalk
Grout poured along the San Lorenzo River levee. The grout was supposed to be poured to fill only rodent burrows, which can threaten a levee’s integrity — but that’s not what happened.
(Kevin Painchaud / Lookout Santa Cruz)
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Gophers, grout and FEMA: How a rodent-hole debacle rocked the San Lorenzo River levee

Ahead of a July FEMA deadline to repair the San Lorenzo River levee, the City of Santa Cruz hired contractors to pour grout in holes in the levee made by rodents. River stewards say workers mistakenly poured the grout in holes containing seedlings, destroying 150 native plants and damaging efforts to rehabilitate the area’s biodiversity. The city says it plans to revamp its bidding process for such contracts in the future, moving away from requirements to accept the lowest bidder.

Laurie Egan’s office at the Coastal Watershed Council on Dakota Avenue overlooks the San Lorenzo River riverwalk path near downtown Santa Cruz.

This summer, she could see contractors working to fill squirrel and gopher burrows along the river’s levee as part of efforts by the city’s public works department to maintain the levee.

Egan, the council’s executive director, knew that kind of damage by animals can create a “Swiss cheese effect” inside the levee, weakening its structure and leaving it vulnerable to flooding and collapse.

But shortly after contractors began laying grout to cover these holes, Egan and other Coastal Watershed Council (CWC) staff who see or visit the river every day saw what looked to them like large amounts of grout being poured inappropriately.

The contractor’s work raised alarm bells for staff and other river stewards. Eventually, on June 19, Egan said, they noticed that contractors were mistakenly laying grout in areas thought to be burrows, but which were actually spots throughout a habitat restoration site where CWC staff and volunteers had planted native species as part of the organization’s goal to rehabilitate the river’s biodiversity.

Since 2017, the CWC has been focused on removing highly invasive species in its habitat restoration site — the stretch of river levee between Soquel Avenue bridge and the Laurel Street bridge — and replacing them with a biodiverse array of native plant species including deer weed, mugwort, black sag, and coyote brush. Planting these native species, Egan said, is foundational to creating a thriving habitat along the river.

Holes along the San Lorenzo River filled with grout.
(Kevin Painchaud / Lookout Santa Cruz)

When CWC staff assessed the city contractor’s work, they realized it had covered 150 of the organization’s plants with grout — a mix of cement, water and other components that act to seal and strengthen a structure. Most of those plants likely won’t survive, Egan said.

In total, river stewards said contractors incorrectly laid grout along several sections of a 2-mile stretch of the San Lorenzo River levee between the Highway 1 bridge and the Beach Boardwalk. It’s a mistake stewards say has undone environmental restoration efforts along the river’s levee and that Egan and others believe should have been dealt with by the Santa Cruz Public Works department more proactively.

City public works officials acknowledge the issues, which they say stemmed in part from a requirement to accept the lowest bid on a project, and say they are working to improve the process for choosing a contractor for such projects in the future.

The city took over management of the levee from the U.S. Army Corps of Engineers in July 2020 following the completion of the levee construction, which began in 1955, according to Egan.

The management changeover started a three-year clock, which runs out this month, for the city to get accreditation for the levee from the Federal Emergency Management Agency (FEMA), said the city’s director of public works, Nathan Nguyen. If received, this would allow residents living near the river to maintain their discounted flood insurance. Nguyen said that though he is confident the city will receive FEMA accreditation, he cannot say for certain whether the insurance rates will stay the same; that will be up to insurance companies.

The city hired consulting firm MBK Engineers to assess the work needed to be done on the levee in order to meet FEMA’s accreditation criteria. The consultant recommended in a report last year that the city improve two issues with the levee. First, some vegetation needed to be removed to make sure it wasn’t covering any burrows or structural deficiencies in the levee. Second, there was a significant population of burrowing rodents along the levee, and the holes they created needed to be filled to ensure the viability of the levee’s structure.

The Public Works department hired Pacifico Construction to fill the burrows this summer. A different contractor, Community Tree Service, was hired to work on vegetation management earlier this year. Pacifico Construction did not respond to calls for comment for this story.

Christina Alberti, supervisor at the Public Works department, said that completing these projects, especially the burrow mitigation, was important for the safety of the city and surrounding habitat.

“The failure of the Pajaro River levee, which included unmitigated burrowing rodents, was a vivid reminder of how necessary this work is for the safety of our community and the San Lorenzo River habitat,” she said.

Jane Mio, director of the Women’s Club Estuary Project, believes this FEMA accreditation process is where the recent issues with river levee projects started. The Estuary Project cares for the estuary portion of the river from the Laurel Street ridge to the Boardwalk, where it empties into the ocean. Mio said she felt the process to hire contractors was rushed and didn’t leave time to incorporate community and expert input. She said she didn’t understand why the process to hire contractors to carry out these maintenance projects couldn’t have started earlier.

“It’s hard to consider you hire a consulting firm that tells you at the last minute that you have to do this work,” Mio said. “If they are experts in FEMA accreditation, wouldn’t you think they are aware of all the components that go into that accreditation?”

Grout poured along the San Lorenzo River levee.
Grout poured along the San Lorenzo River levee.
(Kevin Painchaud / Lookout Santa Cruz)

Nguyen said the FEMA accreditation process simply takes time: First the city had to hire MBK to carry out an in-depth inspection of the city’s flood control system, which included at least six different studies, like a structural analysis of the levee. That process took close to two years. After the levee passed the inspections, putting the vegetation management and burrow mitigation projects out for bid, hiring contractors and completing the work took around another year.

“We were hoping in invitation for bids that the scope was defined enough and that we could get it to be a quicker turnaround but it ended up to be quite challenging. There weren’t a lot of contractors that this is their bread and butter,” he said. Few contractors had experience in laying grout for burrow mitigation projects, Nguyen added.

Egan said CWC was ultimately happy with how the Community Tree Service handled the vegetation management on behalf of the city, though Mio said she felt the contractors removed too much vegetation from the estuary portion of the river, including some native plants.

Community Trees Service said its workers “meticulously followed the specifications provided by the [city] throughout the project.” The company said it had an in-house, certified arborist on site — required of it by the city — and frequently met with nearby residents to incorporate feedback within scope of the work requirements.

“Our goal was to ensure that we removed and trimmed exactly what was required and nothing more, as we understand the significance of environmental preservation and the community’s well-being,” Community Tree Service said in an email response.

But while Egan said she was happy with the way vegetation removal work was done in the CWC’s portion of the levee, when it came to filling the rodent burrows, CWC wasn’t so lucky. Egan said CWC staff were concerned that it seemed the grout was being poured in CWC’s habitat site beyond the places where burrows had been marked.

Laurie Egan's office at the Coastal Watershed Council looks out over the San Lorenzo River.
(Kevin Painchaud / Lookout Santa Cruz)

Egan and CWC river ecologist Kaiya Giuliano-Monroy later noticed that contractors had filled in the dinner-plate-sized shallow basins at CWC’s habitat restoration site on the levee, mistaking them for rodent burrows, when in fact they were areas where CWC staff and volunteers had planted native seedlings. Egan said her organization has not calculated the cost of those 150 plants — many of which will likely not survive the damage.

“We all fell out of our tree, so to speak, when we saw what had happened and alarmed everybody to stop doing what they were doing,” Mio said.

Mio thinks part of the problem had to do with flags. She said she and CWC staff used pink flags to mark the locations of native plants along the levee. Contractors also ended up using pink flags, but to mark where they saw rodent burrows. Mio said this might have played a role in the confusion. The estuary portion of the levee fared better than CWC’s habitat restoration site — partly because when Mio saw the issue the same colored flags might pose, she spent eight hours replacing hers to ensure the same thing didn’t happen there. Still, she thinks contractors poured too much grout and also placed grout in areas where there were no burrow holes.

In addition to mistakenly pouring grout over plants, Egan said, CWC staff were alarmed to see contractors pouring grout too close to the river’s edge, outside the bounds of the map they’d been given by the city mandating where they were permitted to pour.

“There is a real threat here to the river water quality,” Egan said.

Mio said she also saw the grout contractors digging holes into the ground for no apparent reason. She noticed that after digging the holes, once they saw there were no burrows, the contractors put the soil back in, but did not pack it in. This will pose a hazard come storm season, she said, because more space in the soil will cause it to dry out even more than it already is, leaving it more vulnerable to erosion.

“It made me really upset, angry and sad that, once again, nature had to pay the price for human failure,” Mio said. “It’s very hard to take.” For example, she said, right now is bird breeding season. The river’s bird population has been in drastic decline for decades, and these mistakes will only exacerbate that.

Cracked cement road.
The path along the San Lorenzo River opposite rising downtown construction.
(Kevin Painchaud / Lookout Santa Cruz)

Nguyen said Community Tree Service performed the vegetation maintenance work in accordance with the city’s requirements, even if the work came as a shock to Mio. He said for years, the U.S. Army Corps of Engineers had not kept up with its own vegetation maintenance standards for the levee. So the city had little choice but to cut back the vegetation more drastically than river stewards like Mio might have been used to seeing.

“What we need to maintain [the levee], I don’t think that ever got translated over to Jane’s crew … over the years,” he said.

Nathan Nguyen, Santa Cruz's new director of public works
Nathan Nguyen, Santa Cruz’s director of public works.
(Kevin Painchaud / Lookout Santa Cruz)

However, Nguyen acknowledged flaws in the process with Pacifico Construction. He said after being made aware of ongoing issues, the Public Works department assigned an additional staff inspector to be on the ground with the grout contractors, sometimes every hour, to try to ensure there were no more problems. Egan said due to Public Works’ intervention, the remainder of the burrow filling project has run smoothly. According to Nguyen, this project was finished on Tuesday.

But Mio said Public Works should have had more expert inspectors on the ground to supervise at the start of each project. The process should have begun with community input and input from environmental experts, she added.

“Public Works is an engineering department. They would never do an engineer[ing] project without getting all the information and expert advice,” she said. “Yet, when it comes to the environment project, they never asked the environment groups, the groups that are involved with doing the work.”

The city is working on changing the process for similar projects in the future to involve more community input, Nguyen said. Part of the problem with the process of carrying out these kinds of projects, he said, is that the city is legally obligated to accept the lowest bidder on such contracts. Lowest-bidding contractors often work out well. But sometimes, he said, they don’t, and the city is left with a contractor who does not understand the nuances of the job it was hired to carry out.

The Public Works department plans to replace its current process with a request for proposal, which would allow the city to include more qualifications in their search for a contractor. An RFP takes more time and resources from Public Works staff, but Nguyen said he thinks it’s worth it.

“We just know with community sentiment that we want to be including others in this way of making sure that we get a contractor that checks most of the boxes we want to see,” he said.

The city plans to carry out an annual RFP for vegetation maintenance on the levee. For burrow filling, staffers are planning an RFP for a five-year contract to create a consistent relationship with contractors.

While the levee maintenance work might be necessary to ensure the levee doesn’t overflow and harm humans, Mio said it can often come at the cost of the river habitat’s health. The burrows are home to various snakes that help control the insect and rodent populations. The grouting took its toll on them, in particular the gopher snakes, she said. A bald eagle was a regular resident of the estuary until the contractors started to remove vegetation, she said. It hasn’t returned since.

Egan believes it’s possible that humans and nature can coexist. The CWC plans to create a “new vegetation management plan” that works within Army Corps of Engineers requirements but still creates a thriving river habitat.

She cites mugwort as a perfect example of one such plant that can work within the limitations of vegetation management. “It’s an amazing native plant, it can actually handle being cut back a bit,” she said. “It will grow again.”

As environmental stewards working to preserve the river levee’s natural vitality, Egan said she sees her work as balancing the inherent tension between man-made inventions and the natural world.

“The levees ensure that downtown doesn’t flood and at the same time, the river is home to endangered species and threatened species,” Egan said. “And so it’s incredibly important to have this habitat there because if we don’t care for these species, they can be gone forever.”

For Mio, the effects of the levee projects, whether done within or outside of the city’s official scope of work, go beyond immediate damage done to the river — they serve to further separate local residents from the natural environment and wildlife that also makes its home here, she said.

“It impacts the community on so many levels and that part is what is painful as well,” she said. “I have so many people now that go and use the path and they say they don’t enjoy it as much as before, because now it’s so barren, so many less birds. Less, less, less. That is not good for the health of the community.”

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