Six months ago, historic winter storms bludgeoned San Luis Obispo County with rain totals the region hasn’t seen in decades. A Jan. 9 deluge brought the most precipitation ever recorded at Cal Poly in a single day—and that turned out to be just one of several severe storms to hit the Central Coast.
Hundreds of local roads, bridges, lift stations, and other public infrastructure sites remain damaged or destroyed. New Times reached out to public works officials to compile the largest, most expensive, and most important storm repair projects that are either underway or in the works. The total cost for all this work—in this list and beyond—surpasses $50 million, but officials hope that much of the expense will be reimbursed by the Federal Emergency Management Agency (FEMA).
SLO Creek bank repairs on San Luis Drive
Cost: $6 million
Completion date: End of year
Project: Over the course of the storms, a gushing San Luis Obispo Creek eroded several feet of creek bank along San Luis Drive across from SLO High School. The erosion was so severe that a section of the San Luis Drive sidewalk broke off, leaving a precarious cliff drop near the street—the only route to about 100 homes past the high school. The repairs involve installing steel beams tied together by wood and concrete to restabilize the creek bank. As of press time, crews were laying down temporary pipe in the creek to divert its flow to allow for safe access to the bank. “We put the entire creek into a 4-foot diameter pipe,” city Project Manager Wyatt Banker-Hix explained. “At the end of the project, you peel that plastic up and the creek bed is ready to go.” The steep cost estimate for the project is largely due to the specialized nature of the work, Banker-Hix said, which involves drilling 30-foot-deep holes into the ground to insert the steel beams. “Hopefully, it’s our biggest [most expensive] one,” Banker-Hix said, ” … that’ll last 50 to 100 years.”
Chimney Rock Road temporary bridge
Cost: $2.5 million
Completion date: June/July
Project: While the Jan. 9 storm severely damaged a portion of Chimney Rock Road near Lake Nacimiento, a March storm completely destroyed it. “After the March storm, it was just gone. It was a canyon between the two sides,” SLO County Public Works Deputy Director John Waddell said. A nearly 200-foot section of road traversing a 40-foot-tall embankment with three culverts collapsed into the violent, sloshing stormwaters. Now, SLO County is installing a temporary bridge to reconnect the sides. “It’s a military style, one-lane temporary bridge,” Waddell said. “Originally, we were going to use a crane to fly it in, but we couldn’t get a crane big enough, so we went to Plan B.” Plan B is to truck over the individual bridge parts and assemble it on-site. While the temporary bridge is only a few weeks away from completion, a permanent fix is likely years off. “It is a challenging project,” Waddell said. “The location is very remote. It’s a long ways and a slow, windy road.” At first, the road collapse left residents of south Lake Nacimiento stranded. But in the weeks since, SLO County built a temporary road for locals and worker crews.
Prefumo Creek sediment removal near Laguna Lake
Cost: TBD
Completion date: TBD
Project: The Laguna Lake neighborhood in San Luis Obispo suffered severe flooding and property damage during the Jan. 9 storm. One reason for that, according to the city, was significant sediment buildup in Prefumo Creek, which runs alongside the neighborhood and drains to Laguna Lake. Years of buildup combined with the recent storms resulted in city storm drains sitting at a lower elevation than the creek itself. “That’s not a good thing,” SLO’s Banker-Hix said. “When we have rainstorms, that means the creek level rises and the storm drains end up filling up. That’s why the city is interested in removing a whole bunch of sediment there.” He noted how the recent storms sent an extra 4 feet of silt into the creek. “That piece of Prefumo Creek was actually manmade in the 1960s,” Banker-Hix said. “When we constructed that, we weren’t thinking about sediment transport. We were just trying to get a lot of water into Laguna Lake.” The removal project is a top priority for the city, since the lake neighborhood is now “at risk of perennial flooding.” Still in its design phase, a cost estimate for the project was unavailable, but Banker-Hix said it’d likely be in the range of “several million dollars.”
Arroyo Grande Creek levee repair
Cost: $1.5 million and counting
Completion date: TBD
Project: The Jan. 9 storm breached the Arroyo Grande Creek levee and flooded hundreds of acres of public and private land south of Oceano. Communities in that area endured several rounds of evacuation orders—putting a fix for the levee at the top of the county priority list. While an emergency repair withstood the subsequent March storms, the levee suffered more damage, necessitating another round of temporary repairs that were completed in mid-March. Now, the county is analyzing the steps needed to further stabilize the levee and remove storm debris and sediment from the creek. “[We] don’t quite have the cost estimates yet,” county Water Resources Division Manager Courtney Howard said. “The design process has involved getting aerial surveys of the sedimentation and vegetation impacts, field visits, computer modeling of flow capacity, geotechnical borings, and levee structure alternatives analysis to determine the needed and appropriate fixes.”
Nacimiento Water Pipeline repair
Cost: $6 million to $8 million
Completion date: August/September for temporary repair, 2026 for permanent
Project: During the Jan. 9 storm, the Salinas River swelled beyond its capacity, eroding a portion of soil that was covering and protecting the Nacimiento Water Pipeline, which runs from the reservoir south to the city of SLO. Hundreds of feet of pipeline in the Atascadero area was exposed and damaged, forcing officials to shut off water deliveries to SLO. A permanent fix for the pipe will take three years to complete, but in order to restart deliveries to the city, the county is constructing a temporary, above-ground pipeline that will get water flowing again. “The repair will involve installation of about 800 feet of pipe to reconnect the broken segment of pipe located just south of Rocky Canyon Road and Halcon Road in Atascadero,” county Utilities Division Manager Nola Engelskirger said. SLO is currently relying on its other water sources, including Santa Margarita Lake and Whalerock Reservoir.
Atascadero Creek debris removal
Cost: $2 million
Completion date: End of year
Project: This winter’s storms flushed tons and tons of debris—vegetation, tree branches, trash, etc.—into creeks throughout the county. “We haven’t had major storms and runoff since, really, the ’90s,” Waddell with SLO County Public Works explained. “And then we had all the droughts. So there’s just a lot of downed trees and debris in the creek beds. We haven’t seen these types of flows and haven’t seen anything flush out all the logs and debris in a long time.” In the city of Atascadero, debris and sediment buildup has impacted the entire Atascadero Creek corridor and reduced its flow capacity. The city is currently working on a project to identify key locations along the creek—near critical infrastructure, like bridges and utility crossings—to remove debris and sediment before the next rainy season. As an initial step, the city is contracting with a consultant to provide hydraulic modeling of the entire creek channel within city limits.
Huasna Townsite Road temporary bridge
Cost: $1.5 million
Completion date: June/July
Project: Dramatic images of a collapsed Huasna Townsite Road bridge, snapped in half by raging Jan. 9 floodwaters, may have shocked locals. But SLO County officials said that the 70-year-old bridge was already vulnerable. “This [bridge] was just approved to be replaced through a Caltrans bridge replacement program last fall,” Waddell, with county Public Works, said. “We knew it was deficient. We knew it was old and needed to be replaced.” With the bridge now destroyed, the county is poised to install a temporary bridge, similar to the Chimney Rock Road bridge, in the coming weeks. “We want to get it in before the fire season,” Waddell said. He explained that the road is an important emergency access route to and from the remote Huasna Valley. As an east-west road, the bridge connects Huasna and its residents with a few large ranches and National Forest property. Similar to Chimney Rock Road, the county plans to replace the temporary bridge with a permanent bridge, but it will take a few years.
San Marcos Road landslide repair
Cost: $1.3 million
Completion date: TBD
Project: A landslide on San Marcos Road in west Atascadero wiped out 40 feet of its southbound lane and destabilized another 145 feet. The road damage is especially significant to the city, according to Deputy City Manager Lara Christensen, because San Marcos is a key thoroughfare for the west side of the city. “San Marcos Road serves as an important route to a large portion of west Atascadero, and was the only local detour route available toward Morro Bay when Highway 41 was closed due to a landslide in March,” Christensen said. “Reopening both lanes of San Marcos Road is essential, as there are a limited number of roads serving this portion of the city.” The road repair project will entail installing a 200-foot-long soldier pile wall (similar to the SLO Creek project) on the west edge of the roadway, as well as a repair of the road itself, the guardrail, and its erosion controls. The impacted area is located about a quarter mile south of its intersection with Los Altos Road, which then connects to Highway 41. Δ
Assistant Editor Peter Johnson can be reached at pjohnson@newtimesslo.com.
This article appears in Jun 8-18, 2023.