In his first update to the City Council since the initial storm on Dec. 31, Shikada suggested that staff was somewhat surprised by the magnitude of the downpour. The day before the storm, the National Oceanic and Atmospheric Administration had predicted that the region would receive about 2 inches of rain. When the storm arrived, it dumped about 6 inches in observed rainfall, he said.
The tripled rainfall, he added, resulted in a tenfold increase in anticipated flow at the volatile San Francisquito Creek, which saw its flow rate peak at 6,300 cubic feet per second (cfs) on Dec. 31, well above the predicted peak of 600 cfs, he said. And while the water level quickly subsided, the storm caused some flooding on local streets and at properties near the creek.
City crews mobilized to deal with the damage and prepare for the next wave of storms. Public Works crews delivered materials for about 100,000 sandbags, Shikada said. City workers also cleared fallen trees from roadways and removed debris from creeks and storm drains. At one point, city workers were asked to clear out mud from the storm drain system to allow the California Department of Transportation to reopen El Camino Real after flooding.
"We had staff working around the clock really to deal with issues of storm drain clearance," Shikada said.
The city's tree crews were also busy over the week since Dec. 31, with reports of about 50 tree-related emergency calls, eight of which involved trees causing impacts to power lines. Crews removed about 150 tons of wood and tree debris over the course of the storm, he said. City workers were also monitoring and restoring damaged trails, including at Los Trancos Trail at Foothills Nature Preserve.
In many cases, trees contributed to significant power outages. In one case, a tree that fell on Embarcadero Road took out a power pole; in several others, they hit power lines. Overall, Shikada reported 20 outages between Dec. 31 and Jan. 9, with about 5,800 customers losing power.
The problem extended into Jan. 10, with about 4,500 customers in south Palo Alto losing power, an outage that the city attributed to a lightning strike and a tree falling on power lines. Utility crews restored power to most customers by just before 4 a.m., according to utilities. Another storm-related outage affected 54 customers in the Duveneck/St. Francis neighborhood, according to Palo Alto Utilities. Power was restored by 9:39 a.m., the department announced on Twitter.
Shikada said the city had received 13 reports of damaged homes as a result of the storms. Building staff have been following up to assess damages and work with local hotels to provide emergency accommodations, he said. City staff also opened a Community Resource Center in a room at Rinconada Library to provide shelter for residents in need of shelter. The center received 15 visitors, Shikada said, with seven staying overnight.
The flooding, he said, could have been far worse if not for recent improvements to the city's pump stations, which allowed the city to pump water back into creeks. New pump stations at the San Francisquito Creek and at Matadero Creek were completed in 2009 and 2019, respectively. The city had also upgraded storm drains at Channing and Lincoln avenues.
These improvements, he said, effectively doubled the city's pumping capacity to draw stormwater out of Palo Alto proper.
"That increase in capacity we believe did have a significant impact in reducing the extent of flooding when the creek did overtop over the last week-and-a-half," Shikada said. "As such, it was really the city's storm drain system that reduced the impact of the creek itself overtopping into Palo Alto."
He also called out the recent work by the San Francisquito Creek Joint Powers Authority, which in 2018 completed its first major flood-control project. That effort included widening the channel and modifying levees in the vulnerable downstream area between U.S. Highway 101 and the Baylands. The creek authority is also slated to replace the Pope-Chaucer Bridge and widen the channel in the flood-prone areas at Palo Alto, Menlo Park and East Palo Alto as part of its "Reach 2" project. That work cannot proceed, however, until Palo Alto replaces the Newell Road Bridge further downstream, a long-delayed project that the city is hoping to kick off later this year.
Council member Pat Burt, who represents the city on the creek authority's board of directors, said the benefits of the downstream work became evident during recent storms. In the massive 1998 storm, water pooled in the area around U.S. Highway 101 and West Bayshore and East Bayshore roads, creating a giant lake. Overflows from the creek went down into the area and made the lake grow. That did not happen this time around, Burt noted.
"That lake didn't exist this time because all of that choke point went away," he said. "We still badly need to do those Reach 2 elements to give us the full protection, but we have already received significant protection as a result of the downstream measures. And that's something I don't think we've conveyed to the community well enough, but it really matters."
The recent storms have spurred some residents in the flood-control neighborhoods of Crescent Park and Duveneck/St. Francis to push the city to move ahead with the bridge-replacement work as soon as possible. Hamilton Hitchings, who lives in Duveneck/St. Francis, said he had walked past two houses that were made uninhabitable by the Dec. 31 flood.
When it comes to Newell Road Bridge replacement, he urged the city to "expedite the permitting, put the construction project out to bid and start construction this year." If the city opts to wait for outside funding to help with the project, construction costs will only escalate further, he argued.
"Replacement bridge will restore the natural flow of the creek and significantly increase capacity," Hitchings said.