The construction of a tourist attraction at the harbor showcasing Crescent City’s relationship to tsunamis is far off, but the port’s CEO told harbor commissioners on Tuesday there will likely be new guidelines in 2019 that could affect the facility’s construction.
In addition to housing exhibits, including a 3D/4D theater, devoted to tsunamis, The Tsunami Experience, or Northcoast Tsunami Center, will provide a safe place for people in and around the harbor to evacuate to if an actual tidal wave occurs, according to Harbormaster Charlie Helms.
Proposed for the corner of U.S. 101 and Citizens Dock Road, the three-story structure will serve as a vertical evacuation center, allowing people to shelter-in-place during a tsunami, Helms said.
On Tuesday, Helms said after speaking with Rick Wilson, a senior engineering geologist with the California Geological Survey, and Kevin Miller, of the California Office of Emergency Services, he found out that the facility’s third floor should be 40 feet above ground level.
“Under the new building guidelines for 2019, which we have to comply with, it’s got to meet a 2,475 year projected tsunami level,” Helms told commissioners.
On Wednesday, Helms said he’s not as alarmed as he was when he first heard the news. The Tsunami Experience was always planned to be on stilts, at least 20 feet above ground level, putting the third story at least 35 feet in the air, he said.
If approved by the California Building Standards Commission, the new building code that takes into account a 2,475-year tsunami would only apply to critical facilities, Wilson said. These include hospitals, emergency operations centers, toxic material storage facilities and vertical evacuation structures, he said.
A 2,475-year tsunami is a tsunami inundation level that has a 2 percent chance of happening in 50 years, Wilson said. He described it as a “very, very low potential event” and said that standard is already mentioned in the International Building Code.
“It doesn’t really compare to an event that we’ve had recently,” Wilson said trying to explain what a 2,475-year tsunami may look like. “We haven’t seen an event that would reach this level in historic times in California, but we also haven’t had a large Cascadia Subduction Zone (earthquake). The last one was in 1700.”
The 2,475-year tsunami standard is also based on data collected through prehistoric sediment deposits that show that within the last 10,000 years there have been 19 Cascadia events, Wilson said. He noted that the inundation and evacuation maps for the North Coast, designed for a Cascadia event, would still apply despite a potential change in the building code.
“The key is that these are for building codes of very critical facilities, so the standards are set fairly high and in this particular case it would be quite a large structure that would have to be designed to probably withstand that,” Wilson said, referring to a Cascadia tsunami. “Preliminary maps identify that the flood could be over 30 feet at the harbor itself, so it would have to be quite a large structure for vertical evacuation.”
According to Helms, The Tsunami Experience will be a concrete elevated structure set on stilts allowing the inflow and outflow of a tsunami, including any debris, to wash past it. The cost estimate to build the facility is between $6 million and $8 million, he said.
Helms noted that such a structure has never been built. He estimated the cost will be $250 per square-foot and that the second and third floors will each be about 20,000 square feet. The building will also have to meet special roof requirements as well since a heliport is planned to assist in evacuations, Helms said.
In a report to the harbor commissioners, Helms said there are about 347 hotel rooms, 299 RV spaces, eight tent camping sites and 500 crew members working on commercial fishing vessels that may seek shelter at the vertical evacuation center during a tsunami evacuation.
Some of the environmental permitting work has been done for the Tsunami Experience, Helms said. The harbor is using some of the California Environmental Quality Act documents and studies for an interagency visitor center that had been planned at that location, Helms said. But he said he’s still looking for money.
“I’m still hunting for money and I don’t have many takers yet,” he said Wednesday.
In other matters, three harbor commissioners took up discussion about the debt situation again. Commissioners Ron Phillips and Jim Ramsey were absent.
Commissioner Brian Stone said the Del Norte Commercial Fisherman’s Marketing Association and representatives of the Save the Harbor 2018 campaign have begun collecting signatures for a citizens initiative to increase the transient occupancy tax in the county.
Stone’s colleague, Wes White said a rumor that if proponents of Save the Harbor 2018 collect between 3,000 and 3,500 signatures the Del Norte County Board of Supervisors would be forced to pass the citizens initiative without it going on the ballot was false. If the citizens initiative goes before the board of supervisors, they can either ask for more information or approve it to go on the November ballot, White said.
“If, however, the harbor commission decided they wanted to take it to the supervisors, we could do that, but it would no longer be a citizens initiative and there will be no question that it will require a 2/3rds vote,” White said.
White asked that the full harbor commission take a vote on supporting the citizens initiative at a future meeting.
In a previous interview with the Triplicate, Bob Black, the harbor’s legal counsel, said it may be up to the county counsel’s office or the board of supervisors to decide whether a citizens initiative would be successful with a simple majority or a 2/3rds majority vote.
On Tuesday, Stone said the county counsel’s office has yet to make a decision on whether the citizens initiative would require a 2/3rds majority vote to pass.
“They’re still waiting to make a determination,” he said. “I think what they’re doing is waiting to see whether or not the citizens initiative pans out and whether they can reach the (signatures) they need to.”
Proponents of Save the Harbor 2018 must collect 704 signatures and bring the measure before the board of supervisors to be placed on the November ballot by June 28.
Reach Jessica Cejnar at email@example.com .