Caroline Griffith, NEC Executive Director
The first mention of Sea Level Rise (SLR) in EcoNews was the February 1981 issue, so readers of this publication should be well aware of the concept and local implications of this phenomenon. The article in question quotes a report by the President’s Council on Environmental Quality (Ronald Reagan had just taken office, so we can assume that this report came out of the Carter administration) which warned that if we didn’t take immediate steps to reduce our CO2 emissions we could expect a 15 foot rise in sea levels by an unspecified date. As the methodologies used to predict SLR have been honed, it has been determined that Humboldt Bay can expect to see the highest sea level rise rate on the West Coast due to a combination of rising water levels and land subsidence in and around the Bay.
In a call to action for regional decision-makers the Humboldt Grand Jury, an investigative body made up of citizens tasked with the detection and correction of flaws in government, recently released a report entitled The Sea Also Rises calling for regional collaboration to protect communities and infrastructure from rising seas. Although predictions vary, according to the report, “a two-foot increase in Humboldt Bay’s shoreline will be possible by 2050 and a three-foot rise may occur as early as 2070.” These predictions are based on the “low risk” projections from a 2018 study by the Ocean Protection Council. “High risk” projections are three feet by 2050 and around five and a half feet by 2070.
- A three-foot rise would affect local infrastructure such as:
- The only access road to King Salmon
- PG&E’s Humboldt Bay Generating Station and the interim spent nuclear fuel site
- Highway 101 as it traverses South Bay, Elk River Slough, and Arcata Bay
- Highway 255 on the Mad River Bottoms
- Approximately 12 miles of railroad and the current and future sections of the Humboldt
- Bay Trail within the Humboldt Bay Area Plan (HBAP) planning area
- Approximately 9.6 miles of municipal water transmission lines
- The Truesdale pump station, seven wastewater lift stations, and 10.5 miles of sewer lines
- 30 electrical transmission towers and 113 transmission poles
- Sections of the South and North Jetties (867 ft. and 1,214 ft. respectively)
- Three of the 10 bulk cargo/commercial docks
- Several contaminated sites, including former pulp mills (Simpson in Fairhaven, Sierra
- Pacific in Manila) and former Southern Pacific Railyard (Eureka)
- 52 Wiyot cultural sites
Although many of these affected sites are within the jurisdictions of different municipalities, the fact that they are all on Humboldt Bay and will be similarly affected by SLR necessitates a coordinated approach to the problem. As the report states, “reinforcing a shoreline dike in one section of the bay is not a solution if a neighboring dike crumbles from poor maintenance, allowing bay water to inundate the area these dikes are designed to protect.”
Collaborative, coordinated regional planning can position Humboldt County favorably to receive the state and federal funding that will be necessary to protect critical infrastructure from SLR. The report states, “it has been estimated the cost to repair or enlarge shoreline dikes could average $2 million per mile. There are 41 miles of shoreline dikes around Humboldt Bay.” The California Sea Level Rise Mitigation and Adaptation Act of 2021 mandates allocation of up to $100 million annually for SLR planning efforts statewide, which could potentially help Humboldt County manage some costs associated with SLR planning.
The report recommends that the Humboldt County Board of Supervisors, the Cities of Arcata and Eureka, and the Humboldt Bay Harbor District vote to make a commitment to prioritizing SLR adaptation and mitigation, and to direct their staff to incorporate this commitment into their planning efforts by September 30, 2022. It further recommends that they join efforts to create the Humboldt Bay SLR Steering Committee to work collaboratively to develop a regional approach.
Find the he full report of The Sea Also Rises at humboldtgov.org/DocumentCenter/View/107182/The-Sea-Also-Rises
