State addresses urgency to prepare roads, water systems for rising sea
Benchmark of 10 feet of rise by 2100 is called unreasonable by some cities and agencies
Guidelines for how cities and local agencies should adapt roads, railways and water systems to accommodate rising seas were unanimously approved Wednesday by the state Coastal Commission.
The 230-page document sets a controversial benchmark by urging communities to prepare for the Pacific Ocean to rise 10feet by 2100, a projection so far beyond current calculations that climate scientists haven’t yet determined the probability of it occurring. The prospect of 6 feet of rise by 2100 has been given a 1-in-200 chance of happening.
Focusing on crucial longterm public projects that require significant funding and planning, the commission’s guidance underscores the urgency to get ready for oceans overtaking existing infrastructure. It emphasizes approaches that allow the Pacific’s landward advance, encouraging relocation of facilities farther inland and discouraging the use of coastal armoring such as seawalls.
Commissioners said the document is designed to assist cities and agencies in figuring out how to take appropriate steps at a time when there is no unified vision.
“The quality has been so varied in the coastal adaptation plans we’ve seen and this will help with that,” said Commissioner Mark Gold, who is also executive director of the state’s Ocean Protection Council.
The document, titled “Critical Infrastructure at Risk: Sea Level Rise Planning Guidance for California’s Coastal Zone,” drew objections in advance of the meeting from several highprofile agencies and their representatives, including the League of California Cities, the Orange County Transportation Authority, the California Association of Sanitation Agencies, the Los Angeles County Sanitation Districts and the city of Huntington Beach.
The most prominent concern was the document’s use of the scenario of 10 feet of sea level rise by 2100, which they complained was unreasonably extreme, would force excessive costs and, in some cases, was unfeasible.
The California Association of Sanitation Agencies and Los Angeles County Sanitation Districts suggested instead using a benchmark 3.7feet of rise by 2070, the latest projection used by United Nation’s Intergovernmental Panel on Climate Change.
The U.N. projection “is very conservative already and is consistent with a future in which there are no significant global efforts to limit or reduce emissions,” wrote the Los Angeles County Sanitation Districts in a letter to the commission.
However, Coastal Commission staff pushed back on the complaint over the 10-foot rise standard, saying that current calculations haven’t taken all pertinent information into account.
“It is because the climate models used to generate the probabilities had not yet incorporated the mechanisms of extreme ice sheet melt from recent research that rise to the (10-foot) scenario,” according to the commission staff report.
Staff also noted that a more extreme level of risk should be employed for road and water infrastructure because they are typically multimillion dollar commitments built to last for decades or more, raising the specter of big consequences if they need replacement or repair. Staff said it would be much more cost effective to relocate or otherwise adapt that infrastructure in the near term than to pick up the pieces after it was too late.
Other city and agency complaints included the emphasis on relocation and the document’s disfavor with coastal seawalls, saying the commission approach could be particularly difficult in urbanized areas.
There also appeared to be concern from local jurisdictions that the guidance would be forced upon them, despite the document stating it was to be used “as interpretive guidelines, not regulations.”
Though the vast majority of the 23 letters filed with the commission were from representatives of agencies and cities opposed to aspects of the guidance, most of the public and commission discussion at Wednesday’s online meeting concerned the fact that desalination plants weren’t included among the facilities mentioned.