Study details areas in danger from sea level rise by mid-century, 2100

A comprehensive vulnerability report summary written for a technical advisory committee and community advisory group warns that despite local and world efforts, “climate change is already happening.”

The Climate Change Vulnerability Report Summary, based on the Benicia Climate Change Vulnerability and Risk Report, said the San Francisco Bay Area — including this city — should expect greater impacts in the years ahead.

But the report praised Benicia for its “proactive planning for the challenges of a changing climate,” specifically for assessing its vulnerability and developing an adaptation plan designed to manage risks and make the city more resilient to those impacts.

The report summary, funded by a California Coastal Conservancy Climate Ready grant, says Benicia already faces naturally occurring hazards that threaten residents, businesses and city infrastructure, such as earthquakes, storm surges, flooding, wildfires, landslides, extreme temperatures and drought.

“Some of these existing stressors are projected to be exacerbated by climate,” the summary said.

The two advisories for which the summary was written helped develop seven “aspirational” goals for Benicia, such as protecting assets that support the city’s quality of life, including its historic districts and buildings, the shoreline and its recreational features, wetlands and marshes.

Both their beauty and their functionality should be preserved, the summary said.

Another goal is to help residents and businesses that are vulnerable to climate change prepare for emergencies.

The third goal is to have the municipal government and its departments plan for climate change.

Also on the list is revising land use plans, development regulations and building codes to protect future projects from climate change; making Benicia a regional climate adaptation leader while working with other agencies; educating the public about the importance of personal disaster preparedness; and using public art to educate the public and to illustrate the effects of climate change.

The summary said the United Nations’ Intergovernmental Panel on Climate Change has indicated four climate change and greenhouse gas scenarios that are equally possible, though some predict lower emissions while others suggest emissions will increase.

“It is unknown how future policies will impact the rate of greenhouse gas emissions,” the summary conceded.

However, Benicia-specific projections were developed using the global models and publicly accessible data, and modeled after the San Francisco Bay Conservation and Development Commission’s Adapting to Rising Tides project that incorporated assessments by the National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center.

They indicate the city could experience extreme temperatures and sea level rise, the report summary said.

During the next 30 or so years, the projections say local temperatures will rise, causing the city to experience 54 to 66 days of more than 92-degree highs, rather than the 18 days residents currently experience.

By the end of the current century, Benicia may experience those temperatures 62 to 101 days a year, the summary said. Average daily temperatures will rise by several degrees, too.

The summary contends that sea levels already are rising at an accelerated rate and that coastal areas are flooding.

Using the California Ocean Protection Council and NOAA data, the summary described three scenarios that suggest sea levels would rise from 1 foot by mid-century to 5 feet as the current century draws to a close.

However, the summary noted that in some cases Benicia features already have protection, such as the wastewater treatment plant’s flood wall that wasn’t considered in the sea level rise model.

Maps in the summary show water encroachment east of Interstate 680 and onto the Benicia First Street Green as well as onto some inland areas; and in other areas in the city’s downtown, the historic Arsenal district and additional coastal places that would be vulnerable to flooding.

More extreme postulations increase the amount of downtown and Arsenal area sea level rise and flooding danger, and project the same for much more land east of I-680, to the point of crossing the highway near East Channel Road.

Researchers examined downtown commercial areas, Portside Village, Benicia Industrial Park, local schools and such municipal assets as the police station, Fire Station 11, Benicia Community Center, City Hall, Fitzgerald Field and the Benicia Marina.

Transportation along East Second and East B streets, East Fifth Street, Bayshore Road, Industrial Way and the Bay Trail also were studied, as were the Port of Benicia, the Benicia Wastewater Treatment Plant, stormwater outfalls at East Second Street and East Fifth Street, Benicia State Recreation Area and marshland near the Industrial Park and the Benicia Marina.
Pacific Gas and Electric infrastructure also was studied.

The summary said vulnerability to climate change is made up of three components — exposure, or the degree to which something is exposed to significant climate variations; sensitivity, the degree to which something is affected positively or negatively; and adaptive capacity, the ability to adjust to moderate potential damage, take advantage of opportunities or cope with consequences.

Among the risks are economic, such as to jobs, incomes, business costs, the city’s own revenue, property value and opportunities to get funding; environmental, particularly to habitat, native species, water quality and public health; and equity, or the ability for the citywide community to have equal access to services and open space.

The report summary indicated that the Benicia Marina would bear the brunt of climate change, because of its history of flooding, inadequate drainage and susceptibility to future water inundations.

The downtown area would be less vulnerable until the end of the next century. Portside Village, Rancho Benicia and Fitzgerald Field, with their histories of flooding and likely inability to handle 60-inch water level inundations, would be affected by then.

The summary projected that local schools, the police and fire stations, the community center and other municipal buildings wouldn’t be inundated, even through the end of the century.

Individual homes and businesses weren’t listed in the report.

But in a table that used 2012 dollar values, the summary predicted that between 41 to 515 homes and 50 to 402 acres could be in the sea level rise inundation zone, with an economic impact that could range from $31 million to $213 million.

Essential mechanical and electrical equipment that are vulnerable to water and salt often are installed below grade or on the ground floor, the summary noted, and the buildings themselves are made of water and heat-sensitive materials such as wood and plaster.

Certain people also would be affected more than others, including children, the elderly, those without vehicles, those with preexisting medical needs, renters and the poor.

Climate change also could impact informal community and business networks. Insurance rates may rise, the report summary said.

Benicia can adapt to some of these impacts with backup fire and police stations, a plan to preserve worker safety that includes providing additional breaks, shutting down equipment threatened by temperature or flooding and establishing cooling centers and shelters.

Benicia’s commerce could be affected because people may decide not to patronize stores on hot days unless they are seeking air-conditioned businesses where they can be cooled, the summary said.

Stores themselves may lose inventory as well as patronage to high temperatures, and reduced sales and property tax in turn would reduce the city’s revenues.

Companies and residents might move, too, the report said.

Increased temperatures may increase air pollution that could affect all residents, especially the young, old and those with cardiopulmonary problems. Heat stroke and heat cramps also are likely to increase.

Public health could be affected by increases in such infectious diseases as Lyme disease and Valley fever, and from molds in buildings.

Should Fitzgerald Field be flooded, residents would be unable to play on the ballfield. Should schools be closed, parents would see their child care costs rise, the summary contends.

Increased flooding also would damage or destroy personal belongings, from personal data to family heirlooms, the summary said.

Transportation also would be impacted, from local, state and interstate roadways to recreational trails, bus routes and railroads.

East Second Street at East B Street already floods, as does East Fifth Street and the Bay Trail. A 12-inch water level daily inundation that could be occurring at mid-century would further impact the Bay Trail.

Those roads, the Bayshore Road, Industrial Way and the Union Pacific Railroad would be affected by a 24-inch water level daily inundation that could take place between 2050 and the end of the century, as well as a 60-inch total water level daily inundation expected by the end of the century.

Roadways at grade are susceptible to flooding, and such equipment as traffic signals may be affected by saltwater flooding.

Asphalt road tops may soften and become rutted in extreme temperatures, and if roads are closed, emergency responders or evacuees would be unable to use them. Though some traffic can take different routes, travel to certain places depends on specific thoroughfares.

Better coordination would be needed among agencies that allocate money and plan for road repairs and improvements, and between transportation agencies and nearby property owners.

Some road repairs, such as overlays, have fairly short lifespans, but they are less expensive than more-intensive approaches that would be less susceptible to climate change. More maintenance is likely to be needed in the future.

Road workers would be vulnerable to increased heat, and may need more breaks to remain cool, the study said.

Those composing the study looked at the Port of Benicia, which is operated by AMPORTS, though the city owns the underlying land. The AMPORTS lease ends in 2032.

The port sees the arrival of such imports as automobiles; one major export is Valero Benicia Refinery’s products.

While the port is protected by levees, the summary said Sulphur Springs Creek may flood its property. Climate change could affect mechanical equipment, paving, shoreline protection, backup power and sump pumps, it added.

Port neighbors, including the refinery and Union Pacific Railroad, would need to work with the port to address flooding, and the city also will need to be involved since the land is leased from the municipality.

However, the port has additional storage areas that could be used should flooding occur in its standard storage areas, and the port has protocols to manage flooding.

On the other hand, sea level rise, storm surge or high temperatures may lead to loss of business, higher operating costs and temporary closures, the document said.

The city’s wastewater treatment plant’s flood walls should protect the structure through the mid-century, but water going up East Fifth Street could circumnavigate the walls by the end of the century or during extreme storms, the summary said.

Some equipment is sensitive to flooding, but existing pumps give the plant the capacity to remove the water now. That may change in the future, the summary said, and the treatment plant’s outfall system may not operate properly as sea levels rise.

Other operations have little backup redundancy, and aging sewer pipes could reduce the system’s capacity.

Benicia has committed to monitoring sea level rise and has plans to adapt, reducing the treatment plant’s vulnerability.

The city contracts with multiple companies to assure availability of treatment chemicals. But there is little available land for any expansion, the report summary noted.

The city’s stormwater drainage system is supposed to minimize flooding from runoff that doesn’t seep into the ground.

While precipitation also directly causes flooding, the summary dealt only with sea level rise and stormwater outfalls that send the extra water into Carquinez Strait and the bay.

Even so, it said extreme rainfalls may occur a little more frequently with climate change.

Temperature changes aren’t as likely to impact city storm drains, but the outfalls at East Second and East Fifth streets may be permanently submerged by mid-century. Gravity-fed outfalls won’t operate when submerged, causing flooding up the line, and erosion may undermine the outfalls, too.

Benicia’s most recent stormwater management plan, adopted in 2003, ran through 2008. Its update may not be finished for three years.

The summary said some information, such as the cross connections between storm and sewer lines, weren’t available, and other information wasn’t detailed enough for site-specific assessments.

But flooding cleanup and repairs to buildings and landscapes would be expensive and could result in the loss of business or productivity, it said.

Storm drain flooding could impede emergency responses, cause increased breeding for disease-carrying insects and spreading contaminants.

Marshes, such as those at the State Recreation Area, the Industrial Park, near the marina and along Waterfront Park, provide flood protection, wave energy dissipation, water filtration and carbon sequestration as well as other ecological benefits.

They won’t keep up with sea level rise on their own, though, so those habitats are expected to change, the summary said. In fact, the document anticipated “an extreme loss of marsh areas” by century’s end.

City and state agencies will need to work together to respond to those impacts, and there isn’t enough money to plan or put in place any large-scale approaches. Nature’s ability to “self-repair” would be outpaced by anticipated changes in temperature and sea levels, the summary said.

That would mean a loss of the protection the marshy shorelines provide, as well as reduced recreation, aesthetics, wildlife habitat and environmental quality.

Economically, shoreline changes would impact the Benicia Marina and the Industrial Park.

Pacific Gas and Electric’s transmission lines are used to deliver power, even to customers whose accounts have been transferred to Marin Clean Energy.

The summary said PG&E employees know the risks of climate change and are conducting their own vulnerability assessments. The city of Benicia is working with the utility to formulate an appropriate response. The summary noted that PG&E’s concerns about sharing information publicly limited how much it could report.

Increased temperatures would create more energy demand, and emergency operations may need updating, the summary said. PG&E, MCE and the city of Benicia eventually must share information to respond to vulnerabilities, it said, because loss of power and sustained outages would reduce workplace and school productivity, and telecommunications components and pumps could be forced out of service unless backup power is available.

However, the report noted that the electrical grid “is highly redundant,” and loss of any one particular substation is unlikely to have an impact on the city of Benicia.”

Now that the summary has been released, its developers and the city of Benicia expect to collaborate with others to confirm the vulnerabilities identified in the document.

Once that is done, the information will be used to develop adaptation strategies, such as physical changes, management changes, information gathering and monitoring to increase resiliency to climate change.

A copy of the summary is available on the city’s website by CLICKING HERE.