How can already existing plans for urban and rural hazards be used cohesively to build a picture of multi-hazard areas, and improve community resilience to climate change and other disasters?
What more is needed to prepare us effectively in multi-hazard areas, using a more integrated approach, especially as the risk of climate change increases?
An insightful presentation by an internationally recognised urban planner Laurie Johnson (who has spent time working with national and local agencies in New Zealand) was delivered virtually on 2 June to kiwi-based planners. It paved the way for strategies through which Aotearoa New Zealand might better approach climate change, including implementation of tough plans like resettlement.
The special virtual event combined the experience of multiple experts around the world, and was supported by the EQC.
Laurie began with a case study of the town of Portola Valley, south of San Francisco. The San Andreas fault passes directly through the valley. The area is the home of the “titans of Silicon Valley,” says Laurie. In the 1960s, geologists mapped the town, and translated that into a risk-based ground movement potential map. Land uses and the permissible amount of development on a site were then defined by the ground movement categories thus created. Then, the town employed a geologist and established a geologic safety committee that review all development applications in geologically vulnerable areas.
“This was not just for buildings,” says Laurie, “but for roading and infrastructure. The effect was to move development back from the most difficult geological areas.”
Open space that was most hazardous was then purchased by a ‘regional open space district’ established by the citizens of the area.
“In summary, the collaboration that went on in Portola Valley has since been used as a model for seismic hazard management across California,” says Laurie. Setting back from active faults was translated into a state act, adopted after the Los Angeles area suffered a major earthquake in 1971. In 1989, when another major earthquake struck, this time in Northern California, the state adopted similar legislation to address other seismic hazards – liquefaction and landslides.
“Now the state is adding tsunami to the list of hazards that it maps,” says Laurie. All mapping is done centrally by California’s Geological Survey. Councils are required to use it, and the regulatory zones trigger geologic investigations when development is proposed.
While there are mapping gaps, she says, largely because of budget constraints and time delays, the effort is continuing.
“The concept of state mapping has continued with fire mapping,” she added. CalFire, the state’s forestry and fire protection service, provides the lead with mapping of high fire hazard severity zones.
“These are not just mapping; they’re a regulatory tool,” she says.
“Safety is a foundational element of local planning in the state,” says Laurie.
The safety element is one of seven required elements in all city and county general plans in the state —akin to district plans in New Zealand. Originally the safety element only had to address seismic hazards, but over time, the hazards that must be addressed in a safety element were expanded to consider flooding, fires, climate adaptation and resiliency. The state now requires that there is policy and strategy consistency across the entire general plan. This helps ensure that safety related policies are reflected in land use, transportation and housing strategies as well.
Laurie also described an holistic approach to thinking about community resilience planning. It includes policies and programmes that address risk reduction (reducing risk exposures, sensitivities and consequences). It also includes policies that increase adaptive capacity, such as to moderate potential damages, to take advantage of opportunities, or to cope with hazard and disaster consequences.
Strategies to reduce risk exposures included prohibiting development in the most hazardous areas.
“We have to think multi-hazard,” she says. “More prohibitive development policies are most appropriate in areas where multiple hazards overlay one another, such as areas prone to flooding and liquefaction, or landslides and wildland fire.”
“In San Francisco, we have a major problem with our sea wall which really stabilises the city’s waterfront. It’s vulnerable to seismic events as well as floods. A collapse of the seawall could result in major flooding of San Francisco’s downtown area,” says Laurie. “The Port of San Francisco has used a multi-hazard risk assessment to coalesce agencies into supporting action.”
She likewise advocated planning to reduce sensitivity of areas to hazards over time, citing the City of Santa Rosa, which experienced major wildfires in 2017 and 2020.
“The city is currently updating its general plan and considering policies that will enhance safety in high fire risk areas and limit future growth in these areas,” she says.
Plans, policies and strategies need to talk to one another too. Consistency is a key, she says, across all documents and thinking, and it behoves planning authorities to ensure this. A long time-horizon is also vital especially in addressing disaster-related risks.
“Mapping and using the best available science are an absolute must, including high resolution maps and making them widely available to people,” she says. “For instance, the San Francisco Bay Conservation and Development Commission have created online tools that look at current and future flooding scenarios and conditions, even king tides. People can view these and see the impacts of sea level rise along with storm surge likely in the future.”
Another aspect of major consideration is identifying vulnerable communities and developing equitable resilience strategies for these communities.
Laurie studied potential long-term recovery challenges which local communities could face after a magnitude 7 earthquake on the Hayward Fault east of San Francisco. She identified areas with the highest concentration of potential earthquake damage and areas with populations with high social and economic vulnerabilities, to identify communities most at risk of long-term disaster-related population displacement.
“These are areas where we need to invest more in resilience planning ahead of time,” she says.
In the end, says Laurie, if disaster strikes, communities with up-to-date plans and resilient rebuilding policies generally recover faster than those without. These includes policies and implementation plans for difficult planning challenges like managed retreat and community relocation and resettlement.
“How are you going to deal with managed retreat when disaster strikes? How will you implement this?” she asks. “How do you actually retreat, giving up land rights? Where will folks go? And who pays?”
There are social and economic risks that have to be weighed in any implementation, she stresses.
“It’s not purely about the hazard science,” she adds.
Getting communities on board ahead of time is vital if the interlinked plans and policies are to be successful.
“The more impact a disaster has, the more change that’s going to result from the policies and plans involved with it,” she says. “And therefore, the more intensive our levels of engagement with communities must be – ahead of time, right now.”
Laurie ends with reflection on the style of governance and community engagement that’s needed. It’s not directive, she says. It’s more informative, facilitating, suggesting ways of thinking about the future.
“Yes,” she finishes. “It’s an exciting time for planning. But it’s also a daunting time.”
Planners must rise to the challenge.
