Planning for sea level rise

With sea level rise, it’s no longer a question of if; it’s a question of how high and how fast.

Arming coastal communities in the Tampa Bay area with practical strategies and decision-making tools to withstand the effects of sea level rise is the focus of the ONE BAY Resilient Communities Working Group. Convened by the Tampa Bay Regional Planning Council, the group brings together a broad network of planners, developers, emergency managers, floodplain managers, scientists, and decision makers, funded through a $100,000 grant from the National Oceanic and Atmospheric Administration.

“We’re not on a mission to stop sea level rise,” notes Maya Burke, senior environmental planner at the TBRPC. “We have nearly 70 years of data showing that sea level is higher in Tampa Bay now than it was in 1950, we’ve already seen change. Our goal is to make sure that the region’s infrastructure, environment and economy can adapt to changing conditions over the next 100 years.”

The first order of business for the working group is developing a baseline understanding of the issue and establishing a framework for effectively communicating potential risk, Burke notes. “This is not an end-of-days situation, but that doesn’t mean we shouldn’t be prepared to make strategic investments to protect our future.”

TBRPC is working with scientists from Florida Sea Grant, the University of South Florida, the National Weather Service, the US Army Corps of Engineers, US Geological Survey, Tampa Bay Water and the Southwest Florida Water Management District to recommend a sea level rise projection methodology that describes likely future scenarios for the Tampa Bay region.

The International Panel on Climate Change is predicting a one- to four-foot increase by 2100, but Gary Mitchum, a professor of physical oceanography at the College of Marine Science at USF and member of the science advisory panel currently developing the regional recommendation, expects that prediction to rise by 2019 when the IPCC issues its next report.

And perhaps most importantly, sea level rise will not stop in 2100, he said. “We’re just not comfortable with projecting beyond then because our models aren’t capable of going out that far.”

Cost-benefit models guide infrastructure priorities

With a consensus on the potential problem in hand, the second challenge will be developing cost-benefit models and decision-support tools for potential changes in infrastructure or building codes to minimize the impact. For instance, rebuilding the Courtney Campbell Causeway between Clearwater and Tampa would obviously be a very expensive project but models might show that losing the transportation linkage could cost the regional economy even more.

Another important goal of the working group is bringing local planners on board with adaptive planning strategies. Results of a recent survey of Tampa Bay local governments and planners by the University of Florida indicates that most do not consider sea level rise to be a serious threat.

The same survey, however, also shows that 96% of planners do believe that sea level is rising and about 70% expect to see an impact in the Tampa Bay region within the next 25 years. “The planners need additional information on actions that can be taken, models that compare costs of adaptive actions, and tools that allow them to communicate with the public and decision makers on the issues of sea level rise,” said Zhong-Ren Peng, UF professor of urban and regional planning.

A UF scenario (online at plaza.ufl.edu/dengyujun11/SLR7.0.html) shows infrastructure vulnerability at one, two and five feet. Peng is currently working on a cost-benefit analysis that would provide clear data on the costs of new infrastructure vs. the potential losses, including indirect costs.

Top objectives for the ONE BAY Resilient Communities Working Group:

  • Convene practitioners for information sharing related to sea level rise and other coastal resilience issues.
  • Create a website that inventories existing Tampa Bay-specific research, programs and decision support tools.
  • Promote a consistent, regionally appropriate sea level rise projection methodology for planning purposes and policy development.
  • Identify, develop and enhance existing decision-support tools such as GIS models, risk/vulnerability assessments, model ordinances, Best Management Practices, etc.
  • Provide technical assistance for preparedness, recovery and adaptation planning; incorporating sea level rise and other coastal hazards into comprehensive plans, land development regulations, local mitigation strategies and business continuity plans.