Concerned about increased risks of urban flooding due to climate change, UK Water Industry Research Ltd commissioned a 2002 study to quantify potential future affects of climate change on rainfall, run-off, and flooding across Great Britain. The study also assessed the costs of managing future flood risk.
The team first extracted data from global climate models, and then downscaled the data to predict impacts on a local scale. After modeling the impacts of climatic changes on urban drainage systems, researchers predicted an increasing flood risk. The models showed that localized, intense rainfall could increase up to 40% by 2080, which would double urban flood volumes and increase flood damage threefold. Of even more concern, the cost of remedial work to maintain current levels of flood risk could be up to eight times greater in certain circumstances. These results were obtained regardless of the locality or type of urban area and could likely be applicable to most drainage systems in the developed world.
A follow-up study concluded that conventional solutions to managing urban flood risk, such as increasing sewer capacity or providing additional storage, would not be sustainable in the long term. Therefore, current thinking replaces conventional approaches to flood defense with actions to improve flood resilience. This approach can be summarized as 'learning to live with floods.'
This strategy fosters innovative ideas for managing urban flooding, such as using roads and sidewalks as flood pathways and designating 'sacrificial' areas that can retain flood water temporarily during extreme events. Flood flows can be directed along routes that minimize potential property damage or threats to health and safety. Low-lying areas normally used for parking, recreation, or sports fields can provide flood storage in extreme events. Simple changes to curb heights and vegetation areas can modify roads to serve as flood channels, allowing more water to flow safely through urban areas.
Buildings in flood risk areas must be made more resilient, and improved forecasting systems will be introduced to protect the public.
Transferring Knowledge Globally
The climate change challenges facing Britain are similar to those faced by other parts of the developed world, particularly northwestern Europe and the U.S. Eastern Seaboard. In fact, municipalities across the United States have shown interest in the climate change work being done in the UK. However, whereas much of the scientific knowledge can be applied to U.S. circumstances, this transfer needs to consider different governmental, legal, and financial systems, and even different cultural norms. For knowledge transfer to succeed, a return to a 'first principles/ is often most effective. This allows stakeholders to benefit from advances in science and technology while considering the required response in the context of local needs.
One effective approach is to hold workshops in which local stakeholder groups share information and brainstorm to identify, debate, and prioritize needs. This technique helps generate enthusiasm and 'buyin' from the responsible organizations. Successful workshops of this type have been held in New York, San Francisco, Seattle, Chicago, and Broomfield, Colo.
Building on the initial enthusiasm without delay is important. Stakeholders should move quickly to establish some specific projects, develop systems for making and implementing decisions, and build their ability for effective action.
Establishing a Framework
After stakeholder workshops, logical next steps in transferring knowledge include baseline assessments, gap analyses, and setting up a methodology for prioritizing appropriate measures.
Benchmarking and gap analysis. An initial climate change preparedness assessment can help stakeholders understand best practices and compare them with their own current capabilities. This gap analysis can then be used to prioritize activities needed to achieve an organization's objectives. It also helps stakeholders compare their performance to that of similar cities, municipalities, or industries.
Assessing and prioritizing adaptation measures. Building on the gap analysis findings, the next step is to rate and prioritize all relevant risk-reduction measures. Associated multidepartmental workshops allow staff to compare notes on implementation issues and share ideas on adaptive capacity.
This is particularly important for smaller municipalities and departments, which often lose their initial enthusiasm and momentum simply because there are insufficient resources to provide support. Engaging in regular conference calls with other professionals facing similar challenges can make a substantial difference. Such 'support clubs' can also share training and research costs. Experts in climate change mitigation and adaptation, especially those who have established global knowledge-sharing facilities, can be a resource.
In summary, communities can respond to increased climate change risks by supporting incremental growth in knowledge, transferring this knowledge, using suitable tools and processes, building capacity, and seeking continual feedback and review. The results will be greater awareness of climate change risks, access to useful information resources, and the formation of an enduring collaborative network.
David Balmforth, Ph.D, a technical director with Broomfield, Colo. based MWH, works in High Wycombe, U.K. Elise DeGeorge, P.E., is an MWH business consultant.