Climate Change Adaptation of Urban Stormwater Infrastructure

Project summary:

This project transfers coupled-climate model projections to stormwater infrastructure in a form understandable to planners, resource managers, and decision makers. The study models capacities required for the infrastructure to convey peak flows from projected mid-21st century climate-changed precipitation and population growth, and the potential for green stormwater infrastructure methods to provide more economical and effective management of peak flows than drainage-system upsizing.

The adaptation plan generated from the technical analyses incorporates procedures to manage residual uncertainty in coupled-climate model output and downscaling. These include 1) providing sensitivity analyses of the incremental cost of oversizing components to provide a safety margin for possible underestimated climate-change impacts, 2) prioritizing the upgrade schedule based on a simple risk analysis of the extent of undersizing and flood damage at each component, and 3) incorporating adaptation methods including an increase of storage, expanded storm-sewer size, the addition of infiltration practices, and increased evapotranspiration. The choice of adaptation methods optimizes the cost-effectiveness of adaptation. Outreach on the solutions for the three communities show the best means of adapting to climate change and describe the framework for such an analysis in other communities.