Climate change risk and adaptation costs for stormwater management in California coastal parklands

ABSTRACT

Extreme precipitation from climate change may strain many existing stormwater systems. While studies have evaluated such effects on stormwater infrastructure, other sources of uncertainty not yet explored should also be considered. This paper presents an analysis of adaptation costs for new stormwater infrastructure to mitigate increases in design storm precipitation depth with climate change, including how economic and managerial uncertainty related to life cycle unit costs and knowledge of existing infrastructure affect costs. For case study areas in California, we quantify adaptation costs for new green infrastructure capacity by evaluating future design storms. Results indicate that design storm depths increase by an average of 28%, but lack of knowledge of the condition of existing infrastructure and life cycle unit costs result in wide cost ranges. The findings illustrate how climate change planning for stormwater should also consider economic and managerial uncertainty when estimating long-term adaptation costs.

KEYWORDS:

• Urban drainage
• climate change models
• non-stationarity
• risk assessment
• stormwater
• asset management

Acknowledgments

This research was supported by the California Department of Parks and Recreation. Many thanks to David Alderete in the Office of Water Programs at Sacramento State for helpful comments in reviewing prior versions of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Data availability statement

Climate change model simulation data is publicly availablefrom the Cal-Adapt (https://cal-adapt.org/) and NA-CORDEX (https://na-cordex.org/) websites. Software used to perform the analysis is included with the submission as a supplementary file. Detailed calculation spreadsheets are available from the authors by request.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the California Department of Parks and Recreation [n/a].

Notes on contributors

Erik Porse

Erik Porse is a Research Engineer at the Office of Water Programs and an Assistant Adjunct Professor at the UCLA Institute of the Environment and Sustainability.

Cristina Poindexter

Cristina Poindexter is a Research Engineer at the Office of Water Programs at Sacramento State.

Christian Carleton

Christian Carleton is an Assistant Professor in the Department of Civil Engineering at Sacramento State University.

Michael Stephens

Michael Stephens is a Senior Engineering Geologist at the California State Department of Parks and Recreation.