Resilient Stormwater Management in Allegheny County

Helping the Pittsburgh Metropolitan Region build resilience to climate change and other future challenges

Pittsburgh skyline with Point State Park and the Allegheny River

Downtown Pittsburgh

Photo by Steve Elgersma / CC BY-NC-ND 2.0

Climate change is challenging planning assumptions and standard practices in cities around the world. Climate impacts on coastal cities or water-scarce areas have been a point of focus in recent years, but inland cities in the eastern United States are also expected to face new challenges from heat waves, flooding, and degraded water quality. These urban areas will need innovative ways to withstand and adapt to any negative changes that may occur.

RAND, with support from the John D. and Catherine T. MacArthur Foundation, is helping to bring new analytical and planning capabilities into cities across the United States. Allegheny County in southwestern Pennsylvania is the first of three pilot studies identified for this project. The region, which includes the City of Pittsburgh, already faces major challenges in effectively managing its water resources. Much of its combined storm- and wastewater infrastructure, for example, needs costly upgrades in order to meet EPA water quality standards. In addition, large rainfall events and the county’s hilly topography can lead to regular flooding in many low-lying areas. These challenges could grow with climate change and future population and economic growth, complicating the billion-dollar investment decisions currently faced by local decision makers.

Findings

Goals

Allegheny County Office Building green roof

Allegheny County Office green roof

Photo by Margaret Stanley, Allegheny County Photography

The goal of this pilot study is to support improved stormwater and climate resilience planning in Allegheny County. The metropolitan region currently lacks key information about climate change and potential future vulnerability, and needs a framework to evaluate different stormwater management options and identify cost-effective solutions that are more robust to future change. This pilot study is designed to help decisionmakers identify a path forward.

Research Questions

  1. How might future stormwater runoff, water quality, and flood risk vulnerability grow with changing climate and land use?
  2. How much stormwater in the region could be captured or diverted using innovative approaches, either in current conditions or with future change?
  3. How do green infrastructure and other source reduction solutions compare with "gray" solutions in terms of benefits, costs, cost-effectiveness, and socioeconomic impact?
  4. What tradeoffs and barriers need to be resolved to implement improved stormwater management across the county?

Methods

RAND is working in close collaboration with local partners and stakeholders in a participatory planning exercise to help address the key questions described above. This process includes adapting and applying existing simulation models, running vulnerability analyses, evaluating existing strategies, and determining alternate or improved approaches to addressing vulnerabilities.

Objectives and Outcomes

Study Partners Meeting, May 2015

Study partners meeting, May 2015

Photo by Melissa Finucane

The pilot effort ran from early 2015 to June 2016. The project included multiple participatory meetings with study partners and stakeholder advisers over the course of the study. At the conclusion, researchers documented the process and emerging recommendations in a report and in briefings with partners, stakeholders, and other local audiences to widely disseminate the results across the city and county. For more information on the Allegheny County stormwater management study, please contact Linnea Warren May at Linnea_Warren_May@rand.org.