Researchers Link Climate Change to Urban and Suburban Stormwater Management: “What we design now is in place for 20 or 30 years, so we should design it with future climate conditions in mind as opposed to what the past rain has looked like,” said Dr. Mitchell Pavao-Zuckerman, University of Maryland

Note to Readers:

Stormwater green infrastructure (GI) practices are implemented in urban watersheds to control stormwater runoff, reduce pollution, and adapt to climate change. This study evaluated the robustness of a watershed with stormwater GI and a watershed with traditional stormwater controls in Clarksburg, Maryland, to future climate change.

The USDA Soil and Water Assessment Tool (SWAT) was calibrated to USGS daily streamflow data from 2011 to 2016 to evaluate watershed-scale daily and seasonal runoff responses to multiple future climate and management scenarios. 

Assessing Watershed-Scale Stormwater Green Infrastructure Response to Climate Change in Clarksburg, Maryland

University of Maryland researchers are connecting climate change to urban and suburban stormwater management, with the ultimate goal of increasing resiliency to major storm events. With models not only predicting more rain, but an increased frequency of particularly intense and destructive storms, flooding is a major concern in communities that are becoming more settled with more asphalt.

In a new case study published in the Journal of Water Resources Planning and Management, researchers examine two distinct watersheds and demonstrate that even small decentralized stormwater management practices like rain gardens can make a big cumulative difference to the resiliency of a watershed, using predictive modeling to assess what climate change will demand of our future stormwater management systems.

“What we design now is in place for 20 or 30 years, so we should design it with future climate conditions in mind as opposed to what the past rain has looked like,” explains Dr. Mitchell Pavao-Zuckerman, assistant professor in Environmental Science & Technology. “This work puts emphasis on what’s happening in local upland spaces that has immediate implications for the people who are living in these watersheds for future flood mitigation, but connects this to the broader issues of how increased runoff links to the health of the Chesapeake Bay.

Research Findings

Ultimately, Mitchell Pavao-Zuckerman and Emma Giese found that the watershed with more green infrastructure was able to buffer and absorb more of the increased rainfall than the more traditionally designed watershed with larger stormwater basins. However, with larger or more intense rain events, both systems failed to handle the amount of rain successfully.

  • The stormwater GI watershed had less runoff than the traditional management watershed in climate change scenarios for most days with rainfall (>98%>98% of days). However, the climate change scenarios resulted in increased seasonal fall and winter runoff compared to current conditions in both watersheds.
  • Simulated expansion of GI implementation reduced runoff in both watersheds under future climate scenarios. This study assesses climate robustness of existing stormwater GI at a watershed scale and confirms previous evaluations of hypothetical stormwater GI effectiveness for adapting watersheds to climate change.

“Our work allows us to see what the added return on investment in these different climate and stormwater management scenarios might be,” says Mitchell Pavao-Zuckerman. “It’s more concrete than just saying more green infrastructure is better, which isn’t practical and might have a cost-benefit trade off.”

To Learn More:

To read a synopsis of the research report, download a copy of Researchers Link Climate Change to Urban and Suburban Stormwater Management

Or, download the author copy of accepted manuscript.

Then visit Mitchell Pavao-Zuckerman’s website: https://pavaozuckerman.wordpress.com/publications/

Journal reference:

Giese, E. et al. (2019) Assessing Watershed-Scale Stormwater Green Infrastructure Response to Climate Change in Clarksburg, Maryland. Journal of Water Resources Planning and Managementdoi.org/10.1061/9780784479018

(A) Three study watersheds in Clarksburg, Maryland: Soper Branch (forested control), Tributary 104 (study watershed with LID), and Crystal Rock (urban control). (B) Inset showing locations of 73 infiltration-focused stormwater facilities in Tributary 104 and their types