The effect of stormwater infiltration and surrounding built infrastructure on local groundwater dynamics: a case study for regenerative stormwater conveyances

ABSTRACT

Infiltrated stormwater from a regenerative stormwater conveyance (RSC) investigated in Knoxville, TN, was found to substantially interact with the surrounding groundwater system. The degree of interaction resulted from seasonal fluxes in water table elevation, varying weather patterns and event sizes, and most significantly, the presence of two underground sewer lines. Mounding was observed below the RSC during small to medium storm events, which shifted to a sink for areas adjacent to the conveyance during larger events. The most prominent factor influencing trends in groundwater interactions appeared to be the presence of the sewer lines. This study shows the importance of understanding how the urban subsurface infrastructure network will influence groundwater interactions in order to avoid unintended consequences or short-circuiting of treatment mechanisms. These findings inform the scientific community of potential challenges when constructing infiltration-based stormwater controls in urban environments where a high density of buried infrastructure may be present.

KEYWORDS:

• Regenerative stormwater conveyances
• stormwater control measures
• groundwater
• groundwater mounding
• buried infrastructure
• urban karst

Acknowledgments

The authors would like to acknowledge Knox County Stormwater Engineering and South Doyle Middle School for their contributions to this study. This material is based upon work supported by the Tennessee Healthy Watershed Initiative.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Jessica M. Thompson

Jessica Thompson received her PhD from the University of Tennessee, Knoxville, where she studied a regenerative stormwater conveyance, specifically focusing on three-dimensional modeling of system geometry, groundwater interactions, and water quality and quantity performance of the system.

Jon M. Hathaway

Jon Hathaway is an Associate Professor in the Department of Civil and Environmental Engineering specializing in sustainable urban water.

Edmund Perfect

Edmund Perfect is a Professor and Interim Department Head of the Department of Earth and Planetary Sciences specializing in vadose zone hydrology.

John S. Schwartz

John Schwartz is a Professor in the Department of Civil and Environmental Engineering and Director of the Tennessee Water Resources Research Center. His research interests include watershed hydrology and sediment modeling, river mechanics, ecological engineering, ecohydraulics, stream restoration, and water quality.