ABSTRACT:

This data is the outcome of a research study titled as "Variations of Urban Water Balances Considering Subsurface Sewer Fluxes: A Hydrologic Modeling Study" which is currently in preparation. The study investigates the overlooked yet critical interactions between urban stormwater infiltration, subsurface soils, and buried sewer infrastructure. Using HYDRUS-2D, a series of simulations were conducted to evaluate how sewer-related water fluxes — specifically inflow and infiltration (I&I) and exfiltration—respond to variations in soil texture, groundwater table depth, pipe defect size, and trench backfill material. The analysis demonstrated that soil texture and groundwater depth significantly influence water partitioning. Fine-textured soils led to increased surface runoff and evapotranspiration, while limiting groundwater interactions and I&I. In contrast, shallow groundwater conditions significantly elevated I&I, with minimal impact on surface processes. Larger pipe defects further intensified both I&I and exfiltration. A statistical feature importance analysis reinforced the influence of groundwater depth and pipe integrity. The findings highlight the necessity of incorporating detailed subsurface interactions into urban hydrologic modeling to better inform infrastructure design and management.