About

Lauren McPhillips is an Associate Professor in the Department of Civil and Environmental Engineering and Agricultural and Biological Engineering at Penn State University. Her research focuses on Water Resources Engineering, with particular interests in water quality, stormwater management, green infrastructure, urban ecohydrology, and biogeochemistry. She has contributed to understanding streamflow dynamics in urbanizing watersheds, the impacts of climate change on coastal infrastructure, and the development of sustainable stormwater management practices. Her work emphasizes resilience and sustainability in water systems, integrating interdisciplinary approaches to address environmental challenges related to urbanization, climate change, and infrastructure adaptation.

Research topics

• Computer Science
• Environmental science
• Sociology
• Ecology
• Political Science
• Environmental planning
• Geography
• Environmental resource management
• Demography
• Business
• Economics
• Cartography
• Psychology
• Economic growth

Selected publications

• Streamflow Dynamics Across an Urbanizing Karst Watershed in the Ridge and Valley Province

  Water Resources Research · 2026-02-01

  articleOpen access

  Abstract Effective freshwater management depends on understanding how human activities and geological processes influence streamflow dynamics. Urbanization disrupts natural hydrological processes, altering both stormflow and baseflow. Karst watersheds, characterized by complex and heterogeneous surface‐groundwater interactions, pose unique challenges for predicting the impacts of urban development on streamflow. This study investigates how urbanization and karst groundwater interactions influence streamflow variability in a mixed land‐use watershed within the Ridge and Valley Province of central Pennsylvania. We analyzed 24 years (2000–2024) of streamflow data from 14 monitoring stations spanning gradients in urbanization (10%–90% developed land) and karst geology. Streamflow metrics including flow duration curves, baseflow index, Richards‐Baker flashiness index, master recession curve slopes, and low‐flow trends, were used to assess land use and groundwater controls. Urbanization increased stream flashiness, steepened recession rates, and decreased the proportion of base flow. Streams with the highest levels of development exhibited most sensitivity to further increases in urban land cover. In contrast, streams with substantial groundwater inputs exhibited more stable baseflows and were less sensitive to drought conditions. Stormwater infiltration and wastewater recycling supported low‐flow regimes, partially offsetting development effects, whereas recent growth combined with groundwater withdrawals led to reduced low flows in some areas. These findings highlight the need to account for hydrological complexity and groundwater recharge when managing water resources in increasingly urbanized karst watersheds.

  PublisherOA PDFDOI

• Scaling Nature‐Based Solutions for Fluvial Floods: A Worldwide Systematic Review

  Wiley Interdisciplinary Reviews Water · 2025-03-01 · 10 citations

  articleOpen access

  ABSTRACT Despite increased understanding and adoption of nature‐based solutions (NBSs) within urban and coastal areas, large‐scale NBS for fluvial flood mitigation remain challenging to study and implement. A stronger evidence base is needed to identify critical research gaps and to best inform the design and deployment of NBS on the watershed scale. We synthesize evidence of the performance and co‐benefits of NBS for fluvial flood mitigation based on a systematic review of 131 peer‐reviewed papers worldwide, developing an Ecosystem Focus Type (EFT) to compare flood mitigation across large‐scale NBS. While we find that NBS can mitigate fluvial floods across all EFTs, our study also highlights that inconsistencies in measurement methods, a dearth of empirical case studies, and large variability in reported values limit generalization and comparison across NBS. Co‐benefits for fluvial flood NBS are numerous, but few are quantified, and study methods vary with regard to specific NBS. Social benefits of NBS, including benefits to communities most in need of support, are infrequently part of these studies. There is a clear need to develop common design and performance standards for large‐scale NBS and for guidance on which measures are key to consider and monitor for flood mitigation and co‐benefits. The success of large‐scale NBS for fluvial flood mitigation will depend on research and practice guided by transdisciplinary systems thinking approaches that can deliver evidence‐based, community‐driven outcomes.

  PublisherOA PDFDOI

• Internal Water Storage as a Means of Improving Nitrogen Retention and Reducing Greenhouse Gas Emission in Stormwater Treatment

  ACS ES&T Water · 2025-02-27

  articleSenior authorCorresponding

  Internal water storage (IWS) is gaining interest as a design element in stormwater control measures. It is implemented via an upturned elbow or elevated underdrain to create a subsurface storage zone with saturated conditions conducive to nitrogen removal via denitrification. However, IWS can potentially alter emissions of microbially produced greenhouse gases due to changes in subsurface redox conditions. These greenhouse gases include carbon dioxide, methane, and nitrous oxide. We investigated these biogeochemical dynamics using mesocosms mimicking free draining, IWS, and fully saturated stormwater treatment basins. In a series of simulated storm events, we quantified nitrogen removal, dissolved gas concentrations in the outflow, and surface soil emissions of greenhouse gases. IWS and fully saturated mesocosms had the best nitrate reduction, although fully saturated mesocosms exported other forms of nitrogen. Regarding greenhouse gas emissions, fully saturated mesocosms had the highest methane concentrations in outflow water and higher overall greenhouse gas fluxes from the soil surface compared with IWS. Free draining mesocosms sometimes had significantly higher nitrous oxide emissions, particularly after induced drought periods. These results suggest that stormwater basins with IWS have the potential to enhance nitrogen removal while minimizing biological greenhouse gas emissions compared with other stormwater basin drainage configurations.

  PublisherDOI

• Understanding and managing impacts of solar farms on landscape hydrology: insights from field monitoring and modeling 

  2025-03-14

  preprintOpen access

  The rapid growth of large-scale ground-mounted photovoltaic solar panel installations, commonly known as 'solar farms,' has raised concerns about their impact on hydrologic processes and the need for appropriate management practices. Literature review shows a lack of comprehensive field and modeling research on the hydrological impacts of solar farms, and guidance for stormwater management on solar farms varies substantially across the region and US. We have conducted Modeling and field investigation on soil moisture patterns, runoff generation, and solar radiation at two solar farms in central Pennsylvania, USA that are representative of the complex terrain in the region (e.g., high or variable slopes). Soil moisture monitoring and vegetation surveying has occurred at several key locations relative to the panels. Solar radiation has been collected under the panels to understand changes in evapotranspiration. Both solar farms included engineered infiltration basins or trenches, which were instrumented with water level or soil moisture sensors, allowing us to understand the efficacy of these structural stormwater management features in managing runoff in these sites. We have also developed a modelling framework to represent the unique hydrology of solar farms. We are leveraging a freely available, new tool called OpenHydroQual, since this model allows us to represent unsaturated flow in soil. The observed soil moisture data from the solar farm has been used for calibration and validation of the model at one solar farm site. Additional scenarios are in progress to evaluate changes in runoff compared to pre-development conditions, along with selected design storm scenarios, and selected land management scenarios.

  PublisherDOI

• Controls From Above and Below: Snow, Soil, and Steepness Drive Diverging Trends of Subsurface Water and Streamflow Dynamics

  Hydrological Processes · 2025-04-01 · 7 citations

  articleOpen access

  ABSTRACT The importance of subsurface water dynamics, such as water storage and flow partitioning, is well recognised. Yet, our understanding of their drivers and links to streamflow generation has remained elusive, especially in small headwater streams that are often data‐limited but crucial for downstream water quantity and quality. Large‐scale analyses have focused on streamflow characteristics across rivers with varying drainage areas, often overlooking the subsurface water dynamics that shape streamflow behaviour. Here we ask the question: What are the climate and landscape characteristics that regulate subsurface dynamic storage, flow path partitioning, and dynamics of streamflow generation in headwater streams? To answer this question, we used streamflow data and a widely‐used hydrological model (HBV) for 15 headwater catchments across the contiguous United States. Results show that climate characteristics such as aridity and precipitation phase (snow or rain) and land attributes such as topography and soil texture are key drivers of streamflow generation dynamics. In particular, steeper slopes generally promoted more streamflow, regardless of aridity. Streams in flat, rainy sites (< 30% precipitation as snow) with finer soils exhibited flashier regimes than those in snowy sites (> 30% precipitation as snow) or sites with coarse soils and deeper flow paths. In snowy sites, less weathered, thinner soils promoted shallower flow paths such that discharge was more sensitive to changes in storage, but snow dampened streamflow flashiness overall. Results here indicate that land characteristics such as steepness and soil texture modify subsurface water storage and shallow and deep flow partitioning, ultimately regulating streamflow response to climate forcing. As climate change increases uncertainty in water availability, understanding the interacting climate and landscape features that regulate streamflow will be essential to predict hydrological shifts in headwater catchments and improve water resources management.

  PublisherOA PDFDOI

• Soil moisture, electrical conductivity, and soil temperature for two stormwater basins with different levels of salt inputs in Lancaster, Pennsylvania

  Zenodo (CERN European Organization for Nuclear Research) · 2025-12-22

  datasetOpen accessSenior author

  This dataset contains measurements of soil moisture, electrical conductivity, and soil temperature collected from two stormwater bioinfiltration basins in Lancaster, Pennsylvania, between January 2022 and May 2023. The two basins were selected to represent contrasting levels of road salt inputs during winter maintenance activities, allowing for comparison of soil hydrologic and salinity dynamics under different salt exposure conditions. Soil sensors were installed at multiple depths (approximately 3 inches and 6 inches below the soil surface) in each basin to capture vertical variability in moisture, temperature, and salinity. Electrical conductivity measurements are used as a proxy for soil salinity, enabling investigation of salt transport, accumulation, and persistence following winter storm events. The dataset also includes indicators of salt application days to support event-based analyses. The dataset is provided as two comma-separated value (CSV) files corresponding to the high-salt and low-salt basins, along with a README file that documents sensor locations, variable definitions, units, and data structure. These data support research on stormwater infrastructure performance, road salt impacts on urban soils, and seasonal hydrologic processes in cold-climate urban environments.

  PublisherDOI

• Stormwater Control Measures Performance: Predicting Behavior under Climate Change Using Historical Data

  2025-05-15

  articleSenior author

  As climate change impacts accelerate, the characteristics (frequency, depth, intensity) of rainfall events are expected to become more intense and volatile. This study seeks to use historical data to examine stormwater control measures’ (SCMs’) ability to remove common pollutants during high intensity/depth storm events. This study examines bioretention and grassed swales, due to their prevalence within stormwater systems, varying susceptibility to scour, and depth of data available. Pollutant and rainfall depth data was extracted from the International Stormwater Best Management Practice (BMP) Database. Percent removal as a function of rainfall depth was then calculated. Findings suggest that assumed correlations between pollutants could be inaccurate under expected conditions. Findings also suggest that scour becomes concerning in SCMs that do not contain standing water or have a ponding depth to still water. Future work includes further analyzing assumed correlations between pollutants, expanding SCM types to further investigate effects of scour, and exploring percent removal as related to rainfall intensity.

  PublisherDOI

• Soil moisture, electrical conductivity, and soil temperature for two stormwater basins with different levels of salt inputs in Lancaster, Pennsylvania

  Zenodo (CERN European Organization for Nuclear Research) · 2025-12-22

  datasetOpen accessSenior author

  This dataset contains measurements of soil moisture, electrical conductivity, and soil temperature collected from two stormwater bioinfiltration basins in Lancaster, Pennsylvania, between January 2022 and May 2023. The two basins were selected to represent contrasting levels of road salt inputs during winter maintenance activities, allowing for comparison of soil hydrologic and salinity dynamics under different salt exposure conditions. Soil sensors were installed at multiple depths (approximately 3 inches and 6 inches below the soil surface) in each basin to capture vertical variability in moisture, temperature, and salinity. Electrical conductivity measurements are used as a proxy for soil salinity, enabling investigation of salt transport, accumulation, and persistence following winter storm events. The dataset also includes indicators of salt application days to support event-based analyses. The dataset is provided as two comma-separated value (CSV) files corresponding to the high-salt and low-salt basins, along with a README file that documents sensor locations, variable definitions, units, and data structure. These data support research on stormwater infrastructure performance, road salt impacts on urban soils, and seasonal hydrologic processes in cold-climate urban environments.

  PublisherDOI

• Optimal life-cycle adaptation of coastal infrastructure under climate change

  Nature Communications · 2025-01-27 · 13 citations

  articleOpen access

  Climate change-related risk mitigation is typically addressed using cost-benefit analysis that evaluates mitigation strategies against a wide range of simulated scenarios and identifies a static policy to be implemented, without considering future observations. Due to the substantial uncertainties inherent in climate projections, this identified policy will likely be sub-optimal with respect to the actual climate trajectory that evolves in time. In this work, we thus formulate climate risk management as a dynamic decision-making problem based on Markov Decision Processes (MDPs) and Partially Observable MDPs (POMDPs), taking real-time data into account for evaluating the evolving conditions and related model uncertainties, in order to select the best possible life-cycle actions in time, with global optimality guarantees for the formulated optimization problem. The framework is developed for coastal adaptation applications, considering a wide variety of possible action types, including various forms of nature-based infrastructure. Related environmental impacts of carbon emissions and uptake are also incorporated, and social cost of carbon implications are discussed, together with several future directions and supported features.

  PublisherOA PDFDOI

• Analysis of the Hydrologic Performance in a Lined Bioretention Basin and Implications for Monitoring and Design

  Journal of Sustainable Water in the Built Environment · 2024-12-13 · 3 citations

  articleSenior author

  Lined bioretention basins can be an optimal solution for urban stormwater runoff problems in regions with karst geology or high-density urban environments. In this study, inflows and outflows of a lined bioretention basin in central Pennsylvania were monitored for a year from June 2020 to June 2021. These data were used to generate hydrologic performance metrics, such as peak flow ratio, peak delay ratio, and runoff reduction. The basin displayed an impressive capacity in total volumetric runoff reduction, achieving an overall efficiency of 94%. This exceptional performance was primarily attributed to the basin’s effectiveness in capturing and managing smaller storm events. The basin’s performance declined when dealing with larger and more intense rainfall events, with a decrease in runoff reduction to as low as 64%. There was excellent control of peak outflow rates from the basin, with nearly 97% of events meeting the target peak flow reduction threshold. The basin did not perform well in delaying its peak outflow, which is likely due to the location of an underdrain very close to the inlet. When evaluating contributions to runoff reduction, the total evapotranspiration, overflow, and storage could not match this reduction volume, indicating leakage and exfiltration from the system. Although there are potential sources of error in this water budget, this indicates possible issues with the integrity of the basin’s lining and the importance of proper construction and maintenance. Overall, this study demonstrates the hydrologic benefits that lined bioretention basins can provide but also highlights important monitoring and design considerations. For monitoring, this includes the challenge of closing the water budget and assessing liner leakage. For design, this includes the need to ensure liner integrity and appropriately place underdrains for increased peak flow delay.

  PublisherDOI

Frequent coauthors

• Timon McPhearson

  New School

  11 shared

• M. Todd Walter

  Cornell University

  10 shared

• Rebecca L. Hale

  Smithsonian Environmental Research Center

  10 shared

• B. Rosenzweig

  Sarah Lawrence College

  9 shared

• Peter M. Groffman

  The Graduate Center, CUNY

  8 shared

• Nancy B. Grimm

  Arizona State University

  8 shared

• A. Marissa Matsler

  Environmental Protection Agency

  8 shared

• Heejun Chang

  Portland State University

  6 shared

Labs

• Lauren McPhillips LabPI

Education

• PHD, Biological & Environmental Engineering

  Cornell University

  2016

• MS, Environmental Engineering, Biological & Environmental Engineering

  Cornell University

  2013

• BS, Science of Earth Systems, Earth & Atmospheric Sciences

  Cornell University

  2007