About

Aditi S. Bhaskar is an Associate Professor in the Department of Civil, Architectural and Environmental Engineering at the University of Colorado Boulder. Her research specializes in changes to water resources that accompany urban development, with a focus on interactions between streams, groundwater, stormwater, and urban irrigation. She has a background in geology, physics, and mathematics, holding a Sc.B. from Brown University, and earned her PhD in environmental engineering from the University of Maryland, Baltimore County. Bhaskar was a trainee of the National Science Foundation Integrative Graduate Education and Research Traineeship in 'Water in the Urban Environment' and a National Science Foundation Earth Sciences Postdoctoral Fellow, which took her to the U.S. Geological Survey in Reston, Virginia. She has also been affiliated with Colorado State University before joining CU Boulder. Bhaskar is a recipient of the NSF CAREER award.

Research topics

• Computer Science
• Environmental science
• Geography
• Environmental engineering
• Ecology
• Geology
• Engineering

Selected publications

• Lawn Irrigation Contributions to Semi‐Arid Urban Baseflow Based on Water‐Stable Isotopes

  Water Resources Research · 2021 · 47 citations

  • Environmental science
  • Geography
  • Environmental engineering

  Abstract In semi‐arid cities, urbanization can lead to elevated baseflow during summer months. One potential source for additional water is lawn irrigation. We sought to quantify lawn irrigation contributions to summertime baseflow in Denver, Colorado, USA using water‐stable isotope (δ 18 O and δ 2 H) analysis of surface water, tap water, and precipitation. If lawn irrigation contributed significantly to baseflow, we predicted the isotopic composition of Denver's urban streams would more closely resemble local tap water than precipitation or streamflow from nearby grassland watersheds. We expected tap water to be distinctive due to local water providers importing source water from high elevations. Thirteen urban streams and two grassland streams were selected for sampling. None of the streams had high‐elevation headwaters or wastewater effluent, and the grassland streams did not receive irrigation. Tap water was sampled from five water service areas. The grassland streams flowed for 60% of summer 2019 while urban streams flowed for 90%–100% of the summer. An isotope mixing analysis using tap and precipitation end‐members over a two week antecedent period estimated that tap water contributed 65% ± 10%–93% ± 3% with a mean of 80% of urban baseflow on specific days in late summer. After taking contributions from infrastructure leakage into account, we estimated that lawn irrigation return flows made up 32% ± 10%–82% ± 21% of analyzed baseflow. Quantifying lawn irrigation contributions to urban baseflow provides a basis for understanding how changes to lawn irrigation efficiency would affect water yield in the Denver metropolitan area.

  DOI

• Stormwater control impacts on runoff volume and peak flow: A meta‐analysis of watershed modelling studies

  Hydrological Processes · 2020 · 42 citations

  • Computer Science
  • Environmental science
  • Computer Science

  Abstract Decades of research has concluded that the percent of impervious surface cover in a watershed is strongly linked to negative impacts on urban stream health. Recently, there has been a push by municipalities to offset these effects by installing structural stormwater control measures (SCMs), which are landscape features designed to retain and reduce runoff to mitigate the effects of urbanisation on event hydrology. The goal of this study is to build generalisable relationships between the level of SCM implementation in urban watersheds and resulting changes to hydrology. A literature review of 185 peer‐reviewed studies of watershed‐scale SCM implementation across the globe was used to identify 52 modelling studies suitable for a meta‐analysis to build statistical relationships between SCM implementation and hydrologic change. Hydrologic change is quantified as the percent reduction in storm event runoff volume and peak flow between a watershed with SCMs relative to a (near) identical control watershed without SCMs. Results show that for each additional 1% of SCM‐mitigated impervious area in a watershed, there is an additional 0.43% reduction in runoff and a 0.60% reduction in peak flow. Values of SCM implementation required to produce a change in water quantity metrics were identified at varying levels of probability. For example, there is a 90% probability (high confidence) of at least a 1% reduction in peak flow with mitigation of 33% of impervious surfaces. However, as the reduction target increases or mitigated impervious surface decreases, the probability of reaching the reduction target also decreases. These relationships can be used by managers to plan SCM implementation at the watershed scale.

  DOI

• The Case for an Open Water Balance: Re‐envisioning Network Design and Data Analysis for a Complex, Uncertain World

  Water Resources Research · 2020 · 61 citations

  • Computer Science
  • Environmental science
  • Computer Science

  Abstract The discipline of hydrology has long focused on quantifying the water balance, which is frequently used to estimate unknown water fluxes or stores. While technologies for measuring water balance components continue to improve, all components of the balance have substantial uncertainty at the watershed scale. Watershed‐scale evapotranspiration, storage, and groundwater import or export are particularly difficult to measure. Given these uncertainties, analyses based on assumed water balance closure are highly sensitive to uncertainty propagation and errors of omission, where unknown components are assumed negligible. This commentary examines how greater insight may be gained in some cases by keeping the water balance open rather than applying methods that impose water balance closure. An open water balance can facilitate identifying where unknowns such as groundwater import/export are affecting watershed‐scale streamflow. Strategic improvements in monitoring networks can help reduce uncertainties in observable variables and improve our ability to quantify unknown parts of the water balance. Improvements may include greater spatial overlap between measurements of water balance components through coordination between entities responsible for monitoring precipitation, snow, evapotranspiration, groundwater, and streamflow. Measuring quasi‐replicate watersheds can help characterize the range of variability in the water balance, and nested measurements within watersheds can reveal areas of net groundwater import or export. Well‐planned monitoring networks can facilitate progress on critical hydrologic questions about how much water becomes evapotranspiration, how groundwater interacts with surface watersheds at varying spatial and temporal scales, how much humans have altered the water cycle, and how streamflow will respond to future climate change.

  DOI

Recent grants

• CAREER: Science and Education for Connecting Urban Irrigation Efficiency to Streamflow in Semi-Arid Cities

  NSF · $286k · 2021–2023

• Impacts of Novel Stormwater Management on Groundwater Recharge

  NSF · $174k · 2014–2016

• Collaborative Research: Connecting local stormwater decision-making to environmental outcomes

  NSF · $63k · 2018–2022

Frequent coauthors

• Kristina G. Hopkins

  South Atlantic Water Science Center

  19 shared

• Claire Welty

  17 shared

• Benjamin Choat

  11 shared

• Anne J. Jefferson

  Kent State University

  10 shared

• Dianna M. Hogan

  United States Geological Survey

  10 shared

• Chingwen Cheng

  Pennsylvania State University

  8 shared

• R. M. Maxwell

  Princeton University

  8 shared

• William D. Shuster

  7 shared

Education

• Other

  University of Colorado Boulder

Awards & honors

• NSF CAREER Award

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