Urban areas are rapidly expanding and an increasing fraction of the world’s population lives in urban or suburban areas.  Our research in urban areas focuses on quantifying the impacts of urbanization on water quality, and water availability and flood risk. We also look at urban areas as functioning ecosystems – examining how vegetated patches in urban environments – lawns, riparian corridors, storm water detention ponds provide ecosystem services including  nitrogen cycling and carbon sequestration, habitat provision and more.

Research Questions

  • What is the role of vegetation in urban ecohydrology? How does urbanization impact plant water use and productivity, carbon sequestration, streamflow and nutrient cycling?
  • How do can we strategically use urban design to change how water and materials move through the system – e.g how do patterns of impervious area influence urban ecosystem function and streamflow? Under what geoclimatic conditions does restoration of urban streamflows reduce nutrient export? Where should we optimally focus  storm water management actions (detention ponds, riparian restoration)?
  • How will a changing climate alter urban ecosystems and hydrology?


Urbanization in semi-arid landscapes:  Semi-arid landscapes are characterized by infrequent and often extreme precipitation events. We apply the RHESSys model to an urbanizing semi-arid catchment in Santa Barbara, CA to explore the impact of different configurations of impervious area on urban vegetation and streamflow. This work is part of the Santa Barbara LTER (

Storm water management: We combine field-based analysis with RHESSys to investigate how best management practices in urban environments (swales, detention ponds, riparian restoration) can be strategically placed to reduce nutrient export  (

Relevant Research




  • Claessens, L., Tague, C., Band, L., Groffman, P., Kenworthy S. (2009) Hydro-ecological linkages in urbanizing watersheds: An empirical assessment of in-stream nitrate loss and evidence of saturation kinetics, Journal of Geophysical Research – Biogeosciences 114: G04016. doi:10.1029/2009JG001017.



  • Claessens, L., Tague, C., Groffman, P., Melack, J. (2009) Longitudinal and seasonal variation of stream N uptake in an urbanizing watershed: Effect of organic matter, stream size, transient storage and debris dams, Biogeochemistry 98: 45-62. doi:10.1007/s10533-009-9375-z.



  • Tague, C., Pohl-Costello, M. (2008) The potential utility of physically based hydrologic modeling in ungaged urban streams, Annals of Association of American Geographers 93(4): 818-833.