Cathy Reidy Liermann



I am an ecohydrologist exploring human dependencies and effects on freshwater systems. I collaborate on multiple research efforts, as well as teach and advise for Western Washington University's College of the Environment.

My global research focuses on sustaining freshwater goods and services under an ever-increasing human demand, in particular examining the roles of dams and inland fishing. I'm interested in the intersection of freshwater conservation and WASH science and policies within the international aid arena. More locally, my efforts have centered on instream flows, including hydrologic classification, climate change modeling and applied water conservation planning.


PhD, Umeå University; MS, University of Washington; BMusic, Boston University

Research Interests

•Freshwater conservation science
•Ecological effects of flow regulation and channel fragmentation
•Interactions between inland fishing, human dependency and freshwater ecology
•Hydrological classification
•Environmental flow analysis
•Water, Sanitation and Hygiene (WASH)


Reidy Liermann, C.*, McIntyre, P.B.*, Grill, G., Fluet-Chouinard, E. and Lehner, B. Global net losses of inland fisheries due to large dams. In Preparation.

Chaplin-Kramer, R., Neugarten, R.A., Sharp, R.P., Collins, P.M., Polasky, S., Hole, D., Schuster, R., Strimas-Mackey, M., Mulligan, M., Brandon, C., Diaz, S., Fluet-Chouinard, E., Gorenflo, L., Johnson, J.A., Keys, P.W., Longley-Wood, K., McIntyre, P.B., Noon, M., Pascual, U., Reidy Liermann, C., Roehrdanz, P.R., Schmidt-Traub, G., Shaw, M.R., Spalding, M., Turner, W.R., van Soesbergen, A., and Watson, R.A. 2022. Global critical natural assets. Nature Ecology and Evolution.

Grill, G., Lehner B., Thieme M., Geenen B., TicknerD ., Antonelli F., Babu S., Cheng L., Crochetiere H., Filgueiras R., Goichot M., Higgins J., Hogan Z., Lip B., McClain M., Meng J-H., Mulligan M., Nilsson C., Olden J.D., Opperman J., Petry P., Reidy Liermann C., Saenz L., Salinas-Rodríguez S., Schelle P., Snider J., Tockner K., Valdujo P.H., van Soesbergen A., Zarfl C.. 2019. Mapping the world’s free-flowing rivers. Nature 569: 215–221.‐019‐1111‐9

Lange K., Wehrli B., Åberg U., Bätz N., Brodersen J., Fischer M., Hermoso V., Reidy Liermann C., Schmid M., Wilmsmeier L. and C. Weber. 2019. Small hydropower goes unchecked. Accepted, Frontiers in Ecology and the Environment.

Grill, G., Lehner, B., Lumsdon, A. E., MacDonald, G. K., Zarfl, C., and Reidy Liermann, C. 2017. Reply to comment on ‘An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales’. Environmental Research Letters, 12, 038002.

McIntyre, P.* and Reidy Liermann, C.A.*, and C. Revenga.  2016. Critical roles of global freshwater fisheries for food security and biodiversity conservation.  Proceedings of the National Academy of Sciences113(45): 12880-12885.

Grill, G., Lehner, B., Lumsdon, A. E., MacDonald, G. K., Zarfl, C., and Reidy Liermann, C. 2015. An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales. Environmental Research Letters10(1), 015001.

Reidy Liermann, C.A., C. Nilsson, J. Robertson and R. Ng.  2012. Implications of dam obstruction for global freshwater fish diversity.  BioScience62 (6): 539-548.

Reidy Liermann, C.A., J.D. Olden, T. Beechie, M. Kennard, P. Skidmore, C. Konrad and H. Imaki.  2011.  Hydrogeomorphic classification of Washington State rivers to support emerging environmental flow management strategies.  River Research and Applications, doi: 10.1002/rra.1541.

Lehner, B., C.A. Reidy Liermann, C. Revenga, B. Fekete, C.J. Vörösmarty, P. Crouzet, P. Döll, M. Endejan, K. Frenken, J. Magome, C. Nilsson, J. Robertson, R. Rödel, N. Sindorf, and D. Wisser.  2011.  High resolution mapping of the world’s reservoirs and dams to assess the degree of global river regulation.  Frontiers in Ecology and the Environmentdoi:10.1890/100125.

Lawrence, D., Larson, E., Reidy Liermann, C., Mims, M., Pool, T. and Olden, J.  2011. National parks as protected areas for U.S. freshwater fish diversity.  Conservation Letters4:364-371.

Vörösmarty, C.J.* and P. McIntyre*, M. Gessner, D. Dudgeon, A. Proussevitch, P. Green, S. Glidden, S. Bunn, C. Sullivan, C.A. Reidy Liermann and  P. Davies. 2010. Global Threats to Human Water Security and River Biodiversity. Nature, 467: 555-561.

Tullos, D., Tilt, B. and C.A. Reidy Liermann. 2008. Introduction to the special issue: Understanding and linking the biophysical, socioeconomic and geopolitical effects of dams, Journal of Environmental Management , doi:10.1016/j.jenvman.2008.08.018.

Palmer, M. A., C.A. Reidy Liermann, C. Nilsson, M. Flörke, J. Alcamo, P. S. Lake & N. R. Bond. 2008.  Climate change and the world's river basins: anticipating  management options.  Frontiers in Ecology and the Environment, 6: 81-89.

Nilsson, C.* and C.A. Reidy*, M. Dynesius & C. Revenga. 2005. Fragmentation and Flow Regulation of the World’s Large River Systems, Science 308: 405-408.

Teaching Schedule

Fall Winter Spring

ENVS 319 Research and Writing

ESCI 361 Water Quality (odd years) ESCI 429 Stream Ecology (odd years)

ENVS 302 Navigating Environmental Studies

ENVS 326 Climatology (odd years)

ESCI 328 Ecosystem Management (even years)

ESCI/ENVS 498 Senior Research Seminar ESCI 392 Intro to Climate Change (even years)