The water footprint of water conservation using shade balls in California


The interest in quick technologic fixes to complex water problems increases during extreme hydroclimatic events. However, past evidence shows that such fixes might be associated with unintended consequences. We revisit the idea of using shade balls in the Los Angeles reservoir to reduce evaporation during the recent drought in California, and question its sustainability by revealing the water footprint of this technologic water conservation solution.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Number of shade balls and the volume of water used to produce them.


  1. 1.

    Dai, A. Nat. Clim. Change 3, 52–58 (2013).

    Article  Google Scholar 

  2. 2.

    Hogeboom, R. J., Knook, L. & Hoekstra, A. Y. Adv. Water Resour. 113, 285–294 (2018).

    Article  Google Scholar 

  3. 3.

    Craig, I. P. Loss of Water Storage Due to Evaporation—A Literature Review (NCEA, Univ. Southern Queensland, Toowoomba, 2005).

  4. 4.

    Assouline, S., Narkis, K. & Or, D. Water Resour. Res. 47, W07506 (2011).

    Google Scholar 

  5. 5.

    Aminzadeh, M., Lehmann, P. & Or, D. Hydrol. Earth Syst. Sci. Discuss. (2017).

  6. 6.

    De Graaf, M. How the 100 million ‘shade balls’ brought in to protect LA’s reservoir from evaporating are in fact a ‘bacterial nightmare’. Daily Mail (20 August 2015).

  7. 7.

    Hoekstra, A. Y., Chapagain, A. K., Aldaya, M. M. & Mekonnen, M. M. The Water Footprint Assessment Manual: Setting the Global Standard (Earthscan, London, 2011).

  8. 8.

    Boustead, I. Eco-Profiles of the European Plastics Industry: High Density Polyethylene (HDPE) (Plastics Europe, 2005).

  9. 9.

    Feraldi, R. et al. Cradle-to-Gate Life Cycle Inventory of Nine Plastic Resins and Four Polyurethane Precursors (Franklin Associates, Eastern Research Group, 2011).

  10. 10.

    Mekonnen, M. M., Gerbens-Leenes, P. W. & Hoekstra, A. Y. Environ. Sci. Water Res. Technol. 1, 285–297 (2015).

    Article  Google Scholar 

  11. 11.

    Madani, K. & Khatami, S. Curr. Sustain. Energy Rep. 2, 10–16 (2015).

    Article  CAS  Google Scholar 

  12. 12.

    Holland, R. A. et al. Proc. Natl Acad. Sci. USA 112, E6707–E6716 (2015).

    Article  CAS  Google Scholar 

  13. 13.

    Hellweg, S. & Milà i Canals, L. Science 344, 1109–1113 (2014).

    Article  CAS  Google Scholar 

  14. 14.

    Gohari, A. et al. J. Hydrol. 491, 23–39 (2013).

    Article  Google Scholar 

  15. 15.

    Mirchi, A., Watkins, D. & Madani, K. in Watersheds: Management, Restoration and Environmental Impact (ed. Vaughn, J. C.) 221–244 (Nova Science, New York, 2010).

  16. 16.

    Mady, B., Lehmann, P. & Or, D. Geophys. Res. Abstr. EGU Gen. Assem. 20, 11778 (2018).

    Google Scholar 

  17. 17.

    Jaeger, H. M. & Nagel, S. R. Science 255, 1523–1531 (1992).

    Article  CAS  Google Scholar 

Download references


E.H. acknowledges funding from the Swiss National Science Foundation (grant number P2EZP2-165244).

Author information




E.H. and K.M. conceived and designed the study. All authors performed the research, analysed the data and wrote the paper.

Corresponding author

Correspondence to Erfan Haghighi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Haghighi, E., Madani, K. & Hoekstra, A.Y. The water footprint of water conservation using shade balls in California. Nat Sustain 1, 358–360 (2018).

Download citation

Further reading


Quick links

Sign up for the Nature Briefing newsletter for a daily update on COVID-19 science.
Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing