Taha Al-Washali

PhD fellow


Taha AL-Washali is an environmental engineer from Yemen. He is a PhD fellow in the environmental engineering and water technology department. His research focuses on developing tools and methods that enable water utilities in developing countries to manage and minimize losses in water distribution networks.
Taha Al-Washali got his bachelor degree in Civil Engineering from Sana’a University, Yemen. He got his master degree in Integrated Water Resources Management from Cologne University of Applied Sciences, Germany. During his bachelor study, he was selected by the Ministry of Water and Environment in Yemen to work in the water sector. He then joined the water sector from the first day of his bachelor graduation, and becomes more inspired about water by every day goes by. He started as a trainee in a GIZ project, a project engineer at KFW national project, and later became a general director of the projects department in the National Water Supply and Sanitation Authority in Yemen. He did several assignments for several international agencies including GIZ, KFW, USAID, WHO and OXFAM. Mr. AL-Washali has several key contributions including contributions to the Yemeni revised National Water Strategy and Investment Program, and the Yemen Country Profile in the UN-WHO Global Water and Sanitation Assessment Report 2014. 



Losses in Water Distribution Networks: a Study on the Assessment of Water Loss and its Components and Sub-Components in Developing Countries

Research Summary

There is no water supply system with zero losses. Water loss in water supply systems is a global problem that endangers the sustainability of water services in the cities and water resources in the basins. However, its reduction is not a one-step solution, but a continuous process. Water loss monitoring is complicated in developing countries where water losses can’t be assessed accurately and regularly at a component level.  For intermittent water supplies, water loss is hard to be assessed accurately because the level of water loss is influenced significantly by the variation of water production. Besides, assessing water loss components using minimum night flow experiments is also difficult since several water utilities lack appropriate technical capacity and sufficiency of water quantity to ensure the saturation of the ground storage tanks in the network. On the other hand, the high uncertainty of illegal water use estimation influences the accuracy of water loss component assessment through establishing the top –down water audit methodology. Therefore, the objective of this research is to develop methods and approaches for assessment of the water loss and its components and sub-components, addressing the needs of intermittent supplies in a developing country context. To achieve that, the study aims at suggesting normalization approach of water loss level, and developing a new methodology for water loss component assessment. The study also aims to carry out an in-depth analysis of water thefts, which should improve the water loss component assessment through the top-down water audit methodology. The main expected outputs of this study are: (i) new process-oriented and cost-effective methodologies for water loss normalization and component assessment; (ii) a guide for water loss assessment in various contexts; and (iii) a water loss management strategy that demonstrates how proper water loss assessment could be reflected in an effective water loss reduction and management plan.


AL-Washali, T., Sharma, S., & Kennedy, M. (2016). Methods of Assessment of Water Losses in Water Supply Systems: a Review. Water Resources Management, 30(14), 4985-5

AL-Washali, T., Sharma, S., & Kennedy, M. (2018). Non-Revenue Water Component Assessment: an Alternative Method. Water Resources Planning and Management. Accepted.

AL-Washali, T., Sharma, S., Kennedy, M., AL-Nozaily, F., & Haidera, M. (2018). Monitoring the Non-Revenue Water Performance in Intermittent Supplies. Submitted.

LinkedIn: https://www.linkedin.com/in/taha-al-washali-2201ab59/

ResearchGate: https://www.researchgate.net/profile/Taha_Al-Washali

Other information


AL-Washali, T., Sharma, S., and Kennedy, M. (2016). Non-Revenue Water Evaluation in a Complicated Context: The Case of Sana'a Water Supply System. IWA Water Loss 2016 Conference, 31 January – 3 February, Bangloure, India.

AL-Washali, T., Sharma, S. Kennedy, M. and Shwagfeh, Z. (2017). Economic Modeling for Prioritizing Leakage Reduction Measures in AL-Zarqa, Jordan. 4th Arab Water Week, 18–23 February, Dead Sea, Jordan.

AL-Washali, T., Sharma, S., Kennedy, M., AL-Nozaily F, and Haidera M. (2017). Does A Lower Non Revenue Water Level Always Mean Better Performance?. IWA Benchmarking Conference 2017, May 15-17, Vienna, Austria.

AL-Washali, T., Sharma, S., and Kennedy, M (2017). Water Loss Assessment in Developing Countries. IHE-Delft PhD Symposium 2017: Climate Extremes and Water Management Challenges, October 2-3, Delft, The Netherlands.

AL-Washali, T., Sharma, S., and Kennedy, M. (2017). Water Loss Monitoring. German Arab Master Programs Conference 2017, November 2-3, Berlin, Germany.

AL-Washali, T., Sharma, S., Kennedy, M., AL-Nozaily F, and Haidera M. (2018). Water Loss Assessment and Monitoring in Intermittent Supplies. International Conference for Sustainable Development of Water and Environment 2018, January 18-19, ChenYang, China.


Yemen Profile in: UN-WHO (2014). Investing in Water and Sanitation: Increasing Access, Reducing Inequalities. Global Analysis and Assessment of Sanitation and Drinking Water, World Health Organization, Geneva, Switzerland.

AL-Washali, T., Sharma, S. & Kennedy, M. (2016). Non-Revenue Water Breakdown in Zarqa Water Supply System. Summary Report, Jordan.

AL-Washali, T., AL-Derwish A., Lerebours A., Carter S., & Farrington M. (2016). WaSH Assessment in Urban Sana’a: Desk Review Report, Scoping Study of Urban WaSH. Oxfam, Yemen.


AL-Washali, T. (2017). Damage Assessment of Water Supply in Yemen. Forgotten War Conference, 25 February, Berlin, Germany.

AL-Washali, T. (2017). The Overlooked Yemen: Call for Action, Focus on Water. Yemen The Worries Seminar, 27 January, MetaMeta Research, 's-Hertogenbosch, The Netherlands.

AL-Washali, T. (2016). Research Poster Design. Training Seminar, 25 June, Water and Environment Center, Sana’a University, Yemen

Blogs and Articles:

AL-Washali, T., Steenbergen F., Sharma, S. & Kennedy, M. (2017). Let the crisis not get hold of us: water supply in Yemen. Water Blog in Water Channel.

AL-Washali, T. M. (2015). Challenges, Achievements, and Gaps of WASH Sector in Yemen: Brief Summary of UN-WHO WASH Assessment in Yemen. AL-Miah Magazine. Issue No. 86 Print. Yemen.


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