Water Resources Management

Strategic, tactical, and operational decision making for water resource management problems under uncertainty.

Infrastructure - Digital Twins for Water Infrastructure

Link up the real and the digital world for enhanced asset management.

Water in the Circular Economy

Reconfigure water-energy-waste systems and services turning waste into resource.

Cyber-Physical Water Systems

Address challenges and opportunities also for critical infrastructure security.

Environmental protection and Ecosystem Services

Develop optimal plans for environmental systems protection and leverage ecosystem services.

Modelling for Resilience

Use AI analytics and whole water system models to enhance resilience

About Us

Our Mission
We combine advances in uncertainty analysis, cyber-physical systems modeling and new resilience design approaches to deliver Water Infrastructure solutions for a changing world.


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Georgia Kandilioti

Georgia Kandilioti is the founder and CEO of TETHYS. She is an Environmental Scientist specializing in water resources and environmental management and engineering with over 12 years experience. She received her BSc in Environmental Science from the University of the Aegean and her MSc in Water Resources Science and Technology from the National Technical University of Athens (NTUA). During her research and professional career in the Hellenic Centre for Marine Research (HCMR), the National Technical University of Valencia, the UK Environment Agency (EA), the National Technical University of Athens and engineering consultancies in Greece, she has gained experience in a wide range of topics, from water modelling and environmental data collection and analysis to Regulatory Water Frameworks, EU Environmental Directives and Guidelines, multi-disciplinary team management and stakeholder communication and engagement. During her work, Georgia has cooperated with clients, local stakeholders and environmental regulators on the design and implementation of water related plans and projects in Greece, Spain, Cyprus, Norway and the UK. 
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Ioannis Tsoukalas

Dr. Ioannis Tsoukalas holds a Ph.D. in Civil Engineering, NTUA (2018), in the domain of stochastic simulation and optimization water-systems under uncertainty. He has obtained a Diploma in Civil Engineering from Aristotle University of Thessaloniki, Greece (March 2010) and a M.Sc. in Water Resources Science and Technology from National Technical University of Athens, Greece (NTUA) in March 2012. He has worked as a senior researcher in several National (KLIMENESTOS, ALPINE, PROCRUSTES), and European (STOP-IT; as a WP leader, EIFFEL, iWidget, DESSIN, PEARL) projects, as well as a consultant in a wide range of engineering studies. His work focuses on the development of a) statistical/stochastic methods and models for the analysis, modelling, forecasting, and (multi-scale) simulation (and disaggregation) of stochastic processes (e.g., hydrometeorological), and b) surrogate-based optimization algorithms, (inspired from the recent developments in machine learning) with a focus on multi-objective problems. His research contributes in improving decision making and risk management under deep uncertainty. He has authored 40 publications to date, from which 18 peer-reviewed papers in international journals and 22 in international conferences.
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Panagiotis Kossieris

Dr. Panagiotis Kossieris is a Civil Engineer and Senior Researcher. He holds a Ph.D. in Civil Engineering (NTUA), a M.Sc. in Water Resources Science and Technology (NTUA) and a 5-year Diploma in Civil Engineering (NTUA). His Ph.D. focused on the stochastic analysis and simulation of water demand processes, with emphasis on the development of methodologies and tools for the enhancement of the limited availability of high-resolution data in cost-effective ways. Dr. Kossieris has participated as senior researcher and project manager in several EU-funded (SUBSOL, iWIDGET, PEARL, Fiware4Water, Water Mining), as well as National-funded (ALPINE, CRESSENDO, E3WDM, Smart Blue Water Camps) projects. His work focuses on the statistical analysis of large datasets, the stochastic modelling of physical (e.g., rainfall) and non-physical (water demand) processes, as well as the design and development of web analytics and hydroinformatics applications for smart monitoring and management of urban water systems. He has published 10 peer-reviewed papers in international journals and 16 papers in international conferences. He is a member of the Technical Chambers of Greece and the European Geoscience Union.
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Dionysios Nikolopoulos

Dionysios Nikolopoulos holds a Diploma in Civil Engineering and an M.Sc. in Water Resources Science and Technology from the National Technical University of Athens. He has worked in several research projects as senior researcher and applications developer (incl. STOP-IT, NextGen, PEARL, IWIDGET, DESSIN, E3WDM, PROCRUSTES). His work focuses on hydroinformatics, water cyber-physical systems, cyber-security of water systems, hydraulics, hydrology, and water resources management. He develops models and tools for the complete urban water cycle under long term uncertainty and couples cyber control and monitoring systems to physical urban water processes, to assess cyber-physical risks and improve water systems security. He has authored 31 publications, from which 9 in peer-reviewed international journals and 22 in international conferences.
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Archontia Lykou

Archontia Lykou is the Chief Operating Officer of Tethys. She is a Civil Engineer specializing in water resources, hydrology and flood risk management with 10 years’ experience in research and innovation projects and consultancy services. Before completing her undergraduate studies at the National Technical University of Athens (NTUA) in 2011, she had worked in the field of dam construction. In parallel with her postgraduate studies on Hydrology and Environmental Water Resources Management at NTUA fulfilled in 2013, she was working on hydraulic studies and design of water infrastructures in the private sector. In 2013, she started working in various research project at NTUA in the Department of Water Resources and Environmental Engineering. She has successfully delivered several National and European projects (e.g. B-WaterSmart, STOP-IT, ERMIS-F, PEARL, INEWS etc.) in the domains of water security and environment, working as project manager and contributing to research activities. Her research interests are mostly related to hydrologic and hydrodynamic simulations of flood phenomena in inland and urban systems, while utilizing GIS technologies and coupled 1D-2D hydrodynamic models for flood risk assessment and suggestion of resilience measures/strategies. She has co-authored more than 20 journal and conference papers. She also leads Tethys’s consulting services on water and flood risk management in Greece.





Tethys Consulting

24 Ellanikou Str. Athens, Greece