Dams and flows: Afua Owusu earns PhD for research on environment-friendly dam operations
Following PhD research at IHE Delft, Afua Owusu of Ghana successfully defended her PhD thesis titled 'The Practice and Opportunities in Re-operating Dams for the Environment' and was awarded with a doctoral degree on 30 November 2022. Her promotors are Professor Pieter van der Zaag and Professor Jill Slinger (TU Delft) and her co-promotor Associate Professor Marloes Mul. Dr. Afua Owusu shared a few insights as she embarks on a new chapter of her life.
My thesis in a nutshell
My research is about protecting or restoring naturally flowing rivers. The flow of a river shapes the habitats found within and around the river, and impacts water quality. When this flow is changed, for instance by a dam being built, then the nature of that river changes. Consequently, the fish, plants and other organisms in and around the river change and in extreme cases, when a certain species is unique to that river, that species may even become endangered. This is the case in many places worldwide: most of the worlds over 45,000 large dams have negatively impacted the river ecology and people in their locations.
I looked at how dam operations are changed to reduce this harm. How dams affect their environment, that is, how they affect river flows, species and local communities who depend on the rivers for their livelihoods, has been researched well. However, actual implementation of measures that would reduce negative effects has so far been limited.
My PhD looked at cases worldwide where measures have been taken to improve river flows to benefit the environment. I looked at what compromises were made and how that affected water that is used for other purposes, like hydropower or irrigation. These findings can be used to inform efforts in other areas. I did my PhD as part of a European Union project called EUROFLOW. This project trained me and 14 other early-stage researchers (ESR), to be future leaders in the science, business and environmental policy.
I will never forget when my colleagues and I carried out sampling on the Spöl River during an artificial flood release from the Ova Spin reservoir in Zernez, Switzerland. It was interesting to observe and measure the changes in the river. We learnt an important lesson of field work the hard way: fix your instruments well, or they get washed away by the flood!
Challenges during my PhD studies
The most challenging part of my PhD studies was navigating Covid-pandemic travel restrictions and protocols during the data collection phase of my research.
The influence of my PhD research
In an ideal world, my research would lead to improved dam operations that consider the environment as a legitimate water user. Dam operation policies for existing dams would be reviewed to include environmental flows, and these flows would be continuously monitored and adjusted where appropriate. For new or planned dams, the full effect on the environment would be considered with input from all stakeholders - especially riverine communities - and would only be built with provisions for environmental flows.
What's next?
I started a postdoctoral fellowship with the International Water Management Institute (IWMI). I am working with the Water Accounting team contributing to the Digital Earth Africa program which seeks to leverage remote sensing and data processing technologies to generate quality and timely information on water resources in Africa. During this fellowship, I hope to properly account for environmental flows on a continental scale for Africa.
Looking back, if I could advise myself at the start of my PhD, I would say:
I would say to myself, “relax; take time to rest, travel; and enjoy being with family and friends. It will all come together in the end and before you know it, four years will be gone!”
Research summary
Many rivers worldwide have been progressively engineered for agriculture, energy, transportation, flood control and navigation. Dams, in particular, have played a major role in controlling and harnessing large volumes of water to support these anthropogenic uses. While dams have undoubtedly contributed to human development, this has often come at a heavy price to downstream communities and the natural environment. The provision of environmental flows (e-flows), freshwater flows for the environment, is a means to restore or protect the benefits of naturally flowing rivers. Since the 1940s, e-flows science has grown, however, actual implementation remains relatively limited. This research investigated how dams are re-operated for the implementation of e-flows. It began with a systematic literature review and survey of practical cases of dam re-operation followed by a case study of the Lower Volta River, Ghana. The research has generated knowledge on the process of dam re-operation for e-flows, the enabling factors for success and hurdles which typically stall the process, as well as inter-sectoral trade-offs inherent in delivering environmental flows in a unique case study. These insights inform attempts to scale up efforts in e-flows implementation towards the sustainable operation of dams for people and the environment.