Quantifying Cooperation Benefits for New Dams in Transboundary Water Systems Without Formal Operating Rules

Abstract

New dams impact downstream ecosystems and water infrastructure; without cooperative and adaptive management, negative impacts can manifest. In large complex transboundary river basins without well codified operating rules and extensive historical data, it can be difficult to assess the benefits of cooperating, in particular in relation to new dams. This constitutes a barrier to harmonious development of river basins and could contribute to water conflict. This study proposes a generalised framework to assess the benefits of cooperation on the management of new dams in water resource systems that do not have formal sharing arrangements. Benefits are estimated via multi-criteria comparison of historical reservoir operations (usually relatively uncooperative) vs. adopting new cooperative rules which would achieve the best results for riparian countries as evaluated by a water resources simulator and its performance metrics. The approach is applied to the Pwalugu Multipurpose Dam (PMD), which is being built in Ghana in the Volta river basin. The PMD could impact downstream ecosystems and infrastructure in Ghana and could itself be impacted by how the existing upstream Bagre Dam is managed in Burkina Faso. Results show that with cooperation Ghana and Burkina Faso could both increase energy production although some ecosystem services loss would need to be mitigated. The study confirms that cooperative rules achieve higher overall benefits compared to seeking benefits only for individual dams or countries.

Attributing synergies and trade-offs in water resources planning and management in the Volta River basin under climate change

“…However, there is not only competition but also synergy. Often, decision-makers require synergies and trade-offs to be expressed in monetary terms, like the monetary benefits and costs of joint reservoir operation and irrigation [6,7]. In this study, we take another perspective by showing that irrigating one hectare of land reduces hydropower potential between 42 and 117 Watts, depending on the location's hydro-climatic conditions and the number of hydropower stations affected.…”

“…The Volta River basin (VRB) located in the hot semi-arid and tropical wet savanna climate zones of West Africa covers an area of more than 400 000 km 2 and is shared by six riparian countries. The water resources are used to cultivate crops, generate hydropower, livestock, fisheries, mining, and domestic and industrial water supply [6]. About 30 million people depend on the basin's water resources for their livelihoods, which are under constant pressure due to population growth, climate change and variability [7], and other developments.…”

Designing diversified renewable energy systems to balance multisector performance

“…The models simultaneously represent the various resource system supply-demand networks, connecting them where appropriate (in our work, at hydropower generation nodes). The river basin is modelled using a water resource allocation and management model 30,31 at discrete time steps. The power system is modelled using a direct current optimal power flow model at hourly time steps 32 .…”

“…More details of the Volta River basin model can be found in ref. 31 , a previous publication on the model.…”

Quantifying the trade-offs in re-operating dams for the environment in the Lower Volta River

“…In many of the studies where MOEAs have been applied, the e-flow objective in the simulation component of the model either meets a minimum flow release (Zatarain Salazar et al, 2017;Kiptala et al, 2018;Hurford et al, 2020;Gonzalez et al, 2021) or minimizes the deviation of flow from the natural, unregulated flow regime . The former objective, minimum flow releases, fails to thoroughly capture the essence of e-flows which are the "quantity, timing, and quality of freshwater flows and levels required to sustain aquatic ecosystems" (Brisbane Declaration, 2018).…”