Climate Change and Dams with a Focus on Morocco and Investigation of the Piano Key Weir Technology to Enhance the Climate Resilience of Moroccan Dams

Abstract

Climate change has been affecting significantly dams worldwide, particularly by the accentuation of extreme events. The hydraulic insufficiency of spillways is the most hazardous related risk that directly threatens the dams’ safety. Thus, the Piano Key Weir (PKW) technology may be a cost-effective solution for adapting the spillways of the existing dams and enhancing their resilience against climate change. This paper aims to provide the state of knowledge regarding the climate change issues related to dams with a focus on Morocco. It aims also to assess the cost-effectiveness of implementing the PKW in 27 large Moroccan dams in order to increase the flood release capacity. This work has determined, first, the climate change impacts on water resources and dams, and has discussed the adaptation measures including the implementation of PKW. Then, a detailed case study has been conducted to evaluate the interest of implementing the PKW in Morocco, at the scale of each hydraulic basin, with a comparison to the international experience. Results have revealed that the PKW allows increasing the global discharge capacity of Moroccan spillways by 70%, at a total cost of about 600 MMAD. Souss Massa Draa basin has accounted more than 40% of the total discharge capacity increase, and the best cost-effectiveness values have been identified in Loukkos, Oum Er Rbiaa and Sebou basins. These results may encourage the PKW integration in order to enhance the Climate adaptation and resilience of dams.