Author(s): S. Cordero; D. Ganora; P. Claps

Linked Author(s): Silvia CORDERO, Claps Pierluigi

Keywords: Flood attenuation; Reservoirs; Ranking method; Pre-emptive drawdown; Dam management

Abstract: Flood attenuation performance of dams is investigated here considering 56 reservoirs in Piemonte Region. Supervised attenuation through pre-emptive drawdown is assessed using a ranking procedure. The presence of a large number of reservoirs in mountain areas can be viewed as a resource for the flood risk mitigations of the territories downstream. The use of reservoirs as detention tanks that are able to reduce the flood peaks is increasingly popular thanks to the continuous development of weather and hydrological forecasting services. However, most of the application cases available in the literature lack a systematic approach that considers all of the reservoir in a region as part of its flood management plan. In recent years Miotto et al. have proposed an index (SFA) for preliminary classification of the natural attenuation potential of the reservoirs. This index is a function of the lake area, the basin area and the width of spillways. Other authors like Ayalew et al. and Sordoward et al. suggest different approaches to assess unsupervised flood attenuation. Bianucci et al. and Connaughton et al. analyse some downstream effects of gates opening. This work considers the supervised flood attenuation in a system of reservoirs, trying to reach a possibly unbiased classification by mean of straightforward gates operation rules. The method considers a pre-emptive lake drawdown, that rules for flood management in Italy make possible after agreements reached within the individual Management Plan that each dam needs to have. Final aim of the classification is to identify, among all the Dam structures, those that have the potential to provide the greatest benefits if managed in a perspective of supervised attenuation of the flood waves. This information is very useful for the overall planning in the downstream areas, that are often built partially unaware of the possibility that big floods cannot be properly attenuated by the dam.

DOI: https://doi.org/10.3850/978-981-11-2731-1_333-cd

Year: 2018