Dam safety in Sergipe: Jacarecica I and Jacarecica II hypothetical cascade dam-break simulation

Segurança de barragens em Sergipe: simulação do rompimento hipotético em cascata das barragens Jacarecica I e Jacarecica II

ABSTRACT

Despite of benefits such as water security and energy supply dams provide, there are environmental impacts and risks of accidents associated with their usage, i.e. rupture. In these cases, a structured Emergency Action Plan (EAP) must be executed to mitigate impacts and loss of life. To do so, hypothetical dam break scenarios must be simulated to obtain the flood’s spatial coverage in downstream valley. In this regard, this work aimed to obtain the flood maps due to hypothetical ruptures of Jacarecica I and Jacarecica II dams (state of Sergipe), structures that don’t have Safety Plans elaborated. HEC-RAS 2D model was used to elaborate flood inundation maps and assess hydrodynamic results, that showed the breach wave impacts residential, industrial and agricultural areas before reaching the city of Riachuelo, with high depths and velocities, and minimum arrival times of 6 hours. With rural and urban areas at risk, it is mandatory, according to the PNSB, that the dams’ EAPs are prepared.

Keywords:
Cascade dam failure; Dam safety plan; HEC-RAS; Inundation map; Hydrodynamic modelling