Paper Title
Effectiveness of Cascades Reservoir for Flood Control Operation and Electricity Production in Nam Ngum River

Abstract
The paper presents the effectiveness of cascade reservoir for the flood control operation and electricity production. The hydropower plants are Nam Ngum 1 and 2 Hydropower Plants (NNG1 and NNG2 HPPs), which locates in central Laos. Both plants are not only electrical generation but also reduction the flood in downstream area, where it is mainly Vientiane, the capital of Laos. The NNG1 HPP was built in 1971 and the NNG2 HPP was built in 2010. The effectiveness for the flood control means that NNG2 HPP is included in the simulation before 2010. The study compares the reduction of flood period (flooding days) for the cases of with and without NNG2 HPP. The software used is HEC-ResSim3.1. Inflow data used is 34 years data between 1982-2016. The simulation results shown that the flooding days in the flood years are close to the actual recorded data. The flood days reduce, if NNG2 HPP is included into the simulation, for example in 1995 the flood days reduce from 23 days to 13 days. Direct benefit of water control is the increase of electricity production of NNG1 HPP. The simulation shows that, for the flood years between 1994 to 2011, the electricity production for the case of NNG1 HPP is increased 10.29% if NNG2 HPP is added into the simulation. Index terms- Cascades Reservoir, Flood Control, Electricity Production.