Seite - 1320 - in Book of Full Papers - Symposium Hydro Engineering

4.1. VISUAL EVALUATION Based on the recent observation works at the end year of 2017, it is desirable that the downstream channel needs to be normalized. It is suggested due to the rainfall in the canal that flowing into the diversion tunnel may affect the stability of the dam. It is also found that there has been no follow-up for sediment removal of a v-notch drainage channel. Thus, may result that the water from v- notch pools cannot be monitored manually. In invistigation of saddle dam 5 and saddle dam 6, it is proposed that there should be re-emphasized to ban illegal connections (water suction) from River Basin Organization Sumatera I, as there have been scoursing on the dam body of saddle dam 5 and rock pairs of saddle dam 6 due to the wild connections made by the community (Dam Operation Unit Report, 2017) (see Fig. 3). Fig. 3. The Water Siphoning Activities by the Community 4.2. MONITORING RESULTS AND RECOMMENDATION In general, the reading of instrumentation shows a good result without any symptoms of anomaly or deviation. The piezometer at the core zone indicates the filter is working properly and the other located at the foundation illustrates that the wall diaphragm is functioning well. The fluctuation of seepage discharge occurred mostly influenced by the amount of rainfall. The periodic observation works issued some suggestions. Some buildings and instruments have not been in an optimum maintenance. As a deduction, the Dam Operation Unit (DOU) of River Basin Organization of Sumatera - I submitted 1320