Lessons Learned from Flooding in West Sumatera

In January 2016, West Sumatera suffered a devastating flood that caused loss of life and massive damage to local properties. There are 10 Regencies that was badly affected by this flooding. The worst damaged areas were in Pasaman, Lima Puluh Kota and Solok Selatan Regencies. National Agency for Disaster Management (BNPB) has been identifying the flood damages. It was estimated that 1,003 homes hit by floods and 3,863 people are forcefully evacuated. Flash flood in Pasaman has destroyed 340 hectare of farmlands. In Sijunjung, 276 houses were submerged under the flood water and landslide has cut the only access way to Pekan Baru, Riau. Six person were reported died and one person is still missing after flood water swept him away. 400 houses were also badly damaged in Lima Puluh Kota. BNPB also pointed out that the flooding is not receded yet and even it gets wider spread in February 2016. Clean water, sanitation and food supply are the concerns of BNPB after the disaster.

Flooding in Lima Puluh Kota (Photo is courtesy of Sutopo, BNPB)

The Meteorological Department of Indonesia (BMKG) reported that rainfall in West Sumatera for January 2016 generally was categorized as normal rainfall (i.e. 101mm – 300mm). Only in Solok, Sijunjung, and Tanah Datar Regencies which reported has high rainfall (i.e. 401mm – 500mm). Normal rainfall was derived according to the rainfall data which have ranges of 85% to 115% from the average monthly rainfall over 30 years of recorded data. Director General of Water Resources said that the flash flooding happened in Padang is not due to high rainfall but it was caused by severe blocking of the river at the upstream areas. As proof, fallen trees, natural overgrowth, and rubbish were found in the river after flooding. Unfortunately, there is such a comprehensive study showing the main factors of the flooding. Local people in Solok Selatan informed that the flooding is the worst over 20 years. Batang Suliti and Batang Bangko Rivers in Lima Puluh Kota which were never overflowed over 40 years, it caused flooding in January 2016. From the information above, it can be summarized that the flood is not only caused by the high rainfall. There are other factors that probably as the main trigger of the floods happened. WALHI, an environmental organization in Indonesia said that flooding in West Sumatera is not due to climate factor only, it was also caused by environment damages.  Exploitation of natural resources have been tremendously occurred in West Sumatera. According to the data from Ministry of Energy and Mineral resources (ESDM), 262 mining and mineral exploration have been approved in 2015 for various commodities such as gold, bauxite, coper, calcite and coal. In Solok Selatan for example, it has area of 15,786 hectare for mining exploration purposes which certainly influences the infiltration rates. Subsequently, it leads to higher generated runoff. There are also illegal mining explorations along the river of Batanghari which now using heavy equipment in their operation. Besides that, palm oil plantation has become a major commodity in west Sumatera especially in Pasaman Barat.  This also contributed in changing the hydrological processes (runoff, soil moisture, and evapotranspiration). In the future, there will be more natural resources exploration as the government of west Sumatera currently has preparing 74 new contracts for mining exploration.

There are flood action plans that probably can be taken by the authorities to reduce floods in the future.

1. Flood Risk Assessment is necessary to do.This will give information on which specific areas have higher risks of flooding and how much the damage cost is. Subsequently, it will help the authorities to determine priorities in action.
2. Evaluation on permits for exploitation of natural resources. This includes the evaluation on the existing mining exploration and checking their operational procedures whether according to the environmental criteria or not. 
3. Forestation. This is the way to restore the existing catchment as the deforestation activities massively occur.
4. Improvement in river capacity and drainage system including the flood plain areas.
5. Controlled flooding in specific areas where damage can be limited e.g. contructing dikes, detention ponds, weir dredging, etc.
6. Flood forecasting. This is a good way to warn people about flooding and quick actions can be done by the authorities to minimize the impacts of flooding.

Finally, the most important factor in whatever actions that going to be taken is the awareness of government to put this issue as their first priority even pessimistically it would not happen.