Flash Floods in Sumbawa and West Sumatra
In 2023, it seems that disasters cannot be separated from happening in various regions. Like this April 4th, flash floods hit Moyo Hulu, Sumbawa, West Nusa Tenggara, around 15 houses were reported washed away. Hundreds of houses and public facilities were inundated by the floods until the livestock disappeared.
Muhammad Nurhidayat, Chief Executive of the Sumbawa Regional Disaster Mitigation Agency (BPBD), in a preliminary assessment report, said that the flash floods were triggered by several factors. In addition to the high rainfall intensity in Sumbawa and its surroundings, it is also suspected that there is a lot of barren land due to illegal logging which has reduced the scope and intensity of groundwater absorption.
Musmulyadi Yowry , an environmental activist and founder of Sahabat Bumi, said that floods in Sumbawa have become a regular occurrence every year. At the same time there has been no effort to resolve the causes of flooding. Flood disaster mitigation is also not optimal.
West Sumatra also experienced floods and landslides at the end of March. Isril Berd, an environmental expert from Andalas University , said that the topography of the South Coast is a sloping beach area. The location between Bukit Barisan and the beach is not far. If it rains in the forests of the Kerinci Seblat National Park ( TNKS ) or the slopes of Bukit Barisan, the water will quickly enter the river and continue downstream. It gets worse when the forest is cleared, the river body is unable to accommodate the volume of flow, so there are floods on both sides of the river, which are many there .
Throughout 2023, it seems that disasters have occurred in various regions. Like this April 4th, flash floods hit Moyo Hulu, Sumbawa, West Nusa Tenggara, around 15 houses were reported washed away. Hundreds of houses and public facilities were inundated by the floods until the livestock disappeared. In West Sumatra, floods and landslides occurred at the end of March and left two people dead.
In Sumbawa, four houses were washed away in Berang Rea Village. In the village of Batu Terin Gada, five houses were swept away by the floods.
The Sumbawa Regional Disaster Management Agency (BPBD) Center for Operations and Control (Pusdalops) reported that at least 829 people from 208 families live in 13 villages in five sub-districts affected by this disaster.
Flash floods washed away a milling factory and damaged 27 hectares of rice ready for harvest, and submerged 99 hectares of rice fields and three cars. In several videos, residents are hysterical when they see their house washed away and cry when they see the rice that has just finished harvesting is submerged in the flood.
Muhammad Nurhidayat, Chief Executive of the Sumbawa Regional Disaster Mitigation Agency (BPBD), in a preliminary assessment report, said that the flash floods were triggered by several factors. In addition to the high rainfall intensity in Sumbawa and its surroundings, it is also suspected that there is a lot of barren land due to illegal logging which has reduced the scope and intensity of groundwater absorption.
Apart from that, he said, the infrastructure for protecting cliffs and embankments in watersheds (DAS) is not maximal in preventing an increase in water discharge and coupled with severe river sedimentation.
The Lito Bridge also looks porous due to flooding. In the video sent by residents to Mongabay , it can be seen that one side of the bridge is separated from the road. The overflow of water mixed with mud carried wood and bamboo materials. Hit the bridge body and erode the left and right sides of the bridge. As a result, the bridge is not safe for vehicles to pass.
Lito Village in Moyo Hulu District is the worst affected area. Lito Village has three hamlets located not far from the river, 770 people were affected, five houses were washed away, 50 hectares of rice fields were submerged and the connecting bridge to Lantung Village was broken, cutting off access.
Furthermore, in Brang Rea Village, there are three washed-up houses. There are still eight houses, half of which have collapsed in the flash floods and one mill washed away in the flash floods.
Ecological Damage
The flash floods that hit Sumbawa further strengthened the evidence of Sumbawa's ecological damage. Illegal logging, land conversion for agriculture and plantations, including mining, both legal and illegal, exacerbate environmental conditions.
Sendi, who is actively studying ecological damage in Sumbawa, said that according to data from the NTB Energy and Mineral Resources Office for 2021, mining concessions total 128,344 hectares, both mining business permits (IUP) and people's mining permits (IPR).
For Sumbawa and West Sumbawa each have 43 IUP and 16 IPR, with a land area of 40,411.92 hectares and 48,244.79 hectares.
"At the same time, the rate of deforestation in NTB is increasing from year to year," he said.
The current flood was triggered by an overflow of the Moyo watershed. According to Sendi, around 17,000 hectares of critical land with minimal forest cover along the Moyo watershed. This condition has an impact on reduced water supply to the dam, which automatically results in drought on agricultural land.
In the end, this condition can cause natural imbalances such as floods in the rainy season and drought in the dry season.
Conditions like this do not only occur in 2023. In 2017, four sub-districts in Sumbawa along the Moyo watershed were affected by flooding, namely the sub-districts of Moyo Hilir, Moyo Utara, Unter Iwes and Sumbawa with 40,291 people affected.
In October 2022, floods and landslides occurred in Lunyuk District, one of the areas on the mining concession map. This flood affected 1,345 families or 4,035 people, with water levels reaching two meters.
“Several infrastructures such as gutters for irrigation canals and roads were badly damaged. Society ultimately loses,''he said.
In August 2022, 43 villages spread across 17 sub-districts in Sumbawa experienced a clean water crisis due to drought. A total of 69,668 residents of 43 villages were hampered in their activities. Such as bathing, washing clothes, washing dishes, drinking livestock, even for drinking and cooking, the community needs clean water assistance from the local government.
“Every year these two disasters occur. Water crisis in the dry season, flash floods when it rains,'' said the man who is also an activist with the Indonesian Indigenous Youth Front.
Musmulyadi Yowry, an environmental activist and founder of Sahabat Bumi, said that floods in Sumbawa have become regular occurrences every year. At the same time there has been no effort to resolve the causes of flooding. Flood disaster mitigation is also not optimal.
Yowry reminded that floods in West Sumbawa will end in 2022. The city of Taliwang is completely paralyzed, and at the same time floods also occur in Sumbawa. The government should have been able to prepare anticipatory steps.
The government also seems to blame the weather for heavy rains. It has never been openly acknowledged that the flash floods in Sumbawa were triggered by forest destruction.
Yowry said the government should focus on long-term efforts to improve forest conditions. He sees that there has been no effort to improve the critical condition of the forest. Every year, he said, news about critical forests is increasing, and at the same time issuing mining permits is easy.
"Just three months ago there was a flood in Taliwang, recently the government came here not to review long-term flood anticipation measures, but to review land for mining permits," he said.
One of the locations to be opened for mining is not far from Yowry's residence. The area is hilly and in the middle of a residential area. If there is a mining permit, he said, new land will be opened. Trees will be cut down, hill material will be dredged. If it rains he predicts there will be an avalanche.
"The community's grief because of the flood has not finished yet, now it's time to discuss mining permits."
Floods and landslides in West Sumatra
In West Sumatra, at the end of March there were also floods and landslides. Hundreds of houses were flooded, cross-provincial roads were blocked, facilities and infrastructure were damaged and in Agam Regency, two people died due to being buried in a landslide.
Two residents of Baruah Village, Joronggantiang, Nagari Sungai Landia, Agam Regency, West Sumatra died when they were buried in a landslide while in the mosque's toilet, last March 25.
Three days later, on March 28, 2023 to be exact, floods and landslides hit Agam Regency again. The Agam Regional Disaster Management Agency (BPBD) noted that six out of 16 sub-districts were hit by floods, fallen trees and landslides due to high rainfall hitting the area.
"There were no fatalities as a result of the incident but the landslide material closed the road and flooding inundated a school in the Batang River," said Bambang Warsito, Chief Executive of BPBD Agam.
Floods also hit Pesisir Selatan District. At least nine sub-districts out of 15 sub-districts in Pesisir Selatan and around 1,500 residents' houses were affected by this hydrological disaster. The worst area was the Nyalo River, Tarusan District, with water levels reaching 1.5 meters to 2 meters.
Head of BPBD Pesisir Selatan Doni Gusrizal said that in the Nyalo River around 50 heads of families had to be evacuated because the water that had submerged their houses was up to 1.5 meters high.
Research by Lusy Fransiska in 2017 from the Department of Soil Science and Land Resources, Faculty of Agriculture IPB, in general the geomorphological conditions of Agam Regency consist of two regions, namely plains (35%) and hills/mountains (65%).
Considering that there are many volcanoes in and around Agam, pyroclastic material (volcanic ash) dominates the surface material in the hills or mountains. This material, said the research, generally forms relatively thick soil so that the sensitivity of volcanic soils to erosion and landslides is an important issue for environmental management in Agam.
Isril Berd, an environmental expert from Andalas University, said that the topography of the South Coast is a sloping beach area. The location between Bukit Barisan and the beach is not far.
"If it rains in the TNKS forest or the slopes of Bukit Barisan, the water will quickly enter the river and continue downstream."
This situation gets worse when the forest is cleared, the river body is unable to accommodate the volume of flow, so there are floods on both sides of the river, which are many there.
So, he said, data must now be collected on the extent of land conversion or forest encroachment.
From field information, one of the main causes of flooding on the south coast is forest destruction. "If that's what happens, it means that there is open land, open land when it rains with high intensity of course water runoff can occur."
Currently, he said, prevention efforts are by restoring deforested forests and structural measures by installing gabions or terracing.
He said, there must be planting and then structural action. Even if you plant small seeds, the plants will not be able to withstand the sliding or sliding forces of the soil. So the open land, said Isril, must be modified so that it can break runoff and landslides.
"This should be done by the relevant departments. Also structural and nonstructural measures. Structural, by repairing the tributaries. Non-structural, by making regulations."
According to him, the local government has forgotten to address this region as a disaster-prone area. West Sumatra, he said, is a window for disasters, such as floods, landslides, volcanoes, faults, volcanic earthquakes, tectonic earthquakes and others.
Rain Until June
Based on the March 2023 edition of the West Sumatra climate bulletin from the West Sumatra Climatology Station, it is stated that the forecast for West Sumatra's rainfall will continue until last June changing to the dry season. In April, in general, it is in the middle category. For high category rainfall (> 300mm) will occur in the southern part of West Pasaman, parts of Padang Pariaman and southern Solok Selatan.
Meanwhile, forecasts for the nature of rain for the West Sumatra region this April are generally below normal to normal.
Fajar Sukma, Head of Prevention and Preparedness of the West Sumatra BPBD, said flood and landslide warnings from the National Disaster Management Agency (BNPB) had been conveyed and disseminated by the West Sumatra BPBD to prevention and preparedness (PK) sectors throughout the province.
Likewise, dry early warning at BNPB, he said, has also been extended to the ranks of the implementing fields.
BPBD also urges district/city governments to carry out mitigation efforts such as planting mangroves or cypress shrimp along the shoreline to anticipate the danger of coastal abrasion in extreme climates.
For the city of Padang, there has been assistance from the Ministry of Public Works and Public Housing to anticipate coastal abrasion."
Fajar advised not to clear protected trees and trees that absorb water in the upstream of rivers. The people's way of life, he said, is not to throw garbage along the river. Equally important, he said, RT/RW improve urban planning, especially the provision of water absorption land, reservoirs and others.
"Everything comes back to all the people of West Sumatra together to protect the environment so that it is not damaged so that the ecosystem is good"
He said disaster management was not solely the government's business, but all parties including the business world, society, academia and the media.