- Coastal erosion on the west coast of Indonesia’s Sulawesi Island is so advanced that seawater has penetrated the groundwater supply that tens of thousands use for drinking water.
- The communities have yet to be served by utility water provision, so families are resorting to costly supplies of water from private distributors.
- Research shows that rising seas and more frequent and powerful storms will accelerate coastal abrasion, raising burdens shouldered by the world’s coastal communities.
POLEWALI MANDAR, Indonesia — Over the past three decades, the residents of Mampie village have watched their homes and farmland vanish from the west coast of Indonesia’s Sulawesi Island. A grove of orange trees collapsed into the sea some time ago. Buffalo no longer cool off in muddy sumps by the beach.
“It’s gone,” Darwis, the Mampie village chief, told Mongabay Indonesia as he pointed out to sea. “In the past, there were many houses and large farms — now everything is gone.”
Erosion of the world’s shorelines is inflicting high costs on coastal communities like Mampie as rising tides encroach on human infrastructure and settlements.
Darwis is one of at least 88,000 people living on 677 kilometers (421 miles) of coastline in West Sulawesi province who are vulnerable to storm surges and abrasion, according to a 2023 risk index published by Indonesia’s disaster management agency, the BNPB.
The constant impact of water, sedimentary particles and debris from everyday tides and occasional storm surges gradually breaks down the shoreline, causing hundreds of millions of rupiah in damages in just the last two years, including the loss of at least 18 hectares (44 acres) of land.
The trend looks set to worsen not just in Sulawesi but for coastal communities across the globe, as sea levels rise and extreme weather becomes more pronounced.
A 2018 study published in the journal Scientific Reports estimated around 28,000 square kilometers (11,000 square miles) of land had been lost worldwide to coastal abrasion, an area 10 times larger than Hong Kong. Research published in the same journal in 2020 predicted losses due to extreme coastal flooding would be even more severe in near the future, concluding that rising sea levels will “radically redefine the coastline of the 21st century.”
Data released on Nov. 15 by the Pacific Institute, a U.S.-based nonprofit, showed conflicts due to water resources have increased over the last two decades.
“We also see a worrying increase in violence associated with water scarcity worsened by drought, climate disruptions, growing populations, and competition for water,” said Peter Gleick, co-founder of the Pacific Institute.
In West Sulawesi, erosion of the coastline of Wonomulyo subdistrict, where Mampie is located, has already disrupted lives and raised the cost of living here. For the people of Mampie, this has meant both lower incomes and higher costs.
Water from dozens of ground wells around Mampie village has turned the color of rust. The water tastes of brine and grit.
“In the past the well water was clear. That’s what we would drink,” said Hansiani, a resident of Mampie.
Khaeruddin Anas, the head of the West Sulawesi provincial maritime agency, told Mongabay Indonesia that contamination of the aquifer was a function of coastal abrasion.
“The results of our monitoring in December 2022 are that several areas are in serious condition because seawater has entered residential areas,” Khaeruddin said. “We can’t deny that it is seawater intrusion.”
“If you want to find a salty well, this is the place,” said Jumari, a local official in Pesuloang village, about an hour’s drive from Mampie.
Hansiani and her neighbors now harvest the rain as their main source of water. They’ve installed funnels made from discarded bottles on their rooftops, with pipes carrying the water down into a large iron barrel. While it works during the rainy season, there’s no freshwater to be had during the long dry season without rain.
Like much of Indonesia, West Sulawesi province has endured sweltering temperatures and prolonged drought this year owing to the El Niño and Indian Ocean Dipole climate patterns.
Others in Mampie resort to purchasing drinking water by the gallon, a costly means of obtaining water that millions of low-income families nonetheless depend on.
Hasira said her family spends almost 7 million rupiah ($450) per year on water, multiples higher than a middle-class family with access to piped water or a working ground well. Sometimes she washes her children’s school uniforms using the water she buys her family to drink.
The dearth of freshwater has meant many crops here have wilted, while others have been lost as a direct impact of the abrasion afflicting the coastline.
“We usually sold coconuts,” Hasira said. “Since the abrasion, there are fewer coconuts [trees] here.”
Hasira’s family now relies on what her husband can earn from casual labor.
Inflation by the gallon
According to the United Nations Intergovernmental Panel on Climate Change (IPCC), today “roughly half of the world’s population are assessed as currently subject to severe water scarcity for at least some part of the year due to climatic and non-climatic factors, and this is projected to be exacerbated at higher levels of warming.”
For the people of Mampie already facing water stress, extreme weather and loss of land, the risks are particularly pronounced owing to the natural exposure of the West Sulawesi coastline, which juts into the corridor strait linking the Java and Celebes seas.
The topography of the shelf in the Makassar Strait forms a funnel effect that strengthens nearshore currents, amplifying the punch of an incoming tide on West Sulawesi’s coast.
“It’s like this: if a large pipe connects into a small pipe, the current passing through the small pipe will be very large,” said Dwi Susanto, an Indonesian atmospheric and marine scientist at the University of Maryland in the U.S.
These conditions enable more aggressive abrasion, and faster contamination of the aquifer by seawater.
Widodo Setiyo Pranowo, a researcher at Indonesia’s Center for Climate and Atmospheric Research (PRIMA), cited data used by the Maritime and Fisheries Research Agency (KKP) that showed Mampie’s higher vulnerability to coastal erosion.
However, he said the intrusion of seawater into the groundwater supply showed the rate of change was surprisingly rapid, noting that extreme weather events, such as storm surges, have become more frequent over the last 15 years in West Sulawesi.
Muhammad Reza Sahib, from the People’s Coalition for the Right to Water (KRuHA), a civil society organization, said greater government intervention was needed to ensure wider access to piped water.
In Mampie, village chief Darwis stopped at a disused pipe in the ground near the coast. The government installed the water pipe several years ago, but the state utility still hasn’t sent any water through. The villagers built a 5-meter-high (16-foot) water tower, and for a few months the government trucked in water to fill up the tower. Then it stopped. Now the tower just collects rainwater.
Darwis says he asked the local utility, PDAM Polewali Mandar, to supply Mampie with water.
“But they came only once,” he said.
When he asked them to install a regular water supply, he said they refused because the villagers weren’t paying customers.
“I told them that we want to be customers,” Darwis said. “But yeah, we haven’t heard anything.”
Banner image: A woman stands next to a well with water that tastes salty due to seawater interference. Image by Agus Mawan/ Mongabay Indonesia.
Mentaschi, L., Vousdoukas, M. I., Pekel, J.-F., Voukouvalas, E., & Feyen, L. (2018). Global long-term observations of coastal erosion and accretion. Scientific Reports, 8(1). doi:10.1038/s41598-018-30904-w
Taherkhani, M., Vitousek, S., Barnard, P. L., Frazer, N., Anderson, T. R., & Fletcher, C. H. (2020). Sea-level rise exponentially increases coastal flood frequency. Scientific Reports, 10(1). doi:10.1038/s41598-020-62188-4