Cooking and bathing became difficult when taps ran dry in Batam, an Indonesian island where residents are protesting as data centers spring up to power the global artificial intelligence boom.
The area had suffered a "long drought" caused by low rainfall, the local water utility operator told AFP, as a strong El Nino cycle exacerbates dry weather.
But, as in other countries, anger has been directed at the data centers, warehouse-like facilities that keep apps and artificial intelligence tools running, with water often used to cool their humming servers.
Frustration is bubbling over in Indonesia and Malaysia -- especially in regions bordering Singapore that are seen as a prime location for new tech facilities.
At first the main reaction was, "thank God industry is coming" to Batam, 54-year-old tradesman Juniardi Adinda Sembiring Gurukinayan told AFP.
But severe recent outages hitting the municipal water service in some Batam communities meant "sometimes I skipped my shower".
"We cannot eat rice without water. We cannot cook vegetables without water," he said.
At the worst point, dozens of angry residents staged spontaneous protests outside Nongsa Digital Park -- a new cluster of data centers and other amenities, designated a special economic zone.
People in the district believe "that the water shortages... are related to the construction of data centers", Juniardi said.
The drought caused the nearby Nongsa Reservoir to run very low, and supply systems were further disrupted by an electrical fault, said Ginda Alamsyah, a spokesman for water utility operator Air Batam Hilir (ABH).
The tech park receives water from a different source, Duriangkang Reservoir, an industry source told AFP.
- 'Smelly, yellowish' -
Authorities in late September told developers they must build plants to desalinate seawater for cooling, to avoid straining local resources.
Companies behind operational or planned data centers at Nongsa Digital Park include the Singapore-headquartered BW Digital, DayOne, and Princeton Digital Group.
Another owner, Hong Kong-based Gaw Capital Partners, said it was "aware of the distress and frustration expressed by local residents in Nongsa and surrounding Batam communities" over water shortages.
To ensure sustainable operations, "our data center facilities must deploy a combination of advanced engineering, efficient architectural designs, and renewable energy sourcing," it said.
That includes using so-called "closed-loop" water systems that reuse resources and so require less fresh liquid.
As residents demanded a return to normal water supply at one protest last month, AFP saw a police officer filling up buckets they had brought to Nongsa Digital Park.
In nearby coastal village Mata Ikan, people had to use seawater to wash after defecating, said demonstrator Rahmat, 52, who like many Indonesians goes by one name.
"The water crisis has been going on for the past year, but it got worse in the last six months," 38-year-old Sulastri said at her home, where supply was out, so she poured water from a plastic bottle to wash dishes.
"Many of us here run small stalls. We used to make ice cubes, but we can't anymore."
The government has been distributing water from tanks driven around, but Sulastri said it was "smelly" and "yellowish".
AFP contacted the local government BP Batam, and Indonesia's ministry for economic affairs, which regulates Nongsa Digital Park, for comment. Neither responded.
Recent disruption to water distribution "was not caused by data centers or AI or investors entering that sector," Amsakar Achmad, Batam mayor and head of BP Batam said in October, according to local media.
The decline in water supply was instead "due to weather and climate factors", he said.
- Tech boom -
Data center capacity in Southeast Asia is projected to triple from 2025 levels by 2030, driven by a tenfold surge in AI use, according to a KPMG report.
This can put pressure on water supplies, but also electricity grids still heavily reliant on planet-warming fossil fuels.
The data center construction boom in Indonesia and Malaysia began when resource constraints led hyper-connected Singapore to halt new developments between 2019 and 2022.
It has since ramped up, boosting both countries' economies as governments and tech giants pour hundreds of billions of dollars into training and running AI.
Ginda said water provider ABH supports policies to encourage investment and development in Batam, south of Singapore and connected to it by undersea cables.
But he added that water demand must be managed properly, adding that ABH is trying to boost the capacity of Batam's six reservoirs by dredging them, with cloud seeding another option in dry periods.
- 'Inflection point' -
North of Singapore, Malaysia's Johor region has become "one of the largest emerging AI infrastructure clusters in the world", according to researcher James Chai of the ISEAS-Yusof Ishak Institute.
Just half a decade ago, Johor hosted 10 megawatts of data center capacity. That has ballooned by a factor of 200 to 2.1 gigawatts today, Chai said.
The environmental cost could be high.
By 2035, data centers are forecast to swallow up one-third of Malaysia's total energy consumption, the deputy prime minister told parliament in July.
The government said at that time it would only approve data center projects after ensuring sufficient energy and water supply capacity.
Johor residents have protested over dust pollution and flash floods linked to data center construction, as operators build closer to residential areas.
"Johor is at a critical inflection point," Mohd Fadhil Md Din of Malaysia's University of Technology told AFP.
"It has the potential to become Southeast Asia's leading sustainable data center hub," but only if it manages resources and spatial planning carefully, he said.
- 'We all feel it' -
Pushback sometimes works.
In Kota Damansara on the outskirts of Kuala Lumpur, a plot of land intended for a data center remains empty after local opposition.
The developer withdrew its planning permission application in August, after its neighbors spoke out online, lobbied their MP and gathered more than 9,000 petition signatures.
Jahaidi Harun, 72, had been concerned that the proposed data center could be noisy and pressure existing infrastructure.
Data centers "use a lot of water," the retiree told AFP, adding that, as in Batam, "if the rain doesn't come for one month, we all feel it".
Following the withdrawal, Malaysia's human resources minister Ramanan Ramakrishnan told local media he wasn't against "development or investment".
But "for large-scale projects that could affect the residents' lives, the people must have a say".
