What Decides When a Fab Restarts Is Water — Kumamoto Day 5, and Why Kikuyo and Ozu Vanished from the Outage List

This article follows our day-4 update from the previous day, July 31, organizing the situation as of the morning of day five, August 1. Please also see our day-3 update and our initial status report from the night of the quake. No new official statements from any company could be confirmed on Saturday, August 1, but two government primary sources — the Ministry of Land, Infrastructure, Transport and Tourism's 14th damage report and the Prime Minister's Office's disaster-response meeting held on July 31 — laid out in concrete terms the preconditions for the fab restarts planned for next week.

[August 3 update] For the situation on day seven, August 3 — the national government taking over management of Yatsushiro Port, the Kyushu Shinkansen's recovery slipping past August, and Tokyo Electron Kyushu's full restart — see our day-6 report.

Why Does a Fab Restart Depend on Water?

Cleaning processes account for roughly 30% of all semiconductor manufacturing steps, and the water used for that cleaning isn't tap water — it's "ultrapure water," water with virtually zero impurities. A single large fab can consume thousands to tens of thousands of tons of it in a day. Making ultrapure water requires drawing a large, stable supply of raw water from the local water utility, and a water outage cuts off that supply at the source.

This has already played out once in this earthquake. The day after the quake, on July 29, a wall leak at Renesas's Kawajiri plant (Minami-ku, Kumamoto City) temporarily halted its pure-water supply. Because air conditioning and power held up and cleanroom conditions themselves were preserved, it didn't turn into a major problem (our day-2 update; Nikkei Cross Tech, July 29, 2026) — but it's a real example of how a water outage or leak can stop a fab through its water systems rather than through the production equipment itself. How far water outages have recovered by day five is a precondition that will determine whether the several restarts planned for next week actually happen on schedule.

How Far Have the Water Outages Recovered?

According to the Ministry of Land, Infrastructure, Transport and Tourism's 14th damage report (as of 7:00 a.m., August 1; the water-supply section as of 5:30 a.m. the same day), water outages fell from a peak of about 108,100 households across 4 prefectures and 15 municipalities to about 71,000 households across 1 prefecture and 10 municipalities (Ministry of Land, Infrastructure, Transport and Tourism, August 1, 2026). By municipality: Kumamoto City 3,200 households; Yatsushiro City 25,269; Uto City 12,200; Kamiamakusa City 7,290; Uki City 17,000; Amakusa City 1,100; Mifune Town 500; Kosa Town 400; Hikawa Town 3,231; Ashikita Town 1,000. Yanagawa City (Fukuoka Prefecture), Tara Town (Saga Prefecture), Minamishimabara City (Nagasaki Prefecture), Koshi City, and Hitoyoshi City have already resolved their outages entirely, down to zero.

The most striking thing about this list is that Kikuyo Town and Ozu Town — where semiconductor sites are concentrated — don't appear on the water-outage list at all. Kikuyo Town is home to JASM and Sony's Kumamoto Technology Center; Ozu Town is home to a Tokyo Electron Kyushu site. The absence of both towns from the list means either that no outage occurred there or that recovery is already complete and they've simply dropped off the list — but the Ministry's report alone cannot confirm which. Koshi City's outage has also fallen to zero and recovered, but it's worth noting that the city's own peak outage figure is listed as "unknown."

It bears noting that the peak outage figure of about 108,100 households is a simple sum of each municipality's peak value, and not all municipalities peaked at the same time — the actual number of households affected simultaneously may well have been lower. Even so, of the roughly 71,000 households still without water, Yatsushiro City (25,269) and Uki City (17,000) alone account for nearly 60% — the center of gravity of the outage remains in these two cities.

Is Electricity Still Being Held Up by Power-Supply Vehicles?

At the Prime Minister's Office's fourth disaster-response meeting, held from 5:20 p.m. on July 31, Prime Minister Takaichi instructed relevant ministries to "maintain the power-supply-vehicle system for the time being" (Prime Minister's Office, July 31, 2026). The instruction to "maintain" it is itself evidence that some areas still haven't been restored to grid power — electricity supplied through the normal transmission network.

The prime minister also went into specifics on water. "On water, we need to strengthen cooperation with the Self-Defense Forces and deploy water-supply trucks held by other municipalities, so that supply to medical, welfare facilities and shelters doesn't run short," she said, and outlined a policy of "arranging support from water and sewage engineers nationwide … to accelerate the recovery of the water and sewage infrastructure itself." She also stated that "the supply of gasoline and other fuel oil must also be fully secured" (Prime Minister's Office, July 31, 2026). The fact that three separate measures — power-supply vehicles, water-supply trucks, and fuel supply — were all being ordered at once is itself the flip side of how much time full infrastructure recovery still needs.

What Are Next Week's Three Milestones?

As of the morning of August 1, no new statements from any semiconductor company could be confirmed — meaning the situation as of the night of July 31 remains the latest. Three milestones lie ahead next week. Tokyo Electron Kyushu plans to resume full production from August 3 (Yomiuri Shimbun, July 30, 2026); Sony's Kumamoto Technology Center (Kikuyo Town) plans a phased restart of operations from August 4 and expects to return to pre-earthquake operating levels by mid-August (Sony Semiconductor Solutions' official second statement, July 31, 2026); and Renesas's Kawajiri plant plans to resume production progressively from August 5, aiming to return to pre-earthquake production capacity within about three weeks of restarting (Renesas's official third statement, July 31, 2026). The Nishiki plant had already returned to pre-earthquake production capacity on the morning of July 31.

JASM, meanwhile, has had no update since its third statement at 8:47 p.m. Taiwan time on July 29 — which said equipment inspection and recalibration work was continuing and did not declare full recovery — and had still not issued a fourth statement as of the morning of August 1 (Taipei Times, TechNews, July 31, 2026). Mitsubishi Electric's Koshi and Kikuchi plants likewise remain limited to partial-process restarts, with the timing of a full restart still undecided (Mitsubishi Electric official statement, July 30, 2026). How the three restarts planned for next week will be affected by municipalities still without water, or by areas still dependent on power-supply vehicles, remains to be seen.

What Is the State of Ports, Rail, and the Government Response?

At the ports, Yatsushiro Port's container crane has rail damage and an oil leak, and port operators, the crane manufacturer, and port-construction contractors are on site examining repair options; no recovery timeline has been given yet (Ministry of Land, Infrastructure, Transport and Tourism's 14th report, as of 5:30 a.m., August 1). The same report shows that the seismically reinforced quay wall's 20-meter section received emergency repairs in the early hours of July 29, and that the container quay (12m deep, 200m long) is accepting Japan Coast Guard patrol vessels and Maritime Self-Defense Force support ships for water-supply assistance. In other words: the quay wall itself can be used, but the container-handling function itself remains shut down.

On rail, Kyushu Shinkansen service between Kumamoto Station and Kagoshima-Chuo Station remains suspended. The Ministry's 14th report (as of 10:30 p.m., July 31) states "no additional routes planned to be suspended going forward," but that only means no new suspensions are expected — it says nothing about a recovery outlook. Damage extends to more than 200 locations including fallen soundproof-wall panels, two rail breaks, and one shifted bridge girder. Conventional lines remain halted too: JR Kagoshima Line between Kumamoto and Yatsushiro, and the Hisatsu Orange Railway between Yatsushiro and Sendai.

An "extremely severe disaster" designation still cannot be confirmed in primary sources as of the morning of August 1 — it appears in none of the Prime Minister's Office, the Cabinet Office's disaster-prevention division, or the Ministry's 14th report (confirmed August 1, 2026). Instead, the government decided on July 31 to advance 61.6 billion yen in regular local-allocation tax grants. Prime Minister Takaichi stated at the same day's fourth disaster-response meeting: "We will decide today on an advance disbursement of a total of 61.6 billion yen in regular local-allocation tax grants" (Prime Minister's Office, July 31, 2026). The number of eligible municipalities and the actual disbursement date have not yet been given.

The local response headquarters was set up at the Kumamoto prefectural government office on July 30, headed by Vice Minister Tsushima. The disaster-response meeting has now convened four times, from the first meeting at 7:49 p.m. on July 28 through the fourth at 5:20 p.m. on July 31 (Prime Minister's Office, July 28-31, 2026). As for damage-cost estimates, the Ministry's 14th report (23 pages in total) contains no mention of a "damage amount" or "total damage," and none has been published as of the morning of August 1.

Where Does the Human Toll Stand Now?

A discrepancy remains between government primary sources and media reporting on the death toll. The Fire and Disaster Management Agency's 26th report (as of 7:00 a.m., August 1) puts the death toll at 35, explicitly noting "unchanged from the previous report." The breakdown is Yatsushiro City 20, Uki City 2, Kashima Town 7, Kosa Town 1, Hikawa Town 4, and 1 still under review (Fire and Disaster Management Agency, August 1, 2026). At the Prime Minister's Office's fourth disaster-response meeting (July 31), Prime Minister Takaichi likewise stated: "Including cases still under review for their relation to the disaster, the toll stood at 35 as of 3 p.m. today" (Prime Minister's Office, July 31, 2026). Jiji Press, however, reported a death toll of 36 in an article filed at 8:53 p.m. on July 31 (Jiji Press, July 31, 2026). This one-person gap has not been confirmed in primary sources as of the morning of August 1. It's also worth noting that the 35 figure is not "35 disaster-related deaths" — it's a total that includes the one case still under review.

The figures given for evacuees also differ in nature. At the fourth disaster-response meeting, the prime minister stated: "About 9,200 people, mainly in Kumamoto Prefecture, are staying in shelters, and I understand many others are also being forced to sleep in their vehicles" (Prime Minister's Office, July 31, 2026). Meanwhile, the Cabinet Office's damage-status tally (as of 7:30 a.m., July 31) lists 399 shelters and 9,637 evacuees (a peak of 506 shelters and 9,931 people). The prime minister's figure of about 9,200 is a floor value based on shelters alone, and does not include evacuees outside shelters, such as those sleeping in vehicles. The population subject to evacuation orders totals 116,909 households and 246,540 people (Fire and Disaster Management Agency's 26th report, August 1, 2026).

Key Takeaways

• Water outages fell from a peak of about 108,100 households (4 prefectures, 15 municipalities) to about 71,000 households (1 prefecture, 10 municipalities). Kikuyo Town and Ozu Town — where semiconductor sites are concentrated — disappeared from the outage list, and Koshi City's outage has also resolved, but the remaining outages are concentrated in Yatsushiro City (25,269 households) and Uki City (17,000 households) (Ministry of Land, Infrastructure, Transport and Tourism's 14th report, August 1, 2026).
• At the Prime Minister's Office's fourth disaster-response meeting (July 31), Prime Minister Takaichi instructed officials to "maintain the power-supply-vehicle system for the time being." She also ordered the deployment of water-supply trucks, the arrangement of water and sewage engineers from across the country, and secure fuel-oil supplies — all signs that full restoration of grid power and infrastructure will still take time.
• Next week brings restarts at Tokyo Electron Kyushu (Aug. 3), Sony's Kikuyo plant (Aug. 4), and Renesas's Kawajiri plant (Aug. 5). Renesas's Nishiki plant had already returned to pre-earthquake production capacity on the morning of July 31. JASM, meanwhile, has issued no fourth statement, and Mitsubishi Electric's timeline for a full restart also remains undecided.
• At the ports, repair options for Yatsushiro Port's container crane remain under review, and Kyushu Shinkansen service between Kumamoto and Shin-Minamata remains suspended. An "extremely severe disaster" designation still cannot be confirmed as of the morning of August 1, but the government decided on July 31 to advance 61.6 billion yen in regular local-allocation tax grants. Damage-cost estimates also remain unpublished as of the morning of August 1 (Ministry of Land, Infrastructure, Transport and Tourism's 14th report; Prime Minister's Office, July 31-August 1, 2026).
• The death toll stands at 35 in the Fire and Disaster Management Agency's 26th report (unchanged from the previous report), but Jiji Press reported 36 on the night of July 31, leaving a one-person discrepancy. The number of evacuees also has two figures: about 9,200 (a floor value, based on shelters, cited by the Prime Minister's Office) and 9,637 people across 399 shelters (per a Cabinet Office tally).