Tokyo's plumbing system has been under extra pressure due to toilet breaks at halftime during the FIFA World Cup, according to the city's waterworks bureau.
World Cup viewership has reached an annual high of 48.7 in Japan, beating the previous best of 33.9 per cent.
But the extra eyeballs have had an unusual consequence, especially when the national team plays.
Choosing to leave their viewership momentarily at halftime, water use jumped 24 per cent in Tokyo during the break.
“We presume it’s because a lot of people holding off on a trip to the bathroom all went at once," an official from the waterworks bureau told the Japan Times.
“Water use can fluctuate, especially during football matches, which only have one break in the middle.
“It also can be affected by a period of time, excitement and other factors.”
Following the match, fans again headed towards the bathroom with a 50 per cent rise in water pressure confirmed.
Officials said they had prepared for the changes to the water supply.