The New Zealand Blood Service's Tauranga branch was expected to shut for the rest of this week after staff arrived at work today to find the building awash with water.
Tauranga firefighters used industrial-strength squeegees and a wet vac to remove most of the water, leaving sodden carpets throughout the Cameron Rd centre.
Senior Station officer Phil Price said it took firefighters about an hour to get rid of the water which had gushed from a water filter connection in the kitchenette at the front of the office.
Mr Price said it was not unheard of for hoses to come off water filters and he had been to a number of call-outs in similar circumstances over the years.
The water was 30mm to 40mm deep when firefighters arrived just after 7am to begin the cleanup. Floodwaters were mainly contained to the blood service's part of the building and had just started to come through to the Jenny Craig Weight Loss Centre next door, he said.
It was the second time the blood service had been flooded in the past 12 months. The service was meant to have reopened today.