Thousands of litres of treated sewage are running through the Lower Hutt suburb of Seaview.
The flood began around noon after a seal broke on the major sewage outfall pipeline. The break was located just south of the sewage treatment station on Seaview Rd.
At its peak, the sewage was flowing at a rate of 100 litres a second, said Hutt City Council's general manager of city infrastructure Bruce Sherlock. That was decreasing as the treated sewage was diverted into the Waiwhetu Stream, he said.
The cause of the break was not yet confirmed, but it was possible a power cut caused an air bubble that put pressure on the pipe, Sherlock said. It would take up to four days to fix the pipe, at a cost of about $100,000, he said.
Water was pooled on Seaview Rd for several hundred metres at the intersection with Barnes St. Traffic had not been affected.
At one stage the flooding reached a kilometre down the road to the E Sime building at 61 Seaview Rd.
Although the sewage was treated, it was best to avoid touching it, Sherlock said.
Three pump trucks - each able to hold 3000 to 7000 litres - were clearing the scene. One truck had already taken 13 loads of sewage back to the treatment plant by 2pm, said Dawsons driver-operator Gareth Wick.
Hamish Dawson, also from Dawsons, said the pipe line was shut off earlier today but there was a backlog of sewage which was still coming through.
Robbie Geerlings, from Dynaflow NZ on Seaview Rd, said the ''thousands and thousands of litres'' started running from a site where workers were working on a pipe this morning.
Water was still running at 1.30pm and, while it had not flooded his work, it was covering a lawn outside.
Customers were having trouble getting to the showroom, he said.
Earlier this morning it was running as ''brown water'' but was now running clear, he said.
- The Dominion Post
Is New Zealand's airport security stringent enough?Related story: Risky objects bypass Wellington Airport security