Summertime enjoyment has been marred in the streets north of Mount Maunganui shopping centre by a putrid stench from nearby stormwater drains.

“It really stinks bad,” says one Commons Avenue resident.

A nearby neighbour, Edna, found it wafting through her upstairs window from the culvert below. As a long-time Commons Avenue resident she’s experienced flooding during storms and king tides and neighbours using sandbags to stop water rushing up their driveways. The council eventually widening the drains to allow greater water flow. And now this.

Contractors flushing out the stormwater drains in Commons Ave. Photo: Rosalie Liddle Crawford.

“There has been a putrid smell from the stormwater/effluent/drains throughout our western end of Commons Ave since Christmas Day,” says Margo Greenville, a nearby neighbour of Edna.

“We need the water entering the harbour from our drain tested. It really seems that the sewers are doing something they shouldn’t.”

Margo and other residents started making multiple calls to council, and one evening contractors arrived with a truck to lift the grates and take a look at what lay below. Despite doing some pumping in the middle and at the end of the street, the foul smell lingered, and seemed to spread into other streets such as Maunganui Road, Pacific Avenue, Grace Avenue and May Street.

Pete Andrews is an engineer who also lives on Commons Avenue. He says he spoke to council some time ago about the issue.

“I provided photos of the problem pipeline to Pilot Bay and how it becomes blocked,” says Pete. “I think the smell has arisen as the drain has been blocked once again and is still blocked.

“Unfortunately it is somewhat expected as we are in the midst of a dry period, so the pipeline is not being flushed of seaweed.

“But the issue might not be an issue if the pipeline is extended as I have suggested to council, to match the other outlets along The Mall.”

Pete has gone down to Pilot Bay on more than one occasion to find the end of the stormwater pipe and dig the sand out from over it, so that water can flow out of it once again.

The end of the Commons Ave stormwater pipe in Pilot Bay after being uncovered following being buried again in sand. Common Ave residents are asking Council to extend the pipe. Photo: Supplied.

Tauranga City Council environmental programme leader Radleigh Cairns says that over the past two weeks, council has received a number of complaints about offensive odours in the Pilot Bay and northern Mount Mainstreet area.

“After several investigations of the wastewater and stormwater networks, the source was identified as rotting vegetation pushed up the stormwater network by the exceptionally high tides we have been experiencing,” says Radleigh.

“Contractors have already flushed a number of stormwater sumps and pipes to remove this vegetation and will continue to do so over the coming days.

“The stormwater outlets along Pilot Bay are also being regularly checked to ensure they are open and can be flushed by the tides.”

Tauranga City Council say that rotting vegetation in the stormwater network due to high tides has caused the offensive smell. Photo: Rosalie Liddle Crawford.

Radleigh says sea lettuce produces large blooms in the right growing conditions and can be a nuisance when washed up on beaches and foreshore areas in the inner harbour. Rotting sea lettuce can produce large amounts of hydrogen sulphide gas, creating offensive odours.

“We appreciate this can be unpleasant for nearby residents and visitors and will continue to monitor the situation in the Mount and act accordingly if the issue continues,” says Radleigh.

“As the water temperature rises, sea lettuce growth starts to drop off so we should see a reduction in sea lettuce on our beaches over the rest of summer.”