As torrential rain drenched Patcham in Brighton on Thursday, people who live in the area saw sewage erupting from drains and manhole covers.
The deluge is reported to have particularly hit Jasmine Court, a community for older residents, as well as roads including the Deneway roundabout in London Road, Carden Avenue, Winfield Avenue and Wilmington Way.
Those living in Patcham reported seeing “rivers of sewage” flooding the streets, with one claiming manhole covers had become dislodged by the influx of wastewater.
Brown water was seen pouring along streets, with tissues and sanitary products spotted by manhole covers and drains after the torrent of sewage had subsided.
Patcham resident Allison Packman said this is a frequent occurrence in the neighbourhood.
She said: “My mum lives in Winfield Avenue which is a flooding hotspot. We get sewage and tissues running through the street every time there is heavy rain. She has even had it come up in her back garden – it is extremely smelly and frankly disgusting.
“It also floods close to a school crossing and parents have to stop their children from jumping in the puddles because it’s not rainwater, it’s sewage.
“There are new houses being built all around this area and the neighbours are concerned this is going to put even further pressure on our water systems. It’s a health risk.”
Residents claim that planned development at Patcham Court Farm for a new Royal Mail site will worsen flooding in the neighbourhood as well as affect the city’s water supply.
Campaign group Patcham Against Royal Mail says the site at Patcham Court Farm plays an important role in the area’s flood defences and development would put more pressure on sewers which could increase the frequency and severity of flooding.
Anne Meadows, Conservative city councillor for Patcham and Hollingbury, said: “Patcham always floods when there is heavy or persistent rain, especially around the bottom of Ladies Mile Road, Winfield Avenue and Vale Avenue.
“It gets very murky and leads residents to believe it is sewage coming up. It may well be and it will only get worse if Patcham Court Farm is developed.
“I do not understand why Southern Water don’t check this problem out for themselves.”
A spokeswoman for Royal Mail said a flood risk assessment had been undertaken and the current site discharges more surface water than the proposed development would in an “extreme rainfall event”.
She said: “It is very important to us that we mitigate or remove any potential impact the new development may have on residents in Patcham.
“We would like to reassure residents that there will be additional measures to guarantee no off-site flooding risk resulting from the development.”
Brighton and Hove City Council and Southern Water were approached for comment.