Sewage spills at a beauty spot totalling more than 1,200 hours in a month have been branded an “assault on the environment” by campaigners.

Chichester Harbour, which is a designated area of outstanding natural beauty (AONB), had sewage water pouring into the bathing site from October 24 to November 23.

According to Southern Water, these longer releases, which are legal, were because of weeks of heavy rainfall and were worsened by Storm Babet and Storm Ciaran.

At the time of writing, the firm’s real-time data showed the outfall at Thornham had been releasing sewage for 710 hours and five minutes between October 24 and November 23.

The outfall at Bosham shows multiple, smaller releases, including one of 281 hours and 24 minutes between October 27 and November 8, and another of 213 hours and seven minutes between November 12 and 21.

SOS Whitstable, a sewage pollution campaign group for Kent, Sussex and Hampshire, flagged the outfalls and told the PA news agency: “That a coastal bathing location such as Chichester Harbour, a designated area of outstanding natural beauty, should suffer over 1,200 hours of sewage pollution in under a month is nothing short of an assault on the environment.”

The wildlife site is one of 34 in England protected by law to conserve and boost its natural beauty.

Southern Water uses storm overflows, which capture rain and wastewater to stop flooding of homes and communities, as emergency outlets when the sewer systems become overwhelmed.

The recent spills were categorised as “genuine” releases, which means the incidents were reviewed and confirmed as taking place.

The chief executive of Chichester Harbour Conservancy, Matt Briers, said: “Water quality sampling in the harbour has confirmed increased levels of pollution following recent heavy rainfall.

“This highlights the inability of local infrastructure to cope and the critical importance for urgent improvements to infrastructure essential in preventing pollution entering the harbour from storm overflow and run-off.

“We will continue to pressure for practices that contribute to pollution in the harbour to be tightly controlled and highly regulated in a manner that is fit for a protected national landscape.”

Read more: Southern Water slammed for 'tsunami of human waste' in Sussex sea

He added that the conservancy, which maintains the harbour, is “extremely concerned” about the impact of pollution in the harbour resulting from human activity.

This can range from sewage entering the harbour water but also microplastics, chemicals and nitrates.

“Chichester Harbour AONB is one of the most important sites for wildlife in the UK,” he said.

“Already threatened, its protected habitats were assessed to be in an ‘unfavourable declining’ condition in 2021.

MOST READ:

​To have access to all of our best stories subscribe to The Argus using our Black Friday deal here

“Good water quality is essential for the health of the harbour; particularly for the wildlife that depend on it.”

Chichester Harbour is one of three harbours that Southern Water is spending £72 million on treating more wastewater and reducing storm overflows to help the natural habitats.

SOS Whitstable further discovered a release for 862 hours and 56 minutes from one outfall in Lidsey, near the West Sussex village of Felpham from October 18 to November 23.

During this period Storm Babet hit the UK from October 18 to 20, with the Met Office recording the three-day period as the third wettest for England and Wales since 1891.

Storm Ciaran also followed from November 1 to 2, causing a major incident in Hampshire and the Isle of Wight as it worsened existing flooding problems. The Lidsey area was also subject to flood warnings.

SOS Whitstable member Ed Acteson said: “The astonishing length of the sewage releases into Chichester Harbour, Sandown and Felpham will have a devastating environmental effect on these areas and, despite the heavy rainfall in recent weeks, there can be absolutely no justification over this level of water pollution.

“Storm overflows are supposed to be used in exceptional circumstances to ease pressure on the sewage network, how could anybody seriously claim that a month of consecutive sewage pollution is ‘exceptional’?”

On November 16, Southern Water announced its Clean Rivers and Seas Plan backed by £1.5 billion investment.

As part of its pledge to cut spills by 8,000 a year by 2035, the firm said phase one will invest £700 million on areas such as bathing waters and environmentally sensitive sites.

A spokesman for Southern Water said: “We agree with campaigners and our customers that storm overflow releases are not acceptable and that’s why reducing this is our top priority.

“These storm overflow pipes are emergency outlets, acting as the last line of defence to stop homes and communities flooding when the sewer system becomes overwhelmed – something we’re seeing more frequently due to erratic weather like during the recent Storm Babet and Ciaran events, driven in part by climate change.”

The average duration of hours of monitored spill events per storm overflow was recorded at 5.8 hours in 2022, and 7.4 hours in 2021, according to Environment Agency data.

The figures are made up of ten water and sewer companies in England, including Southern Water.

Southern Water’s average durations were published at 8.8 and 8.4 hours respectively for 2022 and 2021. In 2022, the country recorded below-average rainfall.