At the start of the bathing season, Southern Water has reemphasised its promise to slash the amount of sewage being dumped in the sea and rivers with the Isle of Wight, Romsey and Southampton among the worst affected areas.

Southern Water was responsible for at least 29,494 sewage overflows in 2023 in the South East of England, analysis by website Top of the Poops revealed.

The findings said that two of the worst locations contaminated by Southern Water were the Isle of Wight, polluted by sewage 3,865 times in 2023, lasting 38,353 hours or 4.44 years, and Romsey and Southampton North polluted 699 times in 2023 lasting 11,946 hours or 1.38 years.

The data showed that on the Isle of Wight, the Sandown wastewater treatment works polluted the English Channel 265 times during 4,000 hours. Also, the Kings Somborne works polluted the river Test 239 times, lasting 4,995 hours.

The Solent is listed as the most polluted area by the water company and sits 16th on the list of rivers with the most sewage overflow in 2023.

Hampshire’s contaminated beaches

The Top of the Poops site also revealed that there were at least 28,151 “sewage spills” onto designated bathing areas in England in 2023, lasting a staggering 202,437 hours.

Contaminated water could lead to serious illnesses, such as gastrointestinal illnesses or stomach bugs, which may cause diarrhoea and vomiting, as well as respiratory, skin, ear, and eye infections.

Gurnard in Cowes, on the Isle of Wight, ranked the first most contaminated beach, with 649 incidents reported, equivalent to 5,360 hours. 

Sandown, Whitecliff Bay, Yaverland, and Shanklin, also on the island, were the second most polluted beaches by sewage 265 times in 2023, lasting 4,000 hours.

Lee-On-Solent, Stokes Bay was the 42nd most polluted bathing area in England and Wales by the duration of sewage overflows, as reported by the water companies. It was contaminated 86 times in 2023, lasting 1,401 hours.

Hillhead, on Lee-on-Solent, Southsea, and Stokes Bay in Portsmouth were also among the most polluted beaches. 

The Solent’s pollution

On average, Southern Water’s systems overflowed 80.8 times daily, lasting 317,284 hours, 36.72 years, in 816 locations across the South East of England.

According to the data, the Solent was polluted by sewage 1,550 times, lasting 16,942 hours, equivalent to 1.96 years.

The Solent coastline is around 241 miles long on the mainland between Selsey Bill and Hurst Spit, including Chichester, Langstone and Portsmouth Harbours, Southampton Water and the tidal extent of the main rivers.

It encompasses a major estuarine system with four coastal plain estuaries, habitats, and marine complexity. The Solent Marine Site is one of several European marine sites in the UK that are designated as internationally important sites for their habitats and species.

In 2023, 31 sewage overflows were reported in the Solent. Pennington wastewater treatment works in Brockenhurst, Lyndhurst, reported 137 sewage dumps, equivalent to 2,321 hours, followed by Norton Headworks wastewater pumping station with 154 sewage dumps, or 2,050 hours, and Ryde (Appley Park) Headworks pumping station with 141 sewage dumps, or 1,976 hours, both on the Isle of Wight.

Regarding rivers in England and Wales, it is estimated that there were at least 559,546 “sewage spills” into rivers in 2023, lasting an almost unbelievable 4,513,992 hours.

The company also polluted the river Test 497 times during 8,504 hours or 11.81 months and the river Blackwater 366 times during 6,835 hours, or 9.49 months.

Southern Water’s promises

Southern Water said: “It’s very important to note that the primary reason for storm overflows is rainfall, and the recent 18 months were the wettest since records began in 1836."

The water company said that in the region, £3bn has been spent from 2020 to 2025, and a further £7.8bn is due to be spent between 2025 and 2030. Of that, £3.3bn is set aside to help improve the environment.

To improve water quality in Hampshire, the company has invested £251m in waste and water improvements, such as £68m to improve the disinfection process at Millbrook and Slowhill Copse and stormwater storage at five sites to reduce spills into Southampton Water, protecting shellfish beds.

Director for wastewater operations John Penicud said: “Slashing the number of storm releases is a top priority for us and our customers. Last November, we announced our £1.5 billion storm overflow reduction plan, which will combine innovative engineering with nature-based solutions. 

“The past 18 months have been the rainiest since records began. The ground was utterly waterlogged in many areas, inundating our own sewers and customers’ drains and sewers. 

“We’re extensively relining sewers, to keep sewage in and rainwater out, and our storm release reduction pilot schemes have already proved that nature-based systems can have a real impact.” 

A spokesperson of Southern Water said: “We know storm overflows are not acceptable, and we are working hard and investing heavily to reduce their use. We also continue to be committed to open and transparent reporting of all spills, including via our Beachbuoy reporting app.”