Raw sewage has been released into Berkshire waterways, including the River Thames and River Loddon, during and after Storm Henk, according to Thames Water.

The water company’s online discharge map shows in some areas sewage has been polluting waterways for over three days, including areas in Reading, Bracknell and Windsor.

Over a dozen sewage systems have overflowed in the last three days.

Thames Water says untreated sewage discharges happen when its sewage systems can’t cope with heavy rain, leading to the release of a mixture of rainwater and sewage into local waterways. 

Storm discharge has been recorded across Berkshire, with many sections of Thames Water's network continuing to discharge waste during Wednesday afternoon (January 3).

The map reveals that some discharges began even before the storm arrived, on Monday, January 1.

The longest overflow was in Windsor. Censors reported Thames Water’s systems had been overflowing into the River Thames from 7pm on January 1 – and is still ongoing as of January 3.

A full list of reported overflow sites is below.

  • Aldermaston (Groundwater) discharging for upwards of 5 hours and 7 minutes
  • Arborfield (Barkham Brook) discharging for upwards of 1 hour and 47 minutes
  • Ascot (The Cut) discharged for 7 hours
  • Ash Ridge Wokingham (Ashridge Stream) discharged for 6 hours and 15 minutes
  • Beenham (Webbs Lane Stream) discharged for 43 hours and 30 minutes
  • Bracknell (The Cut) discharged for upwards of 4 hours and 29 minutes
  • Bucklebury (Briff Lane Steam) discharging for upwards of 4 hours and 21 minutes
  • Chapel Row (Tributary of River Bourne) discharging for upwards of 90 hours and 51 minutes
  • Easthampstead Park (Elm Brook) discharging for upwards of 3 hours and 1 minute
  • Hamstead Marshall (Hamstead Stream) discharging for upwards of 2 hours and 54 minutes
  • Kintbury (Kennet and Avon Canal) discharging for upwards of 84 hours and 30 minutes
  • Knights Lane (River Enbourne) discharging for upwards of 87 hours and 24 minutes
  • Newbury (River Kennet) discharging for upwards of 53 hours and 46 minutes
  • Reading (Foundry Brook) discharged for 17 hours
  • Sandhurst (River Blackwater) discharged for 2 hours and 15 minutes
  • Slough (Roundmoor Ditch) discharging for upwards of 6 hours and 12 minutes
  • Wargrave (River Loddon) discharging for upwards of 6 hours and 59 minutes
  • Washwater (Pound Street Brook) discharging for upwards of 92 hours and 55 minutes
  • Windsor (River Thames) discharging for upwards of 43 hours and 56 minutes

Thames Water has come under fire for the number of times it has discharged raw sewage into waterways, having released waste into waterways 8,000 times in 2022.

Now Thames Water claims it will spend more than £1.6 billion on upgrading its infrastructure. 

A Thames Water spokesperson said: “We regard all discharges as unacceptable and are sorry to those affected by this.

"We have published plans to upgrade over 250 of our sewage treatment works, including Bracknell, Reading, Slough and Wargrave. T

"he planned upgrades will improve our ability to treat the high volumes of incoming sewage and reduce the need for overflows during wet weather, as experienced across the UK in recent days. 

“Many of our sewage treatment works have been impacted by Storm Henk and higher than average long-term rainfall across London and the Thames Valley. Groundwater levels are also normal to exceptionally high for the time of the year."