A Suffolk conservation group has called for more water quality monitoring after figures revealed there were more than 2,000 raw sewage spills in the county's rivers in 2021.

Separate research conducted by the Liberal Democrats also revealed 49% of water company Anglian Water’s sewage discharges were not being measured last year.

Analysis by conservation experts The River Trust found there were 2,290 raw sewage spills lasting 17,271 hours which affected the rivers Orwell, Waveney, Gipping, Deben and Stour.

The East Suffolk district recorded the largest number of spills, 920, with Mid Suffolk second with 715.

Colin Nicholson, co-chair of conservationists the River Deben Association (RDA), which seeks to safeguard the river and its valley, called for more measuring of sewage levels so action could be taken and river users advised.

He said: “The RDA supports the need for more and formalised water quality monitoring on the River Deben.

“In the meantime, the RDA welcomes the great efforts that are already being taken by citizen scientists, supported by Woodbridge Town Council and other parish councils to gain initial data at various points along our estuary and catchment areas.

“When there is a clear and agreed picture of any issues relating to the Deben, then the appropriate actions can be taken to improve matters and the correct advice given to river users.”

The Liberal Democrat survey found that Anglian Water was the worst performing water company in the UK for failures in monitoring how much sewage it discharges.

However, an Anglian Water spokesperson said the findings were "historic" and currently 75% of sewage discharges were being monitored, providing some of the "most reliable data" across the industry with an inaccuracy level of 3%.

She added the installation of Event Duration Monitors (EDM), which ensure sewage treatment works adhere to their discharge limits, at Combined Sewer Overflows (CSO) was ahead of schedule and there would be full coverage across all CSOs by 2023.

She said: “Following over £300m of investment in the last decade, all but three of the places designated for bathing in our region are rated as good or excellent for bathing water quality and all have EDM monitors installed on them.

“Storm overflows were originally designed to protect homes and businesses from flooding during heavy rainfall, but we recognise that they are no longer the right solution when sewers become overloaded with rainwater. We’ve been dealing with CSOs for years, tackling those which pose an environmental risk and working through the rest.”

She added that between 2020 and 2025, more than £200 million will be invested to reduce storm spills across the East of England.