Campaigners call for a halt to the annual dredging of a Norfolk chalk stream
It's one of only 200 in the world
Eco-campaigners are calling for a halt to the annual dredging of a mile-long chalk stream that feeds into a Norfolk river.
They argue that the maintenance work to clear vegetation in Gaywood River near Grimston, six miles outside King’s Lynn, is harming the rare habitat that lives there.
But farmers, who pay for the King’s Lynn Internal Drainage Board (KLIDB) to carry out the work, say the practice prevents flooding and ensures the flow of water.
Campaigners, however, say the clearing of plants could potentially increase the risk of flooding downstream in King’s Lynn and are calling for the KLIDB to rethink its strategy.
"The equivalent to habitat annihilation"
Sarah Taigel, a geographer who has been analysing the flow of Norfolk’s chalk streams for more than a decade, said: “I am stunned that the KLIDB would clear a well-functioning and thriving chalk stream which has zero flood risk.
“The vegetation clearance in the channel and on the bank is the equivalent to habitat annihilation, not just for fish and invertebrates but also water voles – a protected species.”
The KLIDB has hit back at these claims, arguing its annual maintenance work is vital to prevent flooding in Grimston and to protect the Anglian Water sewage plant in Grimston from weed blockages.
The organisation highlighted the Christmas Day floods in 2020, which affected homes in Pott Row and Grimston, as evidence it work is necessary.
What does the KLIDB say?
A spokesman said: “The KLIDB do our best to strike the balance between flood risk management and protection of the local environment.
“We continue to work in partnership with other agencies, landowners and bodies to manage the ecological and flood risk requirements of the Gaywood River and its tributaries for those who live and work around it.”
The drainage board is predominantly funded by local farmers, who pay for the maintenance work in order to keep water flowing to support agricultural production.
The National Farmers Union environment adviser for East Anglia, Rob Wise, said the KLIDB’s actions were necessary to keep water flowing in order to ensure “there is a fair share of water for food production, while meeting environmental responsibilities.”
The KLIDB says it does not dredge the waterway, arguing the machine it uses to clear the weeds – fool’s watercress – does not cause any desilting or removal of the riverbed.
But Russell Biggs, who discovered the incident last week, says evidence at the scene suggests the contrary.
"Could lead to the death of the eco-system"
He has been working with the Norfolk Rivers Trust to monitor the health of the region’s waterways for several years, said: “These actions serve no purpose and could lead to the death of the ecosystem.
“The machine used to remove the plants from the river goes so deep it cuts into the bed causing a lot of damage, and the disturbance of the silt was clear to see.
“This leads to diffuse pollution caused by the disturbed silt, which suffocates life in the stream, be it fish, invertebrates or rare plants.
“The KLIDB think by clearing the plants it prevents blockages downstream, but they need to realise the plants die down at winter and disappear into the silt.
“If it could just leave the chalk stream untouched for a few years, it would be clear chalk streams do a great job of managing themselves.”
The Environment Agency has said the latest evidence on dredging suggests it can actually speed up the flow of water through creating a uniform straightened channel, increasing the risk of flooding downstream.
Chalk streams
Chalk streams are often described as England’s rainforests – unique habitats with the majority of the 200 in the world found in the southern half of England.
The streams are fed by natural springs that produce crystal clear water via the chalk filtration, which were once venerated by the Romans.
But these rare ecosystems are under threat with three quarters of chalk streams in England in poor health after centuries of dredging and straightening to make way for agriculture, as well as the ongoing impact from pollution, according to the Norfolk Rivers Trust.