The region’s main water company has been ordered to pay more than £83,000 after two historic incidents of pollution in Norfolk - one of which resulted in the deaths of at least 20 fish.

Anglian Water was brought before magistrates over two incidents in which waters in Norfolk were polluted, in Great Plumstead and North Walsham.

The cases, both of which happened in 2016 saw sewage find its way from Anglian Water outlets into local waterways, first into the River Ant and then into Hospital Lake.

The company was prosecuted over the incidents by the Environment Agency, which detailed the incidents to Cambridge Magistrates’ Court on Wednesday.

Rebecca Chalkley, prosecuting, told the court that on September 5, 2016, a member of the public reported that pollution coming from an outlet at North Walsham Sewage Treatment Works had entered a tributary of the River Ant.

And the court heard that two months later, on November 7, a dog walker noticed a “greyish” colour in Great Plumstead’s Hospital Lake.

Ms Chalkley told the court that a blockage in pipeworks had led to sewage being discharged into a ditch, feeding into the lake.

Anglian Water officers investigating on the day found at least 20 dead fish, including pike, as well as a number of freshwater mussels.

An Anglian Water spokesperson said: “We take our responsibilities to the natural environment very seriously, and deeply regret the incidents at both North Walsham Water Recycling Centre and on a section of sewer at Little Plumstead.

“Despite regular maintenance work at both locations, the sewage spills occurred as a result of fats oils and grease and other unflushables blocking our pipe and pumps, causing the pipes to overflow and spill into a ditch and lake.

“Since the incidents, we have put extra measures in place at both sites to reduce the chance of future blockages and we have replaced the pumps at North Walsham with those more able to deal with unflushable items in the sewer.

“We take our role protecting the environment extremely seriously, but we also need our customers to play their part. This is why we ask customers to think before they flush and not to put fats oils and wet wipes down the drain.”

The utility company was ordered to pay the court £84,151.04, including £22,000 in fines for each incident.