Severn Trent Water Ltd has been fined £24,000 after polluting Heapham fishing lake in Gainsborough, Lincolnshire for the fourth time in seven years.

Hundreds of fish died in April last year when a blockage in the foul sewer was not cleared for more than a week by Severn Trent Water Ltd, Lincoln Magistrates’ Court heard. The pollution continued into the River Till and more than three miles of water had been affected.

Severn Trent was alerted by the council to sewage flooding at Theaker Avenue Nature Reserve on March 29, 2011. On April 8 the Environment Agency was contacted by the council’s angling club which reported dead fish in the lakes, including pike and some trout.

Severn Trent said it would pay for the restocking of the lake. The company was also ordered to pay full costs of £6,884.