THOUSANDS of fish died in Knutsford’s Moor Pool after torrential rain flooded parts of the town.

The Environment Agency has not yet discovered why the deaths happened.

But bosses said pollution, a legal sewage overflow and the recent heatwave were hypothetical causes.

“Officers are working to try and resolve this situation,” said Darren Bedworth, fisheries team leader.

“This has had a devastating impact on the fish population and we will be carrying out a full investigation.”

Knutsford recently benefited from a heatwave, with temperatures of almost 30C.

But last week torrential rain flooded parts of the town, affecting roads, businesses and a school.

The Environment Agency believes more than 3,000 fish died during the unusual weather.

United Utilities said its nearby sewage pumping station had not broken down.

But the company’s system can allow a legal overflow into the Moor Pool if the water level gets too high during freak weather.

“Our pumping station was operating at full capacity, as designed,” said spokesman Christian Ewen.

“The Environment Agency has been dealing with the issue and we have been liasing with them.”

On Wednesday last week torrential rain flooded parts of Knutsford.

Water had cascaded down steps between Princess Street and King Street.

Staff and customers at Knutsford Wine Bar saw it flowing down Church Hill.

“We were quite lucky in the fact that everything just rushed past us,” said manager Alison Fraser.

The water flooded parts of the road in King Street and came over the kerbs.

A pool also appeared at the junction of Mobberley Road and Parkgate Lane.

“It was just the sheer volume of it. It was like a tropical storm,” said David Oakes, who runs the nearby key cutting and shoe repair shop.

Is it believed Yorston Lodge Primary School in St John’s Road suffered flooding in its cellar and in one room.

King Street Antiques said there was also a pool underneath the King Street railway bridge.

Meanwhile, water poured down steps and flooded parts of Moorside and the Moor.

Then on Friday residents noticed dead fish floating in the Moor Pool.

They called the Environment Agency and an officer was sent out that evening.

Since then staff have used machines to increase the oxygen levels in the water.

This week agency officer Mike Wiggins was testing the readings.

“Officers have taken a number of water samples, which will help to identify any pollution and show if the water had reduced dissolved oxygen levels due to the recent hot and humid weather,” said a spokesman.

As the Guardian went to press the Met Office was still warning of heavy rain in the North West until 10pm.