WATER in a Chobham river ran dark brown for several hours recently, prompting concerned reports to the Environment Agency.

People were wondering why the Mill Bourne was the colour of strong tea instead of running clear, as it usually does when there has been little rain.

Officers sent by the agency to check the stream found no obvious reason for the change in hue.

But an explanation could be the burst main on the A30 at Bagshot that caused around 7,000 properties to lose their water for much of the day. Brooks and ditches run from the affected area into the Windle Brook, which becomes the Bourne at Lightwater.

A spokesman for Affinity Water said this could be a cause of the brown water, adding: “When a water main bursts, that force can disturb the earth and sand around where the pipe is buried.

“The water can also pick up earth and material as it flows away. If ditches nearby to the burst eventually lead to the river it is a possibility that there is a link to the brown colouration.”

An Environment Agency spokesperson said: “We would like to thank the members of the public who alerted us to the discolouration in the Bourne.

“Our specialist officers visited the site and initial surveys of the river found no obvious signs of any adverse impacts on the local environment, but our investigations into the matter continue.”

He urged the public to report environmental incidents, fish in distress and cases of suspected pollution via the agency’s 24-hour free hotline on 0800 807060.