The River Crane has been replenished with thousands of fish as it continues its recovery after two serious pollution incidents in recent years.

The river’s fish population was devastated when a treated sewage sludge pipe belonging to Thames Water was damaged in October 2013.

The people who fractured the pipe, running from the nearby Mogden Sewage Treatment Works, were never caught.

As part of ongoing efforts to rejuvenate the river the Environment Agency (EA), working as part of the Crane Valley Partnership, released 7,500 fish into the Crane earlier this month.

About 2,000 chub, 2,000 dace, 2,000 roach and 1,500 barbel were introduced downstream of Staines Road, Feltham, on December 3.

Neil Winter, EA fisheries technical officer, said: "We want to gently accelerate the increase in fish numbers, so are giving nature a helping hand by adding species commonly found in the Crane and surrounding rivers.

"We are doing this in a carefully phased way, so that we do not destabilise the river’s recovering, but still fragile, ecosystem.

"Not only does the fish stocking boost the river’s biodiversity, it will also return the river to a valuable recreational angling resource for the local community."

The river was also hit by a major sewage spill in October 2011, which devastated the biodiversity of the river and killed thousands of fish.

It was caused by an illegal discharge of untreated sewage and Thames Water was prosecuted and fined and made a £400,000 donation to the restoration programme.

Richard Aylard, sustainability director at Thames Water, said: "No amount of money can make up for the damage caused to a river by a pollution incident, but our financial contribution is funding important work that will help restore and improve the river over time."

The fish were supplied from the EA’s Calverton Fish Farm, where they were bred, and volunteers from London Wildlife Trust, Hounslow Council and the Thames Angling Conservancy helped with the restocking.

The new four-year restocking programme replaces one put in place after the 2011 pollution incident.

That programme, which saw a restocking of fish in December 2012, was undermined by the sludge spill just 10 months later.

The plan is currently open for consultation until April 2015 and can be viewed at gov.uk/government/consultations/update-to-the-draft-river-basin-management-plans.