A £150,000 clean-up project on the River Wandle will see trout swimming in what is hoped will become London’s cleanest river.

The two-year plan will prevent tonnes of silt from entering a one-kilometre stretch of the Carshalton arm of the Wandle River and make it more habitable for a range of wildlife such as brown trout and kingfishers.

During the first six weeks the Wandle Trust will install three silt traps beneath the road on Denmark Road, Mill Lane and Butter Hill before work on the river itself proceeds.

Toby Hull, Catchment Project Officer for the Wandle Trust which is managing the DEFRA-funded project, said: “This is a very exciting plan which will help the river achieve Good Ecological Potential, the first river in Greater London to reach that status.”

Once the silt traps are in place, work will begin on bringing the Wandle back to a more natural state by removing silty deposits already in the water, narrowing the river to cope with future drought conditions, adding meanders and planting before aiming to re-introduce the trout in 2015.

Burying the silt traps under the roads will cause some traffic disruption and Sutton Council’s highways department and the Wandle Trust have been working very hard to ensure that inconvenience to drivers and residents is kept to an absolute minimum.

The work at Butter Hill and Mill Lane will mean that traffic will have to be regulated using temporary traffic lights at night. Denmark Road, however, will have to be closed for up to two weeks while the dig is completed.

Carshalton Central ward Cllr Jill Whitehead, Chair of Sutton Council’s Environment and Neighbourhoods Committee, said: “We know road closures are very frustrating to residents. However, our highways team has worked very hard to organise a schedule which will minimise the impact and keep roads flowing as smoothly as possible.”