Efforts to find a way of lowering the risk of flooding in the Lower Thames have been put on hold after an important creature was discovered living in the riverbed.

The unexpected discovery of the depressed river mussel was made when studies for creating diversion channels were being carried out.

The depressed river mussel (pseudanodonta complanata) is a nationally important species and was found in an area that is also known for its variety and abundance of fish.

The channels being investigated would be used to alleviate flooding between Datchet and Teddington.

The Environment Agency recently put forward a two-part proposal to the Regional Flood Defence Committee. It is made up of engineering and floodplain management projects and if it got the go-ahead would include three diversion channels between Datchet and Walton.

Defences would also be erected to protect small groups of houses between Walton and Teddington from flooding.

The floodplain management aspect includes increasing the number of people registered on the Environment Agency's flood warning system.

Many people living in the floodplain have not signed up to the EA's free system. Only 62 per cent of people living in floodplain from Shepperton Lock to Molesey Lock are signed up to Floodline Warnings Direct and just 44 per cent of people living from Molesey Lock to Teddington Lock are registered.

The engineering project, at an estimated cost of the is £200 million, would need significant funding from Defra.

If the Environment Agency is able to secure funding for the project work on this part of the strategy could begin in 2008.

Phase 4 of the strategy will start in April next year and will include more survey work into the extent of the important species in the Thames riverbed.