THURROCK could find itself under water if future development isn't handled properly and sewage systems aren't upgraded, councillors fear.

A flood risk assessment has spelled out how vulnerable the borough is to flooding. The risks come from water breaching Thames Estuary sea wall defences, potential breaches of the Mardyke river and Stamford Brook, inadequate sewers and surface water that has nowhere to drain away.

The assessment will ultimately guide councillors away from approving building sites in the worst flood risk areas including parts of Tilbury, which is built on marshland but currently the assessment doesn't include a list of the best and worst places that councillors can easily use when deciding applications.

Speaking at the local development plan taskforce Cllr Gary Collins said: "What we need are proper sewers. If the ones that we have got cannot cope with demand then we build new sewers for the lot. We've had too many developers building properties and attaching them to existing sewers that were built in the 60s and 70s and were never meant to take the amount of buildings that have been attached to them."

Homes and cars were damaged by floods in Stanford-le-Hope.

Cllr Collins added: "Most of Thurrock is a flood plain. Most of Thurrock will flood if you concrete it over. You are building an environmental catastrophe. What we should be looking at in Thurrock is getting rid of HMOs. Get rid of flats because it's not a question of how many buildings you build, it's how many people are using the facilities."

Joycelyn Redsell , Conservative councillor for Little Thurrock Blackshots, raised concerns about continuing to build on flood risk areas. She said: "There is a river in Chadwell St Mary which I only found out the other day, it's been built over. That's got to run somewhere. I don't know if anybody's been round the little tiny roundabout in Chadwell but at the moment you might as well row a boat around there.

The Mardyke floods frequently and there has been no dredging or clear-put work for several years.

"The Mardyke in South Ockenden is so flooded now. It's higher than it's ever been and that's right out to the A13. They had to remove horses from there because they were getting foot rot. It's so deep in places.

"I don't think at the moment our system in Thurrock can cope with water and sewerage. We've got to find some other way."