East Anglia's emergency services have launched their biggest combined operation since 2007 ahead of the expected wide-scale flooding tonight.

Police are coordinating the response to the threat and have begun preparing families in 9,000 homes in the Great Yarmouth area for evacuation.

Staff from Norfolk County Council (NCC), the Broads Authority (BA) and district councils covering the coast and rivers likely to be affected are also involved.

Norfolk's Deputy Chief Constable Charlie Hall, who is leading the multi-agency response, said: 'This is a significant policing operation underlined by the number of people and properties affected over the next two days.

'We understand people may be anxious, but we would like to reassure residents that Norfolk has tried and tested flood response plans which are being put in place, in line with Environment Agency advice.'

A NCC spokesman said: 'We will be providing transport to get people to and from rest centres and the fire and rescue service are on standby.

'Highways teams are preparing for potential road closures; they are ensuring they have people available to assist, as well as sandbags and road closure signs as required.

'Staff from adult social services are contacting by phone all the older and vulnerable people we work with in the affected areas to check they are OK and whether they need help.'

They were also liaising with care homes and home care agencies to check they were prepared, offering assistance and ensuring any risks to services to older and vulnerable people were managed.

She said: 'We are diverting our staff to work in the affected areas this evening, tonight and tomorrow and identifying people who can act as drivers to assist transport. We have been working closely with the district councils in preparing rest centres.'

A spokesman for North Norfolk District Council said their flood wardens were on the ground talking to potentially vulnerable people and ensuring that when evacuations take place they are done properly.

Evacuation was currently being planned from homes at risk in Wells, Salthouse, Cley, Blakeney and Morston.

Rest centres had been set up at Alderman Peel High School in Wells, Holt Community Centre and Stalham High School.

He said: 'Stalham High is being prepared in case of flooding from rivers backing up on the Broads.'

In Yarmouth, the likely worst hit place, rest centres have been set up across the borough in Flegg High, Martham Primary, Caister High, Cliff Park High, Orimiston Venture Academy and Lynn Grove High; Waveney District and Suffolk Coastal council have also set up centres.

Sandbag locations for the Yarmouth area include Beach Coach Station, Pasteur Road car park (opposite Topps Tiles), Southgates Road, Quay Road, Gorleston and the Runham Road junction.

BA rangers are on standby to help police wherever required.

Conservationists are bracing themselves for serious damage to the Broads' delicate ecosystem with saline incursion up the rivers and flooding of important wildlife sites.