PAT McNEIL is not happy. At 3am she was awoken by a policeman banging on the door of her Grade II home and told to leave everything and get out. Mrs McNeil lives in the shadow of Ulley Dam, near Rotherham, South Yorkshire. At the height of last week’s floods, engineers worked round the clock to prevent the dam wall from bursting and sending a 20ft-high wall of water rolling into the surrounding houses.

“We were just told to go,” she says. “There was an evacuation centre at a school in Dinnington, but I took one look and said ‘I’m not stopping there’. So we stayed up. My husband went to work at 5am. The next night we stayed at an hotel. We were allowed home after three days.”

Mrs McNeil, 47, runs a printing company with her husband, Colin. They have three adult offspring, with only their son Ross, 17, still at home. They put their five-bedroom, 17th-century home on the market in March and plan to move to a smaller place. Does she think the drama will put buyers off? “Well, they might think twice, but this is not in a flooding area,” she says. “I don’t think that the water from the dam would have hit us. I know the authorities have to do the right thing, and that’s why we were evacuated, but I’m not happy. We had to leave our home, all our possessions. We even had to leave the parrot.”

Across South Yorkshire, thousands of residents have been affected by the most severe flooding to hit the area in living memory. In Sheffield on June 25 the Don burst its banks. Rain came down so heavily that storm drains were overwhelmed. Parts of the city centre and the Hillsborough, Chapeltown and Ecclesfield areas were up to 8ft under water. In Winn Gardens, in the suburb of Middlewood, 100 council properties were evacuated. Around Ulley Dam and the nearby villages of Treeton and Catcliffe, to the east of Sheffield, where the city borders Rotherham, 156 households had to be evacuated to temporary accommodation. Residents of Treeton and Catcliffe saw their homes engulfed by water when the River Rother copied the Don and burst its banks.

The flood-hit houses will be cleaned up eventually, but residents fear what might happen when torrential rain comes again. A survey for Direct Line Insurance reports that nearly four in ten residents of flood-prone areas feel more threatened today than ten years ago. “We had just spent £15,000 tanking out [damp-proofing] our basement and installing a gym and office,” says one woman. “The water table rose and lifted the floor. There was nothing we could have done to prevent it, and nothing we can do to stop it happening again.”

Will the Sheffield market lose confidence too? On the face of it, the floods couldn’t have come at a worse time. The Halifax Building Society reports a 15 per cent rise in Sheffield property prices between 2006 and 2007’s first quarter; the average price of a home went from £133,892 to £153,627. Average growth in the Yorkshire and Humber region was 8 per cent.

Tearle Phelan, head of residential development at Knight Frank, has lived in Sheffield all his life. “You have to remember that the last time the River Don broke its banks was 150 years ago,” he says. “What is of concern is the effect that the flooding has had on businesses in the city centre. Some of those are going to take a long time to recover, and that could affect the economy. Even Meadowhall [a huge shopping centre east of the city] was under 3ft of water.”

So did he sell anything that week? “Yes, we sold three at City Lofts,” he replies. The City Lofts St Paul’s development comprises two linked 32-storey and 12-storey towers, under construction in “the heart of the city”, well away from any of Sheffield’s five rivers, the Don, the Sheaf, the Loxley, the Rivelin and the Porter.

Proud Sheffielders will tell you that their city, like Rome, is built on seven hills. If you live on the right part of a hill, then you’ve probably been safe these past few weeks. In the popular suburb of Walkley, close to Sheffield University, James Lovegrove, 25, an auditor, is getting on with selling his three-bedroom Victorian end-of-terrace house. He put it on sale in May for £150,000 and it went in less than a week. “We had offers of up to £160,000 in the first weekend,” he says. “Several housesin the street have sold recently for above the asking price. It’s a really popular area with students.”

Although serious flooding hit Treeton and Catcliffe in 2000, many didn’t expect their homes to be at risk again. “We thought it was a one-off,” says a woman who has lived here all her life. “But these are our homes, what can we do? I don’t want to move anywhere else.”

This, for thousands of homeowners, is the most worrying long-term issue: how do you know if the house you thought was safe is actually on a flood plain? “When we make our assessment [of the Sheffield crisis], one of the crucial things we will do is to establish ‘the known extent of the flood plain’,” says Robin Bailey, strategic and development planner for the Environment Agency, which offers flood maps on its website. “This contributes to a calculation that helps to give us a ‘risk factor’ of flooding in that area. This is taken into account if planning permission is sought for further development.” That is not much comfort if you already live there. It doesn’t take a genius to work out the implications for house prices and insurance premiums in “new” flood plain areas, and it will be months before Sheffield discovers whether the floods were a one-off catastrophe.

Buyers worried about flooding should follow Bailey’s advice: “Choose a house on the highest side of the road so water falls down into the main drain, don’t buy a house with a drive that slopes towards the front door, and avoid houses at the ‘hammerhead’ of a cul-de-sac, as surface water will collect at that end.” Sensible advice, but those not convinced might do well to seek refuge in one of Sheffield’s new skyscrapers.

Details of City Lofts: 0114-272 3855 www.citylofts.co.uk For a flood map of your postcode, go to www.environment-agency.gov.uk

For the latest news and information on the property market, go to: timesonline.co.uk/property

FACTFILE

The cheapest properties in Sheffield are terraced houses, which sold for an average of £106,080 in May.

The largest increase in prices during the year to May was for detached houses, up on average by almost £25,000 to £278,026.

The cheapest parts of the city are the northern and northeastern suburbs, such as Firth Park and Parson Cross, where properties cost £96,897 on average.

The average price of a home in the flood-hit areas of Treeton and Catcliffe, to the east of Sheffield, is £151,679.

The most expensive parts of the city incorporate the villages of Dore and Totley, where you might pay on average £546,802 for a detached house.

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