100,000 properties in Scotland at risk from flooding

from Sunday Herald, 29 July 2007

Nearly 100,000 homes and businesses in Scotland are in areas at risk of flooding, according to unpublished new estimates from the Scottish Executive.

Housing estates in most cities are under threat, as well as airports, roads, railways, hospitals, schools, shopping centres, sports facilities, sewage works, farms and distilleries. Communities in Glasgow, Paisley, Kilmarnock, Kirkintilloch, Perth and Moray could be inundated.

Virtually all of Scotland's most dangerous industrial complex - the massive oil and chemical works at Grangemouth - could disappear under water, as could Scotland's biggest power station at Longannet near Kincardine. Even the Executive itself is vulnerable, with part of its headquarters at Victoria Quay in Leith in the official flood hazard zone.

Last week, torrential downpours caused some of the biggest floods ever seen in England, damaging 15,000 properties and 1,500 businesses, mostly in Gloucestershire. Though Scotland escaped this time, experts are warning that it may not always be so lucky.

The frequency and severity of flooding is expected to increase because of the disruption to the climate being caused by pollution, they say. And radical measures - such as building a causeway across the Forth and rehousing people - now need to be considered.

"There are tens of thousands of properties at risk," says Dr Richard Brown, head of hydrology at the government's green watchdog, the Scottish Environment Protection Agency (Sepa). "If we were to get the same level of rainfall as parts of England last week, we would get some serious flooding."

The Sunday Herald understands that earlier this year officials in the Executive's geographic information service produced an internal report providing the latest estimates of the numbers of low-lying properties at risk. It suggests that nearly 4% of Scotland's 2.5 million properties are located within flood hazard zones.

The majority of properties - 78,000 - are inland and close to rivers that could burst their banks, including 73,000 private dwellings and 5,000 commercial premises. Another 18,000 are properties around the coast vulnerable to stormy seas.

The Executive's new analysis is based on the latest "indicative" maps of flood hazard areas drawn up last year by Sepa. These show significant areas of housing at risk in Glasgow, Edinburgh, Inverness, Stirling and elsewhere.

Amongst the commercial premises under threat are Glasgow, Edinburgh, Dundee and Inverness airports, Edinburgh's New Royal Infirmary, Murrayfield rugby stadium, Rosyth naval base and the Seafield sewage works in Leith. Parts of the M8 at Whitburn and some railways are in hazard zones, as are many other important facilities like Grangemouth, Longannet and Victoria Quay.

In Elgin a distillery and a museum are at risk, while another distillery and a school in Forres are vulnerable. In Perth a sports centre, a sewage works and nearby Scone Palace are in hazard zones.

Premises on the edge of flood zones include the Faslane nuclear submarine base on the Clyde, as well as nuclear plants at Hunterston in North Ayrshire, Torness in East Lothian and Dounreay in Caithness. Sepa's headquarters in Stirling is on low-lying ground surrounded on three sides by flood zones.

The Executive's latest estimates update research from the University of Dundee in 2002 (pdf) suggesting that as many as 170,000 premises might be at risk from flooding. More detailed contour maps have now enabled researchers to come up with a more accurate figure.

But even so they may downplay the real risk, according to a leading UK expert on flooding, David Crichton. He points out that the estimates don't take account of flooding caused when drains can't cope with heavy rain, as happened in Hull last month, or of dams being breached.

The risks are also going to increase as global warming brings more rain and more extreme weather, he argues. Crichton, who has advised governments on climate change, is a visiting professor at University College London and an honorary research fellow at the University of Dundee. He lives near Perth.

In a new report (pdf) passed to the Sunday Herald, he suggests that more than 6,000 low-lying homes around the Firth of Forth are at risk of flooding. The Grangemouth oil and petrochemical complex is "very exposed to the risk of coastal flood", he warns.

"This is one of the biggest major accident hazard sites in the UK and is responsible for supplying 40% of the UK’s fuel oil," he says. "If it were disabled by a storm surge or river flood, the national economic consequences would be disastrous."

Crichton points out that a series of expensive flood prevention schemes are being planned, including a £40m barrier to protect Grangemouth and a £8m barrier to protect Bo'ness. But he thinks there might be a better way to spend the money.

He is proposing a four-kilometre causeway to the west of the existing road bridge from Blackness Castle on the south shore to Charlestown on the north. This could carry trains and road vehicles, he argues, linking to the M9 in West Lothian and the M90 in Fife.

A causeway could also act as a tidal barrage, and produce electricity from the natural ebb and flow of the tides, as well as being a site for wind turbines, he says. Furthermore, it could help contain oil spills or sewage leaks, both of which have contaminated the Forth in recent months.

A causeway could also avoid the need to build a new bridge or tunnel, Crichton argues. "Before the Executive commits to spending £10 billion on a new Forth crossing, perhaps it should investigate the feasibility and costs of a causeway," he says.

"There will no doubt be environmental problems to be overcome, but possible ecological impacts need to be balanced against the risks to human lives and property as climate change produces more extreme events. Society needs to decide where its priorities lie."

The Executive agency Transport Scotland, however, has previously rejected the idea of a causeway because it would restrict shipping and damage wildlife. Environmental groups aren't keen on the idea either.

According to Dr Richard Dixon, the director of WWF Scotland, it will probably have to be ruled out because of the impact it would have on the Forth's internationally important wildlife habitats. He proposes other solutions.

"We must certainly stop building in flood risk areas and we need to look at the idea of rehousing people living in properties that it no longer makes sense to protect," he says. "There will be more flooding misery unless we fundamentally change our ways."

Dixon argued that the traditional method of building concrete walls to "straitjacket" rivers to try and prevent flooding wasn't sustainable. He urged government agencies to work with nature to enable natural flood plains upstream to take the pressure off conurbations downstream.

Sepa and the Scottish Executive both point out that they are already doing a great deal to reduce flooding risks. The Environment Minister, Michael Russell, last week asked emergency response teams across Scotland to review their flood relief plans in the wake of England's experience.

A spokesman for the Executive confirmed that officials were working on new estimates of the number of properties at risk from flooding. But he said that the figures had not yet been finalised.

Critics, meanwhile, can't resist highlighting the ironies implicit in the locations of the Sepa and Executive headquarters in or near to the flood hazard zones which they are warning others about. "It's very clever of them," remarked one, "because it will concentrate their minds most wonderfully when they look out and see the water."