Wildlife finds a haven on former MoD firing range

"We could have had the Margaret Thatcher Memorial Theme Park here," said Bill Oddie yesterday, as he trained his binoculars on a flock of lapwings as they whirled above the Essex marshland.

In the late Eighties and early Nineties, Westminster politicians thought the future for this former Ministry of Defence firing range on the eastern fringes of London was as the prospective site for Eurodisney. But Mickey Mouse went to France, while Rainham Marshes was yesterday opened as the South-east's most important new nature reserve.

Acquired by the RSPB in 2000, the 352 hectares of grazing marsh and lagoons is a magic kingdom of ecology, serving millions of people in one of the most densely populated and rapidly developing parts of the UK.

Bordered by the M25 and the new Channel tunnel rail link, the site had been severely polluted by heavy industry and the military. Now it is a site of special scientific interest.

Oddie, the patron saint of Britain's growing army of naturalists, has been visiting the site for 40 years. Its transformation, he says, is a "dream come true".

"There was a period here when the land was actually on fire with methane gas. I remember wandering around with my binoculars - it was enough to bring a tear to your eye," he recalled.

Cleaning up the site has not proved easy. A bomb disposal expert worked for five years to remove unexploded anti-tank mines, millions of live shells, and even radioactive waste.

The area has now been restored and birdwatchers are free to wander new paths along the seawall and between the pools, ditches and reeds.

Wintering wildfowl numbers have soared, with record numbers of wigeon, teal and pintail seen. There are 50 breeding species, including reed buntings, skylarks, meadow pipits, and even peregrine falcons.

Some 250 species of birds have been recorded at Rainham Marshes, according to the Essex bird recorder, Howard Vaughan. He said the site would play a key role in monitoring the effects of climate change as species able to survive Britain's milder winters are found.

Recent ecological surveys have recorded 25 species of butterflies and 21 types of dragon and damselfly among the wildflowers that have colonised the area. It is also home to 10 per cent of Britain's water voles.

In 2012 an adjacent landfill site, known as the "Rainham Chilterns", will be reclaimed as a nature reserve, doubling the area of open space available. "The result will be 600 hectares of internationally-important inter-linked ecological green leisure space for wildlife and the people of London and the South-East," Mr Vaughan said.

Also hailing the achievement yesterday was the Secretary of State for Communities and Local Government, Ruth Kelly, whose department is overseeing the creation of 160,000 new homes along the river, part of the Thames Gateway project to meet soaring demand for housing.

Opening the site's new eco-friendly visitor centre, she said that the Gateway would become "an exemplar for low and zero carbon development".