Wonderful weirs save Cornish wetlands from running out of water

The largest lowland heath and wetlands area in the south-west has been saved from running dry by Plymouth University researchers.

Geographical scientists and civil engineers from the university have raised water levels on Goss Moor, west of Bodmin in Cornwall, by constructing a series of granite weirs in the River Fal.

Their work, in collaboration with English Nature and the National Rivers Authority, should mean the moor, a national nature reserve, will continue to sustain rare plants and inspects. And it may be modified for use on other rivers in the south-west where water levels need to be raised.

Andrew Williams, a senior lecturer in the department of geographical sciences and coordinator of the project, explained how the rescue plan came about.

"English Nature, who are responsible to the Government for the maintenance of fragile sites like Goss Moor, were concerned that this wetlands area was drying out. They approached the university, asking us to investigate the hydrology of the area - and to devise a scheme which would put the wet back into the wetlands. Without it, the uniqueness of the habitat could be destroyed," he said.

Martin Borthwick, a lecturer in the school of civil and structural engineering, designed the weirs made out of granite blocks using a computer model to determine water flow and levels.

"We used granite blocks because they look good and you can modify their position according to changing conditions. So far they seem to be performing as expected," he said.

Dr Williams said wetlands used to be regarded as being valueless, and had been heavily dredged to improve drainage for surrounding farmland. But now they were recognised as assisting in flood control and water quality improvement, as well as supporting rare plant and wildlife.

"This is an excellent example of community involvement - academics applying the fruits of their research to the benefit of the environment, helping to solve complex problems of land management and nature conservation," he said.