Sluice gate leading to the road engines, a set of beetling engines still in operation. Locally made sluice gates, manually operated, control the water level in the five dams which supply the works. Water is taken from the river and stored in the dams at weekends and times when the works does not require it, to be released whenever needed.

At the height of the Upperlands water system - described by an inspector in 1929 as "the best-developed small hydro scheme in the world" - it produced 500 horse power from a two-mile stretch of river, on a series of small falls totaling about 150 feet. Manageable rivers like our own Knockoneill-Clady, with a fall of say ten feet every 200 yards, were one of the blessings of the Irish linen industry - and the envy of its rivals in the flat lands of Holland or northern France. But small Irish rivers can dry up quickly when rainfall is short, so it is essential to build dams to store water. The first small dam in the Upperlands area was built by seal-master Alex Clark in 1760.

In 1815, a larger area, which we now call the Green Dam, was dug out. By that time there were five wheels on the river. As well as beetling, they were used for dying cloth, scutching flax and grinding corn. The dams were again enlarged in 1857 and 16 new beetling engines were installed in a building we call the Lower House. The problem of "balancing the load" at each of the six stations became tricky. If enough water was released from the dams for the beetling engines on the lower stretch of the river, it would be too much for the starching and dying machines near the top. So an extra four beetling engines were added at the top of the system. There seemed to be no end to its expansion.

This century, turbines have proved far more efficient than the old water-wheels, but the fundamental principles are the same. The use of water power has fallen off since the 1960s, but we hope to reverse that trend in 1998 - with the construction of a new turbine and 110 kW generator. Any power that Upperlands does not use will be resold into the national grid - and our village will have made its own contribution to the cause of "green" or renewable energy.

The Knockoneill river, with its source some 10 miles to the east in the Sperrin mountains, can produce up to 500 horsepower when properly harnessed. A new turbine at the road engines will produced 600,000 kilowatts per annum, with a peak flow of 3 cubic metres per second and average flow of half a cubic metre per second. Below the bridge, the river changes its name to Clady and joins the Bann, Ireland's most famous salmon river, which eventually reaches the sea at Portrush on the north coast.