Some 200m north east of Pant-y-gynnau farm, on Nant Mynian, there is a 330m-long leat leading to a dam, sluice and wheelpit. The water was formerly used to power a waterwheel, about 7 metres in diameter, of which only a stone-built pit remains set on the steep slope between the dam and stream. The system supplied power for a saw mill at the farm by an endless wire rope carried on pulleys.
Nothing of this is shown on the Ordnance Survey 25in maps of 1874 or 1899, but the waterwheel and leat are shown on the 1912 edition. About 15m to the south east of the waterwheel pit is a small building (grid reference SJ 08917 50877) containing a twin turbine driving an electrical generator which provided electric power to the farm, superceding the waterwheel.

B.A.Malaws, RCAHMW, 27 April 2009 and including additional information from Clywd Jones, formerly of Pant-y-gynnau Farm, 14 February 2020.

Information recieved from Clwyd Jones, 6 February, 2020:

'I was brought up at Pant-y-Gynnau and lived there during 1950's to the 1970's. My father and grandfather farmed there since the mid 1920's. I believe I can shed some light on the history of the waterwheel and trurbine as follows: The pit housing the water wheel was huge, it must have been about 7m in diameter but no trace of the water wheel, and being wooden it probably rotted away. At the farm, near to the barn, there were the remains of a very large old saw mill, wooden construction, around 10 metres long with a movable table, winding handles and a very large circular saw table. This thing must have been originally built to saw whole tree trunks lengthwise, probably to make large wooden beams for roofs etc.

On the route where the electricity lines ran from the turbine to the farm (that my grandfather built), there were some old lengths of thick rusty wire rope lying along the ground. So, in my opinion, the water wheel drove the sawmill via a wire rope running along a system of pulleys mounted on poles all the way to the farm, a distance of around 200m.

The sawmill and the water wheel would have fallen into disuse during the early 1900's, probably due to the arrival of steam traction engines, until my grandfather bought the farm in the late 1920's, and then built a new electricity generating turbine, using the old leat and reservoir that drove the water wheel, as a power source'.

'"Gynnau" (derived from 'gowns' I think), was so named because there was a small textile mill nearby at Pandy'r Capel on the bank of the River Clwyd, which is now a residential property'.