The first scheme initiated and funded by Newport Corporation was completed in 1927 and led to the initial depopulation of the valley. This involved a weir and catchment pond to directly divert water from the Caefanell river to a water treatment works and then by pipeline to Newport. This was hugely expensive fiasco as within two years it was apparent that during dry spells the river water sunk below the weir into the alluvial deposits beneath. Local inhabitants could have predicted this had the engineers condescended to ask them. Building a dam to create a reservoir followed the abandonment of the 1926 scheme with construction between 1932 and 1939. The site had to be moved down stream, making the earlier water works redundant, due to the lack of solid rock on which to build. The dam is an earth embankment with a clay core and has a stone pitching on the water side to prevent erosion. The works has been extended and the water treatment process up graded over the intervening years including the construction of a partially underground service reservoir.