THE LAKE VYRNWY SCHEME
Our July talk - reviewed by Mike Chitty
Peter Cahill, who used to work for North West Water/United Utilities (and, before that, the Liverpool Corporation Water Works) gave us a talk on 22nd July about the construction of the Vyrnwy reservoir and aqueduct, which still supplies about 90 percent of Liverpool's water. He explained the pioneering achievements of George Frederick Deacon, the Liverpool Borough Water Engineer in the 1870s-80s, who was responsible for many aspects of the scheme. He also gave a mention to John Hays Wilson, the Liverpool brassfounder who lived at Lee Hall, was Chairman of the town council's Water Committee when the scheme was approved, and whose memorial in the centre of Gateacre village is our logo.
The Vyrnwy valley was chosen because of its high rainfall. Peter showed us extracts from a video - 'The Changing Valley' - featuring pictures of the village of Llanwddyn which was demolished when the valley was flooded. Liverpool Corporation built new houses and a new church for the villagers nearby. The River Severn Commissioners benefited from the scheme, because the reservoir regulated the supply of water during times of flood and drought. The seizing of Welsh land to supply water to English cities was always controversial, but Peter reminded us that compensation was paid to those directly affected, and without Welsh water we would not have been able to attract Fords to Halewood in the 1960s.
The first part of the talk concerned the construction of the dam and reservoir. It was a masonry dam - possibly the first in Europe designed to allow water to flow over the top - rather than a traditional earth embankment with spillways. The Earl of Powys laid the foundation stone on 14th July 1881. A special railway transported the stone from a newly-opened quarry nearby, and the steam cranes and excavators were employed directly by the Liverpool Corporation rather than by subcontractors. It took about a year to fill the reservoir with water. The 'Straining Tower' - looking like a miniature castle - was of pre-stressed concrete faced with stone, and housed ingeniously-designed machinery for filtering the water.
In the second part of the talk, Peter showed us pictures of the Vyrnwy Aqueduct - the miles of giant pipes which transport the water to the Prescot reservoirs via the Oswestry Treatment Works, the Norton Tower in Runcorn (housing one of the 'balancing tanks' constructed to 'break the pressure' along the route) and a tunnel under the River Mersey near Warrington.
All of this was interspersed with anecdotes, including Peter's own reminiscences of the coach tours he used to organise for water customers 30 or so years ago. Perhaps we should have arranged our own coach tour to visit the features described - but certainly this talk was a very acceptable alternative.