The dam submerged the original village of Llanwddyn, which was completely rebuilt on higher ground.
The masonry structure relies on gravity, utilizing 260,000 tons of stone from local quarries.
The reservoir is officially known as a 'compensating reservoir' because it was required to release water into the Vyrnwy River to sustain downstream flows after the water was diverted to Liverpool.
The Straining Tower contains a hydraulic mechanism originally designed to strain the water before it entered the pipe system.
The project set a precedent for the 'Liverpool Corporation Waterworks' acts, which significantly changed how UK cities sourced water from remote rural areas.
Lake Vyrnwy Dam is a prominent Victorian-era masonry dam located in the Berwyn Mountains of Wales. Completed in 1888, it was the first large-scale stone dam built in the United Kingdom. The structure was engineered to create a reservoir that supplies drinking water to Liverpool via a 68-mile aqueduct. Its design features a distinctive Straining Tower set into the water, built in a Neo-Gothic style with a copper-covered roof. The reservoir covers approximately 1,120 acres and is surrounded by an RSPB reserve known for diverse birdlife. The dam itself is pedestrian-accessible, allowing visitors to walk across its length for views of the Vyrnwy valley. The area is maintained as a visitor site by Severn Trent, incorporating the natural landscape with industrial heritage.
The center of the dam walkway looking back toward the Straining Tower.
Walk the full length of the dam for the best vantage points looking down into the valley.
Check weather conditions before arriving, as the mountain location is prone to rapid visibility changes and high winds.
Bring binoculars if you plan to visit the RSPB hide areas near the dam surroundings.
Do not attempt to swim in the reservoir, as deep cold water and underwater machinery pose extreme safety risks.
Keep dogs on leads due to livestock and nesting birds; take all litter home.
