Skip navigation 
Previous Page
28
ENERGY INTERNATIONAL
February/March 2012 www.esb.ie/em
A dam fine inspection gives Poulaphouca top marks
Bernie Healy returns to Poulaphouca, one of the Liffey Stations, to find that staff there have been working on major improvements to maintain the life of the station.
HOW MANY DUBLINERS crossing the River Liffey realise that the water flowing beneath them has played a part in keeping on their lights at home?
Indeed, the Liffey’s waters play a three-fold role in hydro-generation with the river being home to three power plants, located at Poulaphouca, Golden Falls and Leixlip, which together provide 38MW of power - there are two 15MW generators at Poulaphouca and two 4MW generators each at Golden Falls and Leixlip. Built between 1937 and 1947, Poulaphouca was the second hydro-electric station built in the country after Ardnacrusha.
Few members of the public will have seen or visited the Liffey Stations but the impact on the landscape of the station at Poulaphouca, in particular, is phenomenal. The 100ft dam has created the largest reservoir in the country, the Poulaphouca Reservoir, which covers an area of 4,000 acres and has a 50-mile long shoreline. The reservoir is also known as ‘Blessington Lakes’ because it actually involves the flooding of two different river valleys –the Liffey Valley and that of the King’s River Valley.
In addition to providing a 150 foot head of water for the generation of electricity, the Poulaphouca reservoir is key to ensuring that Dublin and its surrounding districts and towns have a clean, reliable source of drinking water – 85% of the water that comes out of Dublin’s kitchen and bathroom taps come from Poulaphouca and the Leixlip Reservoirs. Poulaphouca also provides most of the water used in County Kildare and a substantial amount of County Wicklow’s water supply.
When the reservoir was first flooded by ESB in 1940, Dublin Corporation was scheduled to take 25 million gallons per day, but the amount extracted has now grown steadily to 110 million gallons per day. Obviously, in times of low rainfall, the amount of drinking water extracted affects the amount of water available for power generation.
The Poulaphouca and Leixlip reservoirs also play host to a wide range of water sports activities. ESB plays a key role in ensuring that they are both havens for anglers: at Poulaphouca, for example, some 12,000 fish are released into the reservoir each year and, on some weekends, you can find more than 200 anglers fishing from its shores. Roach is the dominant species in the lake with some perch also available. In recent years, some roach catches over 100lbs have been recorded. It is also considered one of the best locations for pike fishing in the country. Much of the surrounding lands are also managed by ESB, which has provided a number of amenity sites around the reservoir shore. These and the numerous walks and forests in the area provide leisure activities for thousands of people every day during the summer.
Poulaphouca, Golden Falls and Leixlip stations are today operated remotely from the pumped storage power station at Turlough Hill, near Glendalough. These Liffey Stations are visited and inspected regularly to make sure that they are maintained to maximum levels of efficiency and public safety.
Perhaps, the most important visit to Poulaphouca and its sister stations is by the External Dam Safety Committee (EDSC), which operates according to a rolling 5 and 10 year inspection cycle. The EDSC acts as an external auditor to ensure the good maintenance of all dams, reservoirs and waterways operated by ESB. The dams are formally inspected annually by an internal inspection team, with a more thorough inspection every five years by the EDSC.
“The Poulaphouca and Leixlip reservoirs also play host to a wide range of water sports activities
Holding back millions of gallons of water, it is critical that each of these dams is well maintained – a structural failure would cause
