Poulaphouca Reservoir, officially Pollaphuca (), is an active reservoir (for both water supply and electricity generation) and area of wild bird conservation in west
County Wicklow
County Wicklow ( ; ga, Contae Chill Mhantáin ) is a county in Ireland. The last of the traditional 32 counties, having been formed as late as 1606, it is part of the Eastern and Midland Region and the province of Leinster. It is bordered by t ...
,
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
named after the
Poulaphouca
Poulaphouca, officially Pollaphuca (), is the name of a waterfall and bridge on the River Liffey between County Wicklow and County Kildare. It is primarily known for its hydroelectric generating station and the associated artificial lake, k ...
waterfall on its south-western end where the water exits the lake. The lake is also commonly known as the
Blessington
Blessington, historically known as Ballycomeen (, from the Irish surname ''Ó Coimín''), is a town on the River Liffey in County Wicklow, Ireland, near the border with County Kildare. It is around 25 km south-west of Dublin, and is sit ...
Lakes, even though there is just one.
It holds 166 billion litres (43.8 billion gallons, or 0.2 cubic km) and has a surface area 22.26 km
2, making it the largest artificial reservoir in Ireland by capacity and surface area. It has a 44.3 km (27.5-mile) shoreline, and is 39.6 km (24.6 miles) from the sea.
History
It was created between 1937 and 1947, with flooding beginning at 10:00 on 3 March 1940 by
dam
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...
ming the
River Liffey
The River Liffey (Irish: ''An Life'', historically ''An Ruirthe(a)ch'') is a river in eastern Ireland that ultimately flows through the centre of Dublin to its mouth within Dublin Bay. Its major tributaries include the River Dodder, the River ...
at
Poulaphouca
Poulaphouca, officially Pollaphuca (), is the name of a waterfall and bridge on the River Liffey between County Wicklow and County Kildare. It is primarily known for its hydroelectric generating station and the associated artificial lake, k ...
as part of the
Electricity Supply Board project to build a second
hydroelectric
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...
station in
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
,
Ardnacrusha on the
River Shannon
The River Shannon ( ga, Abhainn na Sionainne, ', '), at in length, is the longest river in the British Isles. It drains the Shannon River Basin, which has an area of , – approximately one fifth of the area of the island of Ireland.
The Shan ...
being the first.
![Kaplan Turbine Pollhaphuca](https://upload.wikimedia.org/wikipedia/commons/2/24/Kaplan_Turbine_Pollhaphuca.png)
The reservoir is one of two major sources of
Dublin
Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of th ...
's
water supply
Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. Thes ...
, the other major supply being
Vartry Reservoir
Vartry Reservoir ( ga, Taiscumar Fheartraí) is a reservoir at Roundwood in County Wicklow, Ireland. The water is piped from Vartry to a large open service reservoir in Stillorgan in the southern suburbs of Dublin. The reservoir is operated b ...
in east Wicklow.
Between 1938 and 1940, 76 houses were demolished, and the bridges at Humphreystown, Baltyboys, and Burgage blown up, in anticipation of the flooding of the valley for the Poulaphouca hydroelectric power station.
Technique
The Poulaphouca Reservoir supplies the three power stations along the River Liffey, which are located in Poulaphouca,
Golden Falls and
Leixlip
Leixlip ( or ; , IPA: lʲeːmʲənˠˈwɾˠad̪ˠaːnʲ is a town in north-east County Kildare, Ireland. Its location on the confluence of the River Liffey and the Rye Water has marked it as a frontier town historically: on the border betwee ...
. Poulaphouca has the largest capacity with two 15 MW generators driven by
Kaplan turbine
The Kaplan turbine is a propeller-type water turbine which has adjustable blades. It was developed in 1913 by Austrian professor Viktor Kaplan, who combined automatically adjusted propeller blades with automatically adjusted wicket gates to ach ...
s, the other two stations have a capacity of 4 MW each, so the total capacity of the power stations on the River Liffey is 38 MW.
The Kaplan turbines of the Poulaphouca station were delivered by the Swiss manufacturer
Ateliers des Charmilles from
Geneva
Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...
,
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
. Each turbine has a capacity of 25,300 horsepower at a
hydraulic head
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22.
It is usually measured as a liquid surface elevation, expressed in units of length, ...
of 50.5 m. The contract was executed in collaboration with
English Electric
N.º UIC: 9094 110 1449-3 (Takargo Rail)
The English Electric Company Limited (EE) was a British industrial manufacturer formed after the Armistice of 11 November 1918, armistice of World War I by amalgamating five businesses which, during th ...
from
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
.
Nature
![IMG Poulaphouca5543w](https://upload.wikimedia.org/wikipedia/commons/e/ef/IMG_Poulaphouca5543w.jpg)
The reservoir is sometimes known as "lakes" due to its shape, which arises because it lies in not one but two river valleys - that of the Liffey and, primarily, that of the King's River. The King's River joined the Liffey at Baltiboys, at which point it was the larger flow, and when the Liffey was dammed upstream of the confluence, the King's River Valley was flooded far to the south.
A ridge of land, on which the village of
Valleymount
Valleymount ( or ''An Chrois'') is a small village in western County Wicklow, Ireland.
Location and transport
Vallymount is located approximately 32km from Dublin city centre.
Valleymount is at an average elevation of 198m above sea level and ...
lies, divides the southern part of the reservoir.
The
goosander
The common merganser (North American) or goosander (Eurasian) (''Mergus merganser'') is a large seaduck of rivers and lakes in forested areas of Europe, Asia, and North America. The common merganser eats mainly fish. It nests in holes in trees.
...
, recently arrived as a breeding species in Ireland, can sometimes be seen here.
Blessington Greenway
Th
Blessington Greenwaywalk is 6.5 km in length and links the historic town of Blessington with the Palladian mansion at
Russborough House
Russborough House is a stately house near the Blessington Lakes in County Wicklow, Republic of Ireland. Located between the towns of Blessington and Ballymore Eustace, it is an outstanding example of Palladian architecture, designed by Richard ...
. The trail starts in Blessington village and leads south to the Avon Ri Activity Centre at the southern end of the town and weaves its way along the lake shores and forestry, crosses an ancient medieval Ringfort, and then uses the footpath along part of the N81 before turning back into the forest at Burgage Moyle lane. The Greenway follows the lakeshore and phase 2 is underway, with the goal of a 30 km greenway around the reservoir for walking, cycling and other recreational activities.
See also
*
Ardnacrusha power plant
The Shannon hydroelectric Scheme was a major development by the Irish Free State in the 1920s to harness the power of the River Shannon. Its product, the Ardnacrusha power plant, is a hydroelectric power station which is still producing power to ...
*
Carnsore Point
*
Electricity Supply Board
References
{{Authority control
Hydroelectric power stations in the Republic of Ireland
Buildings and structures in County Wicklow
Reservoirs in the Republic of Ireland