Mourne Wall

Luke Livingstone Macassey (1843–1908), an Irish civil engineer and barrister, was in 1874 appointed consultant hydraulic engineer by the Belfast and District Water Commissioners. The Commission had been set up in 1840 to ensure the water supply for Belfast, at that time an expanding city. In 1891 Macassey advised the construction of a reservoir in the Mourne Mountains, as a long-term solution.[1]

The project required the acquisition of wayleaves and water rights. Private Acts of Parliament were passed, of 1893, 1897 and 1899, on behalf of the Commissioners.[2]

The Silent Valley Reservoir was built between 1923 and 1933 to hold the water from the catchment area enclosed by the wall. The reservoir supplies Belfast via the Mourne Conduit/Aquarius pipeline. The main purpose of the Mourne Wall was to isolate the catchment area from cattle and sheep.

The Mourne Wall at the summit of Slieve Donard where a trig point stands upon the summit tower.

The wall was crafted from natural granite stone using traditional dry stone walling techniques. On average the wall is about 1.5 m (4 ft 11 in) high and 0.8 to 0.9 m (2 ft 7 in to 2 ft 11 in) thick and is estimated to be 19.5 mi (31.4 km) long[3] Stonemasons worked from March to mid-October for 18 years to build the wall.[4]

As the wall was built to contain the catchment area of the Mourne, the wall passes over fifteen of the highest mountains in the area (listed clockwise from the Kilkeel River):

• Slievenaglogh 445 m (1,460 ft)
• Slieve Muck 674 m (2,211 ft)
• Carn Mountain 587 m (1,926 ft)
• Slieve Loughshannagh 619 m (2,031 ft)
• Slieve Meelbeg 708 m (2,323 ft)
• Slieve Meelmore 680 m (2,230 ft)
• Slieve Bearnagh 739 m (2,425 ft)
• Slievenaglogh 586 m (1,923 ft)
• Slieve Corragh 641 m (2,103 ft)
• Slieve Commedagh 765 m (2,510 ft)
• Slieve Donard 850 m (2,790 ft)
• Rocky Mountain 525 m (1,722 ft)[5]
• Slieve Binnian 747 m (2,451 ft)
• Wee Binnian 460 m (1,510 ft)
• Moolieve 332 m (1,089 ft)

The wall is maintained and owned by Northern Ireland Water.[6]