John Carruthers is a great ambassador for civil engineering and revealed the far sightedness of the Loch Katrine Waterworks built over 160 years ago. Cholera and typhus epidemics in the mid 1800s drove the scheme. A public health boon for a growing population and serving expanding industry. Who could not be impressed by the elegant simplicity of water flowing from Loch Katrine to Milngavie by gravity alone! The interlinked hydrology of the Trossachs area including Lochs Lubnaig, Arklet and Venacher was exposed by John. Loch Katrine receives a generous 79 inches of annual rainfall. Enough for Glasgow’s needs and compensatory water to avoid depleting water resources elsewhere. John closed his talk by reflecting on the world’s water resources. He observed that only 2.5% of the world’s water is fresh and most of this is tied up in ice caps, glaciers and ground water. In short, the water in our taps is a precious commodity!
The 1855 Glasgow Corporation Waterworks Act facilitated the Loch Katrine scheme. The project was estimated to cost £522,622, 18 shillings, 11 pence and one farthing! Such precision!! Work was commenced in May 1856 and was officially opened three and a half years later by Queen Victoria in October 1859, an incredibly short time for such a major project. Not all were impressed though, one elderly lady complained the water had ‘neither taste nor smell’. However, subsequent life expectancy increased and deaths from later cholera epidemics dramatically dropped – a positive success.
John’s slides took us along the length of the aqueduct from Loch Katrine to Milngavie. The engineers could only tunnel about 15 feet a month through the tough rocks. This meant digging many shafts to increase the number of faces being worked at one time. It was all done by hand and required painstaking accuracy. Some 3,000 men were employed. John showed photos of the shaft heads, spoil heaps and cast iron channels, pipes and viaducts along the route. He observed that traversing valleys could be a challenge. Nonetheless pipes could dip in places if the inlet pressure was higher than the exit. This added to maintenance because the pressurised pipes can fail!
Since 1859 there have been a many major enhancements, the first being a second aqueduct which was commissioned in 1895. The new aqueduct added 80 million gallons a day, more than doubling the original supply. In the 1960s work was commissioned to take water from Loch Lomond to serve the Central Belt as far as the Lothians. Unlike the Loch Katrine Scheme, the low level of Loch Lomond meant pumping the water East. As a result Scottish Water became the largest electricity consumer in Scotland! While the pipelines cross at Blanefield, interlinking the two systems to improve flexibility and resilience of supply didn’t occur until Scottish Water was created this century. The elevated Loch Katrine water also had the advantage of reducing electricity consumption. Major treatment works have been built at Balmore and Barrachan to meet European standards. Last, but not least, the aqueducts have been securitised, a reflection of modern times.
It’s not possible here to cover all of John’s revelations such as the raising of the level of Loch Katrine and the need to relocate Rob Roy’s burial grounds, not once but twice. In addition, we learn the average Council Tax payer pays only a pound a day for water. ‘Hats off to the Victorians and Let Glasgow Flourish’ said it all, says John.