Scottish Water Loch Katrine aqueducts' £7m upgrade completed
Scottish Water has announced the completion of a £7m project to upgrade aqueducts supplying water to a quarter of Scotland's population.
The company said it was the biggest improvement to the aqueducts from Loch Katrine since they were constructed more than 150 years ago.
Engineers worked on miles of tunnels and 21 bridges along the route to water treatment works near Glasgow.
The system supplies about 550 million litres of water each day.
Treatment works taking their water from Loch Katrine, at Milngavie and Balmore, provide water for 1.3 million people.
John Rae, Scottish Water's operations manager, said: "These aqueducts, which were part of a scheme opened by Queen Victoria in 1859, were a feat of engineering of their day and remain an outstanding example of sustainable civil engineering public works construction, which have stood the test of time.
"But, despite some improvement work over the years, they required substantial capital maintenance to ensure they continue to operate efficiently.
"This investment by Scottish Water will help ensure we continue to provide a first-class service to a massive number of customers for many years to come."
Over the combined length of the old and "new" aqueducts, there were more than 30 historic listed structures and planning permission for the repair work was conditional on full consultation with Historic Scotland.
Project manager Simon Renton said: "Strict adherence to constraints and restrictions was necessary to ensure that the character of the historic structure was preserved.
"Reconstructed areas of masonry on every part of the structure had to match the existing stonework in terms of appearance and painting and protective coating systems were carefully chosen to blend with the surrounding structure."