Rivers of time

Navigable aqueducts played an important role in getting Great Britain’s industrial revolution off the ground. In an age when railroads and commercial highways had yet to be invented, these elevated artificial water bridges proved their worth at the time and have continued to do so for over two hundred years.

The Lune Aqueduct (above) supports the Lancaster Canal and towpath over the River Lune in Lancaster, England. Designed by John Rennie following classical architectural techniques, the 19 meters (62 ft) aqueduct over the River Lune is supported by 5 arched brick piers. It was built between 1794 and 1796, and its cost ran way over budget preventing the Lancaster Canal from connecting to the main canal network via the never-built aqueduct over the Ribble river. The Lune Aqueduct not only looks Roman, it was built using Roman technology adapted by Rennie, to ensure the stone bed of the aqueduct would not leak, Rennie specified the use of Pozzolana powder, a Roman invention that allows concrete to set underwater. The Lune Aqueduct is still in use today.

Avon Aqueduct

 
 At 250 meters (810 ft) long and 26 meters (86 ft) high, the Avon Aqueduct is Scotland’s longest and tallest aqueduct. Built after a design by navigable aqueduct pioneer Thomas Telford, the Avon Aqueduct features a cast iron trough supported by 12 brick and masonry arches.
The aqueduct runs through Muiravonside Country Park, providing a spectacular scenic view from the park’s lush landscape or from the top of the aqueduct itself.
The Avon Aqueduct carried the Union Canal and is located near Linlithgow in West Lothian, Scotland. Three great navigable aqueducts facilitated water traffic on the Union Canal, which opened in 1822 and was closed in 1965, with the Avon Aqueduct being the largest and longest of the three.

Pontcysyllte Aqueduct

Engineer Thomas Telford designed the Pontcysyllte Aqueduct in Wales.It is the longest and highest aqueduct in Britan at 1,007 ft (307 m) long, 11 ft (3.4 m) wide and 5.25 ft (1.60 m) deep, it carries the Llangollen Canal over the River Dee in Wrexham, northeast Wales.
The Pontcysyllte (pronounced “pont-ker-suth-tee”) Aqueduct may have been the height -literally – of technology at the time, but its construction involved some surprisingly unusual and ancient techniques. One example is the mortar used to cement the masonry piers: it was made from water, lime, and ox blood!

It is often the Pontcysyllte Aqueduct in TV programs and tourist publicity shots. It was added to theUNESCO World Heritage List in 2009. The aqueduct is used regularly by pleasure boats and commercial “narrowboats”, and once every 5 years it’s drained (by removing a plug) for cleaning and routine maintenance.
More aqueducts at - you guessed it WebUrbanist's "Slippery When Wet: The UK’s Top 10 Navigable Aqueducts"