Water channels

Next time you are in the Tai Tam Country Park, pause to check out the 21-arch Tai Tam Upper Reservoir Masonry Aqueduct. You are looking at a master feat of engineering.

Broadly used to describe any water-carrying channel, an aqueduct is a bridge-like structure supporting a conduit or canal passing over a river or low ground. The practice of using underground or land pipes and tunnels to transport water is as old as the Harappan civilisation. But it was the Romans who used them extensively to transport water over long distances for drinking and for public baths. It was one such relic known as the Pont du Gard, a UNESCO World Heritage Site, which I visited a few kilometres off Nimes (尼姆) in Southern France (法國).

Pont in French means a bridge. Pont du Gard, or bridge on the River Gard, was built in 1AD “to carry a section of the channels and pipes” of the 50-kilometre aqueduct that transported water from the Eure Spring in the city of Uzes (澤斯) to Nimes, a Roman colony then. It also served as a footbridge for travellers to cross the river.
At 49 metres, Pont du Gard with its three rows of arches – six in the bottom row, 11 in the middle and 47 (only 35 remain) in the top row - is the highest and one of the best preserved Roman aqueduct bridges. Atop the third row is the covered water channel. The structure’s maintenance became irregular by the fourth century and completely ceased by the sixth century.

Watching the bridge as the sun blazes in the backdrop sets the imagination loose. It appears like a grand gate standing guard over a city. It is surreal to observe the signatures left behind by craftsmen and artisans of the Compagnons du Tour de France, a group that has since the Middle Ages travelled afar to apprentice with various teachers. The bridge casts dark shadows on the green river water, neatly dividing it into dark and sun-lit columns.

Trekking down so far to just meet an ancient sentry holding its post may not sound appealing to some of you. But think back to the many arched bridges you may have crossed in trains or watched in movies. Think about the Bowen aqueduct that quenches the Central District. There is history behind everyday phenomena. The present is but rooted in the past and it is the achievements and discoveries of the olden times that have brought the modern world so far.

Photo: Wikipedia