October 23rd, 2018
Waterfalls are often known as “wonders” of nature, and are symbols of the power, strength and force of nature.
“I never saw water falling so gracefully, so much like thin, beautiful threads as here” says George Borrow in his nineteenth century travel guide to Wales. He journeyed through the village of Llanrhaeadr-ym-Mochnant in Mid Wales to reach the mountainous point where the Afon Disgynfa roars and crashes as it tumbles for 240 feet over a cliff face.
“What shall I liken it to? I scarcely know, unless it is to an immense skein of silk agitated and disturbed by tempestuous blasts, or to the long tail of a grey courser at furious speed”, Mr. Borrow continues poetically, obviously moved by the roaring sounds and beautiful sights of one of Wales’ longest waterfalls.
George Borrow wasn’t alone in his awe of the waterfall. They have been inspiring and exhilarating human beings since the beginning of time; we have always been drawn to these awesome displays of the power and wonder of nature. And while Wales’ waterfalls may not be able to compete amongst the giants of the world such as Victoria Falls, Iguassu Falls or Niagara Falls, we have plenty of impressive falls of our own. But just how were these curiosities of nature created?
It may seem that waterfalls have forever been part of the landscape, but they take an incredibly long time to create. They are most often formed in areas where rivers have run over layers of soft and hard rock. Over time, the soft rock is worn away by the water running over it and by the movement of stones and sand along the bottom of the river.
Gradually this erosion causes a step or ledge, which over time becomes larger, steeper and higher because the force of the falling water wears away the bed at the bottom of the ledge, eventually creating a plunge pool where the water collects.
The hard rock at the top of the ledge will eventually become an overhang until one day, the force of the water will break apart the hard rock ledge, causing it to plunge into the pool below.
Over time, the moving water will create a gorge, with the waterfall ledge retreating further and further back across the river bed. Niagara Falls for example, retreats at a rate of a metre a year.
Of course, all this moving water over different types of rock and stone is unpredictable and doesn’t just create one type of waterfall…..
- A plunge waterfall is the most distinctive, where a river creates a single ledge and water spills straight out over the top of it.
- A cascade waterfall is also common and occurs when the water flows down a series of steps, rocks and ledges.
- A punchbowl waterfall forms when a narrow river bursts out over a wider ledge.
- A multi-step fall is a series of waterfalls one after the other.
- One of the most impressive types is a block or sheet waterfall, which is the term for a very wide waterfall because when the water flows over the top of the ledge it looks like a sheet of water.
And it’s not only mother nature who can create waterfalls. Over in Llangollen, in North East Wales, the falls here may not have been created by nature but they are no less impressive. The distinctive water feature is 140 metres wide and sits on the River Dee just north of Llangollen.
The Horseshoe Falls were created as part of Thomas Telford’s grand plan for the Llangollen Canal and the Pontcysyllte Aqueduct. The falls served to divert and feed the canal with water from the river. The Canal, the aqueduct and the falls were all completed in 1808, but the advent of first steam trains and then roads rendered the canal network all but useless for industry. Many British canals were closed and left to ruin, and although the canal here is no longer used for heavy industry, it is one of the most popular leisure canals in the country. Since 2009 the falls, the canal and the aqueduct are all part of a UNESCO World Heritage Site, which points to its extreme historical, cultural and industrial significance.