Horseshoe Falls near LlangollenThomas Telford’s Ingenious Water Source for the Llangollen Canal

Authorised by an Act of Parliament obtained in 1804 by the Ellesmere Canal Company

Horseshoe Falls, located just upstream of Llangollen in North Wales, is one of the most important engineered features on Britain’s canal network. Built in the early 19th century, this elegant stone weir was designed by Thomas Telford to provide a reliable water supply for the Llangollen Canal (now part of the Shropshire Union Canal system). While modest in appearance, Horseshoe Falls plays a vital role in keeping one of Britain’s most scenic canals navigable.

What Is Horseshoe Falls?
Horseshoe Falls is a man-made weir on the River Dee, shaped in a gentle curve which is 460 feet wide, that gives the structure its name.

Rather than being designed for dramatic visual impact, the falls were carefully engineered to raise the river level just enough to divert water into the canal feeder without obstructing the natural flow of the river.

The site is peaceful and picturesque, blending seamlessly into the surrounding landscape while quietly performing an essential function.

Thomas Telford and the Llangollen Canal Water Supply

When Thomas Telford took over responsibility for the Ellesmere Canal project in the early 1800's, one of the biggest engineering challenges was maintaining water levels on the high, exposed summit section near Llangollen.

Telford’s solution was both simple and brilliant

Why Horseshoe Falls Was Built
The Llangollen Canal sits high above surrounding countryside
Natural water sources along the canal were limited
A dependable supply was needed to keep locks operational year-round
The nearby River Dee offered a constant, powerful water source
In 1808, Telford completed Horseshoe Falls to raise the river level just enough to allow water to flow into a feeder channel, which then supplies the canal directly.

How Horseshoe Falls Feeds the Llangollen Canal

Water diverted at Horseshoe Falls enters the canal just upstream of Llangollen Basin. This continuous feed means the canal is river-fed rather than reservoir-fed, which is unusual within the UK canal system.

Key Features of the Water Feed
Gravity-fed system requiring no pumps
Constant flow from the River Dee
Reliable supply even during dry periods
Essential for maintaining levels across long pound sections
This design has allowed the Llangollen Canal to remain navigable for over 200 years.

The Noticeable Current in the Canal
One of the most distinctive characteristics of the Llangollen Canal is the strong current created by the continuous inflow of water from Horseshoe Falls.

What Boaters Experience
A visible flow of water along the canal
Increased steering awareness required, especially at low speed
Stronger movement near bridges and narrows
A sense that the canal behaves more like a river than a traditional canal
For boaters unfamiliar with the Llangollen Canal, the current can come as a surprise, but experienced crews quickly adapt. The flow is generally helpful when travelling away from Llangollen, while extra power and care are needed when heading towards it.

A Unique Canal Engineering Feature

Horseshoe Falls is significant because:

• It is purpose-built solely to supply a canal
• It demonstrates Thomas Telford’s sensitivity to landscape and function
• No dams or reservoirs that would disrupt the river
• It remains in continuous use today

Unlike many canal water systems that rely on reservoirs hidden in upland valleys, Horseshoe Falls is a visible, elegant solution that showcases early 19th-century civil engineering at its best.

Thomas Telford's Horseshoe Falls Today

Today, Horseshoe Falls is:

• A Scheduled Ancient Monument
• A popular walking and photography location
• An educational example of canal engineering
• Still actively feeding the Llangollen Canal

The site can be accessed easily from Llangollen via riverside paths and is often included as part of walks along the Dee Valley.

Why Horseshoe Falls Is So Important
Designed by Thomas Telford
Built specifically to supply the Llangollen Canal
Creates the canal’s distinctive flowing current
Over 200 years old and still operational
A rare example of visible canal water engineering
Few places on Britain’s waterways illustrate the link between river and canal engineering as clearly as Horseshoe Falls.

Conclusion
Horseshoe Falls near Llangollen is far more than a scenic riverside feature. It is a masterpiece of functional design by Thomas Telford, ensuring the long-term success of the Llangollen Canal through a constant gravity-fed water supply. The resulting current gives the canal a unique character, setting it apart from almost every other inland waterway in Britain. Quiet, effective, and enduring, Horseshoe Falls remains one of the most important hidden heroes of canal history.