Experts explain how the water system for the Ilkley fountain will work

Until the late 19th century, virtually all fountains were gravity fed. From the fountains in the Alhambra palace in Grenada, a 1,000-year-old feat of hydraulics which still impresses engineers today, to the magnificent fountains at Hadrian’s villa in Tivoli, and the 410 fountains of the Shalimar Gardens in Lahore... all relied on channelling water from a higher source to provide pressure. Gradually, mechanical pumps replaced gravity and allowed fountains to recycle water in a closed bowl and force it high into the air.

The fountains in the Alhambra palace in Grenada (Image: submitted)

In planning the restoration of the Ilkley fountain, Improving Ilkley was faced with a choice of whether to reinstate the original gravity fed system from the 1860s, - where the moorland water would run through the fountain and onwards to the River Wharfe, - or modernise it with a closed system using an electrical pump which would continually circulate the same water.

Engineer Ian Whitlam explains that using an electrically driven pump was significantly cheaper but had several disadvantages. “Not only would a continuous electrical supply be required, but the water within the fountain bowl would have to be replaced from time to time. However, the major downside of this solution was the formal requirement to monitor and regulate the water quality within the fountain on almost a daily basis. As the same water is being used continually, a trained person would need to be appointed to sample and treat the water with chemical dosing to ensure that harmful bacteria and other contaminants were not building up.”

A moorland ghyll (Image: submitted)

Despite costing more, Improving Ilkley concluded that the traditional gravity feed system was clearly preferable, not least because it is also a fully sustainable and environmentally friendly solution. Since the water is constantly refreshed within the fountain and basin prior to discharging back into the Ghyll, there is no requirement for frequent testing. Rather than re-using the remnants of the original Victorian gravity feed pipework, the decision was made to install a completely new gravity feed and include a number of modern enhancements which will regulate the flow to the fountain and reduce the amount of floating debris including leaves and twigs etc. As the flow will be constant, the fountain will operate continuously throughout the year. Due to the filtered water entering a second chamber prior to running to the feed pipe, it would only be in the event of an abnormal drought that the fountain might stop for a short period of time.

Ian Whitlam, Anthony Barnett and Improving Ilkley Trustee Louise Hepworth-Wood have been working with artists Juliet and Jamie Gutch to research how the nozzle for the fountain will work within the sculpture. Anthony Barnett explains: “The plastic water pipe will connect onto a steel pipe which forms part of the fountain feature (and which can be seen in the model). A nozzle, probably incorporating several adjustable jets, will sit at the top of the steel pipe and will deliver the water sprays onto the fountain sculpture. After flowing over and around the sculpture, the water will collect in the upper steel bowl, prior to cascading down into the original masonry bowl. A circular overflow weir will be concealed within the base of the feature which will maintain a fixed water level in the stone bowl. All health and safety requirements for the general public will be considered.”

Juliet and Jamie Gutch said: “Reinstating the original gravity feed system for the fountain is such an affirmative and visionary idea and was what drew us to the competition in the first place. It was very much part of the inspiration for our design which celebrates pure moorland water.”

For more information on technical details, please visit the JustGiving page and follow the link to ‘Further Design information’. https://www.justgiving.com/campaign/improvingilkleyfountain