A report, published in 1865, suggested that the City Surveyor should make a survey of the district to see what could be done about the situation. The waterworks company, then worried that they might be usurped, employed an engineer to examine their works to see how best they could improve the water supply. He recommended an extension of the pumping station at Stoneyholme, together with filtration and an extra storage reservoir. The city leaders then decided to buy the waterworks in December 1865, for £31,504, and the existing works were extended at a cost of £11,000. A temporary solution had been found, but an increasing population and rising demand for clean water meant that controversy continued over the next 20 years as to the desirability of finding a brand new source of supply – or to try to extend again the existing waterworks.

1887 saw the implementation of the Carlisle Corporation Acts. The new legislation meant that the city’s authorities now had responsibility for supplying water to a much larger area, including Wetheral, Warwick, Crosby-on-Eden, Grinsdale, Kirkandrews-on-Eden, Beaumont, Burgh-by-Sands, Orton and Dalston. And by 1892, the population that needed supplying had gone up to 42,000. In other words, pressure was mounting to find a new water supply for an ever expanding city. Increased sanitary arrangements demanded more water per head too – as well as an increased demand for trade purposes. At that time, a maximum of 1.25 million gallons per day could be delivered from Stoneyholme. And already, by June 1896, over 24 gallons of water was needed per head of population for domestic use and trade use combined – a huge increase.

Investigations continued – until May 1897, when the Waterworks Engineer, Mr C B Newton, reported on three potential schemes:

There were real concerns about the suitability of rebuilding and upgrading the Stoneyholme works in the city. The pumping engines were practically worn out, and huge maintenance costs were predicted for them, as well as for the poorly designed existing filters, which were already struggling to work properly, particularly during the summer months when the need was greatest.

There were many advantages to a new scheme for the Eden. It was efficient, it was simple, and it was relatively cost effective to install. But its one main drawback was that it was a pumping scheme. The ongoing costs associated with that – as opposed to the natural, gravitational scheme proposed for Geltsdale – could become a liability for the Corporation. Water at the Eden was analysed and also found to be of inferior quality to that of the Gelt.

Many visits were made to Geltsdale to test the water there, and to check the valley’s rainfall measurements. Daily readings started to be taken from 1897. The average annual rainfall for 1898 to 1903 was 38.5 inches. Concerns over the peaty nature of the water were allayed, particularly by the helpful impact that having time to settle in a reservoir would have on it. The consistency of the water levels of New and Old Waters, which formed the Gelt at their junction, were assessed throughout the year to check on their reliability, and on their ability to provide water to the river downstream even if some was drawn off upstream. But there was huge support for deciding to go with the Geltsdale option – the clarity of the water, the absence of pollution, the absence of people and buildings getting in the way, and the height and therefore use of gravity that it offered engineers.

It’s also worth bearing mind that in theory, the engineers could have simply opted to go for a water gathering system in Geltsdale, without also having the need to build a storage reservoir further downstream. But in their forward thinking, which proved to be so correct, the decision was made to build a reservoir too, in Castle Carrock, to safeguard Carlisle against water scarcity in periods of prolonged drought. Within a few years, in September 1907, their foresight had been proved to be correct. A prolonged period of dry weather had led to the need to plan for dealing with water shortages in Carlisle—the reservoir was still being built and wouldn’t be ready for another two years. As it transpired, never mind drought, the huge increase in need for good, clean water over the years easily justified the decision to build the reservoir.

And so on October 6th 1897, the Water Committee put forward to the Corporation that the Geltsdale plans should be chosen – estimated at a cost of £129,320, with repayments spread over 50 years. Having been approved, the necessary Parliamentary Bill was promoted, authorising the Corporation to construct and maintain waterworks at Geltsdale and Castle Carrock.

Brampton Rural District Council and the Earl of Carlisle were unhappy. The civic leaders of Brampton were already considering their own water supply scheme for themselves as well as for a number of villages under their jurisdiction. And they were already planning to use one of the springs which fed Old Water. After much argument, and parliamentary time, it was decided that the new waterworks in Castle Carrock would offer a free supply of 220,000 gallons of water per day to Brampton and its hinterland. As far as the Earl was concerned, he fought the Bill in the House of Lords, worried that he was going to lose land, and therefore access to possible mineral extraction and a fine water supply of his own. A compromise was reached whereby the Corporation was required to provide certain benefits to the Earl too, a complicated story to tell for another day, but involving certain guarantees from the Corporation to satisfy the Earl’s demands.

So finally, in 1898, the Carlisle Corporation (Water) Act came into being, giving the green light for action. It gave the Corporation powers to abstract water from the springs and rivers in Geltsdale, and to construct a storage reservoir at Castle Carrock with a capacity of 180 million gallons, with adjacent slow sand filters to process the water. It also permitted the Corporation to lay a 20inch diameter pipeline from Geltsdale to Castle Carrock, and to lay a 16inch water main from Castle Carrock to Cumwhinton where a 5 million gallon covered service reservoir was to be constructed. Finally, it allowed the Corporation to lay a 21inch main from Cumwhinton to supply the city and the immediate surrounding area of approximately 40 square miles. The Cumwhinton operation is still very much in operation today, as are all the pipes.

However, the controversies were not yet over. In 1901, the tenders for the work were discovered to be way over the original estimate of the cost, and the whole process was put on hold for six months. Engineers from Westminster, Messrs Mansergh and Sons, were eventually called in, but they placed the cost of the project at £208,000, in addition to the £35,000 already spent by Carlisle Corporation – a full £123,000, or almost double the original cost. It created uproar in the city, and popular opinion called for the scheme to be abandoned. But, by 19 votes to 17, the Corporation decided to go ahead with the ambitious scheme, and to apply for a bigger loan to cover their costs.

Engineers and contractors were finally chosen in 1903, work started in Geltsdale shortly afterwards, and work began on the actual reservoir in Castle Carrock in 1906, to be officially opened on July 22nd 1909. The waterworks were to be the only source of water supply for Carlisle and the surrounding area for the next 55 years.