Today, Jumbles Reservoir and Country Park is a popular destination for walkers and bird watchers alike. The name ‘Jumbles’ gives us a clue to why the reservoir is here in the first place, and why beneath its waters lie the remnants of Horrobin Mill, a once extensive site. 

Jumbles Reservoir, near Bolton

Jumbles derives from the word ‘Dumble’. This is a northern dialect term, coming from Old English (i.e. Saxon) which means ‘deep wooded valley’ or ‘deep-cut water course’. This describes the valley that Bradshaw Brook, the water course that feeds and drains the reservoir, runs through. Bradshaw is also an Old English word, meaning ‘broad wood’. These descriptive words allow us to imagine how the scene looked before the reservoir was constructed – a fast-flowing water course through a deep valley. Such a place would provide a perfect water source for the once flourishing bleachworks industry in this part of Lancashire.

The Thirsty Mills of Bradshaw Valley

Horrobin Mill, which now lies beneath the reservoir, was a site that spanned either side of Bradshaw Brook. A bleachworks existed here from the 1780s onwards, but really expanded significantly in the Victorian age. Initially two separate factories, it merged into one extensive site.  Such was the demand for water that a consortium of bleachers including the owners of Horrobin Mill and Bradshaw Hall Works constructed a reservoir further north in the valley. This was Entwistle Reservoir and it served the needs of the bleachworks for 25 years.  In 1863, it was compulsory-purchased by Bolton Corporation for drinking water. This meant a new reservoir was required for the industrial needs, which led to the construction of  nearby Wayoh Reservoir. 

A number of local wealthy families owned Horrobin Mill but, in 1937, it was bought by the Bleachers Association, who became its final proprietors. The association already owned a rival business at Bradshaw Hall (see our page on it here). This acquisition would not only shut down a competitor but also give them a larger share in the water from Wayoh Reservoir for their site. Horrobin Mill was finally closed in 1941, and most of its buildings demolished in 1948.

The stone setts (‘cobbles’) of Horrobin Lane that led down the the bleach works

Demand for drinking water for Bolton kept growing, and even the construction of the Thirlmere Pipeline bringing water down from the Lake District could not meet it. The decision was made that, along with Entwistle, Wayoh as well should be given over solely to drinking water. However to do that, a third reservoir would be needed to keep Bradshaw Brook scoured (i.e. free from debris) and to supply the Croal-Irwell River complex downstream.

A decision was made to construct Jumbles as a ‘compensation reservoir’ to fulfil this purpose. No drinking water would be taken from it.  In 1964, Horrobin Mill site was bought by Bolton Corporation for £8,500 and the remaining buildings demolished. 

Jumbles Reservoir is Constructed

Construction started in 1967 and the first task was to clear the site of all vegetation. Next, two surviving chimneys from the mill were demolished.  The valley was then excavated, with huge amounts of earth being moved to sculpt the basin.

In 1969, work on the Overflow Chamber was begun. A long spell of dry weather enabled the 70 men to stick to their demanding schedule, completing it on time the following year. This piece of engineering would enable Jumbles Reservoir to discharge four million gallons of water each day into Bradshaw Brook. By August 1970 the reservoir was complete, but work continued on landscaping the perimeter. It took five months for the reservoir to fill up. At capacity it can hold 450 million gallons of water, at a depth of 75 feet. 


In 1971, Jumbles was officially opened by the mayor of Bolton, Alderman John Monks. In 1973, the surrounding site was designated as a Country Park, which was opened by Queen Elizabeth II. Since then it has become a popular destination, continuing the tradition of walking in the area that stretches back over a hundred years.

Historical Remains

In drought years the ruins of Horrobin Mill can still be seen and such conditions have occurred in both 1976 and 1991.  Photographs taken in 1984 when the reservoir was very low revealed an intact iron footbridge that would have spanned the Bradshaw Brook, close to the site of the mill.

The loading ramp

For the rest of the time, the ruins remain submerged. However, traces of the formal industrial activity of the bleachworks can be seen if one takes the circular walk around the reservoir. A stone loading ramp stands by the path on the eastern side of the reservoir, by what was the old road from Walsh Fold. Horses would haul carts up the road (now a footpath) towards Bradshaw Road, and a water trough for them to drink from can be found on this route. The intriguingly named Coffin Lodge is a sole surviving reservoir from the time of Horrobin Mill, located on the western side of Jumbles, again, close to the designated circular path. Horrobin Lane, also on the western side still has its stone sets (commonly called ‘cobbles’) for much of its length, and would have been a familiar sight to those coming to and from the mill. At Horrobin Fold the old mill stables have been converted into mews houses.

Walking around the reservoir today, visitors are struck by the beauty of the landscape, and perhaps with a little effort they could imagine themselves to be visiting one of the smaller lakes in Cumbria. Birdwatchers can see heron, kingfisher and cormorant. Winter visitors include golden eye, pochard and tufted duck.

The flooded quarry at the north end of the reservoir, starting to look like a natural feature as it becomes  colonised by trees

For over a hundred years the valley of Bradshaw Brook was a popular walking destination, and the creation of the country park has continued this tradition. With its cafe and information centre at Waterfold car park, it is a convenient starting point for the circular three and a half mile walk around the reservoir. Paths also lead north to Wayoh and south to the site of Bradshaw Hall, with its solitary porch standing close by the remnants of its gardens.

Site visited by A. and R. Bowden 2020


Park at Waterfold car park (postcode BL2 4 JS). This is open from 10.30 am to 4.30 pm every day. The Jumbles Country Park cafe is also located there. There is a circular walk from this car park.

The Jumbles Country Park Cafe facebook page is here

Nearby, just a short drive away

Bradshaw Hall and Bleachworks

Turton Tower

Turton Tower Curiosities


Jumbles- Bradshaw Valley,  unknown author, (1988) West Pennine Information Service. Available from Jumbles Country Park Cafe.

Horrobin Mill: Bleachworks in the Jumbles, J.J. Francis (1992) Turton Local History Society. Available from Jumbles Country Park Cafe.