Waterworks at Blagdon: By-wash, Weir and Inspection Bridge, Butcombe, North Somerset

Summary

By-wash, weir and inspection bridge designed by Charles Hawksley as part of the waterworks at Blagdon (1898-1905).

Description

By-wash, weir and inspection bridge designed by Charles Hawksley as part of the waterworks at Blagdon (1898-1905), with late C20 alterations.

The c300m long curved by-wash is lined with stone and has sections of rock-faced stone walling to the edge terminated by square gate-piers with pyramidal caps. At it east end, where it runs under the road bridge on the dam, the by-wash has tall curved rock-faced stone retaining walls with blind three pointed arches. The stepped weir at the top east end was rebuilt in the late C20.

The curved footbridge bridge originally set on top of the weir was relocated in the late C20 to a weir situated further downstream. The bridge is constructed with a cast iron cross-shaped frame and has a planked timber walkway. The inside of the curve has an ornate cast iron railing with floral brackets and spear-headed finials to the posts. The railing to the outside is lower, in order to inspect the weir, its posts formed by the cast iron ribs of the construction frame.

History

The waterworks at Blagdon, Somerset, built by the Bristol Waterworks Company (now Bristol Water) in 1898-1905, were authorised by two Acts of Parliament in 1888 and 1889. They were designed and constructed under the direction of Charles Hawksley of the engineers firm T & C Hawksley of Westminster in a decorative Jacobean style, to house engines and boilers designed and constructed by Hydraulic & Sanitary Engineers Glenfield & Kennedy Limited of Kilmarnock, Scotland. The latter were installed at Blagdon in 1904, and are believed to be the last of the water pumping beam engines that were installed at waterworks in England throughout the C19, the oldest being those at Kew, Greater London.
Charles Hawksley (1839-1917) was a civil engineer, educated at University College School, London. He was the son of civil engineer Thomas Hawksley, who had his firm in Westminster. Charles became his apprentice in 1854, and in 1866 was taken into partnership by his father. After his father's death in 1893 he became head of the firm. Charles' professional work was principally in connection with waterworks: parts of those at Catcleugh, near Rochester are listed, as are those at Butterley, Kirklees. Charles was a prominent figure in the Committee Rooms in Parliament during his career, where he frequently gave evidence as a technical expert. In 1901 he became President of the Institution of Civil Engineers, and in 1907 established the Thomas Hawksley Fund to provide an annual lecture and medal in memory of his father. In honour of Charles, the Institution of Civil Engineers awards the Charles Hawksley Prize.
The Bristol Waterworks Company (BW) was formally established on 16 July 1846 by an Act of Parliament. Their plans for supplying fresh water from the Mendips to the entire city of Bristol, were weighed up by the Government against those submitted by a rival group, the Society of Merchant Venturers, which was backed by Isambard Kingdom Brunel, seeking only to supply water to the wealthier parts of Bristol. The BW was led by prominent local citizens, including William Budd, a physician, George Thomas, a Quaker and philanthropist and Francis and Richard Fry, also Quakers and local industrialists. In 1847 the BW managed to built a 16km long Line of Works conduit to bring fresh water into Bristol. Sand filters were added to treat the water and chlorination was introduced in 1935. Their first reservoir was created in 1850 at Barrow, followed by those at Blagdon, which included the pumping station, Cheddar (early 1930s) and Chew Stoke (1956). Despite the widespread move from private to public ownership of water supplies in the mid- to late C19, as encouraged by the government, BW was one of very few companies in England that remained privately owned.
In preparation for the building of the waterworks at Blagdon, an Inspector’s House was built on raised ground in order to oversee the construction of the earth dam for the reservoir started in 1898. Whilst the reservoir started to fill, reaching its top level in 1903, works on the pumping station began in 1902. The Bristol Waterworks Company supported the construction of the Wrington Vale Light Railway by the Great Western Railway, started in 1898 and opened in 1901. A public station was built and a short branch with siding station (disused since 1950) led to the pumping station, initially to deliver building materials and later to supply coal. The construction of the reservoir, with dam, valve house and road bridge and the pumping station with receiving tanks, outlet and by-wash, are extensively documented in a set of photographs of c1902 (private collection). It also included a small meter house (now a bat sanctuary), and sewage works, now disused (in separate ownership) and replaced in the later C20 with new works nearer the pumping station (in separate ownership).

As reported by the Institution of Mechanical Engineers in 1908 and 1930, the watershed area draining to the Yeo reservoir was c2144ha, and when full the reservoir’s area of surface water covered c182ha, with a capacity of holding well over 1770 million gallons of water. During the construction of its c485m long embankment dam with a maximum height of 13m, a tunnel with a 3m diameter was in use for the passage of floods, which had two sets of valves. The puddle trench of the dam was one of the deepest in England: its construction presented great difficulty as it was found necessary to excavate to a depth of c53m below the valley bottom before an impervious foundation in the red marl was secured. The length of the weir at the head of the by-wash for carrying off floodwater was c55m.

The pumping station consisted of two engine houses with a tall decorative chimney (truncated in the 1960s), each containing two Woolf compound rotative beam engines, a boiler house containing six Lancashire boilers and two sets of Green’s economisers, two coal stores and a number of workshops to the rear. Two receiving tanks, each with a capacity of 567000 gallons, were supplied with water from the Yeo reservoir, and by cast iron pipes from the Rickford and Langford springs. In 1949 two of the beam engines were replaced with smaller electric pumps. The other two have been preserved, one fitted with an electric motor to show it in action. In the 1960s, the tall, decorative central chimney stack to the pumping station was lowered.

After completion of the pumping station, the grounds were laid out as ornamental gardens, planted with a large number of specimen trees such as Scots pine, Cedar, Larch, Spruce, Oak, Beech, Chestnut, Willow, Lime, Holly, and Maple. Extensive ornamental woodland planting also took place around the reservoir, and a grass perimeter walk was laid out, as proposed in 1900. It was probably around that date that the Fishing Lodge was built, on the edge of the reservoir, matching the rustic timber framed style of the nearby Inspection House.
In the later C20 some of the land and properties associated with the waterworks at Blagdon were sold, including the former Inspection House. Replacement sewage works and an electrical substation were built to the rear of the pumping station. Since then, the weir at the top of the bye-wash has been replaced, retaining the decorative, curved inspection bridge, which was relocated further downstream where it crosses the bye-wash. Today (2014) the pumping station remains in use, and the 1960s replacement pump engine is currently (2014) being replaced by a new model. As part of these works a new valve house is constructed on the dam, south of the earlier valve house (itself a later replacement). The meter house standing on the southern edge of the reservoir is now a bat sanctuary. The Inspection House, now in separate ownership, is in use as a private dwelling. Blagdon Lodge has remained in use as a fishing lodge: the receiving tanks in front of the pumping station now in use to rear fish for the reservoir.
The by-wash, weir and inspection bridge were designed by Charles Hawksley as part of the waterworks at Blagdon (1898-1905).

Reasons for Listing

The by-wash, weir and inspection bridge forming part of the waterworks at Blagdon, Somerset, merit listing at Grade II for the following principal reasons:

* Architectural & engineering interest: it is a good example of a waterworks structure built as part of the waterworks at Blagdon in 1898-1905 by the nationally important civil engineer and architect Charles Hawksley displaying good quality architectural detailing and decorations.

* Historic interest: it has a strong and interesting historic association with the Bristol Waterworks Company, whose ambitions as expressed by its founders are expressed in its overall design.

* Intactness: despite the relocation of the inspection bridge and the rebuilding of the weir, it has survived well.

* Group value: it has strong and important group value with the associated contemporary pumping station and other waterworks structures at Blagdon.

External Links

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