development projects planned in the vicinity of the Pontcysyllte (United Kingdom) property. The State Party replied with a detailed memorandum with a document and maps attached (60 pages). The analysis of No 1303 this documentation is included in the present evaluation.

Date of ICOMOS approval of this report: 10 March 2009

Official name as proposed by the State Party: Pontcysyllte 2. THE PROPERTY and Description

Locations: Borough and The Pontcysyllte Canal is in north-eastern , 65km Denbighshire (Wales), south of , not far from . Municipality of , The nominated property consists of the whole length of the County of canal and its banks; 17km of its 18 km length is in Wales (), United Kingdom. and 1km in England. It includes the and adjacent buildings directly connected with its history. At three Brief description: points the property is enlarged in order to include an expanse of land associated with a civil-engineering Pontcysyllte Canal, in the north-east of Wales, is an structure or a stretch of water, forming a typical landscape. example of a waterway which typifies land-use planning This is the case at the water intake and weir at Horseshoe during the in . Built Falls, the , and the Aqueduct. from 1795 to 1808, the canal presented great geographical difficulties, which civil engineer Thomas resolved The Pontcysyllte Canal is a narrow waterway, 8–9m wide in particular by the construction of a very large aqueduct and 1.5m deep, permitting the passage of barges c 2m wide with cast-iron arches supported by masonry piers. This carrying loads of around 30 tonnes, which at the time was a type of construction was totally new, both in its iron standard type in Great Britain. The nominated property, the architecture and its monumental dimensions. Furthermore, Pontcysyllte Canal, forms the end of the western branch of Pontcysyllte illustrates the mastery of canal civil the . engineering in a hilly zone by the British engineers of the The ensemble constitutes a single reach, i.e. there are no time. locks. Avoiding the need for locks called for substantial

civil-engineering works in uneven terrain – two aqueducts, Category of property: two tunnels, trenches, large cuts and fills, lining, etc. It

passes through rich coal deposits and limestone quarries, In terms of categories of cultural properties, as defined in one of the reasons why the canal was dug. Article 1 of the World Heritage Convention of 1972, this is a group of buildings. The hydraulic point of departure of the canal is the water intake at on the River Dee, starting from the weir reservoir (km 0). From there, the canal runs west 1. BASIC DATA along the northern side of the valley. Substantial rock cuts Included in the Tentative List: 21 June 1999 were often necessary on the upper side, in some cases more than 1km long, together on the lower side with masonry International Assistance from the World Heritage Fund for structures or large rubble embankments. The canal passes preparing the Nomination: None the town of (km 3), where there is a port basin. Date received by After running for c 10km from west to east, the waterway the World Heritage Centre: 11 January 2008 reaches Trevor, where there is a large independent basin, Background: This is a new nomination. of around 400m at right-angles to a loop in the canal. Consultations: ICOMOS has consulted TICCIH (The The waterway then turns south and has to cross the River International Committee for the Conservation of the Dee, the wide valley of which is below the level of the Industrial Heritage). canal. Telford, the engineer, had the task of designing the impressive Pontcysyllte Aqueduct (km 10.2). The Literature consulted (selection): difference in water levels is 38.4m and the length of the ICOMOS/TICCIH, The International Canal Monuments List, aqueduct over 300m. It has to support a large mass of Paris, 1996. water while ensuring a high degree of watertightness. Telford designed a bridge with nineteen cast-iron arches Bergeron, L. (ed.), ‘Papers from the Pontcysyllte International supported by tall masonry piers. The metal arch is made of Canal Conference’; Patrimoine de l’industrie / Industrial Patrimony, 17, 2007. cast-iron voussoirs, and the waterway channel consists of abutting cast-iron plates reinforced by an external metal Technical Evaluation Mission: 24–26 September 2008 structure. The whole construction is far lighter than it would have been had stone arches been used, which made Additional information requested and received from the possible the use of conventional but particularly slim piers, State Party: ICOMOS sent a letter to the State Party on 10 giving a light and elegant overall impression, which December 2008 asking it to provide a summary table in contemporaries found very impressive. When completed in which the component parts of the property are defined in a homogeneous way, together with information about any 212

1805 it was unique, both in terms of its technical and architect who had a remarkable ability for finding new performances and its cast-iron superstructure. technical solutions to building and civil-engineering problems. He was already well known when he was The and its buildings, the Pontcysyllte engaged and had just undertaken the construction of Aqueduct, which constitutes the outstanding monumental several cast-iron bridges, such as the Longdon aqueduct to and technical feature, and the landscapes both upstream cross the Severn. He also proposed a cast-iron bridge to and downstream of the crossing of the River Dee form the cross the Thames. In the same region he was also central area of the property. employed to build the road from London to Dublin. The exit from the aqueduct is via a large fill embankment. The aqueduct over the Ceiriog at Chirk was the first Many difficulties then have to be solved to reach the structure to be planned, in 1795, by Jessop and Telford. . Again there are cut-and-fill sections, with After considerable discussion a stone structure was retaining walls, the Whitehouse tunnel (km 13.1) which is c preferred. Shortly afterwards, when the crossing of the Dee 120m long, and the (km 15.6) c 400m long. came up for consideration, the conditions were different. The tunnels are strengthened by brick arches and have The valley was wider and deeper, and a conventional masonry portals. aqueduct would therefore have been be very costly; The Canal crosses the Ceiriog by the impressive Chirk furthermore, cast-iron bridges were beginning to prove Aqueduct (km 16.2). Slightly older than the Pontcysyllte their qualities. The cast-iron bridge solution proposed by aqueduct, it is made of masonry, stands more than 20m Telford was chosen and construction work began under his above the river, and has ten arches. At the time of its supervision. The canal up to Trevor was opened on 26 completion in 1801 it was the highest and largest canal November 1805. The part which extends the canal to aqueduct ever built. Horseshoe Falls was completed in 1808. The nominated property ends shortly afterwards, at Gledrid As soon as it had been built the Pontcysyllte aqueduct Bridge (km 16.7), but the waterway continues under the became famous for its highly innovative technical and name of the Ellesmere Canal. architectural boldness. When completed it was recognised as an outstanding success, eliciting praise from engineers The canal infrastructures include many small masonry and inspiring Romantic artists. After the end of the bridges that allow the passage of streams, and weirs to Napoleonic wars several foreign engineers and scholars control the canal level. came to visit the aqueduct. The property includes various basins and wharves linked to The Pontcysyllte aqueduct made famous. mining and commercial activities and a series of service He was recognised in his lifetime as the greatest builder of buildings along the canal. The buildings are often iron bridges and of his time. He became the first associated with the exploitation of coal mines and president of the Institution of Civil Engineers in London in limestone quarries close to the waterway. The canal is also 1825. Telford and his Pontcysyllte aqueduct had an crossed by a number of bridges, some of which are important influence in the international development of contemporary with the construction of the canal and are in canals at the beginning of the 19th century in Great Britain, harmony with it; two are small lift-bridges. The others are Europe and North America. Telford participated in the from are a later period, in various styles. The largest is the construction of other very well known canals, such as the railway viaduct parallel and adjacent to the Chirk in and the Göta Canal in Aqueduct, built by Brunel. All the technical and Sweden. architectural elements of the property are listed in the dossier and their state of repair is assessed. The economic influence of the canal for the region was considerable during the first half of the 19th century, A very large buffer zone surrounds the property, enabling the rapid development of coal extraction, metal corresponding to the crests of the hills visible from the working, limestone quarries, and the production of lime. canal on both sides of the valley. The slate quarries of the Welsh mountains and agriculture also benefited from the canal. By 1815 the substantial investments it had required had been repaid and the canal History and development became a highly profitable business. Its direct link with a vast network of canals to the Mersey, through the In order to link Chester and the Mersey estuary to the Midlands, and as far as London, greatly encouraged the use Severn and the Midlands canal network, the Ellesmere of the canal. Canal was conceived in the early 1790s. It was undertaken by a private company under the technical supervision of The situation here was different from that in other regions the engineer (1745–1814). The because the railway was not a direct competitor to the construction of three branches was started from the central canal but was instead basically complementary, through point of Ellesmere. The need for water and the rich small private lines that led up to the canal. However, the reserves of coal and limestone in the Dee and Ceiriog activity of heavy cargo transport went into a steep decline valleys, in the foothills of the Welsh mountains, led to the at the end of the 19th century as the growth of local heavy extension of the project in this direction by a fourth industry contracted. Economic traffic dropped to a section. The works began in 1795. negligible level even before World War I. However, linking the northern side of the Dee to the As the landscape environment remained rural and the Ellesmere canals, crossing the Rivers Ceiriog and Dee, valleys were pleasant – despite the presence of industry, which have very pronounced valleys, presented two major which never profoundly changed them – canal tourism obstacles. From 1793 onwards, Jessop worked in began as early as 1884. Throughout the first third of the collaboration with Thomas Telford (1757–1834) for this 20th century canal tourism was both regular and organised, branch of the canal. Telford was an outstanding engineer in the form of small cruises and stays in countryside 213

locations. However, the crisis of the 1930s, followed by Planning a canal layout without any locks in a complex the war, dealt the canal a fatal blow. geographic zone is a deliberate and innovative choice in land-use planning. It required many substantial civil In 1944 the Ellesmere Canal was decommissioned by an engineering works: aqueducts, cut-and-fill, cuts through Act of Parliament, but its western branch was conserved, rock, tunnels, retaining walls, etc. under the name of the , because of its role in the regional water supply. It was, however, in poor Pontcysyllte Aqueduct is a pioneering structure in its condition and no longer navigable, and the aqueduct technological choices and the boldness of its architecture. therefore no longer carried any boats. The use of both and wrought iron enabled the construction of arches that were both light and strong and Efforts to encourage pleasure cruising and the preservation provided a particularly effective load-bearing structure for of the industrial heritage, led by enthusiastic historians and the waterway. The whole construction is both monumental writers, generated a renewal of interest in the early 1950s. and elegant, supported by slender masonry piers. This led to a real lift-off for tourism in the 1960s in Great Britain, which contributed to the restoration of the canal The construction of the canal and of the two aqueducts and its maintenance. Since 1954 it has been managed and illustrates the creative genius of the civil engineers of the maintained in a navigable condition by . British Industrial Revolution, and particularly Thomas This canal is one of the most popular and frequented in the Telford and William Jessop. The Pontcysyllte Aqueduct United Kingdom. was the first major structure by Thomas Telford and was immediately acclaimed by his peers and by foreign During the 19th century the canal and its engineering visitors. He subsequently became the most eminent structures were regularly maintained. No structural engineer of his generation for the construction of canals changes were made; wharves and buildings were, however, and iron bridges and was the first President of the built on its banks to meet transport needs. Institution of Civil Engineers in London, the first society The waterproofing of the was restored in of its type in the world. 1866–68 with the addition of cast-iron plate sections at the The canal and its major civil engineering structures have ends. Some changes of individual metal parts have been been well preserved and have remained set in landscapes carried out on the Pontcysyllte Aqueduct; its towpath was and an environment of great quality. relaid with cast-iron plates in 1879.

Because of the relatively early decline of its industrial activity at the end of the 19th century, it has not undergone 3. OUTSTANDING UNIVERSAL VALUE, any major transformation. It thus well reflects the INTEGRITY, AND AUTHENTICITY Industrial Revolution period and its waterway transport. Integrity and authenticity Fill embankment collapses occurred in 1945, 1960, 1982 and 1985, requiring substantial repair work at certain Integrity points on the canal. This was an important point to ensure The integrity of the waterway has been maintained in the maintaining of the integrity of the waterway. hydraulic and civil-engineering structures that have The Pontcysyllte Aqueduct was completely renovated in remained in their original form. However, the historic 2003–2004 to mark its bicentenary, with every effort being embankments, made of rubble, have raised significant made to respect its technical heritage. The work consisted problems of stability and waterproofing, particularly in the of removing corrosion on the cast iron, changing defective second half of the 20th century (See History). The repairs metal parts by others of the same form and of similar have involved the use of technical solutions that are materials, repairing the pier masonry, and completely different from the simple initial backfills, both for restoring the towpath and its railings, which were in a poor structural resistance and waterproofing: concrete, steel state of repair. pilings, geotextiles, etc. From the point of view of integrity, these works have made it possible to maintain the The Pontcysyllte Canal and Aqueduct have inspired canal hydraulic operation of the waterway and to conserve its preservation policy in Great Britain and have made a overall morphological characteristics. strong contribution to raising awareness of the heritage left behind by the industrial period. The waterway is still dedicated in its entirety to canal transport, the uses, however, having changed to pleasure Pontcysyllte Aqueduct and Canal values boating (since the end of the 19th century) and to self- propelled boats in the 20th century. The canal and its engineering structures were created at the time of the Industrial Revolution in Great Britain, The integrity of the landscapes and the buffer zone of the supporting the development of the country's mining, property contributes to the expression of the value of the ironmaking, and building activities. They are property. representative of the intensification of public works in Great Britain, and the veritable ‘’ of 1790– ICOMOS considers that the property has all the elements 1820, which led to the creation of a remarkable internal of integrity necessary for the expression of its value, as a waterway network which benefited the industrial and major historic canal of the Industrial Revolution. commercial economy of Great Britain. The massive Authenticity development of new means of transport is, moreover, one of the distinctive traits of the Industrial Revolution in The few structural changes that have been made to the two Britain, with the canal network supporting the development large aqueducts have remained secondary, contributing to of toll roads and preceding the well known development of maintaining the property in use. The structure and the form the railway and steam-powered vessels. of the civil-engineering structures of the waterway have not undergone any major modifications, apart from the 214

rubble embankments, which have suffered from damage constructions both in Great Britain and elsewhere in the and waterproofing problems. While the response is world. satisfactory in terms of integrity, it is less so from the point of view of authenticity, particularly when the new ICOMOS considers that the comparative analysis justifies materials are visible. The restoration and conservation consideration of this property for the World Heritage List. programme undertaken in 200–2004 was aimed at proposing visually acceptable solutions, such as wooden rails to conceal the contemporary repair structure. Justification of the Outstanding Universal Value Changes in materials have remained restricted over the The nominated property is considered by the State Party to history of the property. At the Pontcysyllte Aqueduct there be of Outstanding Universal Value as a cultural property was a tendency to replace structural parts made of cast-iron for the following reasons: by equivalent or similar steel parts in the 19th century. – It is an innovative example of the design and This was for reasons of material strength and to increase construction of transport canals, in a difficult safety, but such changes were only limited and partial and geographical setting, at the end of the 18th century did not alter the overall structure. and the very beginning of the 19th century. It required During the 20th century repairs to masonry did not always substantial, bold civil engineering works. use the original types of mortar or stone. – Pontcysyllte Aqueduct is a pioneering masterpiece of The work in 2003–2004 were carried out in a spirit of engineering and monumental metal architecture by the respect for the heritage, as regards both the metal structures celebrated civil engineer Thomas Telford. of the aqueduct and the masonry of the canal, the aim – These are early and remarkable examples of being to return to mortars and stones that corresponded innovations brought about by the Industrial with those originally used. Revolution in Britain, and they enabled made the The buildings associated with the canal and its immediate decisive development of transport capacities possible. environment usually achieve a good degree of authenticity. – They bear witness to very important international Authenticity should be assessed in the light of changes interchanges in internal navigation, in civil resulting from industrial activities and the development of engineering, in land-use planning, and in the housing generated by the canal itself during the 19th application of iron to structural design. century. – The Pontcysyllte and Chirk Aqueducts are particularly ICOMOS considers that the conditions of integrity and enhanced by the landscapes which surround them. authenticity have been met. Criteria under which inscription is proposed

The property is nominated on the basis of cultural criteria Comparative analysis (i), (ii), and (iv). The aim is first to make a comparison with canals which Criterion (i): represent a masterpiece of human creative have already been given international recognition: the genius; Canal du Midi (France) (inscribed on the World Heritage List in 1996, (i), (ii), (iv), (vi)), the Four Lifts on the Canal This criterion is justified by the State Party on the grounds du Centre and their Environs, La Louvière and Le Roeulx that the Pontcysyllte Aqueduct was designed by Thomas (Hainault), (Belgium) (World Heritage, 1998, criteria (iii), Telford using very new and extremely bold concepts. The (iv)), the Grand Canal (China), the Rideau Canal (Canada) construction was particularly well executed, and bears (World Heritage, 2007, criteria (i), (iv)), etc. The canal also witness to remarkable professional expertise. This is a forms part of the general trend of canal building, initiated monumental aqueduct consisting of nineteen cast-iron in England by the Duke of Bridgewater in the 1760s. arches supporting the water channel, which is made of the Telford himself actively contributed to the establishment of same metal. The structure is supported on slender, high this network following his success at Pontcysyllte. Most of masonry piers. This was the first great technical the great canals of Europe and America are later than that masterpiece of Telford and was immediately recognised by of Pontcysyllte, and were influenced by British canals: Erie his contemporaries both in Britain and abroad, which and Rideau in North America; Burgundy, Augustów, contributed to Telford's election as the first President of the Ladoga, Caledonian and Göta in Europe. Telford was, London-based Institution of Civil Engineers in 1825. The moreover, involved in the construction of the last two technical performance of the metal, combined with the canals. quality of construction, make the aqueduct an elegant structure, set in a landscape which fully expresses the value As for hydraulic civil-engineering structures, the of the aqueduct as an icon of the British Industrial comparative study includes a table of the earliest projects, Revolution. both ancient aqueducts and the first canal aqueducts and tunnels. The basis of the originality and innovation of ICOMOS considers that the Pontcysyllte aqueduct and Pontcysyllte is the use of metal, clearly the result of British canal is a masterpiece in terms of its technological expertise which was developed in the regions close to the innovations, its architectural boldness, and the quality of property: Gorge, inscribed on the World its proportions. It is one of the symbols of the Industrial Heritage List (1986, criteria (i), (ii), (iv), (vi)) and, above Revolution in Great Britain. all, the Longdon Aqueduct, Telford’s prototype and test bench for this type of construction on a waterway. The ICOMOS considers that this criterion has been justified. Chirk and Pontcysyllte Aqueducts influenced many later

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Criterion (ii): exhibit an important interchange of human ICOMOS considers that the nominated property meets values, over a span of time or within a cultural area of the criteria (i), (ii), and (iv) and that the Outstanding Universal world, on developments in architecture or technology, Value has been demonstrated. monumental arts, town-planning or landscape design.

This criterion is justified by the State Party on the grounds that the construction of canals in Great Britain bears 4. FACTORS AFFECTING THE PROPERTY witness to considerable interchanges in the creation of Development pressures infrastructures for the transport of heavy cargoes. They follow on, starting in the second half of the 18th century, As the canal is a relatively long linear property (18km), it from the technical synthesis accomplished in France in the is likely to have to face changes in the landscape and urban previous century. Subsequently, the networks of British environment, particularly in the buffer zone. canals, and first amongst them Pontcysyllte and its civil The main risk is that of building and of the renewal of engineering structures, were admired, studied, and taken as housing or the conversion of former industrial sites along examples of territorial development through waterways. the canal, but this is controlled by the protection system Large canals were built in the regions and colonies of the and the land-use plans of the Counties concerned. These United Kingdom (Scotland, Canada) and by many other provisions ensure the compatibility of projects with the countries – the United States, France, Germany, Sweden, expression of the value of the property. Poland, Russia, etc. In its reply dated 10 February 2009, the State Party Canals mark a decisive step in the increase in the transport provides an overview of the system for the control and of heavy cargoes, between the development of roads in the implementation of building and development permits 18th century and the appearance of the railway and of within the property and its buffer zone and its potential steam-powered vessels in the 19th century. repercussions on the landscape associated with the ICOMOS considers that the creation of networks of canals property and the expression of its value. It emerges that in Great Britain, at the start of the Industrial Revolution, of most of the projects concern dwellings, small shops, and which the Pontcysyllte canal is a remarkable example, several projects to convert slightly larger buildings. There represents a synthesis of expertise already acquired in are no infrastructure projects of any kind within the Europe and an innovative ensemble that was to inspire property and its buffer zone. The only major project with a many other projects throughout the world. direct link to the Pontcysyllte Aqueduct site is the closure of a chemicals plant in its immediate vicinity. The project ICOMOS considers that this criterion has been justified. to convert the abandoned industrial site currently involves three activities: commercial businesses, dwellings, and Criterion (iv): be an outstanding example of a type of access facilities to the Aqueduct site. building, architectural or technological ensemble or landscape which illustrates (a) significant stage(s) in The buffer zone has also been established in such a way as human history. to cover a vast surface area, linked to the canal landscapes, in order to control agricultural and forestry uses which This criterion is justified by the State Party on the grounds could affect the expression of the value of the property. that the Pontcysyllte Canal and its civil-engineering structures, built in a complex geographical area, bear ICOMOS notes the project to convert the chemicals plant witness to a key stage in the engineering of artificial with a direct link to the Pontcysyllte Aqueduct and its waterways. They illustrate the advances stimulated and enhancement, and requests the State Party advise it of the made possible by the Industrial Revolution, of which they progress of this project and the landscape options adopted. are, furthermore, outstanding representatives. Tourism pressures It is a canal that testifies in an exceptional way to the contribution of man-made waterways to the development This is a popular destination for canal tourism in Great of transport in regions that had previously been isolated, by Britain: 200,000 people visit the Pontcysyllte Aqueduct human cooperation and the organisation of worksites, by each year and some tourism events attract 5000 people. the use for major projects of cast iron, which was at the There are around 15,000 boat movements on the canal each time produced in large quantities by the Industrial year. Revolution in Great Britain, and by the creation of private Permanent facilities have to be provided to cater for companies capable of making very substantial investments. tourists and efforts have to be made to preserve certain River transport was the first real means of transporting components of the property that could be damaged by heavy cargoes for the benefit of and excessive frequentation. commerce. Such transport thus attained previously Pressure from tourism exists close to the canal and in the unimaginable volumes, over large distances and in short buffer zone. Only projects that are in keeping with the time spans, by the integration of canals in efficient regional expression of the canal's values are authorised by the and inter-regional systems. regulatory and management system, as regards both the ICOMOS considers that the Pontcysyllte canal and its property and the buffer zone. highly innovative civil-engineering structures is an Environmental pressures, Impact of climate change outstanding example of land-use development by humans leading to a spectacular increase in the transport of heavy Climate change models for the region suggest that cargoes for the benefit of early industrialisation, at the end summers will tend to be drier and hotter and storm rainfall of the 18th and the start of the 19th centuries. will tend to intensify over the next decade or so. The consequences will be on the one hand increased pressure ICOMOS considers that this criterion has been justified. on the hydraulic management of the canal in the summer,

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when frequentation is highest, and on the other hand risks Ownership of accidental deterioration to the component parts of the canal by storms and flooding. The canal and its civil engineering structures are public property, managed by British Waterways. A large proportion of the canal is located in a special nature protection zone, in accordance with European Some bridges crossing the waterway are public property, directives. The management of the canal, including the associated with the roads that pass over them; in some management of its visitors, and of the buffer zone, is cases, the bridges are private rights of way. required to take these directives into account and comply The land and built structures located in the property which with them. do not belong to British Waterways are municipal or Natural disasters private. The disasters that could occur on the canal consist essentially of the collapse of an embankment or a civil- Protection engineering structure as a result of exceptional climatic conditions, an accident of human origin, or a failure of Legal protection maintenance and surveillance. The Transport Acts of 1962 and 1968 define the The consequences would involve the large volume of water Llangollen Canal as a waterway for pleasure boating, and retained in a single reach of around 18km, which could they entrust British Waterways with the management of the pour out of the canal. There have already been accidents of canal and its immediate surroundings. The contractual this type at periods when the maintenance of the canal was specification for management was set out by the UK found to be wanting. The seven weirs along the canal and Government in 1999. It explicitly includes a mission of at the intake reservoir in the River Dee should normally heritage conservation and restoration of the property. enable the hydraulic management of the crisis. As for The Pontcysyllte Aqueduct has been on the list of UK prevention, hydraulic surveillance of the canal is carried ancient monuments (a Scheduled Ancient Monument) out on a daily basis by the personnel of British Waterways. since 1958, and the same is true of the Cysylltau Aqueduct In view of the hydraulic management system, the over the Dee, which is within the boundaries of the surveillance, and the technical maintenance of the property. Their protection has been stepped up by the property, the State Party considers that this risk is limited Ancient Monuments and Archaeological Areas Act of and acceptable. 1979. The public organisations and (for Wales) suggest that the whole canal should be Pollution risks seem to be confined to local events of inscribed on the List. Up to the present 32 structures and limited amplitude. The two large industrial sites in the three landscape zones next to the property are on the List buffer zone do not represent any particular danger from of Scheduled Buildings and Spaces under the Planning this point of view. They could, however, be affected by (Listed Buildings and Conservation Areas) Act of 1990 risks of industrial explosion and/or fire. As a result, they Additional projects are under way concerning the buffer are required to follow specific directives and an emergency zone. plan should an accident occur. The regulation of land-use and building permits is subject Because of the large amounts of woodland in the to the Town and Country Planning (General Permitted environment, trees occasionally fall into the canal; the Development) Order (1995), to Planning Policy Wales impact of such events is limited. (2002), and to the Wales Spatial Plan (2004). These national plans are complemented by circulars specific to ICOMOS considers that the main threats to the property in the various cultural and natural heritage situations that may the immediate future are tourism pressure and the arise in a given territory. They are applied in practice in the conversion of a chemicals plant in the vicinity of the context of plans and decisions of the regions, Counties, and Pontcysyllte Aqueduct, and in the longer term the municipalities. The property is therefore affected by three hydraulic management of the canal in summer. regional plans and by a series of County and municipality plans. 5. PROTECTION, CONSERVATION, AND Specific planning for land use and development is MANAGEMENT currently being drawn up for the buffer zone, following the landscape assessment carried out in 2007. No element will Boundaries of the nominated property and buffer zone be left without designation, and without rules governing use and control. Most of them will be protected green The property occupies a surface area of 105ha and is 18km zones. long. There are fewer than 100 permanent inhabitants inside its boundaries. The boats that moor on the canal are Buildings in the Conservation Areas may not be not permanently residential. demolished or altered without the agreement of the local authorities. There are six such authorities in the area of the The buffer zone, defined on a landscape basis, occupies a property and its buffer zone. A study of the specific surface area of 4415ha. There are about 16,000 inhabitants architectural and landscape values of these areas provides in the buffer zone. support to enable guidance for works. ICOMOS considers that the boundaries of the nominated The Llangollen and Valley is one of the 22 property and the buffer zone are adequate. landscapes identified in the Register of Landscapes of Special Historic Interest in Wales. It covers the western part of the buffer zone. The Register of Parks and Gardens

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of Historic Interest in Wales is a complementary document Present state of conservation that provides assistance for the management of public and private properties. The State Party considers that the property is currently in an excellent state of conservation, following the major Some areas of the buffer zone are covered by regimes programme for the restoration and maintenance of the protecting natural species and/or landscape: the special Pontcysyllte Aqueduct and the surrounding area. A report conservation zone and scientific sites of the River Dee and from 2007 provides a detailed report on conservation, and the landscape of the . including an assessment of the integrity and authenticity of all the constituent technical elements of the canal (bridges, In the case of works undertaken by authorities or private tunnels, embankments, weirs, etc), with the definition of individuals, assistance may be requested from the Heritage four levels: excellent, satisfactory with minor reservations, Protection Review, particularly for complex situations. satisfactory with a specific reservation, and poor. These ICOMOS considers that it would be useful for the assessments take into account the works necessary for the protection of the property if it were inscribed in its entirety maintenance of the banks and for waterproofing (See on the List of Ancient Monuments of the United Kingdom, Integrity - Authenticity). and encourages this inscription, while awaiting the For the 27 major structural elements in value terms: two promulgation (scheduled for 2010) of a new Act to protect are classified as excellent, nineteen at level two, four at the British heritage, including a specific section for level three, and two in a poor state of conservation. properties inscribed on the World Heritage List. Of all the 181 component elements of the canal: 30% are ICOMOS considers that it would be useful for the currently judged to be in a poor condition from a functional harmonisation and understanding of protection in the point of view (British Waterways report) and ultimately buffer zone if a single land-use planning document were requiring works. So far as state of conservation is drawn up. concerned (2007 report): 12% of the component elements Traditional protection are judged to be inadequate (level four), and for 9% there is a specific question of authenticity/integrity (level three). People living in the region and canal users attach great importance to the property and its protection. British Landscapes were also assessed in the 2007 report, both for Waterways systematically asks users for their views on the the property and the buffer zone; this report is to be used to property, its condition, and its serviceability. guide land use planning in the buffer zone. Effectiveness of conservation measures An assessment of the heritage and industrial archaeology in the buffer zone and its relations with the history of the ICOMOS considers that the measures taken to protect the canal was also produced in 2007. property and its buffer zone are effective. However, its location, overlapping two national territories and a large ICOMOS appreciates the work done to analyse the number of territorial authorities, makes protection a complex conservation of the property with regard to each structural issue. The drawing up of a comprehensive and harmonised element of the canal, from the dual viewpoints of heritage land use planning document specific to the buffer zone, value linked to integrity/authenticity and hydraulic which has been announced, would be extremely useful. serviceability. ICOMOS considers that the legal protection in place is In its memorandum dated 10 February 2009, in reply to the adequate, pending the promulgation of a harmonised and request for details about the structural elements of the comprehensive plan for the buffer zone. property, the State Party replied that the official inventory of these elements was presented by the ‘Gazetteer’ document, p. 51-74 of the initial file, and once again annexed. There are 168 such elements. The other lists or Conservation statements included in the file, and so in this document, Inventories, recording, research were partial indications linked to the questions considered, to be viewed in strict technical or aesthetic terms. A great deal of documentation exists about the property and its history, in the form of plans, archives, printed texts, Active conservation measures and maintenance and illustrations. They are mainly in the hands of the Royal Conservation and maintenance measures are associated Commission on the Ancient and Historical Monuments of with the permanent monitoring of the property by British Wales , British Waterways, the archives of the Waterways Waterways (see Monitoring). This public organisation has Trust, and the Welsh organisation Cadw. as a prime mission the conservation of the property and the There is a large number of studies of the technical and resulting technical and functional management. industrial heritage of the Pontcysyllte Canal and its civil- The qualitative objectives for property conservation engineering structures. measures are guided by the 2007 report on the state of The study of the heritage of the property and its conservation, in order to improve integrity/authenticity. All environment has been powerfully stimulated by the the works must furthermore maintain the serviceability and preparation of the dossier for nomination to the World the safety in use of the canal and its civil-engineering Heritage List, with in particular a study of the conservation structures. of the property, a landscape study of the property and the Following the major programme of 2003–04, which was buffer zone, and an assessment of the industrial heritage of particularly concerned with the Pontcysyllte Aqueduct, the its environment (buffer zone). upcoming priority works are:

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– renewal of canal lining at Pentrefelin (winters of 2007 surroundings of the canal and for monitoring changes in and 2008); the landscape of the buffer zone. – renewal of retaining wall at Llangollen; The presentation to the public of a historic property with a length of 18km with many facets and of its complex – improvement of water supply at . environment is extremely challenging. An interpretation Effectiveness of conservation measures centre at the Pontcysyllte Aqueduct and another at the Trevor basin have been planned since the 2004–2005 The State Party considers that, as things stand today, there works programme. Other initiatives are necessary; such is no major threat to the state of conservation of the initiatives usually stem from local communities and property because of the maintenance and monitoring of the citizens' associations interested in the canal and its values. property by British Waterways. Some facilities are necessary to cater for tourists and for ICOMOS considers that the conservation measures visits, and some parts of the towpath also need to be currently being carried out are effective. renewed. ICOMOS considers that the conservation measures are In view of the large number of visitors and the probable adequate. growth in this number over future years, ICOMOS considers that it would be useful to draw up a thorough tourism development plan, as a separate part of the Management management plan, covering all matters relating to tourism and the coordination of tourism between the property Management structures and processes, including partners. traditional management processes Risk preparedness The partners in the management of the property are as follows: British Waterways carries out permanent water monitoring and has technical facilities (dam, weirs) and skilled – British Waterways, the owner and manager of the personnel for hydraulic management in the event of a crisis canal; or major accident. At the planning level, the Dee River – The four local authorities involved with the property Basin District of the can set up a and the buffer zone; flooding prevention and management plan. – The responsible national organisations, and in Industrial explosion and fire risks are covered by an particular Cadw and English Heritage. emergency intervention plan by the local authorities and civil protection services. The partners have set up a Steering Group which has drawn up the dossier and the management plan and Involvement of the local communities coordinated the relevant studies of 2007. The Steering The Friends of Pontcysyllte is a group set up by the local Group was then officially instructed to coordinate the community to work in partnership with the property's setting up of the management plan by signing an Steering Committee. agreement between the partners (June 2007). Its role is also to make contact and exchange views with local inhabitants A twelve-week process for consulting the local population and users. was organised, with particular respect to the management plan and what local inhabitants expected in terms of the Policy framework: management plans and arrangements, protection and conservation of the property. including visitor management and presentation Resources, including staffing levels, expertise and training The management plan is a framework document for the major future directions of the heritage management of the British Waterways has an annual budget of around property, the organisation of monitoring of its monuments £150,000 for the canal (2007). This amount is guaranteed and landscape, the assessment of pressures on the property, by its financial investment plan for the period 2007–11. and economic development approaches. It is a tool for Wales and the Counties involved in the management of the coordination between the plans and actions of the various property provide specific property maintenance services: partners. It has been defined for the period 2007–11. It towpath, canal bridges, roads and car parks, tourist includes a recapitulative schedule and an overview facilities, etc. Funds are guaranteed for a set of works timetable of all the actions in progress (plan for 2007) and scheduled in a short-term perspective. to be developed (2008–11). British Waterways has experience in managing canals and The canal is managed by British Waterways in accordance important heritage sites. It has trained personnel and with a financial plan and a works schedule covering the scientific advisors. There are 24 permanent staff on the site period 2007–11. In accordance with the management plan, as well as seasonal staff. the works carried out must not only achieve technical objectives but also seek to improve authenticity. Public organisations for heritage protection and conservation, Cadw (Wales) and English Heritage, can call Building permits and works authorisations are on acknowledged specialists in all fields of cultural administered by the local authorities. They include aid for property conservation: archaeologists, architects, private owners and guidelines for projects. engineers, and historians. The 2007 landscape study showed the need to introduce a The three Counties also have permanent staff with training vegetation management plan for the immediate in heritage conservation.

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A number of other institutions also provide aid including Recommended Statement of Outstanding Universal Value the Countryside Council for Wales, the Institution of Civil Engineers, and The Royal Commission on the Ancient and The Pontcysyllte Aqueduct and Canal demonstrate Historical Monuments of Wales. Outstanding Universal Value: Effectiveness of current management • The Pontcysyllte Canal is a remarkable example of the construction of a human-engineered waterway in a ICOMOS considers that the current management is difficult geographical environment, at the end of the 18th effective. century and the start of the 19th century. It required extensive and boldly conceived civil engineering works. ICOMOS considers that the management plan for the property and its coordination are satisfactory. However, a • The Pontcysyllte Aqueduct is a pioneering masterpiece deeper vision and a more coordinated management of of engineering and monumental architecture by the famous issues related to tourism development and the civil engineer Thomas Telford. It was constructed using interpretation of the property would enrich the metal arches supported by tall, slender masonry piers. management plan. • They are early and outstanding examples of the innovations brought about by the Industrial Revolution in Britain, where they made decisive development in 6. MONITORING transport capacities possible. British Waterways has a system of maintenance and • They bear witness to very substantial international technical monitoring of canals which has proved its interchanges and influences in the fields of inland effectiveness over the last 50 years, backed up by waterways, civil engineering, land-use planning, and the competent personnel. The system assesses and manages application of iron in structural design. risks which could affect the canal, and involves a monitoring method which complies with a strictly defined Criterion (i): The Pontcysyllte Aqueduct is a highly programme, objectives, and timetable. Canal user safety is innovative monumental civil engineering structure, made also one of the objectives of the monitoring process. using metal arches supported by high, slender masonry piers. It is the first great masterpiece of the civil engineer Twenty-five of the structural elements of the canal have Thomas Telford and formed the basis of his outstanding been identified as being likely to cause a major risk in the international reputation. It bears witness to the production event of failure. These elements are especially closely capacities of the British ironmaking industry, which were monitored in the main property monitoring programme. unique at that time. The reports made on completion of each inspection include Criterion (ii): The intensive construction of canals in Great an assessment that indicates the state of conservation of the Britain, from the second half of the 18th century onwards, element and, if necessary, the degree of urgency of the and that of the Pontcysyllte Canal in particular in a difficult works to be carried out (see State of conservation). region, bear witness to considerable technical interchanges The monitoring of the state of conservation of the and decisive progress in the design and construction of monuments and sites inscribed on the various national artificial waterways. protection lists is carried out by Cadw and English Criterion (iv): The Pontcysyllte Canal and its civil Heritage on a six-year cycle. engineering structures bear witness to a crucial stage in the Buildings and landscapes on the property and in its buffer development of heavy cargo transport in order to further zone are monitored by the local authorities (Counties and the Industrial Revolution. They are outstanding municipalities) on a six-year cycle. representatives of its new technical and monumental possibilities. ICOMOS considers that the monitoring of the property is adequate. The authenticity and integrity of the Pontcysyllte Aqueduct and Canal are satisfactory. The same is true of their technical and monumental management by British Waterways. The management plan is acceptable; it clearly 7. CONCLUSIONS defines the objectives of conservation, but it would be ICOMOS recognises the outstanding universal value of the improved by a unified approach to the preservation of the Pontcysyllte Aqueduct and Canal. buffer zone and the drafting of a plan for tourism development and site interpretation.

Recommendations with regard to inscription ICOMOS recommends that the State Party give ICOMOS recommends that the Pontcysyllte Aqueduct and consideration to the following points: Canal, United Kingdom, be inscribed on the World Heritage List on the basis of criteria (i), (ii), and (iv). – The property in its entirety should be inscribed on the Schedule of Ancient Monuments of the United Kingdom; – Protection in the buffer zone should be harmonised by the preparation of a single land-use planning document relating to the landscape and environmental protection of the property and including the various relevant regional regulations;

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– There should be particularly careful monitoring of the conversion project for the chemicals plant directly linked to the Pontcysyllte Aqueduct and its enhancement, reporting the development of this project and the landscape options adopted, and keeping the World Heritage Committee informed of all development projects in accordance with paragraph 172 of the Operational Guidelines;

– In view of the large number of visitors and the probable growth in this number over future years, a thorough tourism development plan should be prepared as a section of the management plan. It should cover all issues relating to tourism, the coordination of tourism between all the property partners, and a homogeneous policy on the interpretation of the property.

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Map showing the boundaries of the nominated property

Aerial view

Pontcysyllte aqueduct

Chirk aqueduct

Wern-Isaf Rock Walls Cutting