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World Heritage Convention

Decision 44 COM 8B.23
Dutch Water Defence Lines (Netherlands)

The World Heritage Committee,

  1. Having examined Documents WHC/21/44.COM/8B and WHC/21/44.COM/INF.8B1,
  2. Approves the significant boundary modification of the Defence Line of Amsterdam to include the New Dutch Waterline and become the Dutch Water Defence Lines, Netherlands, on the World Heritage List as a cultural landscape on the basis of criteria (ii), (iv) and (v);
  3. Takes note of the following provisional Statement of Outstanding Universal Value:

    Brief synthesis

    The Dutch Water Defence Lines represents a defence system extending over 200 km along the edge of the administrative and economic heartland of Holland. It is comprised of the New Dutch Waterline and the Defence Line of Amsterdam. Built between 1815 and 1940, the system consists of a network of 96 forts, dikes, sluices, pumping stations, canals and inundation polders, working in concert to protect Holland by applying the principle of temporary flooding of the land. It has been developed thanks to the special knowledge of hydraulic engineering for defence purposes held and applied by the people of the Netherlands since the 16th century. Each of the polders along the line of fortifications has its own inundation facilities.

    Criterion (ii): The already-inscribed property (Defence Line of Amsterdam) and the nominated extension illustrate in its most advanced and extensive form the technology and arrangements that the Dutch developed to control inundation. Although inundation for defence had been used since the Middle Ages in the low-lying parts of north-western Europe, the Dutch brought the system to an unprecedented level of advancement and scale. The DWDL were not the last to be built: the knowledge developed here was applied and further elaborated to build other defence lines in Europe in the 1930-40s, such as the French Maginot Line, the German Pomeranian Line and, later, in the 1950s, the Ijssel Line in the Netherlands.

    Criterion (iv): the NDW illustrates an ingenious system of defence which has achieved the integrated use of landscape features, careful water management and control for inundation fields, and military fortifications to protect the vulnerable points. In particular the nominated extension offered, due to the very nature of the land morphology, larger opportunities to harness the landscape characteristics. Due to the presence of several rivers, which were points of access for the enemy and needed therefore to be defended, many forts were built for this purpose.

    The NDW also illustrates the development of military architecture in the 19th and early 20th centuries as well as the transition from brick to concrete construction. The rich collection of forts comprised within the NDW exceptionally illustrates the continuous adaptation of military engineering to new defensive challenges and complements the DLA with further attributes, thereby reinforcing the justification of this criterion.

    Criterion (v): the nominated extension represents an ingenious use of the topography and hydrology of the landscape for defence purposes. The knowledge developed over several centuries to manage water for farming purposes was perfected and put to the service of the defence of the country, with the aid of pumping stations, watercourses, sluices, ring canals and dykes, to ensure rapid and precise control of the water flow. Several structures that were built for civil use were integrated into the military defence system. The nominated extension will enhance and complement the Outstanding Universal Value of the DLA as a model of the military system that has ingeniously perfected the use of landscape features and water management to achieve a defensive system of large territorial scale.


    The extension of the Defence Line of Amsterdam through the addition of and unification with the New Dutch Waterline forms a coherent and complete system but each of them had a specific function to play. The extension would add landscape and historical coherence to the existing World Heritage property.

    The boundary of the extension includes all attributes necessary to reflect the proposed Outstanding Universal Value, including the three individual component parts.

    The nominated extension includes a large number of identified physical attributes. All forts are included within the boundary of the nominated extension and none has been destroyed. The identified attributes of all categories are said to be in good condition, although the area of the defence line near Utrecht has lost the inundation basins, which were very narrow in this area due to its elevation.

    The new property DWDL includes almost the whole fortified water system conceived for the defence of the core urban area of the Netherlands.

    The water management system (a complex network of canals, dikes, gates, sluices) is still in use and its maintenance is assured as far as it is necessary for the safety of large cultivated and inhabited areas.

    The strategically deployed landscape is still well visible but its extension is notably reduced and its degree of integrity is uneven. Especially (but not only) on the inner side of the defence lines, urban growth has often overwhelmed rurality and the visual relationships between the forts and the environment have been undermined. On the outer side (the side watched over by the forts), some new developments have occurred and scattered buildings and groups of trees have modified the aspect of the landscape and the visibility of the “Prohibited Circles”.

    Negative impacts from new developments and large infrastructures can be found in the western portion of the DLA World Heritage Property, in the central portion of the NDW, and at the junction between the DLA and NDW, that is to say, next to the cities of Amsterdam, Haarlem and Utrecht, where the defence line passes through dense urban areas. There, fortifications, related ditches, canals and dikes have been preserved but the landscape has changed significantly and several inundation fields have been built upon or are no longer visible. Nowadays these portions of the property are exposed to strong pressure for further transformation.

    The extent of the proposed extension of the property, the abundance of its elements, the strong presence of the rural landscape where it still exists, the effectiveness of the current actions of care and maintenance, can secure the integrity of the property.

    Three areas have been added to the Defence Line of Amsterdam: two are still-preserved inundation fields and one is a wooded recreational area which reinforce the continuity of the DLA and contribute to strengthening the integrity of the already inscribed property.

    Six small areas have been excluded from the former Defence Line of Amsterdam.


    The physical attributes of the proposed extension reflect credibly the proposed justification for inscription through their form and design, their materials, their reciprocal interrelations and relationships with the landscape setting. Although the military use and defence function have ceased, the primary agricultural use of the landscape has been retained alongside the introduction of recreational use.

    Several sources exist that can demonstrate the authenticity of the property, including bibliographical and archival sources. The physical attributes reflect the values and the historic development of the property. Restorations and repurposing of the forts have contributed to maintaining near the main military structures the spirit of the military past of the defence line territory. However, the modifications to the landscape and the developments have, in some zones, reduced conditions of authenticity.

    Protection and management requirements

    The legal framework for heritage and landscape protection and spatial planning is under reform in the Netherlands. From 2022 a revised set of laws, by-laws, strategies and regulations will apply. This new Environment and Planning Act will protect World Heritage stronger and more explicit.

    Currently, World Heritage properties’ attributes and Outstanding Universal Value are given consideration at all national, provincial and local levels through the provisions of the Spatial Planning (General Rules) Decree, Dutch acronym Barro, issued in 2011, which identifies core qualities of the properties inscribed on the World Heritage List or included in the Tentative List. These qualities must be maintained or enhanced in plans and spatial developments.

    The Barro provisions will be incorporated into the new Environment and Planning Act (2016), which stipulates that regulations for the preservation of the Outstanding Universal Value of World Heritage properties and the implementation of the World Heritage Convention must be developed.

    The Spatial Planning Decree, Dutch acronym Bro, stipulates that municipalities must take into account cultural history when elaborating spatial plans.

    All military and many water management structures of the proposed extension have been designated national monuments as per the Heritage Act (2016). On the other hand, in the DLA, heritage designations were issued on the basis of the Monuments and Historic Buildings Act (1988); additionally, a number of attributes are covered by provincial designations, based on the Ordnance of the Province of Noord-Holland, which is considered equivalent to national designation.

    The fortified towns of the NDW are designated urban conservation areas and no development that can impair their heritage character is permitted. According to the Monuments and Historic Buildings Act and the Heritage Act, municipalities must elaborate protection zoning plans for conservation areas, thereby complementing the protection afforded to individual heritage structures.

    In addition to legislation, national, provincial and municipal policy documents provide for priorities and objectives with regards to cultural heritage.

    The Environment and Planning Act stipulates that spatial developments may not jeopardize the Outstanding Universal Value of a World Heritage property, regardless of its location. Furthermore, a Spatial Quality Advisory Team has been established: it issues opinions and recommendations to ensure that the Outstanding Universal Value, integrity and authenticity of the property are not endangered by development proposals.

    The new Environment and Planning Act contains specific regulations for protection of the buffer zone.

    Around the inscribed property and the nominated extension also various additional protection regimes apply that have protective effects on the setting of the Dutch Water Defence Lines (DWDL): these include Natura 2000 areas, National Nature Network, provincial urbanisation buffer zones in Noord–Holland, Schiphol Airport Zoning Decree, and valuable landscape designations. These afford protection to the setting of the DWDL.

    The municipal zoning plan has legal binding force and is the key instrument for implementing protective measures.

    Provinces are responsible for describing the ‘core qualities’ of existing or proposed World Heritage properties and for developing rules for their preservation. These rules are included in provincial by-laws and inserted in municipal zoning plans. In case provinces do not comply with the above provision, the national government has the right to prescribe the rules that must be included in provincial by-laws. Similarly, if municipalities fail to comply with provincial by-laws, a province may give ‘reactive instructions’.

    The government and the provinces have the right to prepare government-imposed zoning plan amendments, as long as a national or provincial interest is at stake (such as in the case of World Heritage or heritage preservation). These amendments have the same legal value as municipal zoning plans.

    The rural zoning plan is the central instrument for the protection of the agricultural land and therefore of the inundation fields. Provincial by-laws prevent construction outside building locations identified by provinces, and agricultural land cannot be turned into buildable land. The application of sustainability principles also require that urban developments must occur in existing urban areas. The necessity to deviate from this principle must be explicitly demonstrated.

    Quality handbooks have been prepared by the provinces to assist applicants and municipalities in achieving a higher quality of development proposals.

    The responsibility for the implementation of the Heritage Act falls upon several actors, including provinces and municipalities, clearly defined in the Act itself.

    The Cultural Heritage Agency is responsible for two government subsidy schemes that support conservation and repurposing of protected monuments; since 2012 the provinces have been responsible for restoring national monuments.

    The assurance of the quality of new developments is also an important factor complementing development restrictions. A Spatial Quality Advisory Team was established in 2005 for the New Dutch Waterline; it provides solicited or unsolicited advice on developments, challenges and trends affecting the NDW at a larger scale. Since 2016 it has a new composition and a new task: issuing opinions (e.g. on energy transition, quality assurance principles, terms of reference for HIA’s) to ensure the balance between spatial development and the heritage value of the NDW. It has drawn up a memorandum on Visual Integrity of the NDW. On inscription the Spatial Quality Advisory Team extends its scope of responsibility to the whole property, including the DLA.

    For highly dynamic areas – three have been identified by the State Party which amount to 20% of the area of the DWDL – more focused area analyses have been devised and are being elaborated to examine what is the capacity of the property, under what conditions and where, to accommodate developments carried out in a way to support or enhance the integrity of the property and where this might pose challenges.

    In 2014 the four provinces of Noord–Holland, Gelderland, Noord-Brabant and Utrecht signed an administrative agreement for the extension of the DLA. As per the Joint Arrangements Act, the four provinces have signed a partnership agreement that establishes they will act jointly as the site-holder and the existing management entities for the DLA and NDW will eventually be fully merged into one single overarching management office as of 1 July 2020. A small portion of the NDW falls within the Province of Zuid-Holland. The five provinces have agreed that the four provinces where the majority of the DWDL is located will look after the small section in Zuid-Holland. However, the Province of Zuid-Holland will continue to perform its spatial-planning and protection tasks.

    The site–holder office will be managed by the four provinces under the direction of an independent Chair, with a representative of the National Cultural Heritage Agency as advisor. The site-holder will rely on the human resources of the Knowledge Centre of the waterlines, the independent Spatial Quality Advisory team. External support will also be provided by the Cross-Waterline Entrepreneurship Foundation, which supports entrepreneurs in and around the DWDL. The think tank Line Expert Team – 16 experts in 8 different subjects – is supported by two Provinces and offers expertise and advice to owners, managers and operators, including municipalities and water authorities.

    The collective site-holder has developed a road map to achieve six key management objectives, among which is the preparation of a joint management plan, from 2021.

    The current management plan covers the period 2018–2020 and outlines the cooperation agenda, based on the six above-mentioned objectives, and on strategic goals. A calendar for implementation of the tasks related to the six objectives is presented.

  4. Recommends that the State Party give consideration to the following:
    1. Strengthening the protection of the landscape dimension, particularly in key sections of the Dutch Water Defence Lines, e.g. in the Utrecht area and Laagraven especially, through ad-hoc plans that enhance the historic landscape features and mutual visibility among the defence elements,
    2. Providing the World Heritage Centre and ICOMOS with upcoming projects, including the final option for the A8-A9 junction, for review,
    3. Finalising all sensitive area analyses and embed their conclusions in planning instruments,
    4. Strengthening the visibility and interpretation of the Defence Line of Amsterdam and its extension,
    5. Providing the six reductions of the property, including the buffer zone, with ad-hoc mechanisms that prevent further pressures and offer the opportunity to recover in the medium- or long-term, at least part of the memory of their past conditions through careful design and landscaping,
    6. Making an inventory of all current planning provisions in force for the property and the whole buffer zone, and assess whether they are coherent to sustain the Outstanding Universal Value of the property;
  5. Requests the State Party to submit to the World Heritage Centre by 1 February 2022 detailed maps at an appropriate scale showing revised boundaries of the property and the buffer zone, and clarifications concerning the status of the project of the housing development near Woudrichem, and also requests the State Party to submit to the World Heritage Centre by 1 December 2022 a report on the implementation of the above-mentioned recommendations for examination by the World Heritage Committee at its 46th session.
    Decision Code
    44 COM 8B.23
    Inscriptions on the World Heritage List
    States Parties 1
    Decisions adopted at the 44th extended session of the World Heritage Committee
    Context of Decision