An Assessment of Deltaplan: The Dutch National Preservation Strategy
An Assessment of Deltaplan: The Dutch National Preservation Strategy

Gerrit de Bruin

I am very pleased to be here in this beautiful city, standing before colleagues and friends from the Library sector. In my opinion there are only emotional borders between Libraries, Museums and Archives. In a way we all are facing the same problems, challenges and obligations: ie, how to continue to build and preserve large collections and enhance their accessibility. So I prefer to speak of Institutions, which are helping to preserve the cultural heritage. In my lecture I will tell you about Deltaplan - its successes and its qualified successes. And I also want to tell you about the effects of Deltaplan on the institutions involved. Furthermore, I will tell you something of my own experiences collected during Deltaplan. Owing to the constraints of space, this is, of necessity, a selective appraisal. Libraries where excluded from Deltaplan. They got there own kind of plan in the Metamorfoze project, an initiative of the Netherlands Ministry of Education, Culture and Science and is coordinated by the National Preservation Office of the Netherlands of the Koninklijke Bibliotheek, the National Library of the Netherlands. [1]

Documents in archives, objects of art in museums and monuments are threatened by a silent decay. This decay is partly caused by air pollution, light, temperature and relative humidity; fungi, insects and rodents also play their parts; and last but not least by people consulting the original documents or books. Before Deltaplan there were conservation backlogs and no effective management strategies to clear them. Moreover, there were insufficient staff and resources across the sector. Also there were cataloguing backlogs, particularly in the museums. In addition the repositories were inadequate and no proper air conditioning had been installed. Restoration was the common policy in place, to restore materials item by item. As a result there was no overarching conservation plan or policy across the sector, a singular lack of knowledge about the conditions of collections, and consequently no prioritisation.


It was first recognized in the late 1970s that something had to be done about preserving archive, museum and library materials. The Institute for Social Policy Research (IVA) conducted a survey into the conservation of cultural objects. The results were reported in 1980 and everyone was shocked by the results. The IVA estimated a conservation backlog of about 70.000 men years of work - a critical situation. In 1988 the Court of Audit, which is the independent authority responsible by law for supervising the spending of public funds in the Netherlands, published a critical report on the institutions, which were maintaining the national heritage. It was after this, and further reports, that Deltaplan was launched.

Starting in 1991 the Ministry of Welfare, Health and Cultural Affairs (from 1994 the Ministry of Education, Culture and Science) launched Deltaplan to save the cultural heritage. Deltaplan was named after the plan launched in 1953 to build a new system of dams and dikes to protect the Netherlands against further disastrous floods. The name also indicates how seriously the Ministry took the battle against the decay of the Netherlands' cultural heritage. The parallel is clear: large parts of the culture were threatened with destruction, and the need to preserve not only our country but also our cultural heritage for future generations was high.

The goal was to clear the backlog in cataloguing items of the cultural heritage and conservation of objects by the year 2000. The emphasis was on the national collections for which the Cultural Heritage Department of the Ministry of Education, Culture and Science was directly responsible, i.e. collections of the 21 state museums and 12 state archives (united in the State Archive Service). The collections for which the Netherlands Department for Conservation and the State Service for Archaeological Investigations are responsible, also fell under the scope of Deltaplan.

It was known that conservation was not being managed effectively and there was an insufficient awareness of the professional requirements. During this period the Government changed from being an agent dispensing funds to institutions audited by annual reports into one which entered into contractual relationships with institutions with agreed objectives and deliverables. Institutions were unaccustomed to this new approach. A plan of attack was required.


Knowledge development was an important aspect of the plan. The aim was, by means of research, training and improving communication, and augmenting international exchanges and publicity, to bring about a change in the level of professionalism and knowledge in the areas of managing and conserving the cultural heritage. The main emphasis was upon dealing with the backlog built up in the conservation and management of the state museums, state archives and other state collections, since central Government has direct responsibility for their management.


  ·   The 18 former state museums, 3 former state-subsidised museums and 3 supporting institutions were regarded as state museums for the purpose of the plan.
  ·   Museums, which came under Ministries other than Welfare Health and Cultural Affairs, or under other public bodies, altogether, were not regarded as state museums.
  ·   A basic distinction was made between management and conservation duties. Thus, administrative responsibility for the proper management of collections, collection records and passive conservation fell under the heading of management. The clearing the backlogs in these two areas was primarily the responsibility of the owners or administrators of collections. The Ministry saw its role as that of providing encouragement.
  ·   In addition to its administrative responsibility for the state museums and the supporting institutions the Ministry is responsible for preserving the cultural heritage as a whole.
  ·   If choices were to be made, these should be based on the historical value of the collection.


  ·   The administrative responsibilities for archives are laid down in the Public Records Act. The Ministry has responsibility for central and provincial government archives kept in state archives, so these were given priority. Municipalities and water corporations are responsible for their own archives.
  ·   Before archives are filed in these archival institutions they have already been subjected to strict selection. The entire archive collection should therefore be preserved in its original form, on account of its intrinsic value both as a source of information and as a piece of cultural heritage; these were included in the Plan.

Archaeological heritage

  ·   The State Service for Archaeological Investigations is responsible for the archaeological record, the historical remains in the ground. The archaeological record is both unique and finite: there is only one specimen of each archaeological site and any intervention is irrevocable.

National heritage sites

  ·   In this area the plan was a modest addition to the current work of the Netherlands Department for Conservation.
  ·   The emphasis in the plan was on the additional damage caused by acidification on top of the natural process of decay. Additional funds had been promised for this under the national Environment Policy Plan +: the idea being to use the funds to repair and protect the most vulnerable parts of the national heritage sites.

Policy tools
The main policy tool under the plan was grant aid. Subsidies were allocated on a project basis. In the case of collections open to the public the Ministry proposed that 60 % should be found by the institutions itself and 40 % by the Ministry. In the case of private collections not open to the public it proposed an 80/20 split. In the case of non-state museums, storage conditions - i.e. storerooms and climate control - would have to meet certain minimum criteria before grant aid could be considered.

In addition to subsidies, essential elements in the Plan of Attack were improving the expertise of those responsible for looking after the cultural heritage and creating a climate where the value of preserving it was recognised, for example:

  ·   developing standards for conservation,
  ·   educational work and promotion,
  ·   research into improving treatment methods,
  ·   improving the professionalism of staff of the institutions,
  ·   instituting training courses.

Central Government could provide encouragement through Government bodies such as the Central Laboratory and the Training Programme for Restorers (current the National Institute for Cultural heritage in Amsterdam).

There were three phases for the Plan of Attack:

1. Identifying the shortcomings in cataloguing (not a problem for the archives), conservation and restoration.
2. Drawing up implementation plans.
3. Actual implementation.

The White Paper in 1991 called "Fighting for Decay" outlined the following criteria:

  ·   Cataloguing as a prerequisite to an effective collection policy.
  ·   Priority would be given to the museums and archives that came under the Culture Ministry.
  ·   Priority would also be given to direct physical protection of heritage of particular cultural value.
  ·   In addition to providing financial aid for the work, the aim should be to improve the conditions for management and conservation in the future.

The emphasis on direct physical protection meant that conservation had higher priority than restoration. The emphasis here was on preventive conservation, i.e. passive conservation is the first step and active conservation the second. The work was undertaken on project basis, with a decentralised approach but within the context of overall central direction.


In 1991 the Court of Audit conducted an audit and this was extremely critical. In the state museums not enough choices were being made, and storage conditions at two-thirds of them were inadequate. The archives were tackling the backlog without a predetermined plan: verifiable targets were generally lacking, storage conditions at half of the archives were inadequate. The cataloguing of heritage sites left much to be desired; and the shortcomings in the maintenance and restoration, cataloguing and conservation of archaeological material were being tackled in an ad hoc and fragmentary manner.

The Court also noted that the Ministry had not sufficiently encouraged the institutions - except the state museums and to a lesser extent the state archives - to identify the shortcomings, set verifiable targets, draw up plans of attack and set priorities. The Ministry reacted very quickly and declared that it took some time to clear the backlog. Known problems, for which there were solutions, were dealt first with. The structural strengthening of management and conservation that was needed required a change in thinking on the part of the institutions concerned, and the Ministry wished to promote this.


Nowadays the Archives services are becoming Regional Historical Centres in which they interrelate with Libraries, Museums and Documentation Centres. On 4 June 2002 the General State Archive became the Nationaal Archief (the National Archive of the Netherlands).

All the state archives were required to draft their own collection policy plan in which they prioritised action. The approach varied, from microfilming to conservation, or a combination of the two and other further action. It was evident from the different damage surveys that not everything could be done. The calculated costs for the conservation of the identified 21 kilometres of problems and the need for mass de-acidification came to approximately 450 million Euros.

Projects developed for saving archives in Deltaplan
There is a hierarchy for preservation, passive and active conservation and restoration. The most effective and cheapest is preservation followed by conservation. Restoration is the most time-consuming. The approach is like a funnel: start with preservation and end with restoration, i.e. comparable to working from the outside of the building to each object inside.

The following elements were involved:

  ·   Upgrading air-conditioning in all repositories in State Archives buildings:
  ·   Installing air purification systems in all State Archives
  ·   Research into the effects of air-purification on the degradation of paper [2]

  ·   Acid-free boxing programme: all the material is packed in acid-free, calcium carbonate buffered wrapping paper and put in acid-free boxes, after removing all ironwork like staples and paperclips. And this was a very important decision because after research and comparing boxing against no boxing policies in several countries, this method has proven to be a good method. It is well known now that even a bad box is better than no box at all! After 12 years, 70 per cent of the total collection is repacked.
  ·   Microfilming projects: creating a surrogate is a method of active conservation and also protects the original. Moreover, it is an intermediary between the original and digitisation.
  ·   Substitution microfilming projects: microfilm is used to replace the original (e.g. modern construction maps).
  ·   Damage survey (damage caused by the acidity of paper): the conclusion after testing 3,000 samples: 6.3 per cent is brittle and 28 per cent is in need of de-acidification (26 km). That means that there is no access to 8,000 linear meters of archive owing to the bad physical condition. Another 13,000 linear meters are in the need of some kind of conservation treatment.
  ·   Research on mass de-acidification: after many tests on seven different methods, the Bookkeeper system was selected.
  ·   Mass de-acidification programme: especially on the 19th and 20th century archives (26 km): 1.5 % is brittle and 6.3 % is weak.
  ·   Universal Procedure Archive Assessment: a management instrument in which the actual conditions are surveyed, independent of the size, in one week
  ·   Collection Policy Plan: a conservation maintenance plan based on priorities of the most wanted and used archives by the public and the national archives.

The museums had to prioritise the collections using four different categories, A, B, C and D. The A category are considered to be national treasures. The D category related to items of no importance; they can even be destroyed.

The archives did the same thing at the start of the new millennium. The year 2000 was the final year of Deltaplan for safeguarding the cultural heritage, and in 2001 the new governmental policy for culture began for a period of four years to 2005. The substantial extra attention and financial means of the last 10 years for preventive and passive conservation have to be adjusted in the direction of treatment of original information carriers. By using instruments developed by the Nationaal Archief, reliable figures about the physical state of the collections are now available. These figures, amongst others, form the basis for the development of a collection policy plan.

Selection criteria that are formulated in the draft collection policy plan are:

  ·   frequency of use,
  ·   stimulation of use by means of special programmes for the public,
  ·   physical condition (especially the threatened collections with an autonomous degradation process such as acidity and ink corrosion,
  ·   the value of information in certain series within a collection,
  ·   unique historical/symbolical value or value owing to the materials used for single items within the different collections.

Based on these criteria four different 'Planning Lists' have been put together. Each of the lists takes a different approach:

A. High frequency of use and stimulation of use by special programmes for the public.
B. Vulnerable collections or parts of collections, with a high degradation velocity (acidity, iron gall ink corrosion, nitrate and acetate negative material and fire damage).
C. Single items with a high intrinsic or historical value (owing to the information or the object itself).
D. Objects that require treatment for exhibition purposes.

The purpose of these different lists is to give equal attention to all factors that play a role in operational choices. The most dominant theme is frequency of use and the stimulation of use caused by special programmes for the public. If this was the only criterion, the first list would be enough. Certain collections, however, suffer from autonomous decay, even when air-purification and acid-free boxes can slow these processes down, and if the frequency of use is very low.

Because the use of already weakened collections will accelerate deterioration, the B list has got a second criterion, i.e. frequency of use as on the A list. In practice this means that certain collections in the B list will also be on the A list. However, it is important to make a distinction between the two. Most of the collections in the A list will not make much effort to microfilm and conserve; many of these collections already had a priority under Deltaplan. The collections in the B list concentrate more on mass-conservation and microfilming. In the C list the most valuable objects or items in the collection of the state archives are selected because whenever a treatment is necessary it will always be full conservation (i.e. restoration).

For the museums it is the other way around; items which are considered as A category are the important ones. The B and C category items can be changed with other items and other museums. D category items can be destroyed.


During the implementation of the Deltaplan period it was obvious that the target of clearing the backlog in conservation and cataloguing was unrealistic. The problems were simply too big. After one of the evaluations in 1994 the objectives were modified: the backlog in conservation, cataloguing and good housekeeping must be manageable for the institutions involved after Deltaplan was ended. That is to say, the backlog had to be managed within a few years after 2000. This meant that a structural approach had to be taken to prevent a backlog in the future.


Good-build repositories and exhibition rooms combined with mechanical improvements to upgrade air-conditioning and install air-purification was infrastructurally required for the benefit of all the collections. The same applied to storage rooms and new exhibition rooms. Whilst Deltaplan had funded the capital costs, the recurrent costs - the running and maintenance costs and the overhead of additional space - were high and largely unfunded constituting up to 10 % of the standard budget. For a few institutions there was an additional subvention above the standard budget.

Today, those institutions, which are charged with keeping the cultural heritage, have more trained staff and conservators, and some of them have a conservation policy plan in place.

Museums in the Netherlands have made an arrangement whereby the Government funds the insurance costs for exhibitions and loans. Also each collection has to have a clear profile. Where an artefact held in one museum fits more closely with the profile of another museum the artefact is placed on permanent loan with that museum.

There has been a renewed interest in archaeological heritage and monuments. New tools, such as photography have been developed to become a new control system and method for maintaining them. Different Ministries such as the Ministry of Education, Culture and Science and the Ministry of Housing and Building Services have combined forces to work together. Also, because there has been an assigned national budget and many problems to solve, the scientific world has met the world of conservation. This partnership has given knowledge and co-operation a boost. The result has been the generation of more ideas and knowledge about the internal and external damage phenomena, which lead to the decay of objects. This knowledge leads to practical solutions for conservation problems. Examples of these are mass-acidification of paper objects, air purification, work on diagnostic tools to detect cellulose acetate in an early state, the tropical box in which the environment is less of importance, and a solution to the browning of paper.

Granting public access to collections has changed the way librarians, conservators and curators think. A management solution is required to resolve the tension between keeping and exposing objects. This issue has also promoted international co-operation between countries and institutions. Articles and presentations related to Deltaplan have given inspiration to colleagues everywhere. The forming of European projects is a new development, which contributes to knowledge exchange and practical solutions to problems, for example, the prevention of ink corrosion, greater knowledge about transition metals in paper, cleaning of paintings with laser beams, and the removal of tapes from paper using laser equipment. Moreover, laser is being used to mark negatives so that restoration becomes cheaper.


During the plan period and to the present, preservation preceded conservation. Restoration was completely out of sight. In the three years since Deltaplan ended restoration is either not done at all or only in a very small way. The idea was that after Deltaplan restoration would be on the agenda again, but the management, e.g. business way of thinking is still ascendant.

Deltaplan indeed awoke a new revival of efficiency and promoted a more business approach in the so-called 'soft sector'. Managers and keepers of national cultural heritage worked progressively more like directors of a private company. However, the budgets available do not meet the needs of the collections. Active conservation has taken precedence over restoration. Moreover, preservation has become the silver bullet. It was clear that good housekeeping practices support solid-build repositories; good quality surrounding air in the repositories and trained employees were instrumental in achieving this. The management approach makes it possible to act in a structural manner. It gives the opportunity to work according to a plan of action. Also instruments like the UPPA method were developed to carry out surveys into the condition of collections. With a business plan it's possible to work in a more efficient way. The control cycles were introduced on the work that was being performed according to arrangements at management level. Conservation policy plans in which priorities can be made were introduced. The idea emerged that mass treatments were needed to accomplish large-scale projects like Deltaplan. In this framework very slowly and full of doubts co-operation between institutions became possible. Today the Nationaal Archief, the Koninklijke Bibliotheek and the Netherlands Institute for Cultural Heritage work together on a structural basis. Extra budget is available for research and conservation on a nationwide scale. The forming of a project bureau has been very important. Such a bureau requires a financial expert, a conservation expert and administrators. This was one of the learning experiences to emerge early on in Deltaplan for a consolidated approach towards project management.


The awareness of the need for conservation on a structural basis seems, three years after the evaluation of Deltaplan, more a matter for the wallet rather than a matter of the heart and mind. And yet I wish to end with a positive note. There will be extra money for projects in the field of conservation. In this time of economic setbacks that is a very good result. It means that the Government and everyone who is involved in being responsible for the collections have made wise decisions. But that does not mean that there can be complacency. Conservation is not a goal on itself; it is integral to the work process of an institute and has to be considered as such. Selection and diagnostic tools are vital now and in the future. Selection is necessary because of the number and the size of the collections. There is never enough money to concentrate on all the collections. The money provider never gives all the money requested, so tough choices have to be made. Not all the items in a collection are of major importance. Some 80 % of public requests for access are for 20 % of the collections. The same goes for archives; probably only 5 % of all the Government decision-making will be retained forever. Historians are not pleased with this selection device, but otherwise it is impossible to manage our history.

Deltaplan has been a blessing for saving our cultural heritage. It was a kind of a renaissance, a new élan came over the conservation land, people were enthusiastic, new hopes raised and new ideas generated; finally there was attention and money to do things and make a change. The results of Deltaplan have been very good and future prospects are hopeful. But it is not good to sit back feeling self-satisfied with what has been achieved. It is necessary to be sharp looking both backwards and forwards to know if the decisions made where the right ones.

The impact of Deltaplan has been enormous. For the first time a large dedicated fund was made available for the sake of culture. Extra money was added for archaeological work in 1997. Also a budget for saving photographic collection was made available. For the renovation of buildings and air-conditioning and air-purification some 58 million Euros was spent. At the end of the plan approximately 150 million Euros was spent.

The new Secretary of State stated that culture has a money value as well. Culture-keeping institutes are charged with bringing culture to the public. Keeping culture and not using it is pointless. Culture is for everyone. A large number of institutions received extra budget after the Deltaplan period, i.e. from 2000 to 2004. This is because some of the major institutions have greater backlogs than the smaller ones. Another reason is that the collections differ in size, variety and importance. And the recurrent costs of maintenance for the renovated repositories and exhibition rooms and air- purification systems are higher. For some institutes like the Rijksmuseum and the Nationaal Archief the problems were too big to bring them to manageable levels within the given timetable, so the work continues.

Currently institutions are in discussion with the Ministry for the period 2004 to 2008, and the outlook is optimistic for more funding for conservation. I am very pleased to announce that the Nationaal Archief will receive more funding during this period. This funding is much needed and will be applied to the replacement of air-conditioning and air purification installations, which are 12 years old. Putting extra money into culture is a very beautiful thing.

I would like to thank my dear colleague Ted Steemers for his information. The same goes for Steph Scholten of the Netherlands Institute of Cultural Heritage. And I also wish to thank colleagues in the Dutch and other national museums abroad for their assistance.

I based my research on the end report named "Management and conservation in the Dutch Delta" with the subtitle: "the Deltaplan for the preservation of the cultural heritage evaluated". Also there were some reports as Cultural heritage under Threat, which listed the conservation and management shortcomings at the museums and state archives. Than we have the Plan of Attack, Fighting Decay, and Amour or Backbone.


Dijken, Koos van, Willem de Haart, Lara ten Broeke ... et al. Management and conservation in the Dutch Delta : the Deltaplan for the preservation of the cultural heritage evaluated. Zoetermeer : IOO bv,, 2001.

IVA - Institute for Social Policy Research.

Koninklijke Bibliotheek, National Library of the Netherlands.


Nationaal Archief.

Netherlands Institute for Cultural Heritage

[1]The Koninklijke Bibliotheek started in 1997 the project Metamorfoze in which literature collections of the Netherlands will be preserved for further generations.
[2] This year, 2004, is the final year of the 10-year programme into the effects on paper-based collections.

LIBER Quarterly, Volume 14 (2004), No. 3/4