Dutch Delta Works: from engineering feat to cultural statement

‘Never again!’: this was the credo after the North Sea flood of 1953, which caused widespread destruction in the UK, Belgium and most severely in the Netherlands. The response of the nations affected was not of depression, however; the event heralded a culture of optimism and masterplanning with several grands projets. In the UK, it materialised with the construction of storm surge barriers on the River Thames, while in the Netherlands, a vast series of dams, sluices and dykes was planned.

The goal was to close off the streams of the delta from the sea, to reclaim the land and keep it safe in the future. Ambitious engineering works would guarantee a near-indestructible delta – even if the catastrophic coastal storm flood appears just once in 10,000 years – leading to what some have since called the Eighth Wonder of the World: the Delta Works. Realised between 1954 and 1997, it was in 1986 that Queen Beatrix announced: ‘The Storm Surge Barrier has been shut, the Delta Works are completed, the Netherlands are safe again.’

Paradoxically, the maakbaarheid (‘makeability’) that has been so emblematic of Holland’s struggle against water is now considered outdated. Climate change, rising sea levels and societal attention to nature have forced engineers in recent decades to update the ‘hard’ Delta Works. With a view to ‘building with nature’, the country is focusing its energy on more ‘natural methods’ such as sand suppletion, to counter the effects of erosion and replenish what the sea eats away. Currently just north of the port of Rotterdam is the experimental Sand Motor, an enormous manmade sand plateau expected to replace the need for manual replenishment as the North Sea currents redistribute the plateau’s sand and reinforce eroding beaches and dunes.

Although the focus shifted from vast civil architecture projects to engineering more natural processes, the Delta Plan is still the most revolutionary and exciting episode in the Netherlands’ long history of water management. The Dutch culture of planning originates in this struggle against water, a tradition of reclaiming land with grand designs that dates as far back as the 17th century, when Jan Adriaanszoon Leeghwater created the ‘De Beemster’ polder – a low-lying tract of land enclosed by dykes. Characterised by multidisciplinary design and integral planning, this tradition dares to tackle nationwide projects – the Delta Works being the fullest and most ultimate expression. They elicit great pride to this day.

Typical of the Modernist period when the Delta Works were conceived, was the application of hard and uncompromising materials on a scale just as uncompromising: gigantic concrete pylons, monstrous steel constructions, colossal asphalt dykes and mountains of Irish basalt. For more than 40 years, the delta served as a construction site of utopian experiences, challenging engineers to invent tools, vehicles and materials. Cable cars conveyed very heavy concrete blocks, huge pylons transported complete ships, drilling machines worked underwater and mesh boats handled city-sized steel foundation meshes filled with stones to be laid on the bottom of the sea.

‘The Dutch culture of planning originates in this struggle against water, a tradition of reclaiming land with grand designs’

After 20 years of experimentation, evaluating and learning from the first components of the Delta Works, the engineers progressed to the masterpiece: the Oosterschelde flood barrier. The first 4km were built as a closed dam, like Grevelingendam, but construction was halted in 1974 due to resistance to the project. In the wake of the environmental movement of the ’70s, renewed appreciation for nature and ecological diversity led to a change of mindsets and militated against the gradual disappearance of the delta’s unique flora and fauna, demanding that the last, and largest, flood barrier would close only in a storm flood – a technical challenge for the engineers. Some 65 colossal concrete pillars of 18,000 tons apiece were prefabricated in special dry-docks and positioned against the strong tidal currents by the gigantic Ostrea construction ships; 62 steel sliding doors ensured that the storm surge barrier could be kept open over a length of 3km, and closed in a bad storm. An architecture of this scale calls for unity, so it was painted in one colour to accentuate scale and repetition, while the different heights of the hydraulic cylinders emphasise the channel depth, allowing this hidden landscape to be read.

While the Delta Works were emerging out of both land and water in the south-west, a lesser known but unique component of Dutch water-management history was under construction on the other side of the country: an open-air hydrodynamic laboratory, built in 1951, in a newly created forest through which water naturally flowed. The Waterloopbos was essentially a laboratory as large as an entire piece of landscape, where scale models and 1:1 tests could be carried out, informing the design and engineering of the Delta Works on the coast, as well as a few water works later on.

Because computer models did not exist at the time, everything had to be built by hand and tested at various scales. Throughout their development and construction, the Delta Works were accompanied by a strong willingness to experiment and innovate. The Waterloopbos’s sheltered environment, protected from the polder’s violent winds, enabled the engineers to safely test their wildest ideas. Several designs were considered for the different flood barriers, many of which were tested at full scale. Fluid mechanics and dynamics were observed and examined, for instance by dropping pieces of paper into the water and analysing the flows and currents against a grid of tensioned ropes. Crucial to the successful development of the Eighth Wonder of the World, the Waterloopbos is integral to the Delta Works.

To simulate high and low tides, the full span of the Oosterscheldekering (kering meaning barrier) was erected in a giant hall. Its innovative open flood barriers were an engineering feat, and it was crucial that the new designs were tested against waves of immense size and force. To achieve this, a new concrete construction was erected at the Waterloopbos: the Delta Flume, another masterpiece of delta experimentation. The first of its kind, this 300m long artificial channel fitted with a wave generator was capable of producing the world’s largest artificial waves – as tall as 5m. Virtually indestructible, the Oosterschelde flood barrier was eventually opened in 1986.

The delta experiments in the Waterloopbos, and the built structures, prompted innovative scientific research that forms the basis of the Netherlands’ strong position in hydrodynamic engineering. This is useful for contemporary computer models used to calculate the impact of new interventions and water streams. The quest for an indestructible delta led to a culture of physical experimentation and innovation on the scale of models and at actual scale in the hydrodynamic laboratory. The Netherlands still benefits from this research, as it remains one of the greatest scientific and engineering Dutch export products.

The hydrodynamic laboratory has been closed in recent years and, although it received the status of national monument, the testing models are deteriorating after decades of inactivity – today, it is a museum-park. The Delta Flume remains the most impressive permanent construction in this landscape of scale models, and the Dutch government consequently decided to turn the structure into a national monument, Deltawerk 1:1. RAAAF was commissioned with Atelier de Lyon by the Dutch Cultural Heritage Agency and Natuurmonumenten to design an architectural/art installation due to open in September 2018.

The proposal Deltawerk 1:1 is the opposite of simple preservation of built cultural heritage. It is rather an experiment in cultural heritage itself. By excavating the sand plateau around the flume, a huge experimental Delta Work, 7m high and 250m long, is unveiled and surrounded by water. Massive concrete slabs are cut out of the 800mm thick walls, turned 90 degrees around their axis and placed at an angle in the resulting void. This new space offers an intense spatial experience of light, shadows and reflections, while opening up vistas on the surrounding Waterloopbos. In future, the slabs will be colonised by nature and the visitors’ spatial experience will change through the days, seasons and years.

The installation will raise questions about how to deal with the future of the Delta Works – when climate change requires new built structures, will they become obsolete? The mere preservation of these projects does not create new meaning or guarantee their relevance in an ever-changing context. Dealing with obsolete and vacant architecture represents a global challenge for the profession, and demands a site-specific approach of carefully designed interventions. Deltawerk 1:1 is a monumental tribute to the majestic architecture of indestructible Holland.

While monuments are typically regarded as immutable and untouchable, and so tend to fade from public imagination and memory, RAAAF’s approach of ‘Hardcore Heritage’ marks a new way of thinking about cultural heritage and a different design approach to monuments. Initiated with Bunker 599 (AR Dec 2013), in which a Second World War pillbox was bisected to create a walkway alongside the Diefdijk, Hardcore Heritage advocates ‘built manifestoes’ and seeks to create a new field of tension between past, present and future, by encouraging deliberate destruction, radical contextual changes and seemingly contradictory additions. This cut-through bunker was part of a wider initiative, following the Belvedere policy, launching new projects to both develop and preserve historical sites. The New Dutch Water Line will be a 21st-century landscape park for the Randstad megalopolis, with innovative design projects, such as Bunker 599 and Fort Vechten (AR Jan 2016) promoting art and culture along the 80km historic defence line.

The preservation of historical heritage needn’t be static and boring – instead, it could provoke architects to confront previous societal evolution and reassess it against contemporary desires. In fact, beyond innovations in engineering, the Delta Works instigated a brand new recreational culture. The ideal way to explore the Delta Works was, after all, by turning to the quintessential vehicle of the modern age: the car. Enjoying their new-found mobility, people visited the manmade asphalt beaches of Brouwersdam and Philipsdam. Even if initially considered obsolete, historical heritage can be injected with fresh relevance.