Finger in the Dyke

Collective Disaster Reduction

When I moved to Canada, I was surprised by the number of people who – as soon as they found out about my Dutch background – jokingly told me The Famous Story of a little boy who put his finger in the dyke. I am almost ashamed to say and disappoint many of you, that I have heard more about this boy in my years abroad than during my years at home.

Growing up in the Netherlands I always thought we were globally known for living below sea level, because we were the only ones, I thought, and it sounded like such a great idea to create land out of water. But what does that mean for the vulnerability of a community, how do they cope with this idea of collective disaster reduction?

Vulnerability

The Netherlands has a population of slightly more than 16.5 million people, and a landmass of 41,000 km2, resulting in a population density of 399.7/km2.  This is about the same landmass size as Vancouver Island in front of Canada’s BC coast, however the island has a population of only 740,000 (www.vancouverisland.com). Close to 50% of the Dutch population and 80% of the country’s GDP is based in three out of twelve provinces, an area also known as The Randstad, which is located in the most vulnerable parts of the country: the parts that are located below sea level.

The Randstad: an urban area located below sea level (blue areas in the map at the right hand side are located below sea level). Source: http://www.technology.amis.nl

 Ultimate Disaster Reduction Tool

Dykes to me are the ultimate example of a collective disaster reduction tool. The Netherlands is rare in how it copes with the high vulnerability of large parts of the country that are located up to 7 meters (23 feet) below sea level. What many of you may not realize is that you might have been there: the airport Schiphol, the third largest passenger terminal in the world, is located at one of the lowest parts of the Netherlands: 6.7 meters (22 feet) below sea level. This is an important issue in a time where community vulnerability and collective mitigation efforts seem to gain importance because of the growing population and the number and impacts of hazards influenced by climate change (Van Aalst, 2006). The Netherlands has collectively created a disaster reduction tool: the Dutch Sea Dike System. The sea dikes are in place to protect the Netherlands for flooding from the North Sea, located at the West of the Country.

A Community Formed By a Mutual Fight Against Water

With a coastline of 450km with the North Sea at its North and West side (see figure 2 for more topographical details), the Netherlands are known for their continuous fight against the water. Which is ongoing for centuries and which was the foundation of the nation as it is right now: the basis for the Dutch democracy is founded in the Water Boards. The first Water Boards were established during the 14th century when farmers decided to cooperate in building dikes to protect their land. (www.wetsus.nl). Nowadays the responsibilities of the Water Boards cover the management of dams and dikes, the level and quality of the ground water table and surface water bodies, regional water management, treatment of waste water and environmental related issues.  Throughout its history the country has had an open-economy and has always used its waterways and the North Sea for transportation of its trade products which explains why the most densely populated parts of the country are near the coast.

The Dutch Continuous Sea Dike System

The Dutch sea dike system forms a continuous network together with the dunes all along the 450km long coast with the North Sea. At several places special waterworks, such as the Delta works in the province of Zeeland (“land of the sea”) and the locks near Rotterdam, are brought into place to increase the resilience capacity of the system. An important advantage of the dikes is that they foster long-term mitigation and resilience and provide equal protection for everyone in the Dutch society. The dikes as a tool of resilience are not only part of the mitigation and preparedness stages of the disaster cycle (see appendix A) but also make life possible as without them the land behind the dikes would be flooded up till the city of Utrecht, in the middle of the country, east of Amsterdam.

The Dutch sea dykes are designed according a so called “probabilistic design”. Flooding is being perceived as a ‘high consequence low-probability’ event; these statistics have been combined with reliability models and the acceptability of flood risks to derive the safety levels. The acceptable level of risk for society and cost-benefit aspects of a certain activity are based on criteria set for national risk levels and are then calculated for local levels and activities (www.vrom.nl; www.rijkswaterstaat.nl and Berendsen, 2005).

Safety measure norms per dike ring area (from 1/10.000 years to 1/1250 years). Source: HVN, 1998.

Legislation and Adaptation to Climate Change

Throughout the years the Netherlands has had several acts and legislature that aim for integrated water policies. For example the Water Management Act form 1989 concerning planning for water management combines not only national and provincial plans but also spatial as well as environmental planning. One of the unique aspects of the Dutch coastline legislation is the safety measure which the government adopted for its dikes and dunes (water level fixed at 5m+NAP[1] with a return period of 1/10.000 per year).

The Delta committee (2008) explains that in her Delta Program she bases her recommendations and estimations of required investments at a relative sea level rise of 0.65 to 1.30 meters for 2100 (these numbers include the effects of the subsidence of the western part of the country and are derived from IPCC data). The costs associated with the Delta Program for investments during the years 2010 to 2050 will be about 1.2 and 1.6 billion Euros.  Natural values of the coastal system will be taking into account as ‘building with nature’ is the credo for the developments until 2050 as suggested by the Delta Committee.

Flooding and Hazard Mitigation in the US

In the city of Tulsa (OK), flood records are being kept since the 1900’s and the Arkansas River that crosses the city has caused many floods. During the sixties levees were built to protect the oil refineries, however during the late sixties and the seventies the perception of the residents of Tulsa changed which led to the ‘regulatory era of floodplain management’. The problem of flood control structures only protecting a specific site was recognized as well as its tendency to give a false sense of security. In contrast to other cities at the time, the city of Tulsa decided to clear its floodplains and widen them to secure and restore the flooding mitigation service of floodplains. After the 1976 elections the new commissioners also implemented new regulations that aimed to make developments in the floodplains impossible and other developments were restricted to drainage criteria and stormwater detention regulations. In 1978 the ‘Non-structural Era of Stormwater Management’ was marked by the Water Policy initiative. This meant a focus on preserving the natural values of the wetlands and floodplains. Structural flood control techniques were equally valued as non-structural flood control techniques. (Patton, 2009 and http://www.cityoftulsa.org/city-services/flood-control/flooding-history.aspx).  According to Patton (2009), the Tulsans always tended to perceive the floods as something they had to ‘endure’. To me  this is a great example of dealing with water in the opposite way of how the Netherlands does it: the Tulsans have found a way to live with nature, accepting how it can interrupt humans’ everyday life, rather than trying to conquer it as the Dutch do.

 Map of Tulsa and the Arkansas River.

Implications for other Flood-Prone Communities

I strongly believe in the power of collective disaster reduction, but admittedly, and sadly enough, the Dutch example can’t be copied “just like that” to other low parts of the world such as Bangladesh. The way The Netherlands is approaching this duality between a very high population density mostly located in the most vulnerable parts of the country, is by emphasizing living together with the water rather than trying to conquer it, but nonetheless its approach is very different from the Tulsans’. I would encourage researchers to come up with an approach integrating both ideas of living with water, to provide hazard mitigation to other flood-prone communities in the world where the financial means and the history of living with water are more challenged.

Author: Marleen C. de Ruiter


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