9.4. Interdependence Factors

Every country needs to deal with the interconnectedness of several water-related interests. Providing inhabitants with physical safety from the natural violence that water can exert is only one of them, but it historically shaped Dutch society’s pre-occupation with water. Besides that, the Netherlands also has a long history in shipping, and even today the (river) shipping trade represents a major water-related interest that is interdependent with agricultural water interests, recreational interests, nature interests, and the interests of drinking water supplies. The Dutch water system itself comprises several interconnected components, which are co-dependent for water quality and quantity (Rijkswaterstaat, 2016). The grounds, polders and rivers of the Netherlands cannot be seen in isolation from each other. Their interconnectedness is the basis for our water system management. Especially in periods of excess rainfall (in the Netherlands and in the countries upstream), or during longer drought periods, the water distribution system is constantly controlled and manipulated so that all water-related interests can be optimally served. Various scenarios, agreements and technologies (like sluice gates) facilitate this process.

Local case example

One main example related to regional water supply for drinking water purposes is the system management around the Amsterdam-Rijnkanaal and the Noordzeekanaal (see Figure 9.2). This system of canals, catchment areas, polders, ditches, sluices, pumps, lakes and locks, next to safeguarding the supply for drinking water production, is also of major importance for shipping connections between IJmond, Amsterdam and Germany. The rivers provide drainage of rainwater catchment areas. The system drains into the North Sea through discharge sluices, but when the sea level is too high a pumping station takes over. In dry times, when river levels are low, and the polders absorb water from the lakes, navigable depth for ships has to be maintained. Extra water from Lake IJsselmeer (previous Zuiderzee, now a nature reserve of national and international importance) or the Waal river can then be supplied through the operation of locks. But the amount that can be supplied from the Waal depends on the amount of water needed to maintain water levels in the Neder-Rijn, downstream of the Waal. When less water from the Waal can be diverted, there is another possibility, feeding the Amsterdam-Rijnkanaal by flushing the Vecht, but only if the level of Lake Markermeer permits this.

Figure 9.2. Map adapted from ideogram (2016)

As for water quality, salinization is an issue in this system. The ships that go through the sea locks at IJmuiden cause salt water to flow into the Noordzeekanaal, all the way up to where it connects to the Amsterdam-Rijnkanaal. Ecologically, the Noordzeekanaal has an important function in the migration of fish (that live in salt water, but bread in fresh water) and the saltwater gradient provides it with unique ecological characteristics (the gradual from salt to fresh water is important for the fishes to be able to adjust to the physiological different circumstances). The fish migration has suffered from the placement of sluices and locks, though (Van der Linden, van Alphen, Wanningen, van Herk, 2012) which necessitates more collaborative arrangements. Currently solutions are found by opening up recreational locks at night for the purpose of fish migration. A related issue, though, is the levels of salt water in the Noordzeekanaal. Since it connects to the Amsterdam-Rijnkanaal, which forms an inlet point for drinking water, it has to be insured that saltwater incursion does not advance too far. To halt this incursion at times water from lake Markermeer is let in. The water from the Amsterdam-Rijnkanaal has an additional function, though. In dry periods in can be used to combat salinization of polders (often consisting of farmland). This provision is subject to a water agreement from the 1980’s entitled ‘Small-scale Water Supply Provisions’ that specifies exactly the m3/s of fresh water that have to be directed to the polders by the system of pumping to the polders during periods of water shortage. The above local case example shows that several scenarios have been worked out, agreements have been recorded, cooperations forged, and technologies applied in this regional system. But the Dutch water system is not only a locally interconnected system as the shippingexample already hinted at this, the Netherlands is also very interdependent with its surrounding countries, through so-called transboundary aquifiers (UNGA, 2008). In terms of hydrological basins, the Netherlands shares its major river basins (Figure 9.3) with other European countries. The main ones are the Rhine and the Meuse.

Figure 9.3. River basin districts

Flowing through eight sovereign European states, the Rhine is an international geopolitical entity (Mediation project, 2016). An International Commission for the Protection of the Rhine has been established. Currently, the Rhine River is a mixed snowfed - rainfed system. Due to climate change, it may change into a predominantly rainfall driven system. The economies of the countries it crosses benefit from access to the Rhine in many ways (navigation, drinking and industrial processing water, agriculture irrigation, hydro-power, discharge of pollutants and cooling water). Most of the Meuse basin area is in Wallonia (Belgium), followed by France, the Netherlands (8,000km²), Germany, Flanders (Belgium) and Luxembourg. As the above example shows, countries can on a (more) global level pursue the development of international water law (e.g., through the ratification of conventions on transboundary acquifiers). In certain cases, development actors such as the Netherlands can also provide (donor) aid on a regional level, providing technical assistance or capacity building programmes based on their knowledge (regarding sanitation, water systems, irrigation solutions, flood control and hydropower, for instance; van Genderen en Rood, 2011).