IABR–Drought in the Delta

For the third time in a row, climate change was not only noticeable due to an excess of water, but also due to the freshwater shortages in the summer. This was unexpected for many. After all, we live in a delta where an excess of water appears to be a problem, and a delta which is designed to discharge water as quickly and efficiently as possible from a water safety perspective. During this summer, with a lot of engineering and quick fixes, we have kept the water machine running, but areas have still not yet recovered from the drought and there is likely to be permanent damage, both in the urban and in the nature and agricultural areas. And, it will not end with that one hot and dry summer of 2018. The Netherlands also had to contend with drought in 2019 and 2020 and it is expected that this will occur much more often.

The Dutch delta is not designed to retain water. Not yet. This requires a change in thinking and acting: from a naturally wet delta that must drain its water as quickly as possible to keep our feet dry, we must move to a delta that can retain fresh water in order to have access to it when we need it. It is a new challenge that the IABR – Atelier Drought in the Delta is portraying through design research.

The Dutch delta consists of a number of sub-systems, each with its own characteristic soil and water system and its own landscape features. The freshwater shortage therefore manifests itself differently everywhere, with different consequences, and thus the urgent need to investigate various solutions. The pressure on land use is great and the spatial claims of different transitions in our energy, water, and food systems only add to them. But if we connect these tasks and use them as leverage, there are also many opportunities.

This Atelier highlights ten sub-areas. For each subsystem, a vision has been outlined in which measures to increase the water buffering capacity serve as leverage for other transition tasks. This methodology of combining above and sub ground solutions in one systematic approach also helps
local governments and provinces to work on their water assignments. An attractive future image of the Netherlands with a wide variety of landscapes emerges. Especially if we make good international agreements about water distribution in the Rhine, Maas and Scheldt catchment areas.

The results of this research by design project have been visualized in the form of two cross-sections of the Dutch delta, the delta in 2020 and in 2050. We look towards Germany, France and Belgium, upstream along the Rhine, Maas and Scheldt - in the distance we see the Alps. The first section shows how our delta now functions and which problems have arisen due to climate change. In the second, we see what the potential building blocks for a new, common freshwater strategy yield, in conjunction with other transition tasks, such as energy transition, food production and urbanization.

The results of the IABR – Atelier provide an attractive vision on the future and, just as important, feasible proposals for solutions. The "new freshwater level" provides building blocks for the national freshwater strategy. It shows how the freshwater scarcity can be used in an integral transformation of our (urban) landscapes and can contribute to a resilient region that is able to cope with climate extremes. A flexible and resilient system that can adapt to changing circumstances and expected extremes by using the strength of the subsurface. At the same time, it shows an attractive vision of the future with a wide variety of attractive landscapes, robust nature and a pleasant living environment. Local and regional authorities can thus tackle their own specific task in such a way that all actions fit optimally into the coherent transition of our delta. It also reveals the urgency for international agreements on water distribution in the catchment areas of the Rhine, Meuse and Scheldt. Germany, Switzerland, France, Belgium and the Netherlands, we are all connected and dependent on the same freshwater system.

The freshwater shortage causes different problems in the lower as well as the higher parts of Netherlands. The low parts of our delta are mainly affected by sea level rise. There is more pressure from the sea on the fresh groundwater, which increases salinization in the coastal areas. There is insufficient counter pressure due to too little rainfall and a low water supply from the Rhine, Meuse and Scheldt. Larger parts of our agricultural area will therefore become less suitable for current crops. It is counterintuitive, but water shortages also pose a threat to water safety. About a quarter of the Dutch flood defenses consist of peat dikes. These contain a lot of water. If this water evaporates, peat dikes can collapse due to collapse or displacement. A major challenge on the higher-lying sandy soils of the Netherlands is the strongly falling groundwater level as a result of prolonged drought. As a result, seepage, groundwater that comes out of the soil under pressure, diminishes and streams, sprinklers and fens dry out. In addition, once dry soil becomes moist again much less quickly. Once the small pores in the soil are empty, the water will quickly run down through the larger cracks.

In the lower parts of the delta, the pressure on space and flood risk management are often greater. Here, agriculture and greenhouse horticulture alternate with cities and industry. Many freshwater measures here will be underground and of a more technical nature. Industry, the city and agriculture can make use of each other's purified residual water as much as possible; fresh water can then remain underground. Increasing and widening the dune landscape means extra resistance to salt water seepage. Freshwater measures will also become much more visible in the city. Landscapes of polder roofs, sponge and retention parks will buffer rainwater and at the same time provide coolness in the summer. The old meanders of the major rivers, together with levee improvements and river widening, will be used in the freshwater system, so that the river landscape in 2050 will be much more dynamic than it is now and sufficient water will remain available when necessary. In the future, agriculture will not only feed people, but also the soil. A fertile soil retains rainwater better during dry periods. Nature on the sandy soils in the higher parts Netherlands will be transformed from evaporating coniferous forest to an open infiltration landscape. An attractive landscape is created with large differences in height, streams and deciduous forests. Spruces make way for oak, birch and beech so that much less groundwater evaporates and there is ecological and spatial diversity. Streams meander again and the return of watermill landscapes ensures that surface water has time to replenish the groundwater. A landscape is formed that has been built up from both the bottom and the top soil with a robust 'new freshwater level.

Fresh water is crucial for all natural ecosystems. But as the world's population continues to increase, natural freshwater supplies everywhere are declining at an alarming rate. Food production dependent on fresh water cannot cope with this population growth. Not even in the deltas of the world, the eminently fertile but vulnerable areas, where more than half a billion of the world's population lives.

Large-scale irrigation of agricultural land means that the concentration of salt in the soil of these delta regions is increasing. The further salinization of coastal areas, where almost half of the world's population lives, exacerbates this problem. Reservoirs all over the world are drying up, aquifers (underground water layers) are being drained but not sufficiently replenished. One billion people have no access to safe drinking water. Where water management is not good, rationing and the fight for fresh water have already begun. The good news is that the problems of the deltas, our own Rhine-Meuse-Scheldt Delta to the Mekong Delta, the Sundarban Delta to the Mississippi Delta, are similar. What mainly differs are the levels of scale of the problem and the extent to which integrated water management takes place. In many places, the complex overview of the relationship between all transition tasks is lacking, so that opportunities remain underused. Potential and conscious management of the subsurface is also usually a forgotten factor. Lessons we learn from working on our own delta can be applied in deltas around the world. And vice versa: if we learn from each other openly and constructively, the water challenge can be used worldwide as a lever, as an opportunity to develop deltas in a resilient and sustainable way.