more flooding and greater freshwater shortage this century

NOS News•today, 6:00 PM

How much water, or how little, should we take into account in the Netherlands this century? And what water policy is needed for this? These are the underlying questions for the scenarios that the Deltares knowledge institute is offering today to outgoing Minister Harbers of Infrastructure and Water Management and Delta Commissioner Co Verdaas.

Deltares creates these scenarios every six years. This outlines the ‘water tasks’ up to 2100 for a Netherlands with more or less climate change and more or less economic growth and population growth. For all scenarios, freshwater shortages increase in summer, rain showers cause more nuisance and the consequences of flooding become increasingly greater. So it will become wetter and drier.

“It will be hard work to tackle all urgent tasks,” says Deltares director Dirk-Jan Walstra. According to him, “fundamental” choices must be made about water management, spatial policy and water use.

An issue that is already urgent and will only become more urgent is the distribution of freshwater. Its supply is decreasing. In all scenarios there will be longer periods of drought and more water will evaporate due to increasing temperatures. During dry summers, less water enters our country via the rivers and salty groundwater therefore penetrates further into the country.

On the other hand, there is an increasing demand for water, from all sides: freshwater is needed to combat salinization, for irrigating fields, rewetting nature and low peat areas, and consumers also use more water on hot days. “Not all functions can be supplied with sufficient water at all times, which leads to social damage,” the report reads.

The so-called repression series will come into effect more and more often. In the event of water shortages, restrictions will first apply to shipping, agriculture and recreation. Preventing damage to dikes and irreversible damage to nature has the highest priority.

The scenarios also look at flooding and water safety. Due to sea level rise and higher river discharges, areas outside the dikes will be flooded more often. This concerns both buildings in floodplains and in urban areas, especially in the Drechtsteden, such as the Noordereiland, the Kop van Feijenoord and the Scheepvaartkwartier in Rotterdam.

But the risk of flooding within the dikes is also increasing. In summer due to peak showers and in winter due to long periods of rain. This leads to problems, especially if several extreme conditions occur at the same time: intense rain, high river discharges and higher sea levels, which makes discharge into the sea more often difficult. Sewers, streams and smaller rivers and reservoirs become overloaded and no longer have enough space to absorb the large amount of rain. This must be taken into account when designing cities.

According to Deltares, the current dike reinforcement program, which runs until 2050, is reasonably concerned about the dangers posed by climate change. After that, a lot has to be done: additional dike reinforcements, sand replenishments for the coast and a decision must be made about the storm surge barriers. These also have to be closed more often when the sea is higher. How much needs to be done depends on how quickly and sharply the climate is changing.

For the first time, possible tipping points are also being considered, such as the irreversible melting of the West Antarctic ice sheet. This could lead to almost 2.5 meters of sea level rise in the Netherlands before the end of the century and much more in the following years. No scenario has yet been created for that case. More research is needed, as can be read in the report.

According to Deltares director Walstra, an ambitious climate policy is in the interest of everyone. “Otherwise it will be difficult for us to keep up with the pace of all the changes that are needed.” In response, Minister Harbers said that according to him, a lot has already been done, but that more needs to be done. “For example, better retention, storage and storage of water to get through dry summers.”

According to Delta Commissioner Co Verdaas, our traditional water approach – with technical measures – is starting to become problematic. “We must organize our country in such a way that we can better cope with extremes. This does not happen automatically, but requires choices that affect our living environment and the way we use our land and water.”

The minister and the Delta Commissioner call 2027 the moment for these difficult decisions. The National Delta Program will then be re-established.