Sufficient water

Natural and technological solutions for freshwater supply

KWR is constantly looking for natural and technological solutions that contribute to a robust freshwater supply, today and in the future. To this end, we carry out research into the natural processes that affect the supply of freshwater, such as evapotranspiration and groundwater recharge, in both the rural and urban environment. We possess thorough knowledge about the use of the subsurface and about innovation solutions for the storage of water until it is needed in dry periods.

Methods, tools and products

Drought

Recent years have demonstrated that our water system is vulnerable to prolonged periods of drought – and climate change will cause these to occur with greater frequency. Prolonged drought has impacts that propagate to different compartments of the water system. KWR works on reliable and accessible knowledge of the water system, as an important first step in identifying solutions. Together with the provinces, Water Authorities, business community and software developers, KWR has developed the Drought Portal which collects current measurements of precipitation, soil moisture, groundwater levels and discharge. 

Subsurface storage

Solutions to the problem of freshwater shortage can include the storage of surplus water in wet periods for later use in dry periods – in a manner that fits within the natural environment. In its search for such solutions, KWR draws on 80 years’ experience with managed aquifer recharge for drinking water purposes in the Dutch dunes. We work on the possibilities of Aquifer Storage and Recovery (ASR) for greenhouse horticulture and for industry in the low-lying west of the country, and on groundwater recharge together with Water Authorities on the sandy soils in the east and south. Based on exploratory research and pilots we work towards full-scale applications, both in the fresh and saline subsurface. With smart techniques like controlled  drainage with subirrigation the infiltrating rainwater can be retained for longer periods. A special example is the Freshmaker in Ovezande, where rainwater is stored in the winter and saline groundwater is simultaneously abstracted to have freshwater available in the summer for irrigation in fruit cultivation.

Evapotranspiration and groundwater recharge

Evapotranspiration is one of the key elements of the water balance, but much is still unknown about the underlying processes. At KWR, we develop knowledge about evapotranspiration, for instance of forests, with the aim of better quantifying the current and future regional groundwater recharge. We also study the possibilities of replenishing regional freshwater resources through the active infiltration of water, particularly in areas with sandy soils in the higher part of the country. With the HydroMonitor platform we apply time series analysis techniques to distinguish between the different factors that influence groundwater levels. This allows a water manager or public authority to quickly assess whether water management measures have had the desired impact on the groundwater level.

Sufficient water in the city

In the years ahead more and more people will be living in cities. Cities are very vulnerable to climate change: they heat up faster and their water provision can also run into problems. Extra green areas in the city contribute to cooling, but also require more water. Working within a wide consortium, including suppliers, public authorities and end-users, we developed the Urban Waterbuffer, in which rainwater is stored in the winter and then used to water the Sparta football pitch in the summer. In the CitySports project we researched how infiltrating rainwater can be temporarily stored in the base of an artificial grass pitch, with the aim of using it later for evaporation, and thereby cooling the pitch.

Future freshwater availability

What is the impact of climate change on the future freshwater supply? This is a very important question for the drinking water sector. Commissioned by the dune water utilities, KWR researches how the combined effects of climate change (sea-level rise, higher evaporation, increased coastal precipitation) impact freshwater volumes in the dunes in the long run. We also conduct exploratory studies with knowledge institutes, public authorities and stakeholders on a climate-robust and future-proof water system, both in higher (Klimaatadaptatie in de Praktijk (KLIMAP) (Climate Adaptation in Practice) project) and lower parts of the Netherlands (Laag Nederland 2050 (low-Netherlands 2050) project).

Projects

Here is a selection of recent projects related to the challenges of sufficient water: 

• Anticipating lengthy drought periods through the timely retention of water is very important as a means of dealing with the effects of climate change in agriculture. At the Rusthoeve experimental farm in Zeeland, we carried out research and pilots on the effect of controlled drainage with subirrigation. The work showed that the subirrigation increased crop yields in dry years, but that the drought damage cannot always be avoided. Moreover, water demand of subirrigation is high. 
• Sufficient freshwater, for all users and functions, presents an increasing challenge in both the Netherlands and Flanders. In the interdisciplinary water supply and drought project, we composed the knowledge base required by the drinking sector in order to realise the water transition that the drinking water utilities, Water Authorities and nature organisations aspire to. One of the project’s outcomes is that drinking water utilities can make a direct contribution to the transition by further optimising abstraction concepts for a sustainable integration into the environment. 
• Climate change is altering the soil and water system on the sandy soils in the higher parts of the Netherlands, with significant consequences for agriculture and nature. Within the Lumbricus and KLIMAP (Climate Adaptation in Practice) projects, working within a wide consortium, we researched how the sandy areas can be designed in a climate-resilient way. Among the outcomes, the project resulted in suggestions for the water transition and insight into the effects the envisaged measures.