Water retention

Water can be scarce at times with increasingly frequent hot, dry summers. To have enough water in every season, more measures are needed to retain water in the area for longer.

Water for later

Water flows from high to low. To retain water in our area for longer, we need to make more effort to slow down the drainage of water to lower areas. Water in higher areas must remain there as long as possible to limit damage to agriculture and nature. This is not easy to achieve. We need to give nature a helping hand by using pumping stations, weirs, and inlets. This will allow water to flow further into our area in smaller ditches and streams. However, the water authority is only responsible for the most important and larger watercourses that play a role in controlling water in the region. For measures that go beyond these main watercourses, we need the cooperation of many other owners and stakeholders. We want to engage in more dialogue with the local community about this: for water for later.

Types of measures

We are not sitting still. All kinds of measures are already being implemented to keep water in the area for longer. For example:

  • Meandering streams: by allowing streams that were once straightened to meander again, the water travels a longer distance from high to low and therefore remains in the area for longer.
  • Creating nature-friendly banks: gently sloping banks provide more space for fish and small aquatic animals, and improve water quality in the process. Shallow water along these banks also flows more slowly.
  • Deliberately making ditches shallower: even without nature-friendly banks, a shallow ditch is a good way to slow down the natural drainage of water.
  • Filling in ditches: going one step further is filling in ditches completely. This is not possible everywhere. In places where it is possible, water does not flow away but sinks into the ground.
  • By improving the structure of the soil, it is possible to retain more water.

Where do we store water?

  • In the Zuidelijk Westerkwartier region, work is underway to develop the Dwarsdiep stream valley.
    The project involves retaining 2.7 million cubic meters of water. The stream valley will be developed in a natural manner.
  • There are already 42 kilometers of nature-friendly riverbanks in the Groningen part of our region. By 2027, that total should reach 60 kilometers.
  • South of De Onlanden lie the high-lying stream valleys of Drenthe. The focus will be on this area in the coming years.
  • When we develop an area to temporarily store water, this often goes hand in hand with restoring nature and the need to retain water for longer periods. For example, the water level in the Dwarsdiep may well be temporarily higher. In that case, we use the Dwarsdiep to store water. At the same time, with the new design of the stream valley, we aim to keep water in the area longer.
    In the Zuidelijk Westerkwartier, the ability to temporarily store water in lower-lying areas is also combined with retaining water in higher-lying parts.
    Thus, the possibilities for “storing” water and “retaining” water are actually always considered in conjunction with one another.

A balancing lake or water retention: what is the difference?

Now that dry periods are becoming more frequent, many people are wondering why we continue to discharge so much water into the sea instead of retaining it in the area. The answer is simple: we have to continue to discharge large amounts of water because otherwise we would no longer be able to live safely in our country. We sometimes have to discharge millions of litres (at once).
We store water to prevent flooding. We store water in low-lying areas. We store the water for a while and then slowly discharge it into the sea.
Of course, the water authority is aware of the need to retain water for longer. We do this to get through times of scarcity and to have enough water in every season.