After twenty extremely wet months in a row, drier times are coming. The month of February was already drier than average and March also started with sunny and warm weather. This has direct consequences for groundwater levels and the associated water systems. The Aa en Maas Water Board will be in action in the coming period to steer this in the right direction. “We are slowly moving to a dry period,” says Jens Verhagen of the water board.
On average, 45 millimeters of precipitation fell in the Aa en Maas water board in February this year, which is located east of our province. That is thirty percent less than what falls on average in February.
In the first two weeks of March, hardly any drop of rain fell and it has been sunny and warm. “That does not mean that the wet period is completely over, but we are slowly switching to a dry period,” says Jens Verhagen of the Aa en Maas water board.
“Slowly over to dry period.”
“If it is just as dry again after a long wet period, we immediately notice that that has an impact.” The water board notices that the groundwater levels that have fallen almost everywhere in East Brabant with twenty to forty centimeters.
In a small part of the province, the groundwater levels are still higher than average, due to months of wetness. These are parts of the Maashorst, the Strabrechtse Heide and other nature and forest areas on the higher sandy soils.
The groundwater drops slower there and stays longer in the area. “The groundwater levels in these areas are now about half a meter lower than last year, when it was extremely wet,” the water board concludes.
In other parts of the province, on the lower grounds and in the polders, the groundwater is up to twenty centimeters lower than is normal in this period.
According to Verhagen, the drier weather does not immediately cause problems. Yet a long wet period does not immediately say that no drought can occur.
“If it has been wet for a long time, it offers no guarantee that we cannot have a dry period this year,” he says. The expectation is that the rest of March will be dry except for a single shower. If this expectation comes out, the water system will dry up further and groundwater levels will continue to sink gradually.
“Groundwater falls when nature comes into bloom.”
How fast that goes depends on the amount of rain and how quickly the water evaporates. “Due to the few pretty hot days, nature is going in motion. Trees and plants start flowering and therefore the evaporation of groundwater increases. Then you see the groundwater fall faster,” explains Verhagen.
On the basis of agreements that the water board makes with residents, companies and interest groups, a target level is established. That is the desired height of the water. On the basis of this target level, the water board adjusts the water level in wet or dry times.
They also take agriculture and local wet conditions into account.
Aa and Maas must increasingly balance between wetness and drought. “Due to climate change, we see more and more extreme weather conditions. That means that we have to make the sails in very dry periods, just like in very wet periods. But not everything can be made for us, if it really becomes extreme,” Verhagen concludes.