Streams in bad shape
In the Dutch sandy soil areas above sea level, streams could serve as climate buffers. In the past, many of these streams were straightened or turned into channels for rapid drainage into nearby rivers. As a result, the peak discharges of rivers such as the IJssel and the Maas have increased considerably. Furthermore, groundwater management has reduced stream water levels, with many stream valley ecosystems at risk of drying out.
As climate change will bring more frequent droughts as well as more extreme rainfall events, streams are expected to run dry, and flood, more often. In fact, due to the poor condition of our streams and the first effects of climate change, flooding and droughts are already a growing problem in agricultural, natural and residential areas. This also threatens the rich cultural heritage - country estates, castles, water mills and attractive small-scale landscape elements - of these stream valleys, which are a popular holiday destination.
By holding on to rainwater (‘Store it where it hits the ground!’), less water will be lost through drainage to the rivers. This relatively simple measure will reduce peak discharges of both streams and rivers, and reduce flooding risks.
Stream water levels should be raised to prevent stream valley ecosystems from drying out. In addition, natural processes such as meandering, flooding, erosion and sedimentation should be restored in the upper and middle reaches, by removing channel walls and allowing more room for the streams. Stream mouths should be broadened to slow the outflow into the river. All these measures will improve the vitality of unique ecological communities, which may include fish species such as brook lamprey and stone loach, and birds such as common kingfisher and grey wagtail.