Stream restoration: nature-based solutions

Understanding key determinants of stream ecosystem functioning is crucial to biodiversity and to mitigate global and climate change. Our field and laboratory experimental research quantifies the effects of e.g. addition of wood and sand, the role of buffer strips, dispersal barriers, and re-introduction of ecosystem engineers in stream restoration. Furthermore, attention goes to ecosystem services of streams and their valleys.

Examples of projects

Hydromorphological restoration: REFORM (EU), Beekdalbreed Hermeanderen (STOWA), Zandsuppletie Hierdense beek (WS Vallei en Veluwe/Natuurmonumenten)
Biological restoration: Habitat- en systeemgeschiktheid van beeksystemen voor beekvissen (OBN), Herstel van laaglandbeken door het herintroduceren van ongewervelden (OBN), Dispersie
Building with Nature in streams: Innovatielab BwN Reg Wateren

Highlights

Wood and sand addition to streams

Stream restoration often benefits more from initiating natural processes instead of large technical interferences. Therefore, the results of applying re-meandering as a restoration measure are often disappointing. Designing a watershed to store and retain water in the upstream areas, for example, by reconnecting incised streams to their valleys by adding sand to the streams, and adding dead woody debris to increase micro)habitat and flow diversity, have proven to be far more successful.

Restoration on a valley-wide scale

Nature-based solutions in stream management will provide more robust ecosystems that are less vulnerable to climate change. Restoration on a stream valley-wide scale makes use of the buffer capacity of the valley, which delivers a number of ecosystem services. Not only do stream valleys store water in the soil and retain water in the inundated areas, but they also are capable of removing nutrients from adjacent agricultural lands before they enter the stream. Furthermore, stream valleys are biodiversity hotspots, which in turn strengthens, among others, recreational and health services.

Stream valleys as ‘sponges’

River and stream valleys store water in the soil, retain water in inundated areas and delay downstream transport of water by increasing the length of the flow path and slowing the speed and force of the current. Such water system based measures on catchment scale are sustainable, but call for a novel approach in landscape planning. Under the flag of ‘Building with Nature’ such solutions are embraced as they provide a robust and cost-effective base for future generations.

Reintroduction of ecosystem engineers

Currently many species characteristic of stream ecosystems of a good ecological quality are not able to reach restored sites. This might influence ecosystem functioning, given that some macroinvertebrates are important drivers of ecosystem processes in streams. Reintroduction might be an option for restored streams which could not be reached by its typical fauna. We study the feasibility of this approach by looking at population development and dispersal and we investigate the ecological mechanisms and processes associated with species introductions.

Major publications

Publications, tools, presentations

Reintroduction