Code
N05
Sector
Hydro Morphology
Other sector(s)
Urban
The complete description of the NWRM
Summary

Streambed (or riverbed) represents the floor of the river, including each riverbank. In the past, riverbeds were artificially reconstructed with concrete or big stones, therefore modifying flows and decreasing fauna habitat and vegetation diversity. Those modifications were aiming at flood prevention or supporting changes of agricultural practices for example. This has led to uniformed flows in the rivers and often having effect of reducing travel time along the river. Streambed re-naturalization consists in removing some concrete or inert constructions in the riverbed and on riverbanks, then replacing them with vegetation structures, in order to avoid these damages and restore biodiversity.

The re-naturalization of river beds and banks could have a high impact on the erosion process. Stabilisation techniques are among the main measures to be implemented. The maximum impact is reached when the stabilisation technique restores the vegetation cover and the naturalness of the banks. Most of the time, techniques use plants for bank stabilization. According to their degree of complexity, these techniques can be grouped into two categories:

-          bank re-naturalization

-          plant engineering

Bank re-naturalization is a stabilisation technique used to correct mild erosion problems and that does not require a high degree of expertise to be implemented.

Plant engineering is defined as the techniques combining the principles of ecology and engineering to design and implement slope, bank and bank stabilisation works, using plants as raw materials for making vegetable frames.

Possible benefits with level
Benefits Level
BP3 - Store river water
Medium
BP4 - Slow river water
High
BP5 - Increase evapotranspiration
Low
BP6 - Increase infiltration and/or groundwater recharge
High
BP7 - Increase soil water retention
Low
BP9 - Intercept pollution pathways
Medium
BP10 - Reduce erosion and/or sediment delivery
High
BP11 - Improve soils
Medium
BP12 - Create aquatic habitat
High
BP13 - Create riparian habitat
High
BP14 - Create terrestrial habitats
Low
BP16 - Reduce peak temperature
Medium
BP17 - Absorb and/or retain CO2
Low
ES1 - Water storage
Low
ES2 - Fish stocks and recruiting
Low
ES3 - Natural biomass production
Medium
ES4 - Biodiversity preservation
High
ES6 - Groundwater/aquifer recharge
Low
ES7 - Flood risk reduction
Medium
ES8 - Erosion/sediment control
High
ES9 - Filtration of pollutants
Medium
ES10 - Recreational opportunities
Medium
ES11 - Aesthetic/cultural value
Medium
PO1 - Improving status of biology quality elements
High
PO2 - Improving status of physico-chemical quality elements
Low
PO3 - Improving status of hydromorphology quality elements
Medium
PO4 - Improving chemical status and priority substances
Medium
PO5 - Improving quantitative status
Low
PO6 - Improving chemical status
Low
PO7 - Prevent surface water status deterioration
Medium
PO8 - Prevent groundwater status deterioration
Medium
PO9 - Take adequate and co-ordinated measures to reduce flood risks
Medium
PO10 - Protection of important habitats
High
PO11 - Better protection for ecosystems and more use of Green Infrastructure
High
PO13 - Better management of fish stocks
High
PO14 - Prevention of biodiversity loss
High

Case studies per NWRM