Code
N03
Sector
Hydro Morphology
The complete description of the NWRM
Summary

A floodplain is the area bordering a river that naturally provides space for the retention of flood and rainwater.  Floodplain soils are generally very fertile and they have often been dried-out to be used as agricultural land. Floodplains in many places have also been separated from the river by dikes, berms or other structures designed to control the flow of the river. They have also been covered by legacy sediments.

Major floodplains roles have thus been lost, due to land drainage, intensive urbanization and river channelization. The objective is to restore them, their retention capacity and ecosystem functions, by reconnecting them to the river.

Restoring the floodplain roles requires measures such as:

-          modification of the channel,

-          removing of the legacy sediment

-          creation of lakes or ponds in the floodplain

-          new/modification of agricultural practices,

-          afforestation, etc.

-          plantation of native grasses, shrubs and trees

-          creation of grassy basins and swales

-          wetland creation

-          invasive species removal

-          riparian buffer installation and development

Illustration(s)

Floodplain before flooding

Source: Thomas Borchers’ presentation,
NWRM Workshop 1 (from: Christian Damm)

Floodplain during flooding

Source: Thomas Borchers’ presentation, NWRM Workshop 1 (from: Nora Künkler)

Possible benefits with level
Benefits Level
BP1 - Store runoff
High
BP2 - Slow runoff
High
BP3 - Store river water
High
BP4 - Slow river water
High
BP5 - Increase evapotranspiration
Medium
BP6 - Increase infiltration and/or groundwater recharge
High
BP7 - Increase soil water retention
Medium
BP8 - Reduce pollutant sources
Medium
BP9 - Intercept pollution pathways
Medium
BP10 - Reduce erosion and/or sediment delivery
High
BP11 - Improve soils
High
BP12 - Create aquatic habitat
Medium
BP13 - Create riparian habitat
High
BP14 - Create terrestrial habitats
High
BP15 - Enhance precipitation
Low
BP16 - Reduce peak temperature
Medium
BP17 - Absorb and/or retain CO2
Medium
ES1 - Water storage
High
ES2 - Fish stocks and recruiting
High
ES3 - Natural biomass production
High
ES4 - Biodiversity preservation
High
ES5 - Climate change adaptation and mitigation
Medium
ES6 - Groundwater/aquifer recharge
High
ES7 - Flood risk reduction
High
ES8 - Erosion/sediment control
High
ES9 - Filtration of pollutants
Medium
ES10 - Recreational opportunities
High
ES11 - Aesthetic/cultural value
High
PO1 - Improving status of biology quality elements
High
PO2 - Improving status of physico-chemical quality elements
High
PO3 - Improving status of hydromorphology quality elements
High
PO4 - Improving chemical status and priority substances
Medium
PO5 - Improving quantitative status
Medium
PO6 - Improving chemical status
Medium
PO7 - Prevent surface water status deterioration
High
PO8 - Prevent groundwater status deterioration
Medium
PO9 - Take adequate and co-ordinated measures to reduce flood risks
High
PO10 - Protection of important habitats
High
PO11 - Better protection for ecosystems and more use of Green Infrastructure
High
PO12 - More sustainable agriculture and forestry
High
PO13 - Better management of fish stocks
High
PO14 - Prevention of biodiversity loss
High
ES5 - Climate change adaptation and mitigation
Low

Case studies per NWRM