Code
N14
Sector
Hydro Morphology
The complete description of the NWRM
Summary

A polder is a low-lying tract of land enclosed by embankments (barriers) known as dikes that forms an artificial hydrological entity, meaning it has no connection with outside water other than through manually operated devices. Its re-naturalization consists in enhancing polders with sub-natural characteristics, allowing better water storage in watercourses inside the polder, as well as increased biodiversity.

Illustration(s)
Possible benefits with level
Benefits Level
BP1 - Store runoff
High
BP2 - Slow runoff
Medium
BP3 - Store river water
High
BP4 - Slow river water
Medium
BP5 - Increase evapotranspiration
Low
BP6 - Increase infiltration and/or groundwater recharge
Medium
BP7 - Increase soil water retention
Low
BP9 - Intercept pollution pathways
Low
BP10 - Reduce erosion and/or sediment delivery
Low
BP11 - Improve soils
Low
BP12 - Create aquatic habitat
High
BP13 - Create riparian habitat
Medium
BP14 - Create terrestrial habitats
Low
ES1 - Water storage
High
ES2 - Fish stocks and recruiting
Medium
ES3 - Natural biomass production
Medium
ES4 - Biodiversity preservation
High
ES6 - Groundwater/aquifer recharge
Medium
ES7 - Flood risk reduction
Medium
ES8 - Erosion/sediment control
Low
ES9 - Filtration of pollutants
Low
ES10 - Recreational opportunities
Low
ES11 - Aesthetic/cultural value
Medium
ES12 - Navigation
Low
PO1 - Improving status of biology quality elements
Medium
PO2 - Improving status of physico-chemical quality elements
Low
PO4 - Improving chemical status and priority substances
Low
PO5 - Improving quantitative status
Medium
PO6 - Improving chemical status
Low
PO7 - Prevent surface water status deterioration
Low
PO8 - Prevent groundwater status deterioration
Low
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
Low
PO13 - Better management of fish stocks
Medium
PO14 - Prevention of biodiversity loss
Medium

Case studies per NWRM