Code
U10
Sector
Urban
Other sector(s)
Agriculture
Forest
Hydro Morphology
The complete description of the NWRM
Summary

Detention basins are vegetated depressions designed to hold runoff from impermeable surfaces and allow the settling of sediments and associated pollutants. Stored water may be slowly drained to a nearby watercourse, using an outlet control structure to control the flow rate. Detention basins do not generally allow infiltration: see U12 for infiltration basins.

Detention basins can provide water quality benefits through physical filtration to remove solids/trap sediment, adsorption to the surrounding soil or biochemical degradation of pollutants. 

Detention basins are landscaped areas that are dry except in periods of heavy rainfall, and may serve other functions (e.g. recreation), hence have the potential to provide ancillary amenity benefits.  They are ideal for use as playing fields, recreational areas or public open space. They can be planted with trees, shrubs and other plants, improving their visual appearance and providing habitats for wildlife.

Illustration(s)

Infiltration basin

Source: Andras Kis’ presentation, NWRM Workshop 1

 

Possible benefits with level
Benefits Level
ES1 - Water storage
Medium
ES3 - Natural biomass production
Low
ES4 - Biodiversity preservation
Medium
ES5 - Climate change adaptation and mitigation
Medium
ES6 - Groundwater/aquifer recharge
Low
ES7 - Flood risk reduction
High
ES8 - Erosion/sediment control
Medium
ES9 - Filtration of pollutants
Medium
ES10 - Recreational opportunities
Medium
ES11 - Aesthetic/cultural value
Medium
PO2 - Improving status of physico-chemical quality elements
Low
PO4 - Improving chemical status and priority substances
Low
PO7 - Prevent surface water status deterioration
Medium
PO9 - Take adequate and co-ordinated measures to reduce flood risks
High
PO11 - Better protection for ecosystems and more use of Green Infrastructure
High
PO12 - More sustainable agriculture and forestry
Low
PO14 - Prevention of biodiversity loss
Medium
BP1 - Store runoff
High
BP2 - Slow runoff
High
BP5 - Increase evapotranspiration
Medium
BP6 - Increase infiltration and/or groundwater recharge
Low
BP7 - Increase soil water retention
Low
BP9 - Intercept pollution pathways
Medium
BP10 - Reduce erosion and/or sediment delivery
Medium
BP14 - Create terrestrial habitats
Medium
BP16 - Reduce peak temperature
Low
BP17 - Absorb and/or retain CO2
Low

Case studies per NWRM