Infiltration basins

Code: 
U12
Sector: 
Urban
Other sector(s): 
Agriculture
Forest
Hydro Morphology
The complete description of the NWRM: 
Summary: 

Infiltration basins are vegetated depressions designed to hold runoff from impervious surfaces, allow the settling of sediments and associated pollutants, and allow water to infiltrate into underlying soils and groundwater. Infiltration basins are dry except in periods of heavy rainfall, and may serve other functions (e.g. recreation). They provide runoff storage and flow control as part of a SuDS ‘train’. Storage is provided through landscaped areas that allow temporary ponding on the land surface, with the stored water allowed to infiltrate into the soil. The measure enhances the natural ability of the soil to drain water by providing a large surface area in contact with the surrounding soil, through which water can pass.
Infiltration basins may also act as “bioretention areas” of shallow landscaped depressions, typically under-drained and relying on engineered soils, vegetation and filtration to reduce runoff and remove pollution. They provide water quality benefits through physical filtration to remove solids/trap sediment, adsorption to the surrounding soil or biochemical degradation of pollutants. Water quality is, however, a key consideration with respect to infiltration basins as the potential for the infiltration to act as a vector for poor quality water to enter groundwater may be high. Pre-treatment may be required in certain areas before infiltration techniques are appropriate for use, for example swales or detention basins to reduce sediment loading and retain heavy metals and oils.
Infiltration basins have the potential to provide ancillary amenity benefits. They are idea 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. They increase soil moisture content and help to recharge groundwater, thereby mitigating the problems of low river flows.

Illustration(s): 

Explicative scheme of the MAR principle

Source: Andras Kis’ presentation, NWRM Workshop 1

 

Possible benefits with level: 
Benefits Levelsort descending
ES6 - Groundwater/aquifer recharge High
ES7 - Flood risk reduction High
ES9 - Filtration of pollutants High
PO9 - Take adequate and co-ordinated measures to reduce flood risks High
PO11 - Better protection for ecosystems and more use of Green Infrastructure High
BP1 - Store runoff High
BP2 - Slow runoff High
BP6 - Increase infiltration and/or groundwater recharge High
BP9 - Intercept pollution pathways High
ES8 - Erosion/sediment control Low
PO2 - Improving status of physico-chemical quality elements Low
PO8 - Prevent groundwater status deterioration Low
PO12 - More sustainable agriculture and forestry Low
BP5 - Increase evapotranspiration Low
ES3 - Natural biomass production Low
PO4 - Improving chemical status and priority substances Low
BP7 - Increase soil water retention Low
BP16 - Reduce peak temperature Low
BP17 - Absorb and/or retain CO2 Low
ES1 - Water storage Medium
ES4 - Biodiversity preservation Medium
ES5 - Climate change adaptation and mitigation Medium
ES11 - Aesthetic/cultural value Medium
PO5 - Improving quantitative status Medium
PO7 - Prevent surface water status deterioration Medium
PO14 - Prevention of biodiversity loss Medium
BP14 - Create terrestrial habitats Medium
ES10 - Recreational opportunities Medium
BP10 - Reduce erosion and/or sediment delivery Medium
Last updated: 09 Jun 2015 | Top