Channels and rills

Code: 
U05
Sector: 
Urban
Other sector(s): 
Agriculture
The complete description of the NWRM: 
Summary: 

Channels and rills are shallow open surface water channels incorporated in to the start of a SuDS train. They collect water, slow it down and provide storage for silt deposited from runoff. They can have a variety of cross sections to suit the urban landscape, and can include the use of planting to provide both enhanced visual appeal and water treatment.

The main role of channels and rills are to capture runoff at the start of a SuDS train, allow deposition of sediment and convey the runoff to downstream SuDS features.  They can also be used in between SuDS features as connectors.  They collect water, slow it down and provide storage for silt and oil that is captured. The outlets are designed to act as a mini oil separator, making them effective at treating pollution and reducing treatment requirements downstream. Clearly channels can be included in many situations and settings, but would not always considered to be NWRMs unless specifically designed to perform these functions and used in conjunction with other measures.

Planting in channels and rills can visually enhance the urban landscape and offer biodiversity and amenity value. These features can be applied to all new developments and can be retrofitted to existing developments.

Illustration(s): 

Channel in urban area

Source: http://www.susdrain.org/delivering-suds/using-suds/suds-components/swales-and-conveyance-channels/channels-and-rills.html

Rill in urban area

Source: Andras Kis’ presentation,
NWRM Workshop 1

Possible benefits with level: 
Benefits Levelsort descending
ES7 - Flood risk reduction Low
ES8 - Erosion/sediment control Low
ES9 - Filtration of pollutants Low
PO9 - Take adequate and co-ordinated measures to reduce flood risks Low
PO11 - Better protection for ecosystems and more use of Green Infrastructure Low
BP10 - Reduce erosion and/or sediment delivery Low
BP12 - Create aquatic habitat Low
ES3 - Natural biomass production Low
ES4 - Biodiversity preservation Low
ES5 - Climate change adaptation and mitigation Low
PO14 - Prevention of biodiversity loss Low
BP1 - Store runoff Low
BP6 - Increase infiltration and/or groundwater recharge Low
BP14 - Create terrestrial habitats Low
BP16 - Reduce peak temperature Low
BP17 - Absorb and/or retain CO2 Low
ES11 - Aesthetic/cultural value Medium
BP2 - Slow runoff Medium
BP9 - Intercept pollution pathways Medium
BP5 - Increase evapotranspiration Medium
Last updated: 09 Jun 2015 | Top