Code
U07
Sector
Urban
Other sector(s)
Agriculture
The complete description of the NWRM
Summary

Soakaways are buried chambers that store surface water and allow it to soak into the ground. They are typically square or circular excavations either filled with rubble or lined with brickwork, pre-cast concrete or polyethylene rings/perforated storage structures surrounded by granular backfill. The supporting structure and backfill can be substituted by modular, geocellular units. 

Soakaways provide storm water attenuation, and storm water treatment. They also increase soil moisture content and help to recharge groundwater, thereby offering the potential to mitigate problems of low river flows. They store rapid runoff from a single house or from a development and allow its efficient infiltration into the surrounding soil. They can also be used to manage overflows from water butts and other rainwater collection systems, or can be linked together to drain larger areas including highways.

As a sub-surface infiltration device, a soakaway requires no net land take. They can be built in many shapes and can often be accommodated within high-density urban developments, and can also be retro-fitted. Soakaways are easy to integrate into a site, but offer very little amenity or biodiversity value as they are underground features and water should not appear on the surface.

Illustration(s)

Principle of a soakaway

Source: Andras Kis’ presentation, NWRM Workshop 1

 

Possible benefits with level
Benefits Level
ES1 - Water storage
Low
ES5 - Climate change adaptation and mitigation
Low
ES6 - Groundwater/aquifer recharge
High
ES7 - Flood risk reduction
High
ES9 - Filtration of pollutants
Low
PO2 - Improving status of physico-chemical quality elements
Low
PO4 - Improving chemical status and priority substances
Low
PO5 - Improving quantitative status
Medium
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
PO11 - Better protection for ecosystems and more use of Green Infrastructure
Low
BP1 - Store runoff
Medium
BP6 - Increase infiltration and/or groundwater recharge
High
BP7 - Increase soil water retention
Low
BP8 - Reduce pollutant sources
Low
BP9 - Intercept pollution pathways
Low

Case studies per NWRM