definition

Soakaways are 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. They can be grouped and linked together to drain large areas including highways. The supporting structure and backfill can be substituted by modular or geocellular units
(Susdrain, Soakaways, accessed on Sept. 2016). Soakaways are one type of "Infiltration Device", a simple way of dispersing surface and storm water in situations where connection to the sewer system system is impractical or unwarranted. The basic principle is that of a 'reverse well' i.e. a 'hole-in-the-ground' that loses water rather than collecting water. Installing a soakaway provides a means by which rainwater from a building can be collected and dispersed into the soil in a suitable location.
(Paving expert, Soakways, accessed on Sept. 2016)

Co-benefits and impacts

Soakaways provide stormwater attenuation, stormwater treatment and groundwater recharge. They require minimal land take, good volume reduction and peak flow attenuation, they are easy to construct and operate, can be retrofitted and they have good community acceptability. On the other hand they are not suitable for poor draining soils, field investigations requires to confirm infiltration rates, they are not suitable for locations where infiltration water may put structural foundations at risk, or where infiltrating water may adversely affect existing drainage patterns, they are not appropriate for draining polluted runoff, the risk of groundwater pollution is increased, there is some uncertainty over long-term performance and possible reduced performance during long wet periods and in cases where the property owner is responsible for operation and maintenance, performance difficult to guarantee.
(Susdrain, Soakaways, accessed on Sept. 2016).

Related Links

---

Last modified: Sept. 16, 2016, 7:37 a.m.