Long-term hydraulic performance of stormwater infiltration systems

Abstract

Despite the common use of stormwater infiltration systems, there is still only limited data available evaluating the long-term hydraulic function of such systems. The hydraulic performance of twelve stormwater infiltration systems (vegetated and unvegetated concrete grid pavers, unvegetated interlocking concrete pavers and grassed swales) was therefore investigated in field and laboratory environments in Växjö, Sweden. The systems investigated had not been subjected to regular maintenance to sustain infiltration capacity. Due to this, and the fact that, for most systems, an inappropriate joint filling material was used and (at the swales) there was severe compaction, most systems showed a reduced infiltration capacity. Despite this, especially the older vegetated systems, were still capable of infiltrating intense design rainfalls. This study showed the influence of some factors (type and age of the system, the type of joint filling material (grass and macadam) and the distance from the edge of the pavement) on the long-term behaviour of the infiltration capacity. In conclusion, there is a significant risk that existing stormwater infiltration systems are not working adequately in praxis. Proper implementation of construction and regular control by the inspecting authority has to be ensured.

Keywords::

• hydraulic performance
• infiltration system
• permeable pavement
• particle size distribution
• stormwater
• urban runoff

Acknowledgements

The authors thank all staff at the Växjö municipality who have helped with sample collection and analysis.

Additional information

Funding

This study was conducted as part of the research cluster Dag&Nät; the support of Dag&Nät by the Swedish Water and Wastewater Association (Svenskt Vatten) and, furthermore, the financial support of the Nordic Road Association (NVF) are gratefully acknowledged.