Improvements in vortex flow control design to increase sewer network flood resistance

Flow controls are used within the water industry to manage the flow through sewer networks by attenuating flows at convenient or critical locations. Many sewer networks, regardless whether the systems have a flow control installed, are predicted to become stressed in the future due to the effects of climate change, population growth and urbanisation. This issue is compounded by the age of the Britain’s sewerage infrastructure as well as the cost and difficulty of replacing and upgrading the infrastructure. Statutory ‘Catchment Flood Management Plans’ have been introduced within the United Kingdom to tackle this issue by better understanding the flow path of flood water on a catchment scale. This paper discusses a method to maximise the use of the current sewerage infrastructure by installing flow controls, meaning a greater volume of the sewer network can be used for stormwater storage. This paper continues by describing a method of increasing a sewer network’s flood resistance by using vortex flow controls with a lower design flow-rate compared to an orifice plate. This paper then concludes by describing three case studies demonstrating the use vortex flow controls when retrofitting sewer networks as well as the impact of implementing the retrofit design method.