The Leen Syphon

What is it?

The syphon carries the River Leen beneath the Nottingham and Beeston Canal near to the QMC in Lenton. All rainfall that falls in the River Leen catchment needs to pass through this structure on the way to the River Trent. The structure itself is a twin culvert that drops beneath the canal before reappearing in the Willow Road Industrial Estate.

Why does it matter?

As the river passes beneath the canal it is confined and requires all available space and capacity to ensure the river is unobstructed during periods of higher flows and floods. Any blockage within the syphon can reduce the ability to convey the river effectively and could increase flood risk locally. To reduce the threat of blockage from large items that are carried in the River Leen a screen with an automated grab collects materials before entering the syphon.

The material carried by the river is increasing and this is testing the automated grab more regularly and it is common for us to fill several skip loads of material on a weekly basis. This material is often material carelessly or even purposefully allowed to the enter the river.

This can cause an increase in flood risk, as well as polluting our water environment, damaging wildlife and its associated habitat and adding an unnecessary burden to public expenditure.

What do we do?

On a 1 to 5 year basis we will clear the syphon of silt that accumulates periodically in the culverts to ensure they function adequately.

On a daily basis we have staff who respond to any alarms generated by a blockage at the weedscreen to ensure that the grab is operating. On occasions due to the amount of floodwater and debris contained within the river the grab can become overwhelmed which has meant in emergencies some of response staff have had to manually clear the screens.

What can we all do better?

We know that most of the people we have encountered working on the River Leen are immensely proud of our city and we can all work together to raise awareness to stop needless littering of our river and threatening the health of our environment and increasing the risk of flooding to property close to the river itself. Where possible limit the waste we generate and encourage others to correctly dispose of waste materials to avoid them washing into the river.