Why were we doing this work?
Ram Wood Beck, located in Roundhay Park, is home to populations of white-clawed crayfish. They’re an endangered species native to the UK that are particularly sensitive to pollution. Our investigations identified that Roundhay Park Lane Combined Sewer Overflow (CSO) was having an impact on the water quality at Ram Wood Beck which feeds the Upper Lake in Roundhay Park and the Environment Agency has asked us to improve the water quality in this area.
You can see a white-clawed crayfish and the location of the CSO below.
What is a combined sewer overflow?
In most places, the wastewater from properties flows into drains and sewer pipes that then connect to the sewer network where it combines with rain and surface water from roads and roofs. We call these pipes ‘combined sewers’.
Sometimes, when it rains heavily, the sewer pipes can’t cope with the volume of water and they can back up and flood properties and roads.
To stop this from happening, combined sewers include overflows which are designed to release some of the excess water in them to a watercourse. Usually this only happens when there's been heavy rain so any water that is released into a watercourse is very diluted and is unlikely to cause environmental damage. Our environmental regulators, in this case the Environment Agency, provide us with a permit that allows a CSO to release the excess water to Ram Wood Beck.
We’ve put monitors on some of our CSOs, these tell us how often they reduce the risk of flooding to properties and streets by releasing excess water and for how long.
What have we done?
We made more use of unused capacity in the existing sewer network. We built:
- A flow control device near Vale Avenue. This will control the flows during light rainfall events and will mean the combined sewer overflow will spill less frequently into Ram Wood Beck. During high rain fall events flow will bypass the flow control device.
- A new highway drain along the north side of Kedleston Road. This will stop water from the road entering the sewer.
- A bioretention system on Roman Avenue.
- A small earth mound on the north side of the watercourse north of Vale Avenue.
You can see these locations in the map, below:
What is a bioretention strip?
A bioretention strip has plants on the surface which take up water to help them grow. Any excess water not taken up by the plants travels down through the soil to a pipe. On Roman Avenue this will flow downhill to the watercourse on Vale Avenue.
What does Roman Avenue look like now the project is finished?
This project was completed in April 2022. Thanks to everyone involved with the project, including those at Stantec, Mott MacDonald Bentley, Leeds City Council and Yorkshire Water. Thank you also to the residents in the area for their patience and understanding while construction took place.
The images below show the completed Bio Retention strip on Roman Avenue shortly after construction:
Frequently asked questions
Who will look after the bioretention system?
Yorkshire Water will own and maintain the bioretention system for a period of approximately 12 months after construction. It will then be adopted by Leeds City Council, who will own and maintain the system from then on.
How can I get in touch with you about the scheme?
You can call us on 0344 848 1099 and quote reference ‘Capital YW.200970’.