The Spider on the River Washburn

Spider Machine, Menzi Muck, places large woody debris in the river bed

Spider Machine, Menzi Muck, places Large Woody Debris and boulders in the riverbed

Innovative spider machine helps restore wildlife habitats on the River Washburn

Yorkshire Water’s trial works to improve the quality of the river environment downstream of Swinsty reservoir is now well underway.

Swinsty reservoir has been a source of drinking water for Leeds since 1878. The historic diversion of water to support the needs of local communities has resulted in the River Washburn receiving unnaturally low flows, which has led to low fish populations and species diversity.

The company is working with partners, Mott McDonald Bentley (MMB), Arup and the Environment Agency, along with local landowners, to monitor the results of various river restoration techniques, aimed at improving ecology in the River Washburn.

Machine in action at Swinsty

Machine in action at Swinsty

Bioengineering specialist Salix is using its innovative ‘spider’ machine to fell and move trees into the channel to concentrate the low flows of the river flow downstream of the reservoir.

The flows in the stream are currently too low to allow fish and invertebrates to thrive. The versatile four-legged walking spider machine has been climbing in and out of the river to position tree trunks and large boulders and local gravels at intervals within the channel.

These new features will create a more concentrated water flow and a series of deeper pools and shallower, faster flowing riffles over a 700m metre reach of the River Washburn just downstream of the reservoir which will improve biodiversity and provide a habitat for invertebrates and fish.

Yorkshire Water’s Environmental Advisor, Jo Baxter says:

“By providing suitable habitat conditions we hope to see an increase in indicators of good water quality – such as macro-invertebrates and plants, which will result in long term improvements and attract more brown trout back to the river and other wildlife like otters and kingfishers.”

David Holland, Technical Director for Salix, adds:

“Our incredibly strong four-legged spider machine can manoeuvre pieces of wood weighing up to two-tonnes each into the river channel. Once positioned, they will be held securely with stainless steel cables and will maintain a good flow for fish and lead to an increase in biodiversity that will shelter in and under the wood.”

This project is part of a wider programme of work across Yorkshire over the next five years. Yorkshire Water will make improvements to 20 reservoirs and improve 100km of Yorkshire’s rivers to demonstrate its commitment to protecting and improving the environment.

Vimeo footage of the machine in action
For more information: contact Tom at Yorkshire Water /
Den at Yorkshire Water or 01274 692653 or Debbie Walker for Salix tel 077486 40577