Companies from Doncaster and Wakefield have worked with the Environment Agency to ‘reset’ a stretch of the River Witham above Grantham to capture of more than 100 tonnes of carbon, help drought and reduce flood risk downstream.
Breheny Civil Engineering, which has a base in Doncaster, and Ebsford Environmental from Wakefield have worked with a landowner and the Environment `agency own the scheme.
The restoration is in a rural river valley where there are no properties or roads within the confined valley floor that can be impacted by the wetter landscape.
The project involved infilling the river channel with soil to allow water to spill out and choose the direction it takes. This will create wetlands and smaller streams. Fallen timber has been added to slow the flow of the water leaving the site.
The wetlands act like a sponge, they encourage water to spill out onto the flood plain during wet periods but also release water back into the river in low flow periods. This means the wetlands will help support wildlife during drought as well as reducing flood risk downstream. The wetlands will also help to trap nutrients and fine sediment resulting in cleaner river water downstream, benefitting fish and other animals.
The works have already raised groundwater levels across the site by 1.5 metres, creating a wetter environment that may not have existed for 2,500 years. This work has combated the historical drainage that took place for land drainage and milling purposes.
Project Manager Katie Murphy from the Environment Agency, said: `”These works link to other projects across the UK and the US where this technique was developed. The project also links to a wider catchment-based floodplain restoration approach led by East Mercia Rivers Trust and the Wild Trout Trust. They have been instrumental in supporting delivery of projects on the Upper Witham.
“It will be fascinating to watch the site, river and wetlands develop and evolve over time. This is especially true now that the river has the freedom to choose its own shape and form without human interference.”
