Project Overview
Severn Trent wanted to improve their approach to preserving water quality. The Three Rivers Project was a partnership between the Nottinghamshire Wildlife Trust (NWT) and Severn Trent (ST) to deliver a programme of essential measures to improve the water environment in three rivers within the Idle Catchment, for which NWT are the Catchment Hosts. The rivers involved were Rainworth Water, Vicar Water and the Bevercotes Beck.
The Challenge
The three rivers suffered from low flow conditions and loss of water in parts of their length into the underlying sandstone. Consequently, the rivers were in poor or only moderate ecological condition and failing to meet Water Framework Directive (WFD) objectives. The three rivers were identified as a high priority for ST to address these problems, as part of a wider programme within their area of operation.
There were also many pressures on wildlife and habitats in the Sherwood sub-catchment of the Idle Catchment, including:
- Channel modification
- Poor water quality (both chemical and physical)
- Loss of habitat through vegetation clearance
- Low flows
- Barriers to fish passage
- Invasive non-native species
The Solution
The construction phase of the project addressed the issues of:
- Low flows due to leakage from the riverbed
- The need for enhancement of channel form and location
- Removal of structures that compromise channel integrity and reduce fish passage
The aims of this project are:
- To address the low flow issues and to prevent water losses as far as is feasible
- To increase the ecological resilience of the watercourses, through a wide range of measures
The planned work included restoring a more natural river channel through ‘deculverting’ and river regrading, introducing berms, riffles, pools and meanders to improve water flow and enhance wildlife habitat. These are in channel features that diversify the hydro-geomorphology of the river, increasing biodiversity opportunities, improve fish passage and increase water quality. In addition to this, creation of floodplains increases water storage capacity and can contribute to flood alleviation and wetland habitats.
Additionally, Beaver analogue dams – structures that mimic the natural impact of dams created by beavers – were installed to slow water flow and create pools and wetland habitat during high flows – delivering transformational change on the landscape. For the first time in approximately 70 years, the river will once again flow above ground using a technique called daylighting. It is believed the river was straightened and culverted during the mining construction in the 1950’s.
Due to mining fissures in the sandstone bedrock that runs under the colliery, the new and existing river channel has been clay lined to stop water losses to enable the river to adapt to low flows.
The Outcome
This project is a great example of the benefits of collaboration and has reinstated flowing river water after over 70 years. By working in partnership and sharing expertise EMEC has helped to deliver real impact for nature and create a wilder Nottinghamshire for all. The Three Rivers project is one of several ambitious and exciting nature recovery programmes EMEC is delivering in partnership with NWT and Severn Trent covering sites the length and breadth of the county.
The three rivers will once more become the green heart of the Idle Valley, transforming the local environment for people to enjoy and value.
Quote
“We work hand in hand with nature, and we’re extremely pleased to have been able to fund this work to reinstate the natural flow at a key section of Vicar Water. We’re working hard to improve river health across our region, which will in turn better protect the wildlife and habitats that live in and around our rivers, working with our partners is just one of the ways we’re doing that.”
Neil Pope, Sustainable Abstraction Team Manager, Severn Trent
