There has been a shift in the way that the Environment Agency manages flood risk, moving towards an ambition for climate resilient places and supporting a broader range of resilience actions. This has led to a stronger focus on restoring natural river function in some locations and a move away from the more traditional flood risk management techniques, where it is appropriate to do so.
This is the case with the River Hayle, which is historically channelized as a result of industrial legacy and flood risk management. The Environment Agency is still actively managing the banks downstream of St Erth. However, they are currently reviewing the management of the river banks along the River Hayle and have identified sections, upstream of St Erth, where maintenance is no longer required to manage flood risk. This reduced maintenance regime has allowed the river to start to re-naturalise in places leading to some erosion of the banks.
This changed management regime has had implications for the footpath along some sections of river bank where the river has started to follow a more natural course. This natural erosion of the bank has led to the footpath being closed in one section due to safety concerns. The Council is working with the Environment Agency to consider sustainable approaches to protect the path and re-establish access along the river whilst also exploring opportunities for habitat creation and nature recovery.
There is a unique opportunity to explore reconnecting the river to its floodplain at several locations which could lead to reduced flood risk, improved climate resilience, improved water quality and nature recovery opportunities such as the creation of wetland and wet woodland habitat.
In order to bring these strategic priorities together and support future funding applications, the Council is working in partnership with both the Environment Agency, the West Country Rivers Trust and the Local Parish Council to develop a Landscape Masterplan.
This Masterplan will support engagement with the community and to guide future works, ensuring that Cornwall Council, Environment Agency, St Erth Parish Council and local landowners are all aligned. This will support community outreach and delivery of priorities.
The Landscape Masterplan, will also be used as a communication and planning tool to support subsequent funding applications and inform investment decisions. It will be used to unlock the River Hayle’s potential value, identify where enhancements can be made with a specific focus on nature & conservation, climate resilience and access & recreation.
- Cornwall Council Countryside Team
- Cornwall Council Environmental Growth Team
- Environment Agency
- St Erth Parish Council
Desktop Study and qualitative geomorphic interpretation of the study area, informed by the latest climate change allowances for changes in flows, to determine the following:
- What sections of river may be prone to meander or are focal points for erosion.
- The extent of future river movement, to include mapping of the likely path / evolution of the river channel over the next 50 years.
- Identify the impact of point based, engineered interventions on channel dynamics i.e. if channel protection measures are installed at one section, what are the upstream and downstream impacts on channel dynamics.
- Determine whether bio-engineering techniques would be sufficient to withstand erosion during high flows.
- Develop an understanding of the sustainability of hard engineering techniques used to protect vulnerable sections.
- Review of designated sites to minimise disturbance and support nature recovery.
Development will see a deeper understanding of the expected change of the River Hayle, its tributaries and catchment area over the next 50 years. It is intended that this evidence base, and the Landscape Masterplan will allow Cornwall Council to better maintain a public right of way that is sustainable in the face of river naturalisation.
Works to improve the northern PRoW links have been undertaken, with further improvement work planned for later this year to ensure sections are more resilient throughout the year. This will ensure that access is still available round the closed sections.
Officers from Cornwall Council met with representatives from the West Country Rivers Trust to consider. Key Actions
- Commission investigation and develop work packages for key “at risk” areas – to be completed October 2021 subject to EA consent
- Undertake high level survey of short/mid-term interventions across walked sections.
- Complete options appraisal with reasoning behind recommended approach, to include consideration of river processes/ecological opportunity