Stage Zero
Stage Zero Pilot Study
In recent years, the U.S. Forest Service has been pioneering an approach to restore floodplain form and function back to a ‘stage zero’ state. Developing a process that effectively resets the valley floor surface and hydrology (Valley Floor Reset - VFR) to create an anastomosing channel form.
About the pilot study.
Stage zero refers to the likely channel form prior to human disturbance of the landscape and floodplain. The key benefits of restoring to stage zero are significant and include:
Reduced downstream flood risk – reduced conveyance and maximum flood attenuation
Improved drought resilience – through increased water retention, which allows the subsequent slow release of water during drier periods
Increased floodplain and wetland biodiversity
Water quality improvements – the anastomosing system acts as a net store of sediment, reducing downstream sediment flux and associated nutrient enrichment.
As part of the Mendip Catchment Strategy review, with support from the Somerset Frome Catchment Partnership, we saw an opportunity for Mendip to broaden the scope of our Natural Flood Management within the catchment.
We therefore commissioned a separate pilot study to look at the potential for Stage Zero sites within the priority sub catchments already identified within the wider Mendip Catchment Strategy. Hydromorph, a specialist geomorphological consultancy and a key collaborator of Calm Engineering, has been pioneering this approach to flood risk management in the UK.
The main aim of the pilot is to identify sites where we might be able to reconnect the watercourses to the floodplain. The outputs from this study will inform our approach to catchment wide natural flood management and will inform the scope of works we implement as part of the catchment strategy.
