Impact
Loss of aquatic macrophytes, geomorphological changes, reduction in invertebrate and fish biomass and reproductive success of gravel spawning fish, impact on infrastructure. Washout of allochthonous material from headwater ecosystems.
Quantum
Change in return period of major floods at Hereford (>5m) from 8 years 1945-2018 to 8 months 2019-2023. 2 largest flows on upper Wye and Ithon occurred in February 2020 and were exceeded in February 2022.
Evidence
- EA and NRW flood records
- Eddleston water paper
Cause
Reduced infiltration rates in upper catchments due to change in practice supported by WG grants. Poor understanding of issue and ineffectiveness of existing NFM efforts. Change in intensity of rainfall events.
Solutions
- Catchment scale NFM. Determine opportunity for change, establish catchment market to fund change
- Remove forage turnips from growing for environment
- Empower farmers to use SFS requirement to reduce risk and reward accordingly
Who?
- WCP / WUF
- Welsh Govt
- Downstream infrastructure owners
Where?
Soils with naturally high infiltration rates in upper catchment after sub catchment response times and source area have been determined.
Cost
Est: Capex £35-50m revenue £25m / year both TBQ due to interaction with farming support schemes
