Options for improving flood resilience in Portreath
- Does this option achieve our aims?
- What are the main constraints of this option?
- Are there any health and safety risks?
- Is it buildable? What are the challenges?
- How will this option impact carbon emissions throughout its entire lifecycle?
- What are the environmental and ecological impacts?
- Will it be difficult to operate and maintain?
- What would the timeline be to deliver this option?
- How do the community and other stakeholders feel? How could they benefit
- What kind of team would be needed to deliver this option?
- How complex would it be to design?
- What are the key risks?
- Portreath continues to flood
- No improvements to the tunnel, which is approaching its 100th year
- Very costly
- Limited space for the ‘inlet’ structure required, to collect and direct the excess water
- Environmental considerations
- Very costly
- Will need enough space for the inlet structure required
- Environmental considerations
- Very costly - High maintenance costs
- Would be classed as reservoirs, which require special management
- The sites investigated would not provide sufficient storage capacity at the peak of the flood
- Challenging to build in narrow channel
- Environmental considerations
- Challenging to build with road closures required
- Impacts on the harbour, both during construction and in the future
- Limited space for the inlet structure required
- Restore and secure flood defences
- Reinstate stream capacity
- Ensure that structures built in the channel do not collet debris, blocking the flow.
How we have considered options
As we have developed our proposals, we have considered our options against the following criteria:
| The Options We Considered | |
|---|---|
| High level option | Key Challenges |
| ‘Do nothing’ - remove all maintenance requirements | |
| ‘Do something’ - continue with current maintenance | |
| Increase the capacity of the existing tunnel | |
| Construct a second tunnel | |
| Construct upstream storage, for each of the 3 tributaries | |
| Reinstate the existing channel | |
| Construct a culvert from the debris screen, discharging into the Historic Harbour |
Our preferred option
Reinstating the existing channel.
Our preferred approach is to reinstate the existing channel from the Debris Screen to Portreath Beach.
Historic alterations and encroachment have affected the channel and its embankment, so these will need to be restored and reinforced to ensure adequate flood protection.
Where the embankment and channel width are sufficient, no changes will be required. However, in areas that have been significantly modified, encroached upon, or lack adequate width, engineered solutions will be necessary.
Other options were considered against the criteria above. Reinstating the existing channel will allow us to: