Overview
Hayle sits at the mouth of the Hayle estuary and can be impacted by “tide-locking”. This is where a rising tide can prevent heavy fluvial (river) flows from exiting to the sea. Hayle is reliant on ageing quay walls to protect the town from rising sea levels and large tidal events.
Hayle is also at risk from coastal erosion and susceptible to changes in sediment movements within the estuary.
Rivers and catchments
The principal watercourses draining to Hayle are:
- The River Hayle
- The Mellanear Stream
- The Angarrack Stream
Other rivers and streams in the catchment include:
- Nance Stream
- St Erth Stream
- Mill Pool Stream
- Godolphin Stream
- Bosworgy Stream
- Nancegollan Stream
Risk of flooding from rivers and tides
Around 280 properties are at risk of fluvial (river) flooding in Hayle. Of these properties at risk, around 230 are residential. With the additional 50 properties being classed as commercial.
190 properties are potentially at high risk of tidal flooding. 110 of these are residential with 80 commercial properties at risk.
Risk of flooding from surface water
Around 575 properties are potentially at risk of surface water flooding in Hayle. Around 430 of these properties are residential with 145 commercial properties at risk. The commercial properties include an electricity substation.
You can view maps relating to the area via the following links:
Flood risk management in Hayle
There are many existing flood defences in Hayle.
Hayle is identified as a Critical Drainage Area (CDA). Any development which occurs in a CDA requires a reduction in flood risk (betterment). Rather than requiring a neutral impact.
Hayle is within the Carbis Bay Policy Unit of the West Cornwall Catchment Flood Management Plan. The policy for this unit is Option 4:
Areas of low, moderate or high flood risk where we are already managing the flood risk effectively. But where we may need to take further action to keep pace with climate change.
Hayle sits in The Shoreline Management Plan’s Project Development Zone 10 under Management Area 27. There are 7 Policy Units in this area. This has a combination of Hold the Line and Managed Realignment in future epochs to manage the coastline.
Main challenges for local flood risk management in Hayle
- Implementing the changes required in the Shoreline Management Plan will require a review of community development
- Balancing the needs of the residential and commercial property owners. This is to ensure that continued growth does not create additional risk
Opportunities for flood risk management in Hayle
- The Hayle River corridor would benefit from realignment of the flood banks to create habitat and reduce flood risk
- Along the Mellanear Stream. Flood wall and embankment raising would provide an improved standard of protection
- There may be potential to allow more flooding of the Marsh Lane County Wildlife Site area. This is to reduce flood risk elsewhere through ecosystem services. It is also to reduce the need for pumping on the Angarrack Stream
- Area would benefit from a Surface Water Management Plan. This would be to reduce the problems around Foundry Square and the area between Copperhouse Pool, Loggans Mill and Marsh Lane
- Target channel maintenance and review current drainage system infrastructure capacity. This would be to reduce incidents of blockage and flooding.
