Find out more and view the three coastal trends reports which have been completed for the Hunstanton to Snettisham coastlines
About the coastal trend reports
Three technical reports have been commissioned in partnership between the Borough Council and Environment Agency. These have been produced to:
- better our understanding of complex coastal processes generated within The Wash
- further understand how coastal processes shape and influence our coastlines
- further inform future coastal management measures
Further information and links to the full reports can be found below.
The Wash trends report
The Wash Trends Report was produced by the Environment Agency Coastal Monitoring Programme and reviewed data collected from across The Wash between 1992-2020.
For the Borough Council frontage in Hunstanton, the main conclusions are:
- Hunstanton is experiencing a long-term erosional trend due to its exposure to strong waves generated in The Wash and cross-shore processes being dominant
- Cross-shore processes are resulting in beach material being pulled down from the beach and deposited on offshore on large sandbanks
- Input of beach material to Hunstanton from erosion of the Hunstanton Cliffs is limited and will not build beach levels to the south
- A large sandbank has developed offshore from Holme-next-the-Sea and Old Hunstanton. This is blocking a fresh supply of beach sediment moved via longshore drift from traveling further around the coast to Hunstanton. This is known as sediment paucity
- The combination of cross-shore processes removing beach material from Hunstanton and an absence of longshore drift supplying fresh beach material is resulting in falling beach levels being observed
For further information you can read the outcomes of The Wash Trends Report below.
Jacobs Groyne Effectiveness Report
The Jacobs Groyne Effectiveness Report was produced by an external consultant Jacobs on behalf of the Borough Council and Environment Agency. Its purpose was to review the effectiveness of the groyne fields between Hunstanton and Heacham based on current coastal processes acting along the coastline.
For the Borough Council frontage in Hunstanton, the main conclusions are:
- Coastal processes acting along the Hunstanton coastline have changed and align with findings of Wash Trends Reports
- The condition and effectiveness of the concrete and timber groynes is poor to very poor, with the structural issues resulting from lowered beach levels and abrasion of structural elements. An absence of longshore drift reaching the Hunstanton frontage, which groynes are designed to trap, limits their effectiveness as no fresh sediment is being supplied for the groynes to trap
- The groynes are too short and too low to trap sediment moved by longshore drift even if it was reaching the Hunstanton frontage
- The design of the permeable timber zig-zag groynes is highly unusual and it is unlikely they were ever designed with the intention of retaining sediment. This type of groyne will not result in retention of sand as this will travel through the gaps in the groyne.
- The current groyne structures cannot prevent further sediment loss by cross-shore processes which are dominant in Hunstanton
- Limited beach material cover and widespread Carrstone exposure has been observed in the past (late 1800s and early 1900s), before groynes were installed
- There is limited benefit in further repair or modification of the timber and concrete groynes other than for health and safety purposes. Repair or modification will not improve sediment retention as dominant erosive coastal processes and lack of sediment arriving by longshore drift remain
- As the groynes have no influence on sediment retention, leaving the groynes in-situ is not doing any harm and will not worsen erosional trends currently
As a result of the above findings, the concrete and timber groynes in Hunstanton will only be maintained from a health and safety perspective going forward. The groynes will not be refurbished or replaced as this will not improve beach sediment retention due to the change in coastal processes which have occurred.
Council officers will continue to regularly monitor the condition of the concrete and timber groynes and will undertake health and safety works when required.
The Borough Council are planning to undertake a full asset inspection survey of all Hunstanton coastal defences in the coming months. This will look at the condition of the defences and any impact erosion of beach levels may be having. We will also continue to monitor beach levels at the base of the sea defences every 2 months. This data is used to further observe changes in beach level which are occurring.
The Borough Council will also continue routine maintenance of coastal defences (i.e. seawall, promenade, rear-wave wall, floodgates, outfalls and navigation markers) in Hunstanton when required.
For further information you can read the outcomes of the Jacobs Groyne Effectiveness Report and two appendices below.
4D radar
A 4D radar trial was deployed at the Hunstanton power boat ramp between August-December 2021 with the purpose of validating The Wash Trends and Jacobs Reports.
4D radar is a high-resolution and long-range sensor what can be used to map geomorphological features and sediment movement to a distance of 4km offshore in areas where traditional bathymetry cannot be accurately used. This is an innovative technology which was trialled in this location.
The main conclusions are:
- Findings aligned with The Wash Trends and Jacobs Reports
- There is an extensive network of sandbanks offshore from Hunstanton
- There is very little evidence of longshore drift brining fresh beach material to the Borough Council and Environment Agency coastlines
For further information you can read the outcomes of the 4D Radar Report below.
Non-technical summaries
A non-technical summary of all three coastal trends reports can be viewed below.